青春双歧杆菌冻干保护剂筛选及高密度冻干工艺优化

Screening of Lyoprotectants and Optimization of High-Density Freeze-Drying Process for Bifidobacterium adolescentis

为了探究青春双歧杆菌最适冻干保护剂配方,提高工业化生产效率,作者对不同糖与蛋白质类保护剂对双歧杆菌冻干保护特性、不同结构的糖类保护剂复配及其与蛋白质复配的保护效果进行研究,同时测定复合保护剂添加其他小分子物质对冻干存活率的影响,最后优化冻干前菌泥干物质与冻干保护剂的比例,以实现高密度冻干。研究结果表明,糖(醇)类保护剂对青春双歧杆菌的保护效果普遍高于蛋白类冻干保护剂,且四糖以下小分子糖的冻干保护效果较好,其中山梨糖醇和棉籽糖效果最优,二者复配(质量比1∶1)后冻干存活率提高到56%左右;将其与蛋白质、抗坏血酸、谷胱甘肽、微量元素等小分子复配,不会提高对菌体的冻干保护效果;考虑到实际应用,将山梨糖醇、棉籽糖与乳清蛋白以质量比3∶3∶2复配以提高菌粉的疏松度;菌泥与保护剂以干物质质量比1∶1.2混合,样品干物质总质量分数为25%时,青春双歧杆菌的冻干存活率达到(77.08±5.20)%。

To investigate the most suitable lyophilization protection formula for Bifidobacterium adolescentis and improve the efficiency of industrial production,the authors examined the lyophilization protection properties of various saccharide and protein protectants for B.adolescentis,the protection effect of compounding saccharide protectants with different structures and the protective effect of that with protein.Finally,the ratio between the dried mush and the lyophilizing agent was optimized to achieve high-density lyophilization.The results showed that the protective effect of saccharide(alcohol)protectants on B.adolescentis was generally higher than that of protein lyophilization protectants,and the lyophilization protection effect of small molecule saccharide below tetrasaccharides was better,among which sorbitol and raffinose had the best effect,and the lyophilization survival rate increased to about 56%after the combination at the mass ratio of 1∶1.The lyophilization protection effects of the bacteria were not improved after compounding with protein,ascorbic acid,glutathione,trace elements,and other small molecules.Considering the practical production applications,sorbitol and raffinose were compounded with whey proteins to improve the looseness of the bacterial powder at the mass ratio of 3∶3∶2.The lyophilized survival rate of B.adolescentis was(77.08±5.20)%when the wet bacterial mass mixed with the protective agents at the ratio of 1∶1.2,and the total dry matter mass fraction of the sample was 25%.