乳业科学与技术Issue(2)：1-5,5.DOI:10.7506/rykxyjs1671-5187-201502001
嗜热链球菌产酸特性及其发酵乳中有机酸组分分析
Acid-Producing Ability of Streptococcus thermophilus and Organic Acid Composition in Fermented Milk
摘要
Abstract
In the present study, 5 strains of Streptococcus thermophilus which were isolated from traditional fermented dairy products were selected to perform fermentation experiments. During the fermentation process and 504 h of storage at 4 ℃, some indexes such as fermentation time, titratable acidity (TA), pH value and viable cell counts were determined, and the composition of organic acids was tested by reverse phase high performance liquid chromatography(RP-HPLC). Fermentation and acid-producing properties of Streptococcus thermophilus were evaluated; meanwhile changes in organic acid composition and post-acidification characteristics during storage were determined. After 2 h of fermentation at 42 ℃, the pH of fermented milk by each of the five strains declined rapidly. The fermentation reached its end-point at 5–9 h, and the shortest fermentation time was required for strains IMAU10632 and IMAU20772. Over the 504 h storage period, the pH of milks fermented by Streptococcus thermophilus was reduced by about 0.5 and finally reached a stable level of about 4.2, and acids were produced at lower rates in al fermented milks until the acidity values reached levels below 90 oT , suggesting the weak post-acidification ability of the 5 strains. Furthermore, IMAU10632 was selected from these strains, which could shorten milk coagulation time, increase acid-producing rate, enhance post-acidification ability and reach a viable cel count exceeding 108 CFU/mL which remained unchanged over the entire storage period.关键词
嗜热链球菌/发酵/贮藏/产酸特性Key words
Streptococcus thermophilus/fermentation/storage/acid-producing properties分类
轻工纺织引用本文复制引用
陈红霞,德亮亮,任艳,张冬蕾,杨彦荣,刘文俊,张和平..嗜热链球菌产酸特性及其发酵乳中有机酸组分分析[J].乳业科学与技术,2015,(2):1-5,5.基金项目
内蒙古自治区自然科学基金项目（2013MS1206）；公益性行业（农业）科研专项 （）
