Utilization of Weissella confusa isolated from soymilk for soymilk fermentation

Faculty of Biology, Universitas Gadjah Mada, Yogyakarta, Indonesia

^* Corresponding author: yekti@ugm.ac.id

Abstract

Soy milk is widely used as a substitute for dairy milk, mainly due to intolerances towards the lactose content in dairy milk. This type of intolerance is prevalent worldwide as over 65% of people are intolerant to lactose, which could cause effects such as bloating and diarrhea. However, a main disadvantage of soy milk is its beany flavor, which is caused by the enzyme lipoxygenase which breaks down polyunsaturated fatty acids. One of the popular methods of remove this flavor is by the fermentation of soy milk. During this study, the fermentation of soymilk is done by Weissella confusa, which belongs to the lactic acid bacteria group, isolated from soy milk and compared with Lactiplantibacillus plantarum. The overall fermentation ability is observed through the (1) colony forming units/mL of the bacteria, (2) pH, and (3) lactic acid content, which was done through the calculation of the titratable acidity of the fermented product, after 6 hours of fermentation at 37 °C. The results showed that the Weissella confusa isolate obtained an overall better fermentation ability than Lactiplantibacillus plantarum, with higher number of CFU/mL, reaching 5.5×10⁹ CFU/mL, a lower pH of 4, and a higher lactic acid content of 0.27%. However, further studies are required to verify the use of Weissella confusa as a probiotic bacteria for human consumption.