INVESTIGATION OF SEVERAL PARAMETERS AFFECTING THE PRODUCTION OF FERMENTED SOYBEAN AND LOTUS SEED SAUCE USING ASPERGILLUS ORYZAE

Abstract

Soy sauce, the traditional condiment in many Asian countries, is produced from the fermentation of soybeans using Aspergillus oryzae. In this study, lotus seeds were used to partially replace soybeans in order to diversify the flavor of the traditional product. The two main stages in the soy sauce production process studied were the koji production stage from the fermentation using A. oryzae and the moromi production stage from the mixture of koji and a 10% brine. The results showed that the suitable lotus seed : soybean ratio for soy sauce production was 7:3 (w/w). The temperature and duration time of fermentation for koji-making were 30oC for 72 hours with a protease activity of 1279.46 ± 13.22 (U/g). The koji was then mixed with 35% (v/w) of a 10% brine and fermented at 50oC for 72 hours. The formol nitrogen content in the moromi was determined to be around 6.01 ± 0.10 (g/L). The research results show that lotus seed is the potential additional material for soysauce production while providing some basic information on lotus seed soy sauce production to support further studies in order to improve product quality.