Soybean variety influences the quality and functionality of soymilk fermented by Lactobacillus acidophilus 1132

Abstract

Fermented soymilk is a widely consumed plant-based beverage, and fermentation enhances its nutritional and functional properties. However, the influence of soybean seed characteristics on the quality and functionality of fermented soymilk remains insufficiently understood. Therefore, this study investigated the effect of three soybean varieties-food-grade (Karune), low-KTI (V23), and black (VL-Bhat-65)- on the nutritional, functional, technological, and sensory properties of soymilk fermented with Lactobacillus acidophilus 1132. All soybean varieties supported bacterial growth and lactic acid production. Fermentation significantly ( p < 0.05) improved the nutritional and functional quality of soymilk by reducing raffinose-family oligosaccharides (RFOs) and antinutritional factors (ANFs), while enhancing isoflavone bioconversion and phenolic content. Black soybean soymilk exhibited the highest protein and mineral contents and viscosity; food-grade soymilk showed the greatest antioxidant activity, lowest phytic acid and trypsin inhibitor activity, and highest sensory acceptability, whereas low-KTI soymilk demonstrated the greatest conversion of glucoside to aglycone isoflavones. These findings demonstrate that soybean variety significantly influences the quality and functionality of fermented soymilk and provide a scientific basis for selecting appropriate soybean varieties for the development of nutritionally enhanced fermented plant-based beverages.