Bianchi F, Careri M, Mangia A, Mattarozzi M, Musci M, Concina I, Falasconi M, Gobbi E, Pardo M, Sberveglieri G
Dipartimento di Chimica Generale ed Inorganica, Università degli Studi di Parma, Parma, Italy.
Talanta. 2009 Jan 15;77(3):962-70. doi: 10.1016/j.talanta.2008.07.061. Epub 2008 Aug 13.
The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene, o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.
采用动态顶空萃取技术结合气相色谱-质谱联用仪，对受微生物污染的罐装番茄的香气特征进行了分析。对被大肠杆菌、酿酒酵母和黑曲霉污染的罐装番茄，在2天和7天后进行了分析。检测到约100种挥发性物质，其中醇类、醛类和酮类是含量最高的化合物。气相色谱峰面积用于统计分析。首先，进行主成分分析以直观呈现数据趋势和聚类情况。然后，进行线性判别分析以检测能够区分分析样品组的挥发性化合物集。发现有5种挥发性化合物，即乙醇、β-月桂烯、邻甲基苯乙烯、6-甲基-5-庚烯-2-醇和1-辛醇，能够更好地区分未受污染和受污染的样品。通过“留一法”交叉验证，计算模型的预测能力估计为100%。随后使用电子鼻装置对相同的受污染和未受污染的罐装番茄样品进行分析。将初步结果与通过动态顶空气相色谱-质谱联用仪获得的结果进行比较，结果显示吻合度良好。
