Characteristic and Isoflavone Level of Soymilk Fermented by Single and Mixed Culture of <i>Lactobacillus plantarum </i>and Yoghurt Starter

Fermented soymilk has better health benefits compared to unfermented soymilk. The health benefits of fermented soymilk are improving blood lipid profile, antioxidants and anti-inflammatory. Fermentation of lactic acid bacteria can increase the content of aglycon isoflavones, namely genistein and daidzein. The purpose of this study was to analyze the characteristics of soymilk and isoflavone level fermented with a single culture of Lactobacillus plantarum and mixed culture of Lactobacillus plantarum and yogurt starter. This research consisted of 4 treatments, namely unfermented, fermentation using L. plantarum, fermentation using S. thermophilus and L.bulgaricus, and fermentation using L. plantarum, S. thermophillus, L. bulgaricus. Samples analyzed proximate, titratable acid , pH, total lactic acid bacteria, total daidzein, genistein and sensory quality. The results showed that the total acid, pH, and total lactic acid bacteria for fermentation with mixed cultures were higher compared to L. plantarum single culture. Total daidzein and genistein for single culture and mixed culture were not significantly different between the two groups. Sensory analysis shows that soymilk with a single culture have the highest value for the parameters of taste, aroma and color.