基于水分活度测定的发酵胡萝卜浓缩汁细菌检测方法  

Bacteria Detection Method of Concentrated Juice of Fermented Carrot Based on Water Activity Measurement

作　　者：杨晓莉 李翠 谢毓华 绳金房 YANG Xiao-li;LI Cui;XIE Yu-hua;SHENG Jin-fang(Shaanxi Institute for Food and Drug Control,Xi'an 710065,China)

机构地区：[1]陕西省食品药品监督检验研究院,西安710065

出　　处：《中国食物与营养》2020年第3期23-26,共4页Food and Nutrition in China

基　　金：国家药典委员会项目(项目编号:2017-15)。

摘　　要：目的:从水分活度测定以及影响水分活度的关键限值(温度和pH)出发,研究发酵胡萝卜浓缩汁细菌生长情况。方法:选取山东绿维胡萝卜浓缩汁,由该发酵胡萝卜浓缩汁剥离提纯的萄球菌、铜绿假单细胞菌、大肠埃希氏菌、腐生酵母菌,用1mol/L的盐酸和氢氧化钠对胡萝卜浓缩汁的酸碱度进行调整,以80%的甘油溶液调整水分活度,测定细菌最大生长率、生长迟滞时间、细菌生长条件理论最低值以及细菌生存概率。结果:水分活度,以及影响水分活度的温度和pH两个关键限值,都是细菌滋生的必要条件,当温度设置在37℃时,随着水分活度的不断增加,以及影响水分活度的关键限值pH值增加,发酵胡萝卜浓缩汁的葡萄球菌、大肠埃希氏菌、铜绿假单细胞菌的逐渐增加,生长速率呈上升趋势,3种细菌的最低水分活度是0.97,水分活度的最低温度以及最低pH值分别是4.53℃和3.93;影响发酵胡萝卜浓缩汁风味的腐生酵母菌随着水分活度的不断升高,最大生长率不断提升,迟滞时间逐渐缩短。结论:水分活度,以及影响水分活度的关键限值温度和pH值在细菌滋生的时候相互作用,水分活度越高,影响水分活度的关键限值温度和pH越高,发酵胡萝卜浓缩汁细菌的生长速率越快,存活率越好。Objective Based on the determination of water activity and the critical value of water activity(temperature and pH),the growth of bacteria in concentrated juice of fermented carrot was studied.Method Choose Shandong Lvwei brand carrot concentrated juice,carrot concentrated juice by the fermentation of stripping purified also aureus,verdigris pseudomonas bacteria,e.coli,metatrophic yeast,with 1 mol per liter of hydrochloric acid and sodium hydroxide to adjust the pH value of carrot concentrated juice,with 80%glycerol solution to adjust the water activity,maximum growth rate,growth retardation time determination of bacteria,bacterial growth conditions theory lowest and bacterial survival probability were determined.Result Water activity,two key limits of temperature and pH value affecting water activity,which were the necessary conditions for bacterial growth,when the temperature was set at 37℃,with the continuous increase of water activity,key limit pH value affecting water activity increased,staphylococcus aureus,e.coli bacteria,verdigris pseudomonas of the fermentation carrot concentrated juice increased gradually,growth rate was on the rise,the minimum water activity of three kinds of bacteria was 0.97,the lowest temperature of the water activity as well as the pH value was 4.53℃ and 3.93,respectively.With the increase of water activity,the maximum growth rate of saprophytic yeast affected the flavor of concentrated juice of fermented carrot was increased,and the lag time was shortened.Conclusion The higher the water activity,the higher the CLS and pH that affecting the water activity,the faster the growth rate and the better the survival rate of bacteria in concentrated juice of fermented carrot.

关 键 词：水分活度 细菌 检测 生长速率 迟滞时间 生存概率 

分 类 号：TS255.44[轻工技术与工程—农产品加工及贮藏工程]