Effect of Whey Protein Concentrate on Bio-Yogurt Properties

Abstract

This study was conducted on bio-yogurt made from full cream buffalo's milk with the addition of different percentages of whey protein concentrate WPC at (2, 4 and 6 %). The chemical, microbiological, rheological and sensory properties were evaluated during storage at refrigerator temperature (5±2°C) for 15 days. Analysis was performed on fresh samples as well as those that had been stored over three storage periods (5, 10 and 15 days). The obtained results indicated that the addition of whey protein concentrate (WPC) led to an increase in total solids, as well as total nitrogen and soluble nitrogen, in addition to the acidity levels, while the addition of WPC led to a decrease in the amount of separated whey. Microbiologically, there was an increase in the total count of bacteria, Bifi. bifidum, Lb. Acidophilus, Stre. thermophilus, while these numbers decreased with increasing storage periods in all the treatments. On the other hand, the coliform group was not detected in all treatments. The results from sensory evaluation recorded that the bio-yogurt added to 4% WPC gained the highest score, followed by the bio-yogurt with 2% WPC in most treatments.