[关键词]
[摘要]
脂环酸芽孢杆菌具有嗜酸耐热的特性和产芽孢的能力,在果汁中萌发繁殖会使产品出现异味,导致腐败。本文将筛选得到的分离菌株XC-6和购自德国菌种保藏中心的标准菌株DSM 3922分别等量接种到6种果汁饮料,采用FOX 4000电子鼻结合主成分分析对接种样品与正常样品进行对比分析,发现电子鼻可快速有效鉴别出经不同处理的样品,其中第一主成分累积方差贡献率均大于95%。GC-MS分析表明接种样品相较于正常样品,挥发性物质图谱存在着差异,特征表向物质含量的差异可以被电子鼻用来鉴别正常样品与污染样品。在水蜜桃乳饮料和水果牛奶混合饮料中均检出了脂环酸芽孢杆菌的特征代谢产物邻乙氧基苯酚和愈创木酚,它们的含量显著高于正常样品。本实验表明电子鼻可以根据样品气味图谱的不同而对污染样品做出准确的鉴别,是可以将电子鼻作为早期快速检测脂环酸芽孢杆菌污染的检测工具。
[Key word]
[Abstract]
Alicyclobacillus has the character of high tolerance to acid and heat and the ability of producing spore, which can germinate and propagate in the fruit juice and then make the products smell bad and cause corruption. In this study, the isolated strain XC-6 and standard strain DSM 3922 obtained from the German bacterial collection center were inoculated equally into 6 kinds of fruit juices, respectively. FOX 4000 electronic nose combined with principal component analysis was used for the analysis of inoculated samples and normal samples. The results showed that the electronic nose could identify the contaminated samples quickly and effectively from 6 kinds of fruit juices and’ the cumulative variance contribution rates of the first principal component were more than 95%. GC-MS analysis showed that the prints of volatile compounds between inoculated samples and normal samples were different. The difference of some typical substances content could be used to identify contaminated samples and normal samples by electronic nose. Adjacent ethoxy phenol and guaiacol, the characteristic metabolites of Alicyclobacillus, were detected in the peach beverage and fruit milk mixed drinks, of which the content was significantly higher than the normal samples. The experiments showed that the electronic nose could identify the contaminated samples accurately according to the difference of the juice samples smell maps, which could be used as a testing tool for early detection of Alicyclobacillus pollution.
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[基金项目]
国家自然科学基金资助项目(31201414);湖北省高等学校优秀中青年科技创新团队计划(T201725)