Abstract:
With tilapia and soybean meal as raw material, neutral protease was added before the fermentation of mixed bacteria including bacillus subtilis, yeast and lactic acid. On the basis of single- factor experiment, the optimize process conditions of mixed fermentation was studied by response surface optimization method, taking degree of hydrolysis as response value, the optimized process conditions were: neutral protease addition 0.1%, fermentation temperature 40℃, fermentation time 53h.Under these conditions, the degree of hydrolysis was 31.94%, which was 4.7% higher than the ones fermented by pure bacteria.