植物乳杆菌真空干燥保护剂配方的优化

Optimization of formula of protectant for vacuum drying of Lactobacillus plantarum

目的采用响应面法对植物乳杆菌真空干燥保护剂配方进行优化。方法在单因素试验的基础上,利用响应面法(Response surface method,RSM)中的中心复合设计(Central composite design,CCD)进行试验,通过试验数据拟合得到二阶响应面模型,最终确定最优实验条件及最佳保护剂配比。检测以优化的保护剂配方制备的菌粉的稳定性。结果优化的保护剂配方为:甘油3.59%,VC1%,谷氨酸钠2%,L-半胱氨酸0.5%,海藻糖15%,蔗糖5%,脱脂乳粉42.82%,玉米淀粉15%,玉米面15%。用此配方保护剂真空干燥样品时,可使菌体存活率达52.86%,与理论预测值(54.18%)较接近。以优化的保护剂配方制备的菌粉于4℃条件下保存12个月,仍有107cfu/g的活菌量。结论已优化了植物乳杆菌真空干燥保护剂配方,对植物乳杆菌的应用、活菌产品的质量稳定及新产品的研发均有一定的指导意义。

Objective To optimize the formula of protectant for vacuum drying of Lactobacillus plantarum by response surface method （RSM）. Methods Based on single-factor test, central composite design （CCD） in RSM was adopted to obtain the experimental data fitted second-order response surface model, and experimental condition as well as formula of protectant were optimized. The bacte- rial powder prepared by using the protectant with optimized formula was evaluated for stability. Results The optimized formula of pro- tectant consisted of 3. 59% glycerol, 1% Vo 29% sodium glutamate, 0. 5% L-cysteine, 15% trehalose, 5% sucrose, 42. 82% skimmed milk powder, 15% corn starch and 15% corn flour. The survival rate of bacteria in test samples containing the protectant after vaccum drying was 52.86%, which was closed to the expected value in theory. The viable particle content in bacterial powder prepared by using the optimized protectant was 107 cfu/g after storage at 4℃ for 12 months. Conclusion The formula of protectant for vacuum drying of L. plantarum was optimized, which provided a guidance for application of L. plantarum, stabilization of quality of live bacterial product and development of novel live bacterial products.