摘要
为了提高乳酸菌在喷雾干燥过程中的可培养性,以德氏乳杆菌ATx为研究对象,在分析不同热胁迫条件对其细胞可培养性的影响的基础上,以20 g/dL脱脂乳(SM)、12 g/dL脱脂乳+8 g/dL菊糖(SMS)、12 g/dL脱脂乳+8 g/dL海藻糖(SMT)、12 g/dL脱脂乳+4 g/dL菊糖+4 g/dL海藻糖(SMST)为保护剂,探讨了喷雾干燥对菌体己糖激酶、乳酸脱氢酶、细胞膜ATP酶、细胞可培养性以及产酸性能的影响。结果表明:德氏乳杆菌ATx的最佳热胁迫条件为(50℃,15 min),此时细胞活菌数仅下降0.107 lg CFU/mL(P≥0.05)。经过喷雾干燥后菌体的细胞膜ATP酶、已糖激酶与乳酸脱氢酶的活性均显著地降低(P<0.05),但均高于对照组。四种菌粉在12 g/dL脱脂乳中的产酸性能良好,凝乳时间为8~10 h,说明喷雾干燥会对德氏乳杆菌ATx的细胞膜与糖代谢关键酶造成损伤,通过添加保护剂可以提高细胞对喷雾干燥中不利环境的抵抗力,从而提高可培养性。
In order to improve the culturability of lactic acid bacteria during spray drying,taking Lactobacillus delbrueckii(ATx)as study objects,culturability of lactic acid bacteria have been investigated after heat stress.And the effects of spray drying on the activities of hexokinase,lactate dehydrogenase,cell membrane ATPase,cell viability and acid-producting capacity have been investigated in four kinds of protective agent(20%skim milk(SM),12%skim milk+8%synanthrin(SMS),12%skim milk+8%trehalose(SMT),12%skim milk+4%synanthrin+4%trehalose(SMST)).The results showed that the optimal heat stress condition of ATx was(50℃,15 min),and the number of viable cells only decreased by 0.107 lg CFU/mL(P≥0.05).It was worth mentioning that after spray drying,the activities of ATPase,carbohydrolase and lactate dehydrogenase were significantly decreased(P<0.05),but all were still higher than the control group.Four kinds of bacterial powderin the 12%skim milk had a good acid-producting capacity and curd time was 8-10 h,these indicated that spray drying could damage the cell membrane and the key enzyme of glycometabolism in ATx.In order to improve the culture culturability,we could add protective agent to improve the resistance of cells to unfavorable environment in spray drying.
作者
蒋艾廷
李宝坤
金丹
乔传丽
杨婕
赵利利
JIANG Aiting;LI Baokun;JIN Dan;QIAO Chuanli;YANG Jie;ZHAO Lili(College of Food Engineering,Shihezi University,Shihezi,xinjiang 832000,China)
出处
《食品与生物技术学报》
CAS
CSCD
北大核心
2019年第11期115-121,共7页
Journal of Food Science and Biotechnology
基金
国家自然科学基金地区项目（31560444）
石河子大学重点科技攻关项目（gxjs2014-zdgg07）
关键词
喷雾干燥
代谢酶活
产酸性能
可培养性
spray drying
metabolic enzyme activity
acid-producting capacity
culturability
