Effect of some preservative methods on the physicochemical and organoleptic properties of pineapple and watermelon fruit juices
Fruit juices are important sources of nutrient and it contains several important therapeutic properties that may reduce the risk of various diseases. This study was based on the effect of different preservative methods on fruit juices (pineapple and watermelon) and determination of the best method. The fruit juice were preserved using sodium benzoate, lime, pasteurization and the combination of sodium benzoate and pasteurization. Twenty three bacteria and twelve fungi were isolated from the fruit juice. Bacteria isolates include; Salmonella spp, Campylobacter jejuni, Shigella spp and Escherichia coli. Fungi isolated from the pineapple juice include: Aspergillus flavus, Aspergillus niger, Ochrocosis gallopava, Geotrichum candidum and Ochrococus gallapava among others. The result obtained shows that the juice maintained colour, aroma and taste when both sodium benzoate and pasteurization were used to compare when no preservation was used. There is a noticeable increase in the microbial load of the juice when lime was used as the only preservatives at day 0 (4 × 10-5) compared to when sodium benzoate and pasteurization was used at day 0 (1 × 10-5). While combination of sodium benzoate and pasteurization was the best among all other preservative methods. The pH value of the juice was also checked and it was observed that pineapple juice had the lower pH when compared with that of water melon.