Optimization of preparation technology of natto from black soybean by response surface methodology

For getting the suitability of natto flavor,black soybean was took as raw material,using response surface analysis method,the sensory evaluation was used as response value. Studying the fermentation technology of black soybean natto.The results showed the optimal fermentation conditions were as follows:soaking time 19.5 h,the fermentation time 23.5 h,inoculation 4.5%. Under the optimal conditions,natto was gray black,with natto smelled,soft. Therefore took black soybeans as raw material to make natto by fermentation had a broad development prospect in the future market.