Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis

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 volatileswere detected, among which alcohols, aldehydes and ketoneswere 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 analysiswas performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatilecompounds, i.e. ethanol,-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 modelwas estimated to be 100% by the “leaveone- 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.