Bioconversion of whey for preparation of beverage was standardized by utilizing yoghurt cultures. The product, wheyghurt drink, made with 4% yoghurt cultures inoculated in deproteinized whey (4.8% lactose, 0.66% ash, 0.46% fat and 0.40% protein adjusted to pH 6.4) and incubated at 42oC for 8h had all the technological requisite and dietetic criteria required in the product. The factors affecting the antibacterial activity of wheyghurt drink against Escherichia coli, Staphylococcus aureus, Shigella dysenteriae and Bacillus cereus were determined. There was a significant variation (P<0.05) in the antibacterial activity of wheyghurt drink with different levels of inoculum (1,2,4, and 8%) and concentration of sugar at 37, 42 and 45oC. Incubation at 42oC with 4% culture in whey exhibited highest inhibitory activity. The product stored up to 5 days under refrigeration was of acceptable organoleptic quality and requisite amount of microbial population (108 cfu/ml) to be potentially beneficial.
whey; yoghurt; antibacterial activity
