Preparation of Probiotic Apple Juice by Lactic Acid Fermentation

Abstract

Fermentation of apple juice was done for 72 hrs by lactic acid bacteria (Lactobacillus plantarum and Streptococcus thermophilus)and physico-chemical characteristics of fermented apple juices were recorded at 0. 24, 48 and 72 hrs intervals. On the basis of highest lactic acid bacterial counts, rate of fermentation (°B/24hr), acidity, sugar utilization percentage, retention of ascorbic acid and total phenols, antioxidant activity and antimicrobial activity against pathogenic bacteria such as E. coli and S. aureus, while lowest pH, coliform, yeast and mold counts, the best treatments L. plantarum 107cfu/ml for apple fermented apple juice was selected for storage study viz. During fermentation both vitamin C and total phenols declined, while, the antioxidant activity, antimicrobial activity, viable cell counts and lactic acid bacteria counts were increased. As the antimicrobial activity increased, the counts of coliform, yeast and mold declined. During storage of selected treatment of fermented apple juice for four weeks at 4°C retained physico-chemical parameters above the value of significance. Lactic acid bacteria remained viable in prescribed number (4.76–6.00 × 106 cfu/ml), acid and bile resistance, imparted antimicrobial activity and antioxidant activity to the apple juices during storage and thus, could be called as probiotics juices. Based on the sensory evaluation (visual colour and flavours) of fermented apple juice, it was concluded that lactic acid fermentation did not influence the desirable characteristics of apple juices. So the probiotic juices were acceptable. Identification of lactic acid bacteria by biochemical test concluded that the bacteria were L. plantarum in apple juices which were inoculated in juices for fermentation, after storage apple juice were suitable for lactic acid fermentation to produce a probiotic beverage. So, this juice can serve as healthy beverage for vegetarians and lactose allergic consumers.