INFLUENCE OF STABILIZERS ON THE FERMENTATION RATE AND NUTRITIVE VALUE OF SET YOGHURT

ABSTRACT

Stabilized yoghurt samples were produced by reconstituting  powdered milk in water along  with sugar and 0, 0.5 and 1.0 % concentrations of carboxyl methyl cellulose (CMC), Corn starch and gum acacia before fermentation. The yoghurt samples were either produced as short set yoghurt by incubating at 42 oC for 5 hours or incubating at 30 ± 2 oC (room conditions) for 24 hours as long set yoghurt. Samples were analyzed at intervals of 1 h for 5 h for the short set yoghurt and at intervals of 4 h for 24 h for long set yoghurt. The proximate, physicochemical, niacin content, microbial and sensory evaluation were carried out in the yoghurt samples as fermentation progressed for both short set and long set yoghurt. Results showed that the addition of stabilizers reduced moisture content from 88.54 ± 0.02 % (no stabilizer) to 84.59 ± 0.02 % (CMC), 85.59 ± 0.02 % (corn starch) and 86.70 ± 0.02 % (gum acacia). Due to dilution effect, addition of stabilizers depressed protein contents from 3.37 ± 0.04 % (no stabilizer) to 3.28 ± 0.51 % (CMC), 3.08 ± 0.03 % (corn starch) and 3.32 ± 0.03 % (gum acacia). Total solids increased on addition of stabilizers from 11.64 ± 0.02 % (no stabilizer) to 15.41 ± 0.02 % (CMC), 14.47 ± 0.02 % (corn starch) and 13.30 ± 0.02 % (gum acacia). Increase in stabilizer concentration and fermentation time decreased moisture content but increased total solids, protein, fat, ash and sugars. The viscosity of the yoghurt samples significantly (p < 0.05) increased with addition  of stabilizers from 1.48 ± 0.03 Cp (no stabilizer) to 78.03 ± 1.14 Cp (CMC), 2.74 ± 0.04 Cp (corn starch) and 1.99 ± 0.03 Cp (gum acacia), with CMC having the highest  increase (p < 0.05) and gum acacia the least. Viscosity significantly increased (p < 0.05) as stabilizer concentration and fermentation time increased. Although CMC increased the pH from 6.19 ± 0.03 (no stabilizer) to 6.26 ± 0.02, corn starch did not affect pH (6.18 ± 0.02) while gum acacia reduced pH to 5.94 ± 0.03. Increase in stabilizer concentration and fermentation time increased pH. Addition of stabilizers increased the titratable acidity from 0.29 ± 0.01 % (no stabilizer) to 0.39 ± 0.01 %( CMC), 0.32 ± 0.01 % (corn starch) and 0.45 ± 0.00 % (gum acacia). Lactic acid production reduced as concentration of stabilizers increased, but increased as fermentation time increased. Vitamin B3 (niacin) increased with the addition of stabilizers from 0.15 ± 0.00 (no stabilizer) to 0.175 ± 0.02 mg/ml (CMC), 0.185 ± 0.01 mg/ml (corn starch) and 0.185 ± 0.00 mg/ml (gum acacia). Niacin production increased as stabilizer concentration and fermentation time increased. The total viable bacteria significantly (p < 0.05) reduced with increase in concentration of stabilizer and fermentation time, while lactic acid bacteria decreased with increase in stabilizer concentration it increased as the fermentation time increased. Significant (p < 0.05) interactions were observed between stabilizers and their concentrations for all parameters studied. Sensory results indicated that yoghurt produced with 1.0 % concentration of CMC gave the best mouth feel while yoghurt produced with corn starch produced the most desirable taste and flavor. Results showed that reaction rates were higher for the short set yoghurt for all parameters studied, resulting to achieving an equivalent effect in 5 h in short set yoghurt compared to the same effect achieved in 24 h in the long set yoghurt.

CHAPTER ONE

INTRODUCTION

  • BACKGROUND OF THE STUDY

Dairy products are generally defined as foods produced from commercially domesticated cows, goats or buffalo’s milk (United Kingdom food Standard Agency, 2009). They are usually high energy-yielding food products. Raw milk for processing of dairy products comes mainly from cows and to a lesser extent from other mammals such as goats, sheep, yaks, camel or horses. Dairy products are commonly found in the European, middle-Eastern and Indian cuisines, whereas they are almost unknown in Eastern cuisines. The United Kingdom Food Standards Agency defined Dairy as “foodstuffs” made from mammalian milk (Bandler and Singh, 2009). Most dairy products contain large amounts of saturated fat and most of them are usually fermented. Examples of dairy products include Cheese, Kefir, yoghurt, etc.

Fermented dairy products, also known as cultured dairy foods or cultured milk products, are dairy foods that have been fermented with lactic acid bacteria such as Lactobacillus, Lactococcus and Leuconostoc. The fermentation process increases the shelf-life of the product as well as adds to the taste and improves the digestibility of milk (Canadian dairy Commission, 2007). There is evidence that fermented milk products have been produced since around 10,000 B.C, and a range of different Lactobacilli strains has been grown in laboratories for a wide range of cultured milk products with different tastes.

Fermented milk products are sour tasting milk products which have been made by either fermenting the milk naturally or by the use of starter culture to produce the desirable milk product. Examples of fermented milk in Africa, Syria, Asia and America are Cheese, nono, buttermilk, yoghurt, irgo, kadam, laban, shenineh, dahi, shirkand, mahi, etc (Ajayi, 2006).

Yoghurt, as a fermented dairy product, is a semi-solid milk product and the best known of all fermented milk products. It is obtained by souring of milk using a pure culture of Lactobacillus bulgaricus and Streptococcus thermophilus (Chandan and Shahani, 1993). It can be manufactured from liquid cow milk, powdered milk and vegetable milk (Soy milk) as base material (Adolfsson et al., 2004). Lactic acid and the other molecules that are formed during fermentation of milk make yoghurt a food product that is both acidic and creamy, appreciated for its taste and nutritional qualities notably for its calcium content (Buttriss, 1997). Yoghurt is thus a very convenient food as compared to milk which is very fragile. Due to the health benefits and taste, it is known to constitute an appreciable proportion of total daily food consumption or even just as a refreshing beverage in several countries (Khan et al., 2008). It is regarded as a nutritionally balanced food, containing almost all the nutrients present in milk and in a more assimilable form (Younus et al., 2002). Yoghurt is a source of highly nutritive protein, energy from added cane sugar, milk fat and unfermented lactose as well as vitamins (Ihekoronye and Ngoddy, 1985). It is actually considered to be more nutritive than milk in terms of vitamins content, digestibility and as a source of calcium and phosphorus (Foissy, 1983). It is believed that yoghurt has valuable “therapeutic properties” and helps in curing gastro intestinal disorders (Adolfsson et al., 2004). It also prevents and controls diarrhoea, capable of modulating the inflammatory response produced by carcinogens, helps in reducing the inflammatory response through an increase in apoptosis.

Yoghurt is characterized as a smooth viscous gel with specific taste of sharp acid and green apple flavor (Bodyfelt et al., 1988). Some yoghurts exhibit a heavy consistency that closely resembles custard of milk pudding, in contrast to others that are purposely soft boiled and are essentially drinkable (Connolly et al.,1984). The most important textural characteristics of yoghurt are firmness and the ability to retain water which is a factor of the type and concentrations of stabilizers used. The type of culture used is also an important factor affecting microstructure and the textural properties of yoghurt (Hussan et al., 1999).

Stabilizers and thickeners are important in several manufactured products and dairy products such as chocolate dressing, milk drinks, ice-cream and yoghurt. These substances prevent separation of various ingredients, increase the viscosity and inhibit the formation of large crystals. Substances used as stabilizers and thickeners include vegetable or tree gums such a gum tragacanth and gum Arabic, agar, cornstarch, gelatin and pectin. Cellulose compounds like methylcellulose and CMC (sodium carboxyl methyl cellulose) are also used (Awan, 1995).

Yogurt is mainly classified based on its chemical composition (full-fat, reduced fat and low-fat), manufacturing method (set and stirred yogurt), flavour type or post incubation process. Yoghurt on the basis of method of production prior to incubation, cooling and final packaging exists as set and stirred yoghurt. Set yoghurt is a type of yoghurt which when produced is incubated and cooled in the final retail package and it is characterized by a firm jelly-like texture (White, 1995). On the other hand, stirred yoghurt is a type of yoghurt that is produced and incubated in a tank and the final coagulum is “broken” by stirring prior to cooling, addition of flavours and packaging (Skriver et al., 1993; White, 1995).

1.1      STATEMENT OF RESEARCH PROBLEM

From previous researches, it is noteworthy to say that fermentation increases the vitamin content of products, more especially some B-complex vitamins due to microbial activities during fermentation where synthesis and breakdown of substances occur (Ochanda et al., 2010). Yoghurt starter cultures utilize some vitamins present in milk during fermentation for their growth. However, this increment depends on the rate of the inoculation, the strain of yoghurt starter cultures and the fermentation conditions (Tamime and Robinson, 1999). Stabilizers or hydrophilic colloids bind water, prevent separation of various ingredients, increase the viscosity and inhibit the formation of large crystals which are attributes for consumer acceptability. It is, therefore, necessary to rebuild yoghurt with stabilizers and thickeners at such concentrations that will give the desired body to the final product. This goal will be achieved by optimum selection of stabilizers with protective colloid properties, by assessing how the activities of the fermenting organisms will be enhanced or inhibited by the hydrocolloids used with respect to vitamin synthesis by evaluating the chemical,   microbiological, nutritional and sensory properties of yoghurt produced under controlled incubation fermented at 42 oC for 5 hours and 24 hours at 30 oC respectively.

1.2   JUSTIFICATION

Yoghurt is a fermented product obtained through anaerobic fermentation of lactose in milk by relevant micro-organism, most of which are classified as probiotic. It is a very nutritious product in terms of vitamin content, digestibility and has valuable “therapeutic properties”. Much research has been carried out in yoghurt in terms of final product. Stabilizer used in yoghurt production are many and varied but there is little information on how some of the stabilizers locally used in Nigeria influence the fermentation rate of yoghurt and consequently the nutritive value for which yoghurt is consumed.

1.3     OBJECTIVES

The main objective of this study is to produce yoghurt with different stabilizers and evaluate their nutritional characteristics. 

Specific Objectives

  1. To evaluate the effect of the stabilizers on the physicochemical characteristics of the yoghurt during fermentation.
  2. To compare the effect of the different types and concentrations of stabilizers with respect to their influence on the changes in the vitamin B3 content during fermentation.
  3. To evaluate the changes in the microbial population during fermentation of yoghurt produced with different stabilizers.
  4. To evaluate the effects of different types and concentrations of stabilizers on their sensory characteristics of yoghurt.

1.4   SIGNIFICANCE OF THE STUDY

Traditionally produced natural yoghurt will require little or no stabilizer to produce a firm, fine gel. However, commercially produced yoghurt that has to be pumped, stirred, fruited and filled would often breakdown to a runny liquid without the addition of stabilizers. So there is need to introduce these stabilizers to prevent separation of whey from yoghurt, a problem known as syneresis (Ramaswamy and Basak, 1992). The use of cellulose compounds like CMC as stabilizers for yoghurt, pectin, gelatin, agar, corn starch, etc, is very popular. In recent times, the use of tree gums or gum tree secretions or exudates has also been introduced in yoghurt production. Examples of such tree gums are Acacia gum, gum tragacanth, carageenans, gum Arabic, etc. Their ability to produce high viscosity in water at low concentrations is a major property that gives them a valuable and widespread use. This will also help in harnessing these tree gums and prevent post harvest losses, which is of great economic importance. It is therefore hoped that the outcome of this research work will provide an insight on the inhibitory or elaborate effects of selected stabilizers and their quantities in the multiplication of microorganisms, production of lactic acid and synthesis of B vitamins.

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EVALUATION OF NUTRACEUTICAL POTENTIALS OF “ATAMA” (Heinsia crinata) and “UCHAKORO” (Vitex doniana) LEAVES

ABSTRACT 

Extracts and powders produced from the leaves of two indigenous vegetables – ‘atama’ (Heinsia crinata) and ‘uchakoro’ (Vitex doniana) were evaluated. Four groups of processes were applied on the vegetables to obtain the samples: blanching, oven drying and milling; oven drying and milling; steam blanching, wet-milling, filtration, and fermentation; fermentation, wet-milling and filtration. After, a preliminary study to evaluate the antinutritional factors at different intervals of blanching and fermentation was carried out, five samples, fresh dried leaf powder (FDPL), blanched (8 mins) dried sample at 500c, fermented (5 days) leaf extract, blanched leaf (10mins)/fermented (5days) extract and blanched (10mins) leaf extract were selected for further studies, fresh leaves (FL) served as control. These were evaluated for proximate composition, mineral, and vitamin contents. Two samples each (fresh dried and blanched extracts) were selected for rat bioassay based on their iron content. Body weights were taken and blood samples collected from the animals on days 0, 14, 18, 21 and 24. Internal organs were weighed at the end of the experiment. The antinutritional studies revealed that blanching, fermentation, and drying reduced alkaloid, phytate, tannin, and oxalate contents of the processed leaf and leaf extracts to a safe level.  The proximate analysis showed that the crude protein content of all the samples ranged from 0.02±0.00-17.29±0.01%; crude fibre of the powders ranged from 1.68±0.03-10.15%, ash contents varied from 0.26±0.01-6.55±0.01%, while total carbohydrate varied from 3.61±0.06-65.55±0.33%. The contents of sodium, calcium, and iron in the samples varied from 0.24±0.01-1.29±0.03mg/100g, 11.69±0.01-63.00±0.22,mg/100g and 3.00±0.00-31.26±0.01mg/100g respectively. The vitamin analysis showed that vitamin C ranged from 1.52±0.37-32.98±0.78mg/100g, vitamin E (0.12±0.00-53.31±0.02mg/100g), vitamin B2, (0.01±0.00-9.13±0.00mg/100g) and vitamin A (55.50±0.64-3583.26±4.68µ/mg). The bioassay results showed that all the samples caused a significant increase (p<0.05) in red blood cell (6.42-7.15 106/µl) and hemoglobin concentration (10.96-15.04 g/dl) in relation to the anemic controls. Body weight evaluation showed that there was significant increase (p<0.05) in weights of all the rat groups fed with the samples at different doses (153.70-177.45g). Relative organ weights of the test rats were observed to show significant differences (p<0.05) among samples for mean liver and kidney weights; and no significant differences (p>0.05) for mean heart and spleen weights respectively. Most of the liver and kidney function tests revealed that the samples did not cause any deleterious effect on the organs. This study has successfully demonstrated that ‘atama’ and ‘uchakoro’ leaves and their extracts have potentials for alleviating anaemia.

CHAPTER ONE

  • INTRODUCTION

            Nutraceutical can be defined as “a food (or part of food) that provides medical or health benefits, including the prevention and / or treatment of a disease (Defelice, 1989).

The term “nutraceutical” was coined from “nutrition” and “pharmaceutical” in 1989 by Stephen Defelice, MD, Founder and Chairman of the Foundation for Innovation in Medicine (FIM) Cranford, New Jersey. There are many ways to think about food. In the simplest sense, food is organic fuel, that is, it provides the energy needed to perform daily functions and maintain normal metabolic processes. Food contains nutrients that are essential to prevent diseases, for example, scurvy will not occur if vitamin C is continually present in the human diet. Similarly, blindness can occur where diets are deficient in vitamin A. The essential nutrients that the body needs to prevent specific disease have been a major focus of human nutrition research for the past century (Beecher, 1999).

What is interesting, however, is that the link between diet and disease, or more important, diet and health, cannot be entirely explained by the absence or presence of the various essential nutrients in our diets. Today, multitudes of components that are found in foods are being studied to determine the role they play in maintaining health and reducing the risk of disease. “Nutraceuticals” and “Functional Foods” are two new terms used to describe health promoting foods or their extracted components (Ames et al., 1993). The beneficial role of many nutraceuticals and functional foods may relate to their protective effects against degenerative diseases, such as cancer and cardiovascular diseases. The interest in nutraceuticals and functional foods continues to grow powered by diverse research efforts to identify properties and potential application of nutraceutical substances, with the public interest and consumer demand (Brower, 1998).The use of nutraceuticals as an attempt to accomplish desirable therapeutic outcomes with reduced side effects as compared to drug -based therapeutic agents, has met with great success (Nelson, 1999; Whiteman, 2001). However, nutraceuticals still need support of an extensive scientific study to prove their effects with reduced side effects (Heyland, 2001)

Examples of claims made from nutraceutical are resveratrol from red grape products as an antioxidant and an anticholesterolemic broccoli (Sulforaphane) as a cancer preventive agent and many others. Several nutraceuticals are known, some examples are flavonoids, antioxidants such as gamma-linolenic acid, beta-carotene, anthoxyanins. Others include tocopherols and poly-phenolics which are extremely effective antioxidants. These antioxidants are found in various levels in fruits, vegetables and non-food plants. (Hasler, 1998; Dixon and Steele, 1999).Most of the nutraceutical products in Nigeria market are made by Tianshi, Tasly, GNLD, Noni, Green World, Natural Pharmacy, among others, are imported and hence very expensive and out of reach of an average Nigerian. The main raw materials for the production of these products are from natural ingredients (Bull et al., 2001).There is a need for extensive research to explore the nutraceutical potentials of our locally available plant resources. Heinsia crinata (atama) and Vitex doniana (uchakoro) are two leafy vegetables eaten and grown abundantly in Nigeria. This will help to provide vital data for food processors and nutrition workers as well as the consumers for selection of these green leaf vegetables.

1.1         Problems Statement

These vegetables are perishable and are mostly used locally for preparing dishes like soup, porridge and many others. There is need to improve identify the nutraceutical potentials of these leaves.

  • Objectives of the Study
  • The general research objective is aimed at the evaluation of nutraceutical potentials of ‘Uchakoro’ (Vitex doniana) and ‘Atama’ (Heinsia crinata) leaves.

Specific Objectives

  1. To produce nutracetuical base from raw and processed ‘Uchakoro’ (Vitex doniana) and ‘Atama’ (Heinsia crinata) leaves and their extracts.
  2. To evaluate the effect of various processing methods on the antinutritional factors of the leaves and their extracts
  3. To determine the effect of processing on the nutritional contents of the samples.
  4. To determine the effects of the products on the red blood cell and other selected physiological body changes through rat bioassay. 

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EVALUATION OF GASOLINE GENERATOR MODIFIED FOR BIOGAS UTILIZATION

ABSTRACT

This study addresses the design and modification of a gasoline generator to use biogas as an alternative fuel. The biogas was produced from fresh cow dung using a 10m3 fixed dome bio-digester and the produced biogas scrubbed to improve its energy content per unit volume.  A 1.0 kW Tigmax air-cooled gasoline generator was used for the investigation. The modification involved the fabrication and mounting of a simple external mixing chamber on the air-duct of the carburetor. A comparative analysis of the performance and combustion characteristics of the engine was evaluated separately with petrol and biogas using ten number 100 watts bulb as variable loads. Power output was optimal at 0 to 500 watts, while rapid power output deterioration was noticed above load condition of 500 watts. Overall rated power output reduction of 47% was observed in the study due mainly to high percentage of carbon dioxide. Exhaust gas temperature of the modified engine was comparable to the unmodified engine at load condition of 100-200 W, above 200 W the exhaust temperature lost the linearity. The exhaust emission revealed an improvement in emission at load range of 100-200 W, while 200 W the achieved superiority was lost due to an increased emission of CO and CO2. Improving the scrubbing capacity of the purification and the external mixing chamber is here-by recommended.

CHAPTER ONE

1.0 INTRODUCTION

Energy is an integral component of any socio-economic development and a central factor for eliminating poverty in any society (Aderemi et al., 2009). In Nigeria located on the west coast of Africa, lack of access to wide range of modern energy services has remained a major barrier to improving key indicators of human development (Onafeso, 2006). Presently over 60% of the country population depends almost entirely on fire wood for cooking, heating and agro-processing activities. Petroleum products such as kigasoline and kerosene are marked by acute shortages and mounting price, with the product sold over 300% above the official pump price (Anonymous, 2008). Additionally, electricity which is the foundation of modern economies is non-available and if available is of poor quality or better still unreliable as less than 4,000 MW of the 7,876 MW installed electricity capacity is been generated (Sambo et al., 2010).

The introduction of mechanization and automation of food processing operations to drive conveyors, pumps, compressors and equipments like steam boilers, dryers, refrigeration equipments, ventilation and ovens has made the use of electricity critical in food industries. The non-availability of electricity supply or poor quality and unreliable nature of electricity supply by Power Holding Company of Nigeria (PHCN) has resulted in the increasing use of stand-by generators of various shapes and sizes (Adegoke and Akintude, 2000), which depends entirely on petroleum products as fuel.  In spite of the obvious advantage offered by these stand-by generators as a dependable solution to erratic power supply; the re-current perennial petroleum products scarcity and it rising cost contribute to high cost of production and loss of competitive advantage of processed foods when placed side-by-side with the imported ones (Aderemi et al., 2009).  Additionally petroleum products are finite in nature and their combustion bye products are major contributors to environmental degradation, climate change and global warmng (Das et al., 2000). Awareness of the limitations of the convectional fuel has enhanced the growing interest in the search for alternate cleaner and sustainable source of energy (Goodger, 1980).  Biogas which has a relatively significant comparative advantage due to the country huge biomass potential estimated to be about 8 x 102 MJ offers a promising sustainable solution (Nwoke and Okonkwo, 2006), however the wastes are usually dumped indiscriminately in landfills and unauthorized areas contributing further to environmental degradation and global warming (Adeola, 1996; Igbinomwanhia and Olanikpekun, 2009). In-order to reduce the current over dependence on fossil fuel, enhance energy availability and safeguard the natural eco-system in the face of Nigeria huge biomass potential (Garba and Sambo, 1992), biogas technology represents a viable alternative due to its simple technology and rural possible adaptability. (Diaho et al., 2005). Biogas is a fuel gas consisting of a mixture of methane (CH4), carbon dioxide (CO2) and traces of other gases, produced through microbial processes under anaerobic conditions from bio-degradable materials (Dennis and Burke, 2001). It’s a renewable high quality fuel that burns without leaving soot’s or particulate matter (Merchaim, 1992). Although biogas technology is yet to be adequately exploited in Nigeria and other Africa countries, the technology is a common place in countries like India, China, Pakistan, U.S.A and most European nations (Nwoke and Okonkwo, 2006). Utilization of biogas as fuel in internal combustion engines have witnessed a substantial breakthrough and improvement over the years (Mitzlaff and Mkumbwa, 1980; Mitzlaff, 1988; Huang and Crookes, 1998; Midkiff et al, 2001; Eshan and Naznin, 2005) Although biogas engines are presently not available in Nigeria markets; the crippling fuel prices and high cost of food processing coupled with the growing problem of food wastes management has remain an intractable national problem. Modifying these existing engines via rural adaptable technology to use biogas produced from these food wastes is an essential springboard for a shift to an eco-system friendly technology and sustainable rural development.

1.2 Problem Statement

Energy is a key instrument in accelerating economic growth, alleviating poverty and creating employment opportunities. Epileptic power failure has resulted in an over-dependence on generators driven by fossil fuel. Apart from this, fossil fuel is non-renewable and fast depleting and contributes to ecological degradation. Due to the endemic power shortage in the country and the current fragile enforcement laws governing waste management and use of generators in Nigeria, it is highly appropriate to researched on the use of biogas produced from food and other biodegradable wastes as alternative fuel source for internal combustion engines.

Gasoline generators represented almost 80% of the population source of independent energy supply. Given that over 70% of the country estimated 150 million people are involved in agricultural activities, and producing diverse varieties of plants and animal wastes. Transforming these wastes into biogas energy for use in existing gasoline generator represents a long-term sustainable approach to energy self-sufficiency and economic development.

1.3 Objectives

1.3.1 General Objective

The broad objective of this research was to adapt gasoline generator for biogas utilization for lower cost energy alternatives from available food and agro-allied wastes.

1.3.2 Specific Objectives

The specific objectives of this research were to:

  • Modify a generator for biogas utilization
  • Evaluate the electricity voltage output and load bearing characteristics of the modified generator
  • Determine the exhaust gas emission and temperature in comparison to petrol based generator.

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EFFECTS OF INCLUSION OF OYSTER MUSHROOM (Pleurotus sajor-caju) ON THE PHYSICO-CHEMICAL, SENSORY AND MICROBIAL PROPERTIES OF HAMBURGER

ABSTRACT

This research was conducted to determine the contribution of mushroom on the physico-chemical, nutritive and sensory properties of hamburger. Four burger samples were prepared with different combinations (0%, 20%, 40% and 60%) of mushroom. The inclusion of mushroom caused a general decrease in the protein, fat, moisture, ash, mineral element, vitamin as well as soluble protein and an increase in the carbohydrate contents of hamburgers. The proximate and soluble protein contents of burgers without (0%) mushroom differed significantly (P < 0.05) from burgers with mushroom. Significant differences (P < 0.05) in the mineral element (Magnesium, iron, phosphorus, zinc, calcium and sodium) content were observed between burgers without (0%) mushroom and burgers with mushroom. The change in the potassium content of all the burger samples did not show any significant difference (P > 0.05). Burgers without mushroom differed significantly (P < 0.05) from those with mushroom in their vitamin C, A, thiamin and riboflavin content, while no significant difference (P > 0.05) was observed for niacin content among all the burger samples. The burgers with mushroom were found to still make appreciable contribution to the daily values (DV) of most of the nutrients in one serving size of 100g. The pH and water activity (aw) of the burgers ranged between 5.40 – 5.65 and 0.84-0.96 respectively. The degree of “likeness” of the organoleptic qualities and general acceptability was rated highest for burgers without mushroom, and reduced gradually with progressive inclusion of mushroom. The least-rating (“slightly dislike”) was observed in the taste of ribeye and chuck muscle burgers with more than 20% mushroom. Chuck muscle burgers were most prefered to burgers from other muscle cuts. The microbial counts (TVC, mould and coliform counts) for burgers at the end of 8 days storage under ambient condition showed that significant differences (P < 0.05) existed among muscle at the various levels of mushroom. No specific trend could be established to account for the addition of mushroom on the microbial activities of hamburger during storage. Coliform and mould counts were generally lower than TVC throughout the storage period. No physical sign of spoilage was observed at the end of eight days of storage.

CHAPTER ONE

1.0  INTRODUCTION

Meat is the flesh or muscular tissue of animals (Fox and Cameron, 1977). Similarly, Forrest et al, (1975) defined meat as the flesh of animals which is suitable for use as food. Although meat eating remains at a high level, there have been distinct changes in the type of meat eaten (Varnam and Sutherland, 1995). The most striking is the rise in consumption of poultry and sea food and less red meat (Kinsman, 1994). It was further emphasized that the success of fast-food outlets means that increasing quantities of beef and, to a lesser extent, other meats are eaten as burgers and similar products. Still according to Kinsman (1994), meat is the preferred food eaten at home.

Mushroom is the fleshy, spore bearing fruiting body of a fungus, typically produced above ground on soil or on its food source (Moore, 2003). Mushroom is more of common application to macroscopic fungi fruiting bodies than one having precise taxonomic meaning (Chang and Miles, 2004). However, according to Bahl (2000), mushroom is a general term applied to the fruiting bodies of the fleshy fungi and as such belongs to different groups of fungi. The majority of mushrooms belong to Hymenomycetes (Basidiomycotina) while others belong to Discomycetes (Ascomycotina).

How long man has been eating mushrooms is, of course, impossible to determine, but one can speculate with reasonable assurance that such fungi have periodically been a part of his diet for many centuries (Gray, 1970). It was further stressed that until recent times in the United States, mushrooms were used primarily as a condiment to garnish steaks. With the development and expansion of the mushroom canning industry however, they appear to be gaining favour as a base for soup and as ingredient in many dishes in which they were formerly seldom used. Bano et al (1963) reported that mushrooms represent one of the world’s greatest untapped resources of nutritious and palatable foods.

Some mushrooms are edible while others are poisonous (Bahl, 2000). Edible mushrooms are distinctive in some ways. Once their distinguishing features are learned, they cannot be confused with any dangerously poisonous species.

Mushroom is being cultivated in many parts of the world presently. Commercial mushroom growing was first initiated in India (Bahl, 2000). Mushrooms have the capacity to convert nutritionally valueless substances into high protein food. It was stressed further (Bahl, 2000) that on an area basis they are a more valuable source of protein (Table 1). Besides being a food article, mushrooms are variously exploited by man (Bahl, 2000).

Table 1: Approximate annual yield of mushroom (Agaricus bisporus), beef and fish (dry protein, kg/ha).

Protein source                                                               yield

Beef, cattle by conventional Agriculture                        78

Fish, intensive pond rearing                                          675

Agaricus bisporus                                                                    65, 000

Source: Bahl (2000)

Hamburger: A Ground Meat Product

According to Wikipedia (2008), ground beef, beef mince or hamburger meat (in North America) or minced meat (in the rest of the English world) is a ground meat product made of beef finely chopped by a meat grinder. Burgers are usually made from ground meat or meat substitute, then reshaped to form patties and cooked and eaten (Uncyclopedia, 2008). Burgers made with beef are traditionally known as hamburgers, though due to the profusion of burger types over the last few decades are also called beef burgers. Uncyclopedia (2008) further emphasized that other meats such as venison, bison, pork, chicken, turkey, and fish can be used. The name generally changes accordingly with the name of the burger prefixed by that of the meat source. For example turkey burger, buffalo burger, jersey burger, vegiburger, etc. Burgers not made from beef are often marketed as more exotic than hamburger or as being healthier than beef patties. In the UK, the word burger often refers to the filling of a burger sandwich (that is what in USA would be termed a patty).

1.1     Statement of Problem

          Though, meat is a versatile item of the diet, several reports have indicted meat in respect of a host of human health problems, which are not commonly found with plant foods. There is too much dependence on the use/consumption of meat, especially red meat in the diet, with a consequent high cost. Meat is an ideal nutritious food. In many communities it is eaten to confer prestige and class distinction. Many plant materials cannot form satisfactory total replacement for meat, nor achieve compatible and acceptable combination with meat as a product to enable reduction of meat intake, yet meeting the nutritional requirements of humans. The role of meat in the diet is so unique that it cannot be completely removed from the diet.

Mushrooms are valuable sources of high quality cheap food, which have been denied attention, especially in Nigeria and hence not utilized in the diet. The nutritional attributes of mushrooms as well as the physical and sensory qualities are such that mushrooms could combine well with meat to produce a novel nutritious and acceptable product.

1.2     Justification of the Research

          Effective combination of meat and mushroom would enhance the utilization of mushrooms in the diet and subsequent need for the cultivation of mushrooms. The meat/mushroom combination should reduce the ultimate intake of meat and minimize the various acknowledged health problems of meat intake. Most of the health benefits derivable from mushrooms are counter effective against the problems of meat consumption. The nutritional values of mushroom and meat are similar; hence partial replacement of meat with mushroom will not cause any significant reduction in the nutritional value of the new product. Mushroom has a property like meat; hence it is expected to form a compatible and acceptable combination with meat without loss of the physical and sensory qualities of meat.

1.3     Objectives of the Study

          The broad objective of this research is to ascertain the contribution of mushroom to the physico-chemical, nutritive and sensory properties of hamburger, when the meat is partially replaced with mushroom.

Specific objectives would include;

  • To determine the effect of mushroom partial replacements on the physico-chemical properties of hamburger.
  • To evaluate the contribution of mushroom to the sensory properties and general acceptability of hamburger.
  • To evaluate the effect of mushroom partial replacement on the nutritive qualities of hamburger.
  • To evaluate the shelf-stability of the mushroom-beef burger.

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EFFECT OF THERMIZATION AND STORAGE ON THE NUTRITIONAL PROPERTIES AND SHELF-STABILITY OF YOGHURT FROM BLENDS OF COW MILK AND COCONUT MILK

ABSTRACT

Yoghurts were produced by blending reconstituted powdered cow milk (100 g of powdered cow milk (CM) : 0.5 litres of water) with 25 % and 50 % coconut milk (CCM) and a control (100 % cow milk) before fermentation. After fermentation for 16 h at room temperature, the yoghurts were subjected to two heat treatments (thermization) namely, 75 0C thermization and 80 0C thermization and a control (unthermized). The proximate, physicochemical, vitamin and microbiological quality of yoghurt samples were investigated during storage at room temperature for 5 weeks. The results obtained, revealed that in each of the three formulations of yoghurt, proximate composition, titratable acidity (TTA), total solids, free fatty acids (FFA), viscosity, microbial load and vitamins decreased as the temperature of thermization increased. The pH and moisture increased from 4.30 and 82.36 %, respectively with increase in thermization temperature to 4.59 and 83.39 %, respectively. Yoghurts samples from 50 % cow milk (CM) + 50 % coconut milk (CCM) had the highest moisture content (83.39 %) and lowest total solid content (17.84 %) compared to 82.98 % and 18.16 %, respectively from 75 % cow milk (CM) + 25 % coconut milk (CCM) and 82.92 % and 18.28 %, respectively from 100 % cow milk (CM). Titratable acidity increased significantly (p < 0.05) with increase in percentage coconut milk ( 0.77 for 100 % cow milk (CM), 0.82 for 75 % cow milk (CM) + 25 % coconut milk (CCM) and 0.87 for 50 % cow milk (CM) + 50 % coconut milk (CCM)). There was significant (p < 0.05) decrease in pH as the percent coconut milk increased (4.48 for 100 % cow milk (CM), 4.40 for 75 % cow milk (CM) + 25 % coconut milk (CCM) and 4.30 for 50 % cow milk (CM) + 50 % coconut milk (CCM)). The highest viscosity of 282.59 ± 2.46 cPs was obtained for unthermized 100 % cow milk which also had the highest protein content of 3.84 ± 0.11 %. Free fatty acid increased significantly (p < 0.05) with increase in percent coconut milk and during storage. B-complex vitamins (B1, B2 and B3) increased significantly (p<0.05) as the storage time increased while the antioxidant vitamins (vitamin C and E) decreased significantly (p < 0.05). Vitamin A was not detected in any of the samples. Total bacterial count increased significantly (p < 0.05) from 2.27 x 102 cfu/ml ± 0.14 to 6.77 x 102 cfu/ml ± 0.10 on storage within 3 weeks. Thereafter, their numbers reduced. Fungi were detected in all the yoghurt samples but they reduced after one week of storage. Sensory results indicated that yoghurts with coconut milk (CCM) and those thermized at 80 0C had significant (p < 0.05) lower consumer preferences.

CHAPTER ONE

INTRODUCTION

  1.  Background of the study

Yoghurt is a fermented product obtained through an anaerobic fermentation of lactose in milk by relevant micro-organisms, most of which are classified as probiotic (Tull, 1996). It is known and consumed in almost all parts of the world. Most Nigerians regularly take yoghurt either as a dessert, snack or as a probiotic food drink to aid digestion and to re-establish a balance within the intestinal microflora. The tangy sour taste and aroma of yoghurt are due to the activities of most commonly mixed cultures of Streptococcus thermophilus and Lactobacillus  bulgaricus which remain active in the product after its production (Bille and Keya, 2002; Douglas, 2005).

Yoghurt making involves the introduction of friendly bacteria in pasteurized milk under controlled temperature and environmental conditions (Granessha, 2005). The bacteria ingest the milk sugar and release as much as 0.9 to 1.2 % lactic acid as waste product, which reduces pH from 6.7 to below 4.6. The increased acidity causes milk protein to coagulate. According to Early (1998) and Douglas (2005), the increased acidity also prevents proliferation of other potentially harmful bacteria. The optimum fermentation temperature for short incubation of 3.5 – 5.0 hours is 42 0C and for long period of 14 – 16 hours is 30 0C.

Yoghurt can be used to prevent and control diarrhea due to its therapeutic effect. It is capable of modulating the inflammatory response produced by carcinogen. It reduces the inflammatory response through an increase in apoptosis. Proteins in yoghurt are more digestible (Jacobson, 1978) than that in raw milk. Yoghurt was found to improve iron status by improving the absorption of iron from other foods (Branca and Ross, 2001).

On the basis of shelf-life, yoghurt can exist as fresh or thermized. Thermized yoghurt is a product which has been heat treated to reduce bacterial load so as to extend the shelf-life of the product outside refrigeration. Incessant power outage in Nigeria and adverse marketing and distribution conditions have stimulated research interest in thermized yoghurt production and its quality improvement. Heat treatment of yoghurt, however, destroys most of the natural viscosity of the original product due to shock and thinning effect (Early, 1998).

Coconut (cocos nucifera) milk is used by confectionaries worldwide to enhance quality, flavour and taste of various products (Perseley, 1992). Coconut milk has been found to be rich in calcium. The milk was reported to be high in minerals and vitamin content (Nieuwentus and Nieuwentus, 2002) while contributing about 10% of the total energy

(Thai Food Composition, 2004). Coconut milk is a complete protein food when taken in its natural form (Ukwuoma and Mauanya, 2003) and it helps in fighting heart disease. The most popular yoghurts known on the Nigerian market are those obtained from cow milk (Sackey- Addaguay, 2008). Yoghurt obtained by using coconut milk has been found to be a delicious and nutritional product (Imele and Atemnkeng, 2001). The nutritional quality of yoghurt can, therefore, be enhanced by addition of coconut milk.

  1. Statement of Research Problem

From the foregoing, it does seem evident that the substrate usually employed in yoghurt production can be evaporated whole milk, skimmed milk solids, powdered milk or fresh milk from cow. Although these substrates produce good quality yoghurt, milk extracts (coconut milk) from plant produce can be used as milk to formulate yoghurt products of good quality and stability, thereby, bringing their potentials to limelight.

In view of the above, this research was designed to evaluate the quality and stability of thermized yoghurt products, produced from blends of cow milk and coconut milk. This goal was achieved by evaluating the physical, chemical, microbiological and sensory properties of thermized yoghurt composites stored at room temperature.

1.3   Specific Research Objectives

The specific objectives of this study are:

  1. To access the possibility of the use of coconut milk in yoghurt production.
  2. To evaluate the physical, chemical, microbiological and sensory properties of thermized yoghurt.
  3. To determine the storage stability of the products.
  4. To determine the vitamins in the product.

1.4   Significance of the Study

Yoghurt from cow milk has been in existence for a very long time. It is realized that strict vegetarians and people allergic to dairy products are also limited in their quest for probiotic yoghurts when only animal-based yoghurt are available. It is, therefore, of great importance to find out and diversify the feasibility of the use of coconut milk extract, which is plant- base for yoghurt production. Yoghurt obtained by using coconut milk has been found to be a delicious and nutritious product (Imele and Atemnkeng, 2001).

It is, therefore, hoped that this research work would motivate and promote the use of coconut milk in the production of yoghurt so as to enhance the nutritional quality of yoghurt.

EFFECT OF THERMIZATION AND STORAGE ON THE NUTRITIONAL PROPERTIES AND SHELF-STABILITY OF YOGHURT FROM BLENDS OF COW MILK AND COCONUT MILK

EFFECT OF PROCESSING ON THE NUTRACEUTICAL POTENTIAL OF NTURUKPA (Pterocarpus santalinoides) LEAF

ABSTRACT

Samples from Nturukpa leaf were processed using different processing methods. The first portion was oven dried at 50oC for 8 hours while the second portion was further divided into four parts and steam blanched at 100oC for 2, 4, 6 and 8 minutes, respectively. After blanching, each part was also oven dried at 50oC for 10 hours. Each dried sample was milled into flour. The third portion was wet milled (1:2 leaf: water, w/v), filtered and the filtrate was pasteurized at 65oC for 30 minutes. The fourth portion was further divided into four parts and each part was steam blanched at 100oC for 2, 4, 6 and 8 minutes, respectively. After blanching, each part was also wet milled (1:2 leaf: water, w/v) filtered and each filtrate was pasteurized at 65oC for 30 minutes. Fresh, unblanched macerated sample served as control. Samples from all the treatments were analyzed for chemical composition. Effects of the samples on haematological characteristics were evaluated using albino rats. Chemical composition of the samples revealed that untreated dried vegetable flour showed the highest value of crude protein (19.63%) which differed significantly (P<0.05) from the values exhibited by treated samples. The level of iron (17.77mg/100g) in untreated dried leaf flour was also significantly (P<0.05) higher than the level in the macerated sample (control). The untreated dried leaf flour showed 29.81mg/100g of vitamin C content which was significantly (P<0.05) different from the values exhibited by the treated samples. Processing also influenced the phytochemical contents of the samples. The phytochemical constituents of the untreated dried leaf flour sample was significantly (P<0.05) higher than the levels of phytochemicals in the blanched and pasteurized samples.  The bioassay  data  showed that the group of rats treated with high dose of untreated dried leaf flour had higher values of heamoglobin concentration (13.66g/dl) and red blood cell count (6.01× 106 /µl) which differed significantly (P< 0.05) from those treated with blanched and pasteurized samples.

CHAPTER ONE

INTRODUCTION

The role of diet and nutrition as determinants of chronic diseases is well documented, (Thiam et al., 2006). The cost of these diseases has resulted in social distress, loss of productivity and economic burden on health. The factors contributing to the rapid change in disease pattern include urbanization, shift in diets and adoption of a more westernized lifestyle due to economic development and market globalization (WHO/FAO, 2003). This has resulted in the abandonment of indigenous foods that are rich in nutrient and health protecting components. These components are derived from plant foods and microbial sources and provide medicinal benefits that are valuable for healthy life. Nutraceutical has become a more mainstream supplement to the diet. Research has begun to show evidence that these components found in foods are often effective when processed effectively (Brower, 1998).

The term, nutraceutical was coined from nutrition’ and pharmaceutical in 1989 by Dr. Stephen DeFelice, a founder and chairman of the foundation of innovation Medicine (FIM), Crawford, New Jersey. He defined nutraceutical as a food or food product that provides health and medical benefits, including the prevention and treatment of diseases (DeFelice, 1992). Such products may range from isolated nutrients, dietary supplements and specific diets to genetically engineered foods, herbal products, and processed foods (Hardy, 2000). Kathleen and Stephen (2009) also defined nutraceutical as any non-toxic food component that has scientifically proven health benefit, including disease treatment and prevention. The chronic diseases related to diet and nutrition includes diabetes, high blood pressure, cardiovascular disease, stroke and some cancer (Thiam et al., 2006). The steady increase in the prevalence of these diseases has been linked to increasing intake of diets that are rich in energy but poor in micronutrients, health promoting and protecting compounds provided by such dietary component as pulses, fruits and vegetables (Frison et al., 2006). Examples of these food components with reported medicinal value are antioxidants such as resverastrol , flavonoids, anthocyanins, sulforaphane, iso-flavones, alpha-linoleic acid, soluble dietary fiber and products such as psyllium seed husk that reduce hypercholesterolemia (Weingartner et al., 2008).

Antioxidants have become synonymous with good health. They are a class of compounds thought to prevent certain types of chemical damage caused by excess free radicals and charged molecules that are generated by a variety of sources, including pesticide, smoking and exhaust fumes. Destroying free radicals may help to fight cancer, heart disease, stroke and other immune compromising diseases (Odukodya et al., 2010). Many natural antioxidants, especially flavonoids have been shown to be very important in the prevention of these diseases.

There are many nutraceutical products marketed in Nigeria, such as Tianshi; GNLD, forever living product etc.  The main raw materials for the production of these products are natural ingredients (Bull et al., 2002). Some commonly consumed green leafy vegetables in Nigeria contain substantial amount of nutraceuticals but their nutraceutical potentials are yet to be determined.

  • Statement of Problem

Despite the abundant green leafy vegetables in our communities and their use in preparation of traditional soups and dishes, information on their nutraceutical benefit is scanty in literature. The need to increase the utilization of these vegetables cannot be over emphasized. At present, utilization is constrained by the perishable nature and the inability to identify their nutraceutical benefits. It is against this background that this work was designed to achieve the following objectives:

1.2       Objectives of the Study

The general objective was to evaluate the nutraceutical potential of “Nturukpa” (Pterocarpus santalinoides) leaf and the effect of processing on the leaf.

Specific Objectives

  1. To determine the effect of drying and blanching on the nutritional and phytochemical composition of “Nturukpa” leaf.
  2. To determine the effect of treated “Nturukpa” leaf on heamatological and biochemical indices using rat bioassay.

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EFFECT OF PROCESSING METHODS ON THE QUALITY OF UGBA (Pentaclethra macrophylla Benth)

ABSTRACT

African oil bean seed slices (Pentaclethra macrophylla Benth) were prepared by two traditional methods, packaged in sterilized plastic containers and fermented at two different temperatures (ambient (28 ± 2 oC) and 37.5 oC temperature) for 96 hours to produce Ugba (a Nigerian indigenous protein rich food). Proximate analysis (moisture, ash, protein, fat, carbohydrate and fibre content), physicochemical analysis (peroxide, saponification, iodine, pH value), protein solubility and microbial analysis were carried out.These Analyses were carried out at 24 hours interval for 96 hours. The result showed an increase in protein, fat, crude fibre and ash contents of the samples after 96 hours of fermentation with an increase in pH value and a decrease in carbohydrate content for all samples after 96 hours fermentation. The peroxide values, iodine values, and saponification values of the oils decreased while the protein solubility content increased with fermentation time. The result of the total viable counts were 2.74×1017 Cfu/g, 2.34×1017 Cfu/g, 2.18×1017 Cfu/g, 2.9×1017 Cfu/g, for sample A1 (boiled twice and fermented at 28 ± 2 oC ambient temperature), A2 (boiled twice and fermented at 37.5 oC), B1 (boiled once and fermented at 28 ± 2 oC ambient temperature), B2 (boiled once and fermented at 37.5 oC), respectively after 96 hours fermentation. No mould growth was found in the unfermented and fermented Ugba slices for all the products.  At the end 96 hours fermentation, sensory evaluation showed that samples B1 and B2 were the least accepted in terms of aroma, taste and overall acceptability while, while in terms of texture, taste and overall acceptability sample A1 (control sample) and A2 were most preferred.

CHAPTER ONE

INTRODUCTION

1.1     Background of study

      Ugba is the Igbo name for sliced fermented African oil bean seed (Pentaclethra  macrophylla  Benth).The African oil bean seed is called several names in Nigeria, such as “Apara” by the Yoruba, “Ugba” or ” Ukpaka” by the Igbo’s (Enujiugha and Akanbi, 2005). It is consumed mostly in the eastern states of Nigeria as a local delicacy popularly known as “African salad” prepared with oil, pepper, fish and salt and also prepared with tapioca, stockfish and garden eggs. It can be eaten with boiled or roasted yam and cocoyam (Okafor et al., 1991; Mbajunwa et al., 1998). Ugba is a traditional food generally prepared in homes as a small family business. Its method of preparation varies from one place to another resulting in a non-uniform product (Njoku and Okemadu, 1989). According to Enujiugha (2000), “Ugba” is produced traditionally by boiling the seeds overnight for easy removal of the seed coat. The cotyledons are sliced and cooked until they are soft with reduced bitter taste. The sliced “Ugba” is washed about 5 times or more and fermented for 3 days (Enujiugha, 2000).

According to Enujiugha (2003), the cooked, processed and fermented seed “Ugba” is used to prepare some delicious African soup and sausages for eating different staples. Enujiugha (2003) also noted that it is a rich source of vitamins and minerals, having a high demand for local and export consumption. Previous research showed that fermentation gives a better nutritional product than the raw seed (Achinewhu, 1986; Enujiugha and Olagundoye, 2001). According to Siggel and Faucet (1976), fermentation is the oldest method of processing legumes. Other workers discovered that less fermented foods are produced and consumed in Nigeria and only few studies have been carried out on them. Onwuliri et al. (1986) and Onwuliri and Ekepenyong (1994) reported the chemical composition of Pito and Burukutu a known Nigerian traditional brand of alcoholic beverage brewed from sorghum and millet, while another worker studied the fermentation of cassava. Enujiugha and Akanbi (2002) reported that fermentation of African oil bean seeds to produce “Ugba” softens the cotyledon, improves its digestibility and nutrients availability. Obeta (1983) showed that “Ugba” is a cheap and important source of protein especially for people whose staple foods are deficient of proteins. The consumption of the Ugba could pose as a means of addressing the prevailing protein energy malnutrition (PEM) in developing countries (Enujiugha and Akanbi, 2008). It is a cheap and available source of plant protein in developing countries of the world. Its protein contains 20 amino acids and 80 % of its fatty acids are also essential (Enujiugha and Agbede, 2000; Ikediobi, 1981). “Ugba” is a low acid food and a product of alkaline fermentation (Enujiugha and Akanbi, 2005). The rise in pH into the alkaline region has been attributed by Njoku and Okemadu (1989) to activities of various hydrolytic enzymes.

In many Eastern communities in Nigeria, “Ugba” is consumed as a meat analogue due to its high protein content, the locally prepared” Ugba” is done through a mixed wild bacteria fermentation of the sliced, boiled and soaked African Oil bean seeds. Its raw seeds are bitter and contain antinutritional factors like paucine, cyanide, oxalate, saponin, phytate and tannins (Achinewhu, 1983; Enujiugha and Akanbi, 2005; Onwuliri et al., 2004). Thermal treatment of the seeds increases the nutrient bioavailability and the digestability and drastically reduces the level of antinutritional compounds while increasing iron, calcium, potassium, thiamine and riboflavin levels (Enujiugha and Ayodele-oni, 2003). Obeta (1983) and Odunfa and Oyeyiola (1985) Observed that the source of micro-organisms in fermenting seeds comes from handling processing, utensils used in processing and the leaves used in packaging. The result of this uncontrolled fermentation of “ugba” is a very short shelf- life product that lasts for 3-4 days, thereby, limiting the availability of “Ugba”. This is due to the activities of micro-organisms involved in the fermenting process that remains viable till the product is consumed or continues fermentation till the product becomes unacceptable. The product deterioration or spoilage is evidenced by organoleptic changes in colour, texture, odour and taste (Mbata and Orji, 2008). In this research work, a detailed study will be carried out on improving nutritional quality, freshness and general acceptability of “Ugba”. The chemical composition of hygienically processed “Ugba” fermented at different temperatures will also be evaluated.

1.2     Statement of Problem

The growing profile of “Ugba” has made it an important snack food among the low and middle income earners. It is also seen as food for the elderly in the south eastern part of the country, especially during festivities. The increased acceptance and consumption of “Ugba” has led to its high demand. However, due  to its long fermentation time of about 3-4 days for an unreasonable quantity and its short shelf life,” Ugba” processors have encountered daunting tasks in keeping up to the demands and maximizing gain as a result of loss of quality due to its continued fermentation, even days after the desired texture has been attained. The lack of uniformity in texture of fermented Ugba is also a major worry. Nevertheless, good processing and storage techniques that can impact improvements in nutrient availability and digestibility are very essential to producing quality Ugba while at the same time ensuring the elongation of its shelf-life and maintaining quality.

1.3 Research Objectives

The main objective is to compare the quality of Ugba produced from two traditional methods. The specific objectives are:

  1. To evaluate the physico-chemical characteristics of Ugba at different fermentation temperatures.
  2. To monitor the microbial population of Ugba fermented at different temperatures.
  3. To determine the general acceptability of Ugba produced under different fermentation temperatures.
  • Significance of study

Ugba has the potential of achieving prominence and featuring regularly in the food menu as one of the traditional dishes. Its roles in providing the needed protein requirements of the body among the low and middle income earners and the aged people in most rural villages in eastern Nigeria ,coupled with providing employment for the processors are being limited by all the problems stated above. This work therefore, attempts to find out the best processing (fermentation temperature) conditions of Ugba in order to help Ugba achieve its nutritional and industrial potentials.

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EFFECT OF OKARA AND Detarium microcarpum INCORPORATION ON THE QUALITY OF ‘TALIA’ PRODUCED FROM WHEAT AND SORGHUM FLOUR BLENDS

ABSTRACT

The effect of Okara and Detarium microcarpum seed flours on the quality of talia noddles produced from wheat and sorghum flour composites was investigated. Composites of wheat semolina/sorghum flour blended in ratio of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50 were prepared and evaluated for water absorption capacity, soluble solids and swelling capacity. Cold extruded talia produced from each flour composites dough was evaluated for cooking time, cooking losses and total organic matter. The 100:0, 90:10, 80:20 and 70:30 wheat semolina/sorghum flour composites were selected and blended with different levels (0-20) % of Okara and Detarium microcarpum flours, evaluated for physico-chemical properties and talia produced from the flour blends were evaluated for cooking test and sensory qualities. Four best talia products were selected, stored for six months (30 ± 2oC, 85±5% RH) and evaluated for pH, moisture content, TBA number and mould count. Presence of sorghum in the composite flour increased the water absorption capacity from 7.33% to 12.33%, decreased swelling capacity from 52.0% to 45.4%, while talia made from the composites showed increased cooking loss (0.14% to 0.82%), total organic matter (1.26 to 2.84) and reduced radial expansion (3.0 to 2.0) relative to the control. Sorghum addition at 30% level was acceptable for talia production based on low water absorption capacity and high swelling capacity. Okara addition increased the protein content (from 10.21% to 13.63%) of the composites and talia. Blends with 10% okara showed low water absorption capacity (12.75%), low cooking losses (0.73%) and high scores in all the sensory attributes except in appearance but differed significantly (p < 0.05) from the control (100% wheat). Detarium microcarpum addition increased the crude fibre (from 1.69% to 3.76%) content of the talia. There was no significant (p > 0.05) difference among samples at 5% levels of Deterium microcaprum incorporation  relative to the control in all the sensory attributes except in appearance. Low water absorption capacity, cooking loss, and optimal total organic matter (2.01) were observed in the samples at 5% level of Detarium microcarpum incorporation. Okara and Detarium microcarpum addition into talia increased the total dietary fibre contents (from 8.61±0.02% to 9.97±0.01%). The total dietary fibre and mineral contents of samples differed significantly (p < 0.05) with the control. Moisture contents and TBA number did not differ (p>0.05) among stored samples but pH and mould count differed (p < 0.05) relative to the control. Low values of TBA (0.6 to 3.17 mg malonaldehyde/kg sample), mould count (0 to 1.4 x 102 cfu/100g) and moisture contents (10.5% to 14.5%) were recorded during storage.

CHAPTER ONE

INTRODUCITON

1.1 Background

‘Talia’ is a Hausa name for pasta (noodles). It consists of thin ribbons or strips of dough locally made from durum wheat semolina and other cereals using manual cold extrusion and drying. ‘Talia’ was probably introduced into Kano many centuries through Trans Saharan Mediterranean trade (Anon, 2012c). The word ‘talia’ was derived from the Italian Pasta called tagliatelle, a type of pasta from Emilia-Romagna and Marches, region of Italy. Individual pieces of tagliatelle are long flat ribbons that are similar in shape to fettuccine and are typically about 0.6cm to 1cm diameter (Italian trade commission, 2009). According to Italian trade commission (2009), tagliatelle was created by a talented court chef, who was inspired by Lucrezia of Este’s hairdo on the occasion of her marriage to Annibale II Bentivoglio in 1487. The recipe was called tagliolini di pasta esugo, alla maniera di zafiran (meaning tagliolini of pasta and sauce in the manner of Zafiran) and tagliatelle has since then become a more common food. ‘Talia’ is a common staple consumed by a large section of the rural poor in northern Nigeria. It can be prepared with other ingredients like tomatoes, oil, and meat/fish, in the form of ‘Jollof’ or white cooked with groundnut oil and spices. The later is the most commonly served due to economic reasons.  Apart from being prepared and eaten in the homes, ‘talia’ is also hawked around schools and market places as street or fast foods. Recent advances in the manufacturing and processing of pasta (noodles) did not have much effect on the consumption rate of ‘talia’ among the Northern natives, probably because ‘talia’ is generally affordable (Anon, 2012c). ‘Talia’ being a cereal based product, has high carbohydrate content (65%) and low protein content (9%) (USDA, 1974).

According to Giese (1992), the nutritional content of pasta is widely based on the ingredients used in its preparation and added sauces. Limiting nutrients in pasta can be augmented by adding foods rich in such nutrients to the base ingredients (wheat semolina) otherwise known as food to food fortification. Wu et al. (2001) reported increase in protein content of spaghetti fortified with corn gluten meal. There was an increase in protein content of macaroni (12.1%-14.2%) when substituted with cellulose-protein complexes (Oifat et al., 1993). Stefania et al. (2010) recorded increase in protein content of semolina spaghetti with legume flour. Most staple foods of the Northern rural poor are cereal based. These includetalia’ ‘tuwo’ ‘masa’, ‘sinasir’, ndaleyi’, ‘madidi’, ‘capa’ among others. Talia a cereal based food is limiting in protein and dietary fibre. To improve the protein and dietary fibre contents of talia therefore, there is need to incorporate foods rich in these nutrients into talia. Okara, a by-product of the soymilk industries, but rich in protein (24%) according to Rinaldi et al.(2000), Glutamic acid  (0.57g), Aspartic acid (0.36g) and Lysine (0.212g) as recorded by Anon (2015) and Detarium microcarpum  an indigenous legume and a good source of  soluble dietary fibre (50g per 100g dry matter)(Ene-Obong and Carnovoule,1982), can be added to the base ingredients to  produce enriched ‘talia’ thus addressing these nutrients’ deficiencies.

Composite flour technologies initially refer to the process of mixing wheat flour with other cereals and legume flours for making bread and biscuit. However, the term can also be used in regard to mixing of non-wheat flours, roots and tubers, legumes or other raw materials (Dendy, 1992). Blending wheat flour with locally available cereal and root crops would be desirable to encourage the agricultural sector and reduce wheat importation in many developing countries. In Africa, there has been an ever-increasing demand for wheat products such as bread and pasta. Africa is not a major wheat-growing region, but produces large quantities of other cereals such as sorghum and millets. It has been reported that replacing wheat with 20% or 30% non wheat flour for bakery products would result in an annual estimated savings in foreign currency of US $320 million and US $480 million respectively (FAO, 1982). In addition, nutritional enhancement is another goal that is frequently addressed in the development of flour blends.

Thus, composite flour technology holds excellent promise for developing countries. Although, actual consumer trials have been rare, products made with composite flour have been well accepted in Nigeria, Kenya, Colombia, Senegal, Sri Lanka and Sudan (Dendy, 1992).  Sorghum is one of the lesser used cereal in Nigeria. Sorghum is gluten free and the starch contains 100% amylopectin. These make sorghum a good substitute for wheat flour (Miche et al., 1977). Therefore, this work seeks to determine the optimal level of wheat substitution with sorghum, okara, and Detarium microcarpum flours in formulating acceptable ‘talia’ pasta.

1.2 Statement of the Problem

Northern Nigeria has the highest prevalence of malnutrition in the country.  More than half a million children in Northern Nigeria faced severe malnutrition in 2013(Anon, 2013). Malnutrition remains an underlying factor in about one third of Nigerian child deaths and communities in the northern parts are among the worst affected (Anon, 2011). ‘Talia’, which is deficient in protein and dietary fibre, is majorly consumed by the rural poor. These people cannot afford the high cost of animal protein and are consequently vulnerable to malnutrition. There is therefore a need to increase the protein content of ‘talia’ which is a staple for these rural communities using affordable plant sources. It is also interesting to note that these rural communities produce soymilk and discard the ‘Okara’ (‘Dutsan-soya’ in Hausa)or use it as animal feed. Incorporating this protein rich waste into talia will address this protein deficiency associated with Talia.

Secondly, the high moisture content (80%) of ‘okara’, makes it difficult to handle and too expensive to dry by traditional or conventional means. Many people therefore dispose it on land (land fill). Discarding ‘okara’ as waste on land constitutes an environmental problem (pollution), because ‘okara’ is highly susceptible to putrefaction and produces bad odour (Rinaldi et al., 2000). Incorporating ‘okara’ into ‘talia’ could help to eliminate a possible source of pollution while at the same time adding economic value to this waste product.

High cholesterol in foods has led to several health conditions such as coronary heart disease, cancer, high blood pressure and obesity among other health conditions.  Fibre in diet plays very significant roles as certain physiological responses have been associated with the consumption of dietary fibre. Such roles include increase in faecal bulk and lowering of plasma cholesterol (Ene-Obong and Carnovoule, 1982).  Pederson et al. (1980) observed that the supplementation of the diets of diabetic patients or those with impaired glucose tolerance with dietary  fibre resulted in an improvement in blood glucose profiles and reduction in urinary glucose. Lack of dietary fibre is one of the problems of food products like ‘talia. Incorporating Detarium microcarpum, a good source of dietary fibre into ‘talia’ could address dietary fibre deficiency in talia.

Nigeria is not a wheat-growing region, but it produces large quantities of other cereals such as sorghum and millets. Blending sorghum flour and wheat semolina for ‘talia’ production could encourage the agricultural sector, reduce wheat importation and promote the use of indigenous crops within and outside the country.

1.3 Justification of Study

The high prevalence of malnutrition among the rural communities in northern Nigeria is a major concern. The idea of re-channeling the waste protein in ‘okara’ to the food chain for human consumption could address malnutrition, reduce a possible source of environmental pollution, add economic value to the waste product, and create job opportunities leading to better socio-economic development in the country.

Increasing dietary fibre in diets can help increase faecal bulk and lower plasma cholesterol (Ene-Obong and Carnovoule, 1982). Incorporating Detarium microcarpum in talia could improve its dietary fibre content and hence reduce the risk of chronic diseases.

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CONTRIBUTIONS OF PACKAGING TO THE EXTENSION OF SHELF LIFE OF PROCESSED GRASSCUTTER MEAT (Thyronomys swinderianus).

ABSTRACT 

This research was carried out to assess the physico-chemical properties, storage stability and acceptability of cured grasscutter meat (Thyronomys swinderianus) products which were smoked and packaged with different plastic films (High Density Polyethylene and Polypropylene). Live grasscutter was slaughtered, dressed, cut-up and divided into three portions. One portion was treated with a solution of 5% salt; second portion was cured with a solution containing sodium nitrite, potassium sorbate, salt and Onion (Allium cepa) extract, while the last portion which was not cured served as control. They were all hot smoked for nine (9) hours at 78+20C. Following smoking and cooling, each portion was further divided into three sets.  One set was not packaged, while another set was packaged with High Density Polyethylene and the last set was packaged with Polypropylene. Following smoking and cooling, samples were analysed for physico-chemical, microbial and sensory properties before storage. During storage at ambient conditions for 92days, samples were withdrawn at 21day intervals for evaluation of quality changes. Results show that smoking, with or without salting and curing of fresh grasscutter meat appeared to be an effective means of preservation. Samples smoked after curing had the least microbial count and high chemical/anti-oxidative stability followed by the samples smoked after salting. The control had the highest microbial load and least anti-oxidative stability. Hot smoking reduced the moisture content and water activity, but increased per unit weight the protein, fat, ash, pH, vitamins (such as vitamin A and C) and minerals (such as iron, sodium and potassium), presumably due to concentration effect. The sensory analysis showed that the samples smoked after salting were generally preferred to the other two samples, based on the colour, flavour and general acceptability. Although no Significant difference (P > 0.05) were found among the samples. During storage, samples packaged in polypropylene were found to have more oxidative stability with the least TBARS, peroxide and acid values. The water activity values were low. Microbial analysis of these packaged samples during storage gave the least mould and total viable counts. Unexpectedly, the vitamin and mineral contents were retained more in the High Density Polyethylene packaged samples throughout the storage period compared to Polypropylene packaged samples. Also, sensory analysis during storage showed no significant differences due to packaging (P>0.05).

CHAPTER ONE

INTRODUCTION                                                                                                                     

1.1       BACKGROUND INFORMATION

Meat products are processed animal tissues which are used as foods. They are complex biomaterials that are subjected to many biological, chemical and physical changes that affect quality and shelf life (Hotchkiss, 2006). Biological changes are caused by micro-organisms (spoilage and pathogenic), insects and rodents. Chemical changes result from environmental influences and include oxidation, flavour deterioration and colour loss among others. Physical changes include moisture gain or loss, textural changes and contamination by foreign materials.

Meat processing is little practiced in the tropics mainly because of crude technological base and entrepreneurial reluctance to take the risks, hence high demand for fresh (raw) meat. Consequently, fresh meat and traditional meat products are just wrapped with paper, and leaves (Obanu, 1986). Meat traditionally preserved by drying is sometimes, packaged in linen bags, baskets or pottery to facilitate storage and transport and to provide some kind of protection against dirt and insects. To extend the shelf-life of these meat products, some processing are necessary.

An aspect of processing in common use is packaging. Proper packaging precludes deteriorative changes in meat products. According to Hotchkiss (2006), the time it takes for a food product to deteriorate to an unacceptable degree (shelf-life) is dependent on processing method, storage conditions and form of packaging. Thus, food packaging significantly affects quality and safety related changes in food and has a profound impact on shelf-life (Bugusu and Bryant, 2006).

Packaging can be seen as an enclosure or wrapping of products (IFIS, 2005). In view of this, food packaging therefore involves the creating of an inert, correct and suitable environment for food, protecting it from biological, chemical and physical changes by effectively acting as a barrier between the internal and external environments. This enables packaging to preserve and protect a product so that it reaches the consumer in the same condition as when it was first made. Packaging as a meat preservation technique operates on the principle of prevention (or reduction) of contamination and protection; its protective technique operates on protection against static and dynamic stresses imposed by storage and transportation (Brody, 1974).

In addition to its preservative and protective function, packaging also performs overtly presentational/technical functions; by increasing sales through displaying what the product actually is and information regarding the product as well as creating brand awareness. It also aids to appeal to the consumer in terms of shape, size, colour and convenience (Fellows and Axtell, 1993).

1.2       PROBLEM STATEMENT

In most developing countries, processed meat products are handled and stored with minimal refrigeration. A fast-turnover system existed traditionally, ensuring that meat slaughtered in the morning are sold and consumed the same day. With higher concentrations of population, however, this traditional system now becomes obsolete and unsatisfactory because more time is needed between slaughtering and ultimate consumption (FAO, 1990). Meat products are highly perishable because of their high initial water content and nutritive content. Heat processed smoked meats have been observed to absorb moisture from the environment, develop objectionable odour and flavour and because they are not stored well, can be easily attacked by rodents, insects, flies and micro-organisms (Kramlich, et al., 1980).

In order to check deteriorative changes in processed meat products to the point of consumption, certain methods of preservation technique have to be applied. Refrigeration is the obvious solution, but this is expensive and frequently unavailable in developing countries. Hence, it is observed that in industrialized countries, only 2% of products are spoilt before they reach the consumer compared to the staggering 30 – 50% in developing countries where the packaging chain is less well developed. Energy-saving storage methods are therefore particularly relevant (Anonimous, 2001; FAO, 1990).

Nigeria is blessed with abundant sources of raw material for flexible film packaging material namely resins. Despite this abundance, packaging is in its infancy, consequently, inadequate packaging films are used to protect indigenous meat products and they fall short of providing maximum protection. For instance, extrusion technology is low, being available only for few extrusion operations. This may be because demand is low too. Odigbo and Ikeme (2008) noted that the cost of using polypropylene films for kilishi packaging added less than one naira to the cost of product. This is not much. It is, therefore, necessary to identify other factors than cost that contributes to low usage rate of appropriate film.

A major contemplation is lack of knowledge of the application of the packaging films. Producers of meat products still prefer to use a selection of traditional packaging material such as leaves and papers among others in an attempt to preserve cherished characteristics.

It is necessary to extend the knowledge that such cherished characteristics can be preserved by modern packaging materials if they are carefully chosen. Additionally, the modern packaging material can help to extend the shelf-life of their delicate meat product.

This work is therefore aimed to assess the contributions of packaging to the shelf-life of grasscutter, an indigenous meat product. 

SIGNIFICANCE OF STUDY

  • To improve our traditional smoked meat packaging.
  • Reduce Contamination and improve marketability of smoked grasscutter meat.

 1.3                         AIMS AND OBJECTIVES OF STUDY

The main aim of this research is to assess the suitability of selected packaging films in the extension of shelf life of smoked grasscutter meat product.

The specific objectives are to:

A:  Package grasscutter meat with the selected films,

B:  Analyse the physicochemical and organoleptic qualities of grasscutter meat stored in the films,

C:  Assess the acceptability of the stored meat products.

It is hoped that this study will help to lay the foundation for the desired improvement of our traditional smoked meat packaging technology.

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CHEMICAL COMPOSITION, HEALTH PROMOTING POTENTIALS AND STORAGE PROPERTIES OF BISCUITS SUPPLEMENTED WITH ORANGE PEEL AND PULP FLOURS

ABSTRACT

Sweet orange (Citrus sinensis) fruits were washed, peeled manually, the juice extracted and the seeds were removed. The peels and pulps were sliced into thin slices of about 2 cm thick, sun dried at 30 ± 2°C to constant weight, milled and sieved to obtain orange peel and orange pulp flours, respectively. The orange peel and pulp flours, respectively were used to substitute wheat flour 5, 10 and 15 % respectively. The flours were analyzed for their chemical composition. Biscuits were prepared from the flour blends and evaluated for their chemical composition, sensory and storage properties. Antioxidant activities of water and ethanol extracts of flours and biscuits were determined. Bioassay study in which five weeks old Wistar rats weighing between 80 and 90 grams were divided into four groups containing six rats each was carried out. Groups 1,2,3 and 4 were fed biscuits containing 10 %  orange peel flour,  10 % orange pulp flour,  100 % wheat flour, and  normal feed (growers mash), respectively. Feed intake, water intake, changes in body weight, blood sugar and lipid profile of the rats were determined. Biscuit samples were stored for six months at 30 ± 2°C and 80 to 90 % relative humidity. Changes in pH, moisture and peroxide value of the biscuits were assessed monthly. The sensory properties of the stored biscuits were also evaluated after every two months of storage. The results showed that the orange pulp flour was significantly higher (p<0.05) in fibre, ash and moisture but lower in fat and carbohydrate contents than the orange peel flour. The mineral contents of the flours were not significantly different (p>0.05).The orange peel flour contained more tannins than the pulp flour, but the flours were not significantly different in their oxalates contents. However, orange peel flour was significantly higher (p<0.05) than the pulp flour in alkaloids, flavonoids, anthocyanins and carotenoids. The biscuit samples containing 10 % orange pulp had higher fibre content than the biscuit containing 10 % peel flour. The mineral contents did not differ significantly (p>0.05) among the biscuits. Baking reduced all the antinutrients of the biscuit samples. The highest antioxidant activity was shown by the ethanol extracts of the flours and biscuit samples in relation to the water extracts. Body weights of all the rats in all the groups increased during the study period.  The rats fed biscuits containing 10 % peel and pulp flours showed least increase in body weight. There were increases in the high density lipoprotein and total cholesterol contents in all the rat groups. However, the low density lipoprotein (bad cholesterol) of the rat groups decreased. The triglyceride contents increased in all the rat groups except for the group fed biscuit containing 100 % wheat flour. The rats fed 10 % orange peel and pulp flour biscuits also showed lower blood glucose levels than the other groups. There were no significant differences (p>0.05) between the peel and pulp biscuits in colour and texture at the end of six months storage. However, the biscuits containing orange peel had higher ratings for flavour, but lower ratings for taste and overall acceptability.  Moisture contents of biscuits fluctuated during storage, values ranged between 5.56 and 8.85 %.  The peroxide values of the biscuits increased slightly after 4 months of storage.

      CHAPTER ONE

1.0                                                INTRODUCTION

            Sweet orange is one of the most important fruits in the tropical and sub-tropical regions of the world. The fruits are usually eaten fresh but are also used for making canned orange juice, frozen juice concentrate, jams, jellies among others. Orange processing industries generate huge amounts of orange peel and pulp as by products from the industrial extraction of orange juices. These peel and pulp contain among other things high levels of vitamin C, dietary fibre and flavonoids. Dietary fibre has been used for the treatment of various gastrointestinal disorders and for such possible health benefits as lowering cholesterol levels, reducing risk of colon cancer and losing weight (Friedman, 1989). Dietary fibre has also been reported to have some nutraceutical potentials (Weingartner et al., 2008). Orange peel and pulp also contain other phytochemicals such as polymethoxylated flavones (PMF) and  hesperidin which have hormonal and antioxidant actions and are also involved in enzyme stimulation (Gardon, 1990).

            Until just recently, analysis of food was limited to sensory and its nutritional value. However, there is growing evidence that other components of food may play an integral role in the link between food and health (Kaira, 2003). Consumers are increasingly interested in the health benefits of food and have begun to look beyond the basic nutritional benefits to the potential disease prevention and health enhancing compounds contained in many foods (Hasler, 2003).

            Nutraceutical, a term combining the words “nutrition and pharmaceutical,” is a food with a medical health benefit, including prevention and treatment of disease. This definition includes any substance that may be considered a food or part of a food and provides medical or health benefits, including the prevention and treatment of disease. Such products may range from isolated nutrients, dietary supplements and diets to genetically engineered foods, herbal products and processed foods such as cereals, soups, beverages among others. (Defelice, 1994). Examples of foods with nutraceutical values are broccoli (Sulforphane), which may help in the prevention of cancer, resveratrol from red grape products as an antioxidant, flavonoids in citrus, tea, wine and dark chocolate (Weingartner et al., 2008). Many botanical and herbal extracts such as ginseng, garlic oil etc have been developed as nutraceuticals. The use of nutraceuticals to accomplish desirable therapeutic outcomes with reduced side effects as compared with other therapeutic agents has met with great success (Whitman, 2001; Nelson, 1999). The peel and pulp of orange fruits have been noted to contain some bioactive substances believed to possess nutraceutical potentials (Kootstra, 1994). Thus, the incorporation of orange peel and pulp into wheat flour for the production of biscuit would enhance greater utilization of phytochemicals in Nigerian diets.

            Biscuit is a confectionary, dried to very low moisture content (Okaka, 1997). Biscuit is a snack food which can be eaten in-between meals or at any time of the day and by any age bracket. An increasing proportion of the household food budget in Nigeria is spent on snacks in which convenience and quality are perceived as most important (Lasekan and Akintola, 2002). Biscuits contain fat (18.5 %), carbohydrate (78.23%), ash (1.0 %) and salt (0.85 %) (Okeagu, 2001). They are generally characterized by a low moisture content (Okaka, 1997), The shelf life is several months under correct storage conditions (Ihekoronye, 1999). However, biscuits must be packaged in containers which prevent moisture uptake (Okaka, 1997).

1.1 STATEMENT OF PROBLEM

 The juice obtained from orange fruits is widely consumed while the pulp and peel are discarded. The amount of peel and pulp obtained from citrus fruit processing accounts for 50% of the original amount of the whole fruit (Chon and Chon, 1997). These Peel and Pulp contain some bioactive substances believed to have nutraceutical potentials.

Biscuit consumption among children and adult is high in Nigeria. Orange peel and pulp could be incorporated into wheat for biscuit production because of their phytochemical content. However, the storage properties and nutraceutical potential of biscuit containing orange peel and pulp need to be assessed.

1.2 BROAD OBJECTIVE OF THE STUDY  

            The broad objective of the study was to determine the chemical composition, health promoting potentials and storage stability of biscuits supplemented with orange peel and pulp flours.

1.3 SPECIFIC OBJECTIVES 

1) To produce biscuits from blends of wheat and orange peel and pulp flours.

2) To determine the chemical composition of the biscuits.

 3) To evaluate the health promoting potentials of the biscuits using bio-assay study.               

4) To determine the storage stability of the biscuits.

CHEMICAL COMPOSITION, HEALTH PROMOTING POTENTIALS AND STORAGE PROPERTIES OF BISCUITS SUPPLEMENTED WITH ORANGE PEEL AND PULP FLOURS

CHEMICAL AND RHEOLOGICAL EVALUATION OF PRODUCTS FROM AFRICAN STAR APPLE (Chyrosophyllum albidum) PEELS AND COTYLEDONS.

ABSTRACT

The seeds and peels of African star apple (Chrysophyllum albidum) (“udara”) were split, followed by removal of mucilage from the seeds and subsequent cracking of the seed shells, and de-pulping of the peels. The seed cotyledons and peels were blanched at 1000C for 2,4 and 6 mins, wet milled with water in 1: 1.5 ratio, sieved with muslin cloth to obtain the extracts which were pasteurized at 800C for 10mins and stabilized with 0.2, 0.4, 0.6, 0.8 and 1.0 (g/litre) concentrations of carboxy methyl cellulose (CMC) and pectin each. A preliminary study was done on the African star apple (“udara”) peels and seeds by ranking to determine the best two stabilized samples from each of the three batches of 2, 4, and 6 mins blanched. Based on the overall acceptability of the panelists, six samples were selected for further study together with their respective controls making a total of twelve samples coded as follows: peel extract control samples A1, B1 and C1 of 2, 4 and 6 mins blanching respectively, cotyledon extract control samples A2, B2 and C2 of 2, 4 and 6mins blanching respectively, stabilized peel extract samples D1, E1 and F1 of 2, 4, and 6 mins blanching respectively, and stabilized cotyledon extract samples D2, E2 and F2 of 2, 4, and 6 mins blanching respectively. The fresh peel and cotyledon had moisture  (22.36%),  protein (1.68% and 4.33%), crude fibre (8.21% and 5.99%), ash (0.18% and 0.30%),  fat (0.50% and 3.05%) and carbohydrate (66.87% and 60.74%), respectively which reduced with increased blanching period. The antinutrients – tannin (0.400% and 0.240%), HCN (1.06% and 1.10%) and phytate (1.21% and 2.73%)- in both peels and cotyledons respectively also reduced appreciably with increased blanching period. Blanching considerably reduced the viscosity while stabilization increased the viscosity. Rheological characterization of “udara” peel and cotyledon samples was found to be shear thinning – pseudoplastic behaviour of non-Newtonian fluid. Freezing at -10°C of “udara” peel and cotyledon products caused significant (p<0.05) sedimentation of their solid fractions and subsequent separation into solids and water phases at all levels of stabilization.

CHAPTER ONE

  • INTRODUCTION

Rheology is the study of the flow of matter, primarily in the liquid state but also as soft solids under conditions in which they respond with plastic flow rather than deforming elastically in response to an applied force (Schowalter, 1978). It applies to substances which have complex molecular structure, such as mud, sludge as, suspensions, polymers and other glass formers (e.g. silictates), as well as many foods and additives, bodily fluids (eg. blood) and other biological materials.

The term rheology was coined by Eugene C. Bingham, a professor at Lafayette College in 1920, from a suggestion by a colleague, Markus Reiner (Steefe, 1996). The experimental characterization of a material’s   rheological behavior is known as rheometry, although the term rheology is frequently used synonymously with rheometry, particularly by experimentalists. Theoretical aspects of rheology are the relation of the flow/deformation behaviour of material and its, internal structure (eg. the orientation of polymer molecules), and the flow deformation behaviour of materials that cannot be described by classical fluid mechanics or elasticity. It is also concerned with establishing predictions for mechanical behavior (on the continuum mechanical scale) based on the micro or nanostructure of the material example the molecular size and architecture of polymers in solution or the particle size distribution in a solid suspension. Materials with the characteristic of fluid will flow when subjected to a stress which is defined as the force per unit area. Much of theoretical rheology is concerned with associating external forces and torques with internal stresses and internal strain gradients and velocities (Schowalter, 1978; Bird et al., 1960; Bird et al., 1989., Faith, 2001). Food rheology is important in the manufacture and processing of food products, it is generally referred to as the material science of food and it is defined as the study of the rheological properties of food that is the consistency and flow of food under tightly specified conditions. Understanding rheology of food is critical in optimizing product development, process methodology, final product quality and chemical analysis as well as result interpretation.

However, the consistency, degree of fluidity and other mechanical properties are important in understanding how long food can be stored, how stable it will remain, and in determining food texture. The acceptability of food products to the consumer is often determined by food texture, such as how spreadable and creamy a food product is.  Rheology attribute such as texture of food, has a substantial influence on the consumer’s perception of quality and mouth feel during chewing and mastication (Fellows, 2000). The   interest in product formulation is growing and stimuli acting various research activities to identify and evaluate the chemical (nutritional) and rheological properties of fruits extracts and their potential application in fruit drink production. Thus, the rheological properties of fruit products are important factors that determine the sensory properties such as mouth feel, texture and consistency. Also stressed materials deform and the rate and type of deformation characterize its rheological properties (Fellows, 2000).  To build up an image of the texture properties of the food, below is an example of food eating process which may be seen as taking place in a number of stages (Szczeniak, 1963):

  • An initial assessment of hardness, ability to fracture, and consistency during the first bite.
  • A perception of chewiness, adhesiveness and gumminess during chewing, the moistness and greasiness of the food together with an assessment of the size and geometry of individual pieces of food.
  • A perception of the rate of which the food breaks down while chewing, the types of pieces formed, the release or absorption of moisture and any coating of the mouth or tongue with food. The focus of this work is fruit product formulation where understanding rheology is critical in optimizing product development efforts, processing methodology and final product quality. One can therefore think of food rheology as the material science of food. Thus an extensive research is required to evaluate the chemical (nutritional) and rheological potentials of our locally available plant resources. Chrysophyllum albidum (“udara”)’ peels and seeds are parts of the main fruit discarded while consuming the pulp. The “udara” plants are grown abundantly in Nigeria.

1.1       Problem Statement

The African star apple fruit is perishable with a shelf life of 3-5 days after picking or harvesting. The pulp is mostly eaten while the peels and seeds are discarded. Thus, there is need to identify and evaluate the potentials of the peel and seeds of the fruit (African star apple – (Chrysophyllum albidium), and formulate acceptable shelf stable products based on their rheological properties. 

1.2       Objective of the Study

The main aim is to identify the chemical components in the peel and seeds of African star apple (Chrysophyllum albidium) and evaluate the effects of processing on the rheological and chemical properties of their products. 

The specific objectives are:

  1. To produce extracts from the peel and seeds of African star apple.
  2. To determine the chemical components of the extracts.
  • To evaluate the effects of processing methods on the rheological and chemical properties of the products.

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CHANGES IN PHYSICOCHEMICAL PROPERTIES OF INSTANT KUNUN ZAKI FLOURS PRODUCED FROM MILLET (Pennisetum typhoiduem) AND MALTS OF COWPEA (Vigna unguiculata) AND SOYBEAN (Glycine max) DURING STORAGE.

ABSTRACT

In this study, instant kunun zaki powders were produced from millet-cowpea malt and millet- soybean malt. The instant powders were packaged in polypropylene plastics and stored for 3 months. During this period, studies of the changes in physiochemical and functional properties of the packaged flour were carried out every 30 days for 3 months. Production of instant powders was by blending millet with malt of cowpea for millet cowpea malt (MCm) and millet with malt of soybean for millet-soybean malt (MSm) each in the ratio of 70:30 w/w. Ginger was added to each blend in the ratio 15:1 w/w. The blends were incubated at 28+30C for 15 minutes and instantized by steam-heating for 10 minutes followed by oven drying at 500C to a moisture content of 6.23% for MCm and 6.34% for MSm. The flour blends were then packaged in polypropylene plastic (12x18cm) and stored for three months at 28+30C. During this storage period, studies of the changes in physiochemical properties of the packaged flour were determined every 30 days. The results showed that diastatic activities of cowpea and soybean increased with malting, with that of cowpea being higher (63.330L) than that of soybean (30.000L). Protein and sugar contents increased after malting, whereas fat and TBA content decreased with malting. During storage however, there was a general increase in moisture content, sugar, fat, TBA, tannin and trypsin inhibitor in all the samples. Protein content decreased with storage. Water absorption capacity, bulk density, solubility, dispersibility and viscosity decreased with storage time. The particle sizes of the flours increased with storage.

  1. INTRODUCTION

       Kunun zaki is a traditional, non-alcoholic and  non-carbonated beverage widely  consumed in Northern Nigeria and is becoming popular in the South .It is consumed at any time of the day by both adults and children, as breakfast drink. It an appetizer and it is commonly served at social gatherings. The ingredients used in its manufacture include, millet (Pennisetum typhoideum), sorghum (Sorghum vulgare), maize (Zea mays), rice (Oryza sativa), spices [ginger (Zingiber officinale), garlic (Allium sativum), red peeper (Capsicum annuum), black pepper (Piper nigrum), clove (Syzygium aromaticum)]. Also Cadaba farinosa, potatoes (Ipomea batatas)(Efiuvwevwere and Akoma, 1995). Tiger nuts (Cyperus esculentus) and groundnut (Arachis hypogea) may be added to sweeten and enrich protein content.

Kunun zaki is rich in carbohydrates, vitamins and minerals but it is low in protein (Ayo and Okaka, 1998). Sugar may be added instead of pepper to meet the demands of some consumers (Onuorah et al, 1987; Akoma et al 2006). Some consumers consume kunun zaki without sugar or pepper (Adeyemi and Umar, 1994). Kunun zaki is accepted based on its colour (cream) and flavour (millet mixed with ginger flavour).

Traditionally, kunun zaki is produced by steeping the grains in water, wet milling with spices and sieving, the overall process taking 24 hours (Adeyemi and Umar, 1994). This traditional method has been improved by shortening the processing time to 12 hours by steeping the grains in warm water containing 15% sodium metabisulphate, wet-milling, liquefication and saccharification with enzymes in the grain, filtering, bottling and pasteurization at 80oC for 30 minutes before refrigeration at 4-8 oC (Gaffa and Ayo, 2002). Traditionally produced kunun zaki has a shelf life of about 24 hours (Adeyemi and Umar, 1994) at ambient temperature. The improved method can however extend the shelf life to 8 days after pasteurization followed by refrigeration storage (Osuntogun  and Aboada, 2004) which can last for 90 days when chemical preservation is applied as has been achieved by FIIRO, Nigeria (Haard, 1998). Also instant kunun zaki flour has been produced by Dala Foods Limited Kano, Nigeria and commercialized Kunun Tsamiya, the product being made only from millet. Further work was done by Amazikwu (2007) where she produced instant kunun zaki flours from millet-cowpea malt and millet-soybean malt to enhance protein content and sensory quality. She also carried out sensory evaluation and the samples were rated acceptable by consumers.  However no packaging or storage studies have been carried out on the instant powders and shelf life is also largely dependent upon the storage conditions and packaging materials used. This work is therefore a follow up of the work done by Amazikwu (2007). Against this background, this project was designed to produce instant kunun zaki flours from millet-cowpea malt and millet-soybean malt combinations and store in good flexible packaging material. Specific attention was therefore directed at;

(i) producing instant kunun zaki powders from millet-cowpea malt and millet-soybean malt by steam heating.

(ii) studying the changes in physicochemical and functional properties of the packaged flours during storage.

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SODOR OIL TERMINAL PROJECT MANAGEMENT AND CONTROL

Summary

This critical appraisal seeks to come up with a methodical assessment of the Sodor Oil Terminal, Planning and Construction Project. It involves an analysis of the project and different aspects of the management approach employed by my team (5) from start to finish. The appraisal approaches the exercise from the standpoint that the requisite project management tools and techniques were applied in all phases of the project. The critical appraisal is based on principles and ideas gleaned from project management theories, journals, case studies and real life experiences. In the end, the evaluation concluded that the Sodor Oil Project followed relevant project management tools and techniques and was overall well managed. The report on the project’s critical evaluation mainly draws supportive literature from journals associated with project management.

Introduction

Manzoor et al. (2011) concluded from an evaluation of real life experience and project management literature that project success is a virtually assured outcome if applicable project planning techniques and procedures are used accordingly. These tools and techniques include pertinent planning, effective communication, team work, monitoring and evaluation, exceptional problem-solving ability, change management abilities, delivery reviews, excellent implementation of project strategy, project reviews, milestone checklists, Gantt chart and scorecards among others (Baker and Day, 2006). That being the case, excellent management skills was absolutely paramount for the success of the Sodor Oil Project. At the end of the report, concluding remarks as well as recommendations on project management will be given. The MS Project Baseline Plan at the beginning and the closeout baseline plan are attached to the appendix.

CRITICAL REVIEW OF HOW THE TEAM WAS ORGANISED

The end goal of the Sodor Project was the construction of an Oil Terminal on the isle of Sodor near Kirk, Ronan.

Team formation

The project began with the selection of a five-member team, scheduling of biweekly meetings and set the team’s goals as designing, planning and construction of the terminal.

The frequent meetings were instrumental in enhancing team building as well as in setting specific objectives to guide the team to achieve the intended goals. During the meetings, the team discussed and highlighted the importance of effective communication, team roles, interpersonal leadership skills, and commitment to the project goals. Huang (2013) describes shared leadership as a collective leadership technique which is effective in promoting commitment of members. Kramer and Crespy (2011) concur with this view, arguing that shared leadership enhances a collaborative approach on members of the group. The team duly agreed to follow this approach in implementation of the project. Under this approach, every group member was afforded a chance to exercise leadership over other members of the group periodically and on specific tasks. Wi et al. (2009) cited that, choosing a competent leader for a position of managing a team and having competent members collaborate as a team is a key to accomplishment in a project. For the purpose of precise control, where each member was aware of their specific role, we chose to apply the team role theory as put forward by Belbin (Aritzeta, Swailes, and Senior, 2007). The approach also helped in selecting a manager and assigning specific roles to each member based on their strengths, weaknesses and professional expertise. The team was broken up into five roles; project manager, IT assistant, whom assisted in updating the project plan, assistant project manager, who performed the minute taking, vendor selection investigator, who took the task of selecting the vendor and account/financial officer, produced the cost model for the sodor project. The core role of the manager was that of supervising the project as a whole as well as coordinating and assigning duty to other members of the team (Baker and Day, 2006).

Team Communication

With the absolute need for effective communication and project success in mind as laid out by Ramsing (2009), the team devised a strategy on achieving effective communication throughout the life-cycle of the project; effective communication is necessary for each project as it helps in setting out and achieving outlined objectives in the foreseen timeline. Effective communication and information management are two useful tools in the designing of project management structures (Mazzei and Ravazzani, 2011). In view of this fact, the team decided to apply a variety of communication channels, including phone calls, whatsapp messaging app and email among others. Google Mail and Drop-box were picked as the platforms of choice in sharing project materials, and this was expected to help us to follow the projected project milestones and critical path.

Team Motivation

It is regularly to team member’s greatest advantage to join a project team in order to complete their tasks in a more proficient way (Zhu, Huang and Contractor, 2013). For example, in a situation whereby a team member with less experience and low skills would bring about a high cost; taking quite a long time or a high risk of inability to finish a task by themselves. In this way, the team member has more utilitarian needs to collaborate with other team members to accomplish assigned tasks. In addition, by working in teams and watching other team members carry out tasks, low-skilled members might learn from highly-skilled team members and enhance their skills. However, few members of the team had little or less skills in utilising the MS project tool during the Sodor project plan, hence we adopted a mutual interest and collective action to motivate the team for effective collaborative work.

SODOR OIL TERMINAL PROJECT MANAGEMENT AND CONTROL

THE EFFECTS OF BLENDING COW MILK WITH SOYMILK ON YOGHURT QUALITY

ABSTRACT

A quantity of 1 litre each of cow milk and blended (cow/soy) milk was pasteurized and each was inoculated with 5g of a mixed starter culture comprising streptococcus thermophillus, Lactobacillus acidophilus and Lactobacillus bulgariuos and incubated at 500C for 5 hours to ferment to yoghurt. Proximate analysis on both yoghurts showed that there was no significant difference (P>0.05) between the moisture content, protein content and fat content of the two yoghurts samples. The ash content and carbohydrate content of the blended (cow, soy) milk yoghurt were significantly (p<0.05) than that of cow milk yoghurt. Also, significant difference (p, 0.05) was observed in terms of colour between the two yoghurt samples. However, no significant difference (p>0.05) was observed in terms of taste, aroma, consistency and general acceptability of the two yoghurts. Physicochemical analysis showed that the specific gravity of blended (cow/soy) milk was significantly higher (p<0.05) than that of cow milk yoghurt but there was no significant difference (p>0.05) observed in pH and T.T.A of both yoghurts. However, the two yoghurt were generally accepted.  

THE EFFECTS OF BLENDING COW MILK WITH SOYMILK ON YOGHURT QUALITY

EVALUATION OF OIL OBTAINED FROM PAW PAW (CARICA PAPAYA) SEEDS

ABSTRACT

Oil was extracted from carica papaya (pawpaw) seeds and analyzed for its physico-chemical properties (percentage of oil yield, moisture content, pH, specific gravity, acid value, saponification value, ester value, iodine value, peroxide value and unsaponifiable matter) and sensory qualities (colour, aroma, taste and general acceptability). The sensory characteristics analyzed by the panelists on the three oil samples (pawpaw, olive and vegetable oil) gave preference for the vegetable oil in all the attributes.

EVALUATION OF OIL OBTAINED FROM PAW PAW (CARICA PAPAYA) SEEDS

PROMOTE COMPOSITION OF PLEUROTUS TUBERRCOGININ FROM ENUGU AREA

ABSTRACT

Proximate analysis of Pleurotus tuberregium was determined to ascertain its nutritional composition. the sample was analysed for its moisture, crude fibre, ash, fat, protein and carbohydrate content. Using the method of AOAC. The results for the analysis showed that the materials has moisture content of 2.5% ash content of 1.50%, fat content of 3.00%, crude fibre content of 3.02% and carbohydrate content of 89.32%. Carbohydrate has the highest composition of the nutrients. This indicates that it could be used as food stablizer, thickening / binding agent in food industries. Based on the findings, Plenrotus tuberregium could compare favourably with other hydrocolloids such as modified starches and celluloses that one normally used as binding agents. It is therefore suggested that the use of Pleurotus tuberregium should be popularized.

CHAPTER ONE

1.0 INTRODUCTION

plenntus tuberregium is a fungi as and an aerobic metabolism and generates energy form oxidation of organic compound. The morphor logical differentiation of plenntus tuberregium is limited. It forms hyphen and develop each type depending on the growth condition. The diameter of the hyphen is usually 5NM. The hyphen is either without septate or has a cellular morphology by septate hyphae. The mass of hyphae represent the mycellium (Stolp, 1988).

plenntus tuberregium posses rigid cell wall. It does not posses chlorophyll and it has a chemoorganotrophic metabolism. It belongs to the group of fungi called basidiomycetes and are the most developed fungi. They produce basidia containing the four basidiospores. The mycellium consist of septate hyphen.

However, plenntus tuberregium supplies the major food types. Protein, carbohydrates, fat and oil as well as minerals (OSO, 1977). It is known to be tastier than meat, fish or seed plant proteins. People who abstain from meat for religious reasons have greater choice of plant protein and superior alternative taste in plenntus tuberregium. The fruiting body as well as sclerotigl mass is more commercially

Demanded and yet minimally exploited.

Several indigenous knowledge and uses of plenntus tuberregium point to the tremendous potential of this biological resource.

(a) As a food stablizer / thickening agent

(b) As binding agent.

(c) As a rich source of foric acid for children and pregnant women.

(d) As a rich source of calcium for the bones of aging men and women as well as treatment for boils constipation and dental caries (Oso, 1977).

A visit tot he market place any where in Igbo land, would show this commodity being processed in the soup condiment section. The sclerotia mass is scrapped and ground with curcurbita (Melon seeds). This causes swelling and bulking of the soup. A local snacks called “Ogbalotic” is prepared from Curcurbita Pepo and plenntus tuberregium it is normally tied in a leaf of cola gigantea and boiled which yields a well known health and energy sustaining snacks. It is cherished till today in the villages. Travelers and farm workers need only this and large volume of water to sustain them for days.

This taxanomic position of plenntus tuberregium has been problematic because it produces eathery fruit bodies and posses of dogmatic hyphen system with interracially skeletal hyphae, many prenous authorities placed it in either panus or lentinus (Corner, 1981, Peyler, 1983).

plenntus tuberregium has been eaten since classical times (Corner, 1981, Nwokolo 1987, and Okhuoya, et al, 1998). The question of sustainability of plenntus tuberregium is guareur teed being a biological resources, the technology has been developed for massive production (Okhuoya et al 1998). Other added advantages include the fact that substrate for cultivation of plenntus tuberregium is waste such as rice straw, wood dust. Sunnlight is not required so that caves and shades could maximally produced plenntus tuberregium industrially.

OBJECTIVE OF THE STUDY

The present study is to ascertain t he nutritional composition of plenntus tuberregium.

PROMOTE COMPOSITION OF PLEUROTUS TUBERRCOGININ FROM ENUGU AREA

PRODUCTION AND DETERMINATION OF FUNCTIONAL PROPERTIES OF PLANTAIN FLOUR

ABSTRACT

Plantains (Musa epp) are important staple foods, which make substantial contribution of the nutrition and economy of millions of people through the developing world and are grown in 720 countries. The gross value of plantain production in sub-saharan Africa extent that of several other main food crops, such as maize, rice cassava and sweet potato. They are considered the fouth important global food commodity after rice, milk and wheat in terms of gross value of production and provide more than 25% of the carbohydrates for approximately 70 million people in sub-sharan Africa. Plantain flour production involves procurement of matured plantain, feeling, chipping, drying, milling and packaging, plantain is an important source of carbohydrate, the starch fat and total sugars in plantain are adequate for the manufacture of plantain biscuit. Blanding considerably reduce the emulsion capacity and viscosity, while built density, water and oil absorption capacities were increased by blanding. Plantain could also be used as an emulsifier and thickner in food system. Plantain flour is a cheap source of iron, protein and vitamin A and the product can be marketed.

CHAPTER ONE

1.0 INTRODUCTION

Plantain is a common name for a herbaceous plants of the genus Dusa, it was classified formally as Musa Acuminata, Musa Balbisoana or Hybrids Musa Acuminataz Balbisoana depending on their genomic constitution. (balell John in 2000) gare the archaic scientific name Musa paradisiacal which is no longer used,. Most plantain come from the hybrid AAB and ABB cultirar group all members of the genus. Musa are indigenous to tropical regions of South east Asia and Oceania including the making Archipelago. (Brian and Allan 1985).

Plantains are a major staple food in equantoria Africa and andian region. Their attractiveness as food is that they fruit all year round making them more reliable all season. This is particularly important for communities living in mountains or forests with Inadequate food storage, preservation and transportation, this tends to be frimer and lower in sugar content than desert, plantains are cooked or otherwise processed and are used either when green or unripe land therefore starchy or overripe and therefore sweet (William 1979) stated that an average plantain has about 220 calories and is a good source of poxassium and dietary fibre. (Murray Tossler 1987).

Plantains is a perennial plant that consist of a roseete of basal leaves and one or more flowering stalks the basal leaves are up to “10 long and ¾ across”, “but more commonly about half this size the tenth most important staple food that feed the world. (Uwaegbufe 1996) plantains are treated in much as the same way as potatoes and with a similar neutral flavour and texture when this unripe fruit is looked by steaming boiling or trying. It (plantain) fruits all year round which making the crop a reliable all season staple, food, particularly in developing countries with inadequate food storage, preservation and transportation technologies, in Africa plantains provide more than 25 percent of the carbohydrate requirement for over 70 million people. Plantain can be eaten raw as well. As it ripen it becomes sweeter and changes colour from green to yellow to black, green plantain are firm and starchy and they resemble potatoes in flavour. UNCST 2007) the yellow plantains are softer and starchy, but sweet. Extremely ripe plantains have softer deep yellow pulp that is much sweeter than the earlier stages of ripeness. (Archy 1987).

Plantains in the yellow to black stages can be used in sweet dishes steam-looked plantains are considered a nutritious food for infants and the elderly. A ripe plantain is used as food for infants at wearing. Ut is mashed with a pinch of salt and is believed to be more easily digestible (FAOSTAT 2011). Plantains are also dried and grouped into flour it is an important food stuff that constitute, water of about 1062%, proteins 55%, Fat 1.15%. Carbohydrates 81.6% and Ash 3.01%. Dried plantain provider is mixed with a little fennel seed powder and boiled either in milk or water to feed small children till they age of 1yr. (Oke 1998) stated that in Southern parts of Indian Roots and tubers, plantains, and bananas is good for human nutrion.

Plantain has been a good source of food and known to different countries with different names like, in Ivory Coast where plantains are dishes when fried with Onion and tomato sauce and serve to eat. It is called ALOCO. It is also used for a dish called Magu in Dominican Republic, where the green plantains are peeled smashed with hot water and boiled then served with sauce. In West Africa plantains are served for eating with stew or beans or any food when fried it is known as BODO (Dough-Bough) (Forcylth 1988). Plantains are also known as fufu De plantan a popular dish in Cuba where the plantains are boiled and mixed with chicken stock and sauce and the served. Plantains can also be fried twice and served as a side appetizer or snack in countries like Columbia, Costa Rica, Ecuador, Honduras, Panama. It is known as potacones. The popular known food Boli is usually made in Nigeria, whereby plaintain is roacted and eaten with red oil sauce. (Adnan and Muyalia 1984).

AIMS AND OBJECTIVES

(i) To produce plantain flour

(ii) To determine the functional properties of plantain flour.

PRODUCTION AND DETERMINATION OF FUNCTIONAL PROPERTIES OF PLANTAIN FLOUR

SOCIO-ECONOMIC CHARACTERISTICS OF VEGETABLE PRODUCER IN ONDO STATE

CHAPTER ONE

INTRODUCTION

Vegetables are nutritionally important to man as they provide the much needed vitamins, minerals and fibre. They are important protective food and highly beneficial for the maintenance of health and prevention of diseases. They contain valuable food ingredients which can be successfully utilized to build up and repair the body. Vegetables are valuable in maintaining alkaline reserve in the body. They are valued mainly for their high vitamin and mineral contents. There are different kinds of vegetables. They may be edible roots, stems, leaves, fruits and seeds. Each group contributes to diet in its own way. Fleshy roots are high in energy value and good sources of vitamin B. Seeds are relatively high in carbohydrates and proteins. Leaves, steam and fruits are excellent sources of minerals, vitamins, water and roughage. The level of vegetable consumption in Nigeria is rising annually owing to greater appreciation of their food value (Haruna, 2003). A distinct class of vegetables in Nigeria are the exotic vegetables. They are known for their unique taste, nutritional value and various health benefits. They help keep a balance between the fluids of the body.

Vegetable is one of the most popular vegetables in the world because of its adaptability to a wide range of climatic conditions and soil types, ease of production and storage, and its food value (Asia Farming, 2015). In Nigeria, production of this important vegetable is mostly carried out in the north especially Ondo State (Ogedegbe and Law-Ogbomo, 2013). Ondo state is the home of exotic vegetables including Vegetable because of its cool weather condition. Other exotic vegetables cultivated on the Ondo include: lettuce, cucumber, carrot etc. They are termed exotic because these are species of vegetables that are not indigenous to Nigeria. They are primarily cultivated in the temperate regions of the world. Vegetable does well in some local government areas of Ondo State. The local government areas are Ondo North, Ondo South and Riyom. Vegetable is predominantly cultivated in these areas because of their high altitude which result in the areas having cool climate. Since it is not a common vegetable that can be cultivated in any part of the country, the demand then outweighs the supply. This ordinarily will enrich the producers of this commodity thereby financially empowering the farmers in this part of the country. Production of these vegetables as a small scale enterprise can financially empower the poor people especially women with little capital, limited access to land and working under labour constraints (Lewis, 1997). The cash they provide contributes significantly to food security at the household level and enables women to attain a degree of financial independence within the family budget.This study examined the profitability of Vegetable in Ondo State and how efficient are the farmers in the production of the crop.

PROBLEM STATEMENT

Nigeria is blessed by nature with vast resources; both human and land to boost optimum output in agriculture to be able to adequately cater for the food/diet requirement of her populace. The weather/climate condition supports the production of most crops. Majority of Nigerians have annexed these endowments of nature by going into agriculture as more than 70% of the population is involved in farming (Usman, 2015). Yet poverty in the land, especially in the northern part of the country is paradoxically equal to the percentage of the populace involved in farming.Majority of these farmers reside in the rural areas and poverty is more predominant in these areas. As Aigbokan (2000) found that an increasing number of Nigerians are living in absolute poverty in the rural areas. This logically connotes that since majority of the populace in the rural areas are farmers, then the fangs of poverty are on these farmers despite the natural endowment. Some of the contributory factors leading to farmers‘ poverty in Nigeria are that agricultural holdings are small and scattered, and farming is carried out with simple tools. Large-scale agriculture is not common. Smallholder farmers, who use simple production techniques and bush-fallow cultivation, cultivate areas of one-half to two hectares each and contribute two-thirds of farm production (Metz, 1991).

Ondo State has the highest altitude among the States in Nigeria, resulting in some parts of the State having cold climate which supports the cultivation of unique crops. Such crops include Vegetable, lettuce, cucumber, carrot and Irish potato. These crops are being produced in large quantity on the Ondo as Jim and Tony (2006) submitted that, Good Performance of Vegetable production has been reported in places like Ondo Ondo , Nigeria to have the highest Vegetable production in Africa. The production of these crops, ceteris paribus, is supposed to fetch the farmers in this region extra finance which will

make them to at least live an average life above the poverty threshold because these crops are predominantly cultivated in this part of the country as a result of the near temperate weather condition. The income of the farmers is also supposed to be on the high side because the demand for these crops is nationwide as Ogbodo et al. 2009 Puts it, The bulk of Vegetable consumed in the Southern part of Nigeria is produced in the Northern section of the Country. This situation has led to prohibitive prices of Vegetable owing to the imputed cost of transportation from North to South of Nigeria. The demand of Vegetable also outstrips the supply; causing scarcity of the commodity. Omeh (2012) buttressed this fact when he opined that Vegetable is used in a variety of dishes, and it is widely consumed raw as well. It is in high demand in Nigeria and sells for reasonably good prices. If farmers have high yield in their crops and the demand for such crops is high, this consequently gives rise to high prices which eventually accrue more income to the farmers. Under the analysed condition, Vegetable farmers in Ondo State should have no relationship with poverty, but the poverty rate recorded in the State is as high as 74.1% (NBS, 2012). Putting into consideration the fact that more than 70% of the Nigerian population is involved in farming as reported by Usman (2015), it is an obvious fact that poverty on the Ondo is still an issue. Also, the farmers still live in traditional houses made of mud and thatched roofs and some of them are unable to send their children to school because of fund constraint.

This unique form of vegetable, because of its strategic region of production, if produced with the required agricultural techniques have the propensity of uplifting the financial condition of the farmers and hence better their standard of living. The cash earned from this enterprise cancontribute significantly to food security at the household level and enable farmers to attain a degree of financial independence, yet poverty still looms.

Thus probing the question, are these farmers producing optimally and efficiently?This study therefore examines the economic analysis of the production of Vegetable in Ondo State by verifying the degree of profit accruable to Vegetable farmers in Ondo State. This study will therefore answer the following research questions:

What are the socio-economic characteristics of Vegetable farmers in the study area?
How profitable is Vegetable production in the study area?

What is the economic efficiency of Vegetable farmers?

What are the constraints militating against Vegetable production in the study area?

OBJECTIVES OF THE STUDY

The broad objective is to analyse the economic efficiency of Vegetable farmers in Ondo State. The specific objectives are to:

describe the socio-economic characteristics of Vegetable farmers in the study area, determine the profitability of Vegetable production, analyse the economic efficiency of the Vegetable farmers and describe the constraints faced by Vegetable farmers in the study

JUSTIFICATION FOR THE STUDY

The importance of vegetables in our diets in maintaining good health cannot be overemphasized. Vegetables are widely under esteemed because few horticultural research institutes publish figures demonstrating that they can give unusually large annual yields of edible dry matter, including protein and βcarotene (provitamin A). It is also not realized that they supply many communities with as much protein as is supplied by fish, and that more communities used to eat them on that scale (Pirie, 1984). Vegetable is an example of this group of vegetable, which contains anthocyanins, which have anti-carcinogenic properties, i.e. it helps the human body fights off cancer. Study into this important class of food will provide information on the level of production and expose the degree of efficiency or inefficiency associated with its production. The findings of this research will provide policy makers the necessary information on how to introduce policies on increasing the efficiency and reducing poverty among Vegetable and other vegetable farmers. This will also provide researchers the basic information and data necessary for further research into vegetable production. The findings of this research will provide vegetable farmers the necessary information on how to improve the efficiency of vegetable production. It will also disclose to them the socio-economic variables that limit efficiency in production.

SOCIO-ECONOMIC CHARACTERISTICS OF VEGETABLE PRODUCER IN ONDO STATE

EXTRACTION OF OIL FROM A LOCAL SEED (GROUNDNUT SEED) AND CHARACTERIZATION

ABSTRACT

This project “Extraction of oil from a local seed (groundnut oil) and Characterization” was carried out using ten cups of groundnut seeds that was purchased from a local market in Enugu metropolis. The oil these seeds were in Enugu using solvent extraction method. Two different solvents were used in the extraction namely: Ethane and order to compare their yield, physical and chemical properties.

The extraction was carried out using 32og of size-reduced groundnut with 100ml of 17-hexane while 1.5litres a 15ooml of ethanol was used on 480g of size reduced groundnut seeds. Ta the end of the extraction operation, the amount of oil-extracted using17-hexane was observed to be far more greater than the amount of oil extracted using ethanol.

The chemical and physical properties of the oil were determined by analysis of the oil. The physical appearance of 17- hexane extract is light yellow in colour this; true colour of groundnut oil while that the ethanol extract has a light bown colour. The colour of ethanol on pigments in the size-reduced groundnut seed.

From the result obtained, it was deduced that 17-hexane remains the best solvent for oil extraction while ethanol is not a good solvent for oil extraction.

KEYWORD: EXTRACTION OF OIL FROM A LOCAL SEED (GROUNDNUT SEED) AND CHARACTERIZATION

The physical and chemical constants/ properties determined were:

PHYSICAL PROPERTIES:

a)Solidification point.
b)Melting point
c)Specific gravity
d)Moisture content.

CHEMICAL PROPERTIES

a) Acid value
b) Saponification value
c) Peroxide value
d) Iodine value
Form the analysis camied out on the extracted oil, the results obtained shows that the extracted oil is a pure groundnut oil because the iodine value which shows the purity of an oil is close to literature value. The iodine value of he oil extracted is 79.95 while the literature value (standard value) rangers from 94-102.

CHAPTER ONE

INTRODUCTION

Extraction other-wise called leaching is the preferential solution of one or more constituents of a solid mixture by contact with a liquid solvent. This unit operation, one of the oldest in the chemical industries, here been given many names, depending to some extent upon the technique used for carrying it out extraction of oil form groundnut seeds can be carried out using any of the two solid-liquid extraction methods namely: mechanical extraction method or the used of solvent other- wise called mass-transfer method. The yield of the second method is higher but contains more impurities than the first method and it requires another unit operation (distillation) in purity it better.

The success of an extraction and the technique to be used will vary frequently depending upon any prior treatment which may be given to he solid. In some instance small particles of the soluble material are completely surrounded by a matrix of insoluble matter. The solvent must then diffuse into the mass, and the resulting solution must diffuse out before a separation can result. Crushing and grinding of such solids will greatly alliterate the leaching action, since then the soluble portions are made more accessible to the solvent.

Seeds like groundnut seeds and other vegetable seeds are cellular in structure, and the natural products to be leached form these material are usually found inside the cells. if the cell walls remain intact upon exposure to a suitable solvent, the leaching involves osmotic passage of the solute through the cell walls. This may be slow, but in is impractical and sometime undesirable to grind the material small enough to release the contents of individual cells.

Oil constitutes a well-defined class of neutral organic substance, which are essential constituents of all forms of plant and animal life. They are soluble in other and organic solvents but not in water. Commercial oils are however from a relatively few member of the plant and animal kingdom available forms. They are primary a product of agriculture although these is also a considerably production from uncultivated tropical plants and from mature animals. Oil can be grouped into edible and non-edible depending on the amount of unspecified matters and impurities. Owing to the fact that the use of oil from crop seed as a major raw materials has increased in recent yeses their has been the need for extended and numerous research works based on the extraction of these oil. Form its seeds as economically efficiently as possible.

The only possible way of obtaining large quality of oil from oil being vegetable or plant materials is by extraction and this could best be achieve using leading process. This process can be accomplished by a variety of ways but as might be expected its efficiency depends to an extant an obtaining intimate contact between the liquid solvent and the solid containing he solute. Leaching reduces the oil content in the residue to about 0.5-1.5 percent as compared.

With about 5-9 percent by mechanical process. The types of solvent available for leaching include 17-hexane, petroleum ether benzene ethyl ether etc which are high petroleum fractions. The choice of a solvent for extraction is a function of its volatility and relative volatility for easy separation by distillation.

Groundnut oil is used primary in homes for cooking and also as an industrial raw material for other usefully products.

SCOPE AIMS/ OBJECTIVES TO THE PROJECT

The scope of this research project is to extract oil from groundnut seeds and compare the yields obtained using different solvents and to standard.

Also the project is aimed at characterizing the extracted oil by determining the physical and chemical properties of the oil.

EXTRACTION OF OIL FROM A LOCAL SEED (GROUNDNUT SEED) AND CHARACTERIZATION

ANALYSIS OF THE HYGIENIC CONDITION OF CANTEEN FOOD SERVICES IN NIGERIA

CHAPTER ONE

INTRODUCTION

BACKGROUND OF THE STUDY.

Canteen services stated way back in the 18th centaury, food and snacks are served as to the taste of the client. It may be seen as a place in the military, factory, camp, school etc. where people may buy food, drinks, sweets etc to eat. As advancement has set in, more services are rendered aside the normal buying and selling of food in modern canteens.

According to the Ministry of Health annual report, 75% of sicknesses admitted in hospital are results of unhealthy food (MOH 2007), majority of which are food serve in the canteen all over the country. It suggests that eating from canteens without basic health consideration is like signing your own death warrant.

Health often said is wealth, we should pay critical attention to the food we eat and the environmental condition under which we eat if only we want to create wealth. Nowadays, children are becoming far more overweight in suburban schools, and on a personally view the schools canteens are a definite place to blame. If you look at an average school canteen, there is no respect for the weight of the child or no help for providing the healthier option; it is all about making money to fund a business. Ways of making the canteen healthier will be discussed and the worst offenders to canteen obesity. Canteens are terrible; people line up with their money, walk in and buy whatever food they want. There is no mother in their ear saying to purchase a healthier option; there is just a child who wants to walk in and purchase the best tasting and in most cases fattiest options. As a personal view, to reduce problems like obesity people who have the power to should try and bring in healthier options, and encourage kids to eat them. There are endless possibilities to making canteens healthier, you can just ban unhealthy food, you can make it super expensive so know child can afford it or want to buy it, or you can just ban the canteen in general. But unfortunately these options won’t work because as much as people want to get rid of the obesity in children you have to think of the people who work at the canteen, as it is their job. A more productive way of improving canteens is having both options to healthy and the bad but making the healthy items appeals more to people. Or from a different approach you can have the unhealthy food but make it smaller in amounts, so you will be having less unhealthy foods, and then the students will be reduced to no choice but buy healthy food or accept there own home made meals, where the parents can control the healthiness of their children

PROBLEM STATEMENT.

It is without doubt that many Ghanaians students one way or the other eat food from a canteen and food cooked in their home as well. In the tertiary institution as Ho polytechnic, canteen services serve food ranging from breakfast to supper to snacks, special meals are also served to customers.

Ghana like most developing countries; is struggling with the means to provide a comprehensive solutions to bad health as a result of bad eating conditions. The current system of ensuring sanitation in the food served in the canteen, restaurant, chop bars, etc. has proven woefully inadequate for the objectives circumspect

Places where better food in the Ghanaian context are served in a hygienic condition are very expensive to customers, hence majority of students, lecturers and non-lecturers in the universities, polytechnics and colleges are unable to afford. In this regard eating food cook by oneself has proven to be more beneficial in taste, cost, health, preferences, etc.

Consequently many students in the colleges, polytechnics and universities preferred preparing their own food. These have being easy due to the increasing supply of gas cylinders and burners. These gadgets are fast and convenient in the cooking and quite affordable.

Many canteens are subsequently getting out of business because they lack modern facilities; there is no better furniture, sometimes food is served in the open air with flies all around. As the existing once are weeping for customers, others all about joining the search for customers. This in one way has drastically changed the canteen service. In spite of this some customers complain bitterly of being served left over meal on regular basis.

The government through the school feeding programme is advocating on serving better meal to children for massive nourishment but, this programme covered only primary education which is even a pilot project. However the senior high school boarding house students repeatedly complain of rotten meal.

Whiles lecturers and non-lecturers (believed to have money) drive extensively to far distant to enjoy good meals from expensive and luxurious canteens; the less privilege who were believed to be student tends to eat anything money can buy. These has be deviled the canteen service in all institution; the basic even to the tertiary institutions.

OBJECTIVE OF THE RESEARCH.

 To determine whether there is any significant differences in the food bought by student, lecturers and non-lecturers. To determine whether there is any significant differences in the factors which influence the population to eat from the school canteen. 

HYPOTHESIS

Null hypothesis: there is no difference between all k populations.

Alternative hypothesis: there is at least difference in two of the k populations.

Mathematically;

H0: K1= K2= K3= 0

Hı: Ki≠ 0; where ί=1, 2 and 3

Where ki =students lecturers, and non-lecturers.

SIGNIFICANCE OF THE STUDY.

The study will bring us a fore insight into the importance of a hygienic condition and the best food to be served. The research will bring to light the socio-economic benefits of better feeding. The researches will additionally increased knowledge in both condition of service and the type of food to be served.

The analysis of this project will provide vital information that will be useful to the government in policy and in decision making specifically to the Ministry of Health (MOH) which is directly responsible for the provision of public health services delivery in terms of policy formulation, monitory and appraisal regulation of the health services.

This study will also provide useful information on the popular perceptions regarding the food bought by lecturers, non-lecturers and students.

Furthermore the study will be useful to groups or organizations currently working in Ghana and other developing countries in developing national policies on the evaluation and regulation of the food hygiene and proper eating habits in promoting safe, effective and affordable product to all citizens.

Finally the research seeks to educate and give possible suggestions to the people on food and other   health related issues.

PURPOSE OF THE STUDY

The primary aims of these researches are to analysis and evaluate the conditions under which food is served and the time it is served and to find out whether there is any significant difference in the food bought by students, non-lecturers and lecturers,

SCOPE OF THE STUDY

This research is carried out in the Ho polytechnic community. It takes into consideration a reasonable number of students, lecturers and non-lecturers who one way or the other  have ever used the service of a canteen more specifically the Ho polytechnic school canteen.

DELIMITATION OF THE STUDY

In the entire ten polytechnics in the country, the services of canteen cannot be overlooked by the student, non-lecturers and lecturers population; however this study was limited to only a school in the Volta region (Ho poly). Also the research is an observational study; this is the key focus experimental study has being ignored.

LIMITATION OF THE STUDY.

Some of the people felt reluctant to answer the questionnaire also few who answered did not comprehend how to answer the questionnaire properly. Certain vital questions relating improvement have being massively ignored.

The researcher was not able to see all the lecturers, non-lecturers and students to share thoughts on the topic, due to busy schedules of the populations.

ORGANIZATION OF THE STUDY.

The study is divided into five chapters.

CHAPTER ONE

Which is the introduction, presents the background information of the research topic, defining the statement of the research concern, stating the purpose of the study and research questions that the project seeks to answer, highlighting the significance of the study, pointing out the limitations of the study and defining the key terms that will de used constantly in this project.

CHAPTER TWO is dedicated to the literature review in the field. it gives a historical overview of the canteen service  in schools in the past time to the present time.

CHAPTER THREE discusses the methodology used in gathering data for the study. It also provides justification for the approaches used in gathering data.

CHAPTER FOUR is the analysis and discussion of the findings of the study.

CHAPTER FIVE includes summary, conclusions and recommendations for further study.

CONCEPTUAL DEFINITIONS

Canteens may be seen as a place in the military, factory, camp, school etc. where people may buy food, drinks, sweets etc to eat. As advancement has set in, more services are rendered aside the normal buying and selling of food in modern canteens.

Food is anything liquid or solid which when eaten provide the body the ability to function properly, the food choice may be due to the taste, satisfaction, and other factors.

P-value is the level of significance where the calculated value of the test statistics is exactly the same as the critical value. It is the lowest level of significance at which the null hypothesis can be rejected.

Calculated value is a value of the test statistics that is calculated from sample data. It is compared to the critical value deciding whether or not to reject the null hypothesis.

Critical value is a value of the test statistics that serves as a boundary between the non-rejections and a rejection region for the null hypothesis.   

ANALYSIS OF THE HYGIENIC CONDITION OF CANTEEN FOOD SERVICES IN NIGERIA