Qualitative Aspects of Probiotic Flavored Soymilk-Based Yogurt

In this study, the effects of soymilk to cow's milk ratio (0:100, 25:75, 50:50, 75:25, 100:0), kind of commercial starter culture (ABY-1 or ABY-2 containing Bifidobacterium lactis BB-12,  Lactobacillus acidophilus LA-5, and yogurt bacteria, and natural fruit concentrations (kiwi, pear, strawberry or apricot) on biochemical characteristics, viability and sensory properties of probiotic flavored soy-yogurt were investigated. These properties were analyzed during and at the end of fermentation as well as during the cold storage (21 days). The highest viability of probiotics (p<0.05) was observed when ABY-1 starter culture with soymilk to cow's milk ratio of 50:50 was applied, whilst the best sensory attributes were related to the treatment with the highest cow's milk content and ABY-1 starter culture. Considering all aspects, the treatment of ABY-1/50:50 (cow's milk: soymilk) which renders the highest viability and acceptable sensory properties was selected as an optimum. Viability was over 108 cfu/mL during the storage period (5˚C. 21 days) for all treatments of ABY-1/50:50 containing fruit concentrates. Those which had apricot and strawberry flavorings showed the best sensory acceptance.