大豆玉米复合肽液态发酵工艺优化

以豆粕和玉米蛋白粉为原料,应用枯草芽孢杆菌液态发酵制备大豆玉米复合肽。首先考察豆粕和玉米蛋白粉配比、发酵温度、摇床转速、发酵时间和接种量对复配蛋白的水解度和肽转化率的影响。在此基础上应用四因素三水平响应面实验设计对液态发酵工艺进行优化,并建立了相应的回归模型。结果表明,豆粕和玉米蛋白粉配比为2∶1时,液态发酵的优化工艺参数为:发酵温度为37℃、摇床转速为184 r/min、发酵时间为51 h、接种量为4%。在此条件下发酵的蛋白水解度为25.73%±1.78%、肽转化率为33.23%±1.06%,与理论预测值基本相符。该研究结果为豆粕和玉米蛋白粉的深加工及综合利用提供科学参考。 

Optimization on liquid- state fermentation process of composite peptides from soybean and corn proteins

Soybean and corn gluten meal were mixed as fermentation materials and inoculated with Bacillus subtilis to produce composite peptides from soybean and corn protein.Firstly,effects of fermentation temperature,shaker speed,fermentation time and inoculum volume on degree of hydrolysis( DH) of proteins mixture and conversion rate of peptides were discussed. On the basis of single factor experiments,liquid- state fermentation process conditions of soybean and corn composite peptides were optimized by using four- factor three- level response surface methodology,and corresponding regression models were established. Results showed that proportion of soybean and corn gluten meal was 2 ∶ 1 and that optimum fermentation process parameters were as follows:fermentation temperature of 37 ℃,shaker speed of 184 r / min,fermentation time of 51 h,inoculum volume of 4%.Under these liquid- state fermentation conditions,DH of composite proteins was 25.73% ± 1.78% and peptide conversion rate of 33.23% ± 1.06%,which was consistent with theoretical prediction values basically. These results contributed to scientific reference for deep manufacture and application of soybean and corn gluten meal.