Survival of Lactobacillus acidophilus and Bifidobacterium lactis and quality properties of yogurt made from goat's milk

Goat's milk is a proper alternative to cow's milk because of its higher digestibility and lower allergic characteristics, as well as its higher functional nutrient. On the other hand, its health benefits can be increased by the incorporation of probiotics into goat's milk. This research aimed to investigate the survivability of Lactobacillus acidophilus and Bifidobacterium lactis (B. lactis) individually and in combination on the physicochemical and sensory properties of yogurt made of goat's milk during 21days storage. In this research, 4 treatments were prepared, including control (with no probiotic bacteria), La treatment containing Lactobacillus acidophilus, Bb treatment containing B. lactis, and LaBb treatment containing a combination of Lactobacillus acidophilus and B. lactis. The results showed that the count of Lactobacillus acidophilus, B. lactis, and their combination reached from 8.54 log cfu/g on the first day to 9.43, 10.06 and 10.75 log cfu/g at the end of the storage period, respectively. At the end of the storage period, the control sample had significantly the highest pH and syneresis and the lowest acidity, water holding capacity, viscosity, and overall acceptability among treatments. However, no significant difference between samples containing probiotic in acidity, pH, viscosity, syneresis, water holding capacity, and overall acceptability was observed. According to the results obtained of this study, yogurt made of goat's milk, in addition to being a suitable carrier for probiotics, its sensory properties improve as a result of the incorporation of these probiotics.