粪肠球菌发酵生棉粕的工艺条件优化

Optimization of technical conditions of solid-state fermentation raw cottonseed meal with Enterococcus faecalis

为降低棉粕中游离棉酚含量,对粪肠球菌固态发酵生棉粕降解游离棉酚工艺条件进行了优化。首先对影响粪肠球菌固态发酵棉粕降解游离棉酚的料水比、初始pH、发酵时间、接种量、发酵温度进行单因素研究,确定对结果有较大影响的料水比、初始pH和发酵时间3个因素。然后利用Box-Behnken设计,对其进行优化。结果表明,料水比、初始pH和发酵时间的最佳条件分别是1∶0.53、6.57和3.06d。按照优化的条件发酵棉粕后游离棉酚含量降为231.68 mg/kg,降解率达67.85%。

To reduce content of free gossypol in cottonseed meal,this paper focused on the optimization of the condition of solid-state fermentation raw cottonseed meal with Enterococcus faecalis by response surface method.Firstly,the effects of independent variables（ratio of material to water,initial pH,fermentation time,inoculation amount and fermentation temperature） were evaluated by single factor analysis.The important factors affecting the content of free gossypol in fermentation cottonseed meal were ratio of material to water,initial pH and fermentation time.Secondly,the optimum fermentation conditions for free gossypol degradation were confirmed by Box-Behnken experimental design.The results showed that the optimum conditions were as follows： ratio of material to water was 1∶ 0.53,initial pH was 6.57,fermentation time was 3.06 days.Under the optimum condition,the content of free gossypol of fermentation cottonseed meal was 231.68mg/kg and the degradation rate of free gossypol was 67.85%.