Abstract: Based on peptide yield, nitrogen solubility index (NSI) and glucosinolate degradation rate, the production conditions for rapeseed peptide by mixed solid-state fermentation using Bacillus subtilis and Actinomucor elegans preliminarily determined by one-factor-at-a-a-time method and further optimized by response surface analysis coupled with Box-Behnken design. The optimal fermentation conditons were 4:1 of Bacillus subtilis-to-Actinomucor elegans ratio, 32.1 ℃ of fermentation temperature, 4.64 d of fermentation time, resulting in a peptide yield of 9.85% and a glucosinolate degradation rate of 67.83%.

Key words: mixed solid-state fermentation, rapeseed peptide, process conditions, response surface methodology