| Soybean milk is a derivative product from soybean that has been known for its functionality effects on human. However further development is needed to improve its organoleptic quality. Fermentation is known for reducing beany flavor on soybean milk, on the other hand diminishing its shelf life. In this study, the effects of soybean milk fermentation using Lactobacillus bulgaricus and Streptococcus thermophilus, and post-fermentation sterilization on quality of soybean milk were investigated. Three soybean milk products, i.e. soybean milk (SM), fermented soybean milk (FSM), and sterilized fermented soybean milk (SFSM) were tested for their physico-chemical properties, proximate analysis, amino acid composition, vitamin B12 level, antioxidant activity, and organoleptic test. Our results showed that fermentation in FSM effectively reduced pH and total soluble solids, increased viscosity, changed amino acid composition, and increased antioxidant activity compared to those of SM. Interestingly, FSM had higher contents of methionine and cysteine than SM. Meanwhile, post-fermentation sterilization in SFSM changed the texture of fermented soybean milk, degraded heat-sensitive compounds, and reducing the antioxidant activity. However, organoleptic profiles for both FSM and SFSM showed a slight decrease in consumer acceptance compared to that of SM. In summary, fermention and sterilization treatments may contribute to the increased quality of soybean milk. |