PRESERVATION OF PALM WINE USING ULTRAVIOLET RADIATION
This study was aimed at the preservation of palm wine using ultraviolet radiation. The experiments were done using an ultraviolet sterilizer at time intervals of 2, 4,7,25 and 29hours. The freshly tapped palm wine was first analyzed and result shows that the pH, sugar content, specific gravity titrable acidity, alcohol and total solids recorded values of 6.60, 5.40, 0.984g/m3, 0.66, 4.2(%by/v) and 10.5g/100ml respectively. On the other hand, the result of the sterilized palm wine shows that as time increases, the pH increases from 6.60-6.69. Also sugar content increases from 5.40 -6.82 as time increases from 0-29hours. However, the alcoholic content decreases from 4.20-1.50(%by/v) as time increased. Conclusively, the ultraviolet radiation was effective in stopping the fermentation of the palm wine.
1.1 BACKGROUND OF THE STUDY
Palm wine is an important alcoholic beverages resulting from the spontaneous fermentation of the sap of which has been attributed to years and bacteria (Okafor, 1978).
Palm wine is consumed in parts of Africa, Asia and South America. In Nigeria, the two principal sources of sap for palm wine. Fermentation is the oil palm (Ecaeis guineesis) and the Raphia palms (Raphia SPP). It is highly perishable liquid consisting mainly of water, sugar, vitamin and mainly of aroma and flavor components in every small amount. Palm wine have several nutritional, medical, religious and social uses which have been reported elsewhere (Faparvunis, 1966). Odemiymi1977; (Ikenebomeh and Omayunil 1988; Uzogara et al., 1990, Iheonu, 2000).to have increasingly enhanced the demand for this natural product.
Fermentation begins immediately after collection as a result of natural yeasts in the air and wine within two hours, the alcoholic content reaches approximately 4%.
At this stage, the product is sweet while mildly intoxicating aromatic beverages continued fermentation for up to 24hours and sour white drink. This palm wine can also be distilled into whisky –like drinks with higher alcoholic content (up to 40%) beyond a certain threshold; the wine no longer gains alcohol (Adam, 1995).
Many factor including the species of the tree, the season of the year, time of day at harvest and type of soil impact the alcoholic content of the wine. In-fact, these factors play a key role in the characteristics of the final product as rudimentary storage and production facilities do little to preserve to avoid fermentation of micro-organism which can affect the pH values, sugar content, alcoholic content, refractive index and specific gravity. These can be affected due to micro-organism and bacterial that has contaminated with the product. If it carefully preserved, it will retains all nutritional values and last for a short periods of time, days and weeks.
Preservation can be achieved in the difference ways either by physical or chemical method, preservation method of palm wine has perfected locally, it involves pasteurizing and bottling of the palm wine which increase its shell life to over six months.
This method of palm wine preservation makes it more hygienic and consequently more attractive to the city dwellers (Rangana, 1986).
Physical preservation entails process such as refrigeration, drying, pasteurization,sterilization etc.
Preservation additives reduce the risk of product borne infection, decrease microbial spoilage and preserve fresh attributes and nutritional quality.
Some physical techniques include dehydration, U.V.C radiation, freezing, drying, refrigeration, pasteurization, sterilization etc. (Ran Gana,1986).
1.2 STATEMENT OF THE PROBLEM
Palm wine is an alcoholic beverages created from the fermented sap of various palm trees. It is collected (or tapped) from tall palm tree or raffia tree which is shorter and thus more accessible. There are reports that some people also collected sap from oil palm tree(Elaisguineenis). However, sap from a palm tree (Raffia tree) is milkier and sweeter. When palm wine is tapped fresh and not fermented, it is considered a fruit juice or drink as it contains no level of alcohol% which makes it highly nutritious and beneficial to the body.
Fermentation of palm wine begins immediately after collection as a result of natural yeasts in the air and wine.
Within two hours, the alcohol content reaches approximately 4%. At this stage, the product is a sweet while mildly intoxicating aromatic beverage continued fermentation for up to 24hours results in a more alcoholic acidic, sour and bacteria.
Formation of bacteria can be achieved by by preservation of palm wine using different method like physical which includes ultraviolet radiation, freezing and pasteurization, and chemical methods which involves introducing a chemical in the palm wine.
This research work seeks to x-ray the preservation of palm wine using UV radiation.
1.3 AIM/OBJECTIVE OF THE STUDY
The aim of the study is to preserve palm wine using ultraviolet rays.
This aim will be achieved through the following objectives.
1. To study the characteristics properties of the raw fresh palm wine.
2. to study the effects of process parameters like time, pH, specific gravity, alcoholic content, refractive index on the preservation.
3. To study the characteristics properties of the palm wine after the preservation.
1.4 SCOPE AND LIMITATION OF THE STUDY
The following areas will be covered in the research.
1. Collection of palm wine
2. Characteristics of the palm wine
3. Preservation of the palm wine using ultraviolet rays.
4. Characterization of the palm wine after preservation.
5. The use of ultraviolet radiation for palm wine preservation leads to poor penetrability.
6. There is the possibility of a decrease in the taste and flavor of the palm wine after preservation.
1.5 METHOD OF RESEARCH
The information on this research project was gotten from chemical Engineering journals, chemical Engineering textbooks, internet exploration, and resource consultants in the field of knowledge as well as practical/experimental work.
1.6 SIGNIFICANCE OF THE STUDY
The following are the contributions of this research:
1. To increase the sugar level and Reduction of the alcoholic content.
2. Destruction of micro-organisms contained in the palm wine.
3. Elongation of the shelf life of the palm wine
4. Increase in the economic value of the palm wine.
5. Availability of palm wine in and out of the season.
6. Increase in the income earning of the palm wine dealers.