Abstract

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Citrullusl anatus (Watermelon) and Psidium guajava (Guava) are tropical fruits with short shelf-lives because of the temperature and relative humidity conditions in tropical countries like Nigeria. Production of wine from these fruits could help to reduce the extent of post-harvest loss and increase the variety of wines. Juice from the fruits was extracted and after treatment were mixed using the following ratio WMJ:GJ, 100:0, 0:100, 50:50, 40:60, 30:70, 20:80 and 10:90; to be labelled A, B, C, D, E, F and G respectively. Wine A and B served as control. Fermentation was done for 7 days with daily analyses of microbiological and physico-chemical parameters. Results revealed yeast and mould counts ranging from 236 x 105to 290 x 105cfu/ml, while there was no viable plate count and coliform growth in the final products. These results fall well below acceptable limits in the formulated wine which is safe for human consumption. During fermentation, consistent increases in titratable acidity and alcoholic content were observed while there were gradual decreases in pH, reducing sugars and specific gravity. Vitamins A and C contents as well as the alcoholic content of the final wines were moderate. The pH values of all the wines were acidic and ranged from 4.05 ± 0.14 to 4.72 ± 0.10. Acidity was within the acceptable limit. Quality assessments reflected that wine product coded 'C' was of higher quality and could be stored at 28 ± 2°C for a minimum period of six months without marked changes in quality.

Keywords: Wine, Guava, Fermentation, Watermelon, Yeast.