低聚糖在瑞士乳杆菌和嗜热链球菌冷冻干燥过程中的保护作用  

Protective effects of oligosaccharides on Lactobacillus helveticus and Streptococcus thermophilus during freeze-drying process

作　　者：黄蓉 周子文 莫乔雅 董明盛[1] 芮昕[1] 张秋勤[1] 陈晓红[1] 李伟[1] HUANG Rong;ZHOU Ziwen;MO Qiaoya;DONG Mingsheng;RUI Xin;ZHANG Qiuqin;CHEN Xiaohong;LI Wei(College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095,China)

机构地区：[1]南京农业大学食品科技学院

出　　处：《食品与发酵工业》2019年第17期26-31,共6页Food and Fermentation Industries

基　　金：中央高校基本科研业务费专项资金项目(KYLH201702、KYYJ201807);国家自然科学基金项目(31571818、31871771);江苏省自然科学基金项目(BK20161448);江苏省“青蓝工程”项目;南京农业大学SRT计划项目(国家级)

摘　　要：为研究瑞士乳杆菌MB2-1(Lactobacillus helveticus MB2-1)和嗜热链球菌(Streptococcus thermophilus MB5-1)的发酵特性,同时考察不同浓度的低聚半乳糖(galactooligosaccharides,GOS)和低聚果糖(fructo oligosaccharide,FOS)在L.helveticus MB2-1和S.thermophilus MB5-1离心和冻干条件下的保护作用,测定了2株菌发酵过程中pH值、残糖量等5个指标,以及GOS、FOS作为保护剂在L.helveticus MB2-1和S.thermophilus MB5-1离心冻干前后活菌数的变化情况。结果表明,L.helveticus MB2-1和S.thermophilus MB5-1均具有较好的底物利用能力和生长情况,可作为乳品等产品的菌种发酵剂来源;在对2种乳酸菌离心的保护作用中,FOS的保护效果均优于GOS,在质量浓度为300 g/L时,菌体存活率分别达到82.82%和68.03%;而在对菌体冻干的保护作用中,质量浓度为200和300 g/L的GOS的保护效果优于FOS,且在相同低聚糖浓度下,对L.helveticus MB2-1的保护效果要优于S.thermophilus MB5-1。该研究表明低聚糖作为乳酸菌发酵剂的保护剂具有广阔的应用前景。The aim of this study was to investigate the protective effects of galactooligosaccharides (GOS) and fructooligosaccharides (FOS) on Lactobacillus helveticus MB2-1 and Streptococcus thermophilus MB5-1 under centrifugation and lyophilization, as well as to determine the fermentation characteristics of the strains. Five indicators such as pH and residual sugar during fermentations of these two strains were measured, and their viable counts before and after centrifugation and lyophilization were determined when GOS and FOS were used as protective agents. The results showed that both L. helveticus MB2-1 and S. thermophilus MB5-1 had good substrate utilization ability and grew well, which could be used as starter cultures for dairy products. Moreover, the protective effect of FOS was better than that of GOS when L. helveticus MB2-1 and S. thermophilus MB5-1 were centrifuged. 300 g/L FOS could remain the bacterial viabilities of L. helveticus MB2-1 and S. thermophilus MB5-1 at 82.82% and 68.03%, respectively. However, 200 and 300 g/L GOS were better than that of FOS in protecting freeze-dried cells. In addition, the protective effects on L. helveticus MB2-1 was better than S. thermophilus MB5-1 at the same oligosaccharide concentration. This study demonstrated that oligosaccharides as a protective agent for lactic acid bacteria starter have broad application prospects.

关 键 词：低聚糖 瑞士乳杆菌MB2-1 嗜热链球菌MB5-1 冷冻干燥 保护作用 

分 类 号：TS201.3[轻工技术与工程—食品科学]