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 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.

Thyroid involvement in chronic inflammatory rheumatological disorders.

The association between rheumatological and thyroid disorders has long been known, the most common being the association of rheumatoid arthritis and autoimmune thyroiditis. Little is known as to possible thyroid involvement in other rheumatological disease of possible autoimmune aetiology, such as psoriatic arthritis and ankylosing spondylitis. We measured thyroid volume and function as well as the prevalence of anti-microsome and anti-thyroglobulin antibodies in 107 consecutive patients with rheumatoid arthritis, 42 patients with psoriatic arthritis, and 12 male patients with ankylosing spondylitis. Fifty-two normal subjects were used as controls. The average thyroid volume, measured at ultrasounds, was increased in all groups of patients, and the prevalence of thyroid enlargement (A-P diameter > 20 mm) was 2-3 fold higher in rheumatological disorders in comparison to controls. Both, patients with rheumatoid arthritis and psoriatic arthritis had higher-than-normal fT4 levels and an increased prevalence of anti-microsome antibodies. In the rheumatoid arthritis group alterations in thyroid volume and function were present irrespective of disease activity, whereas in psoriatic arthritis thyroid involvement was confined to patients with active disease. Our data are consistent with a significant thyroid involvement in rheumatological disorders, which is not limited to diseases with a definite autoimmune aetiology.