Soy-yamgurt probiotic drink as a natural potential of antioxidant

摘要

Yogurt is a popular healthy food, consumed by many people. Probiotic are used for better growth and survival of probiotic bacteria as well as to improve organoleptic, rheological and technological properties of soy-yamgurt probiotic. The aims of this study were to determine physicochemical changes and survival of probiotic bacteria due to the effect of ratio of yam-bean with soy-bean extract on the quality of soy-yamgurt probiotic drink. The quality examined were total bacteria, antioxidant activity, lactic acid content, and acceptability including color, texture, flavor, and overall acceptance. This research had been performed using Completely Randomized Design two factorials, consist of five levels i.e.: ratio of yam-bean with soy-bean extract (100:0; 75:25; 50:50; 25:75; 0:100) and the fermentation time (4,6 and 8 hours), the process was repeated three times. The results showed that ratio of yam-bean with soy-bean extract of 50:50 and fermentation for 6 hours incubation produced the best quality. Acceptable probiotic drink containing 1.44 × 10~9 CFU/mL lactic acid bacteria, IC_(50) of soy-yamgurt in the attenuation of free radical DPPH ranged from 58.718-18.112 mg/L in 5 minutes incubation and 39.7204-11.9925 mg/L in 60 minutes, and 0.48% lactic acid. This appearance of soy-yamgurt had yellow greenish color, desired texture and flavor, and received the highest score of overall acceptance.