Detoxification Conditions of Solid-State Fermentation from Rapeseed Meal by Mixture Strains Using Response Surface Methodology

In order to obtain an effective and stable method of the detoxification of rapeseed meal,the effects of fermentation conditions such as glucose addition,ammonium sulfate addition,the ratio of substrate to water,inoculation amount,initial pH value,fermentation temperature and fermentation time on the degradation rate of glucosinolate were studied by using a single-factor test.Then,the effects of ratio of substrate to water,inoculation amount,fermentation temperature and fermentation time and their interactions on the degradation rate of glucosinolate were evaluated by using a response surface methodology.Data were analyzed with Design-Expert 7.1.6 software.The results showed that a good quadratic polynomial model of conditions of solid-state fermentation from rapeseed meal was obtained,the model was significant(P0.001),and there was no lack of fit.The high degradation rate of glucosinolate was observed in fermentation processes under the optimal conditions: the inoculation amount was 7.7%,fermentation temperature was 44 ℃,ratio of substrate to water was 1.000∶ 0.585,and fermentation time was 53 h.Under these conditions,the degradation rate of glucosinolate reached 94.850 6%.In conclusion,the optimal fermentation conditions of the detoxification conditions are determined.The results can be used as technical parameters and theoretic basis for decreasing the degradation rate of glucosinolate with mixture strains on rapeseed meal.