The aim of the present study was to formulate a fermented whey product using probiotic bacteria and whey protein concentrate (WPC containing 70% of proteins) to obtain a fermented product with low lactose and β-lactoglobulin (BLG) content. Several factors such as starter culture concentration (1, 5, and 10%) and fermentation time (2, 4, 6, 8, and 10 h) were optimized on the basis of growth activity in terms of viable count, pH, and acidity. Starter culture concentration and fermentation time of 5% and 10 h, respectively, show the optimal viable count (9.8 × 1010) and pH (4.42) as per the requirement. Proteolysis of WPC by a mixed culture of Lactobacillus acidophilus and Lactobacillus bulgaricus was found to be 98.8 μg/ml. Hydrolysis of whey proteins by probiotic bacteria was detected by SDS-PAGE. A significant (p ≤ 0.05) decrease in cell viability and pH was observed as the refrigerated storage period goes on increasing (0-15 days).
Keywords: Cell viability; Prebiotic; Probiotic; Whey; β-lactoglobulin.