ABSTRACT

In the present study, spontaneous and induced fermentation techniques were used in fermenting different fruit juices (Pineapple fruit juice, Watermelon fruit juice and Pineapple+Watermelon fruit juices) to determine their microbial and physicochemical changes. A higher bacterial count (8.6±0.58a-9.0±2.19c) log(cfu)ml-1 than yeast count (7.6±3.18a-7.9±1.76e) log(cfu)ml-1 were observed in the spontaneous fermentation. In the induced fermentation a higher yeast count (7.7±2.33a-8.3±5.29c) log(cfu)ml-1 than bacterial count(8.5±1.53a-8.9±6.25d) log(cfu)ml-1 was observed. A higher Lactic acid bacterial count (7.0±1.53a -8.9±2.73e) log(cfu)ml-1was recorded during the spontaneous fermentation. pH and sugar content (0Brix) decreased while TTA and alcohol content increased both in spontaneous and induced  fermentation of the different fruit juices. Nine bacterial species, namely Staphylococcus spp, Bacillus spp, Enterobacter cloacae, Providencia vermicola, Cronobacter sakazakii, Ignatschineria indica, Comamonas testosteroni, Lactobacillus plantarurum and Lactobacillus fermentum and two yeast species, namely Rodotorular spp. and Saccharomyces spp were identified. Also, three yeast species were isolated from Palm wine which is a readily available raw material for the induced fermentation. This study gives an insight into the microbial and physicochemical changes during the fermentation processes of different beverages.