为了检测冷诱导的胡萝卜蛋白质粗提物对嗜酸乳杆菌的冻干保护作用,从冷诱导的胡萝卜中制备蛋白质粗提物,设计6组冻干保护剂配方,以细菌存活率作为指标检测该粗提物的冻干保护效果;并在扫描电镜下观察冻干菌粉的形态特征。试验结果显示:冷诱导胡萝卜在12.5 ku和36 ku分子量处出现疑似抗冻蛋白条带;不同保护剂对嗜酸乳杆菌的冻干保护效应差异显著(P<0.05),添加冷诱导胡萝卜粗提物的复合保护剂冻干保护效果最优,其细菌存活率达到76.02%;最佳保护剂组配方为:10%脱脂乳,10%麦芽糊精,10%海藻糖,1.0%L-Cys,2.0%VC,2.0%甘油,0.8%硫酸锰和15%冷诱导胡萝卜粗提物。

To detect protective effect of crude extracts from cold-induced Carrots on Lactobacillus acidophilus,crude protein extracts from cold-induced Carrots were prepared for SDS-PAGE analysis.Six formulas for cryoprotectants were designed,and protective effect of crude extracts were detected with survival rate as index.The morphological characteristics of freeze-dried bacteria powder were observed under the scanning electron microscopy(SEM).The results showed that two bands from crude extracts of cold-induced carrots were found at 12.5 kD and 36 kD.There were significant differences among the protective effects of different protectants on freeze-dried lactobacillus acidophilus.After addition of such crude extracts into cryoprotective agents,the survival rate could reach 76.02%.The best protectants formula was as follows:10% skim milk,10% trehalose,10% maltodextrin,1.0% L-Cys,2.0% VC,2.0% glycerin,0.8% manganese sulphate,and 15% crude extracts from cold-induced Carrots.