摘要
针对传统微生物卫生指标法检测果蔬产品腐败的局限性,研究利用腐败指示菌的荧光检测表征鲜切莲藕样品腐败的方法。鲜切莲藕样品于4℃冷藏,每间隔3 d取出检测其微生物菌落总数和指示菌自发荧光检出的相关性,分析指示菌荧光强度与微生物数量的关系并优化荧光检测条件。结果显示:鲜切莲藕冷藏第6天菌落总数为6.4×104 CFU/g,达到腐败标准,而自冷藏第6天开始,莲藕悬液培养后均能检测到荧光,表明荧光检出时间与样品腐败时间点一致;激光共聚焦荧光检测显示样品悬液的荧光强度随其冷藏时间的延长而增强,随其稀释度的增加而降低,表明荧光强度与微生物数量间呈正相关;最终确定该荧光检测方法的最优条件为样品悬液稀释10倍、接种量5μL,对随机10个样品进行检测验证,准确率达90%,操作简单、便捷可行。
In order to overcome the disadvantages of the traditional microbial hygiene indicator tests,a fluorescence method based on spoilage indicator bacteria for determining the spoilage of fresh-cut lotus root products was developed.The samples were refrigerated at 4℃.Total colony count(TCC)and the fluorescence of the indicator bacteria were measured at 3 d intervals,and their correlation was analyzed.The optimum conditions for fluorescence detection were also studied.The results showed that the TCC of the samples stored for 6 d was 6.4×104 CFU/g,indicating spoilage.The fluorescence of the suspension culture of lotus roots was detected starting from the sixth day,suggesting that the time point of fluorescence detection and spoilage were consistent.The fluorescence intensity detected with confocal laser scanning microscope showed an increase with storage time but a decrease with the dilution of the suspension,indicating a positive correlation between the fluorescence intensity and the number of microorganisms.Finally,the optimal conditions for this fluorescence method were determined as follows:10-fold dilution of the suspension,and inoculum volume 5μL.The accuracy of this method was up to 90%when it was verified with 10 randomly selected samples.It proved to be a simple and convenient method.
作者
刘永乐
唐倩
俞健
刘小芳
陈善辉
李彦
王发祥
LIU Yongle;TANG Qian;YU Jian;LIU Xiaofang;CHEN Shanhui;LI Yan;WANG Faxiang(Hunan Provincial Engineering Research Center for Food Processing of Aquatic Biotic Resources,School of Chemistry and Food Engineering,Changsha University of Science and Technology,Changsha 410114,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2020年第8期270-274,共5页
Food Science
基金
国家自然科学基金面上项目(31571867)
中央引导地方科技发展专项(2018CT5010)
湖南省教育厅科学研究项目(17B016,17C0059,18C0233)。
关键词
鲜切莲藕
腐败
荧光
菌落总数
检测
fresh-cut lotus roots
spoilage
fluorescence
total colony count
detection