干酪乳杆菌冻干保护剂筛选及贮藏期预测

Screening of Freeze-Drying Protectants for Lactobacillus casei and Prediction of Storage Period

为探究一种高保护效率的干酪乳杆菌冻干保护剂配方,以干酪乳杆菌为研究对象,以冷冻干燥技术为研究手段,首先,利用单因素试验对冷冻保护剂、抗氧化剂、填充剂、酸碱调整剂进行筛选;再通过正交优化设计,对以海藻糖、硫代硫酸钠、甘露醇和山梨醇作为冻干保护剂材料进行复配优化;最后,建立冷冻干燥后活菌数的预测模型。结果表明,复合冻干保护剂的最佳配方组合为海藻糖15%、硫代硫酸钠2%、甘露醇15%、山梨醇3%,冷冻干燥后菌种存活率为90.20%。经过4周的长期效果验证,得到的菌种存活率为88.04%。所建立的线性和指数模型对冷冻干燥后活菌数的预测精度高,R^(2)均为0.80。说明研究所得到的复合冻干保护剂对干酪乳杆菌具有长期且有效的保护效果。

In order to explore a high-efficiency lyoprotectant formula for Lactobacillus casei,this study took Lactobacillus casei as the research subject and employed freeze-drying technology as the research method.Initially,cryoprotective agent,antioxidant,filler and acid base regulator were screened through single-factor experiments.Subsequently,an optimized composite formula was developed using trehalose,sodium thiosulfate,mannitol,and sorbitol as lyoprotectant materials through orthogonal optimization de⁃sign.Finally,a predictive model for the viable cell count after freeze-drying was established.The results indicated that the optimal combination of the composite lyoprotectant was 15%trehalose,2%sodium thiosulfate,15%mannitol,and 3%sorbitol,achieving a survival rate of 90.20%after freeze-drying.After 4 weeks of long-term efficacy validation,the survival rate of the strain was 88.04%.The established lin⁃ear and exponential models demonstrated high predictive accuracy for the viable cell count after freeze-drying,with both R^(2) values being 0.80.This suggests that the composite lyoprotectant developed in this study provides effective and long-term protection for Lactobacillus casei.