Comparison of two extraction methods (homogenization and MSPD) for analysis of bioactive amines in tomato products by liquid chromatography

Most amines in foods originate from corresponding amino acid which have undergone decarboxylation by putrefactive bacteria or lactic acid bacteria. When formed by microbial enzymatic decarboxylation of amino acids they are called “biogenic” and have detrimental effects on health. Many techniques have been developed for extraction and/or clean-up of bioactive amines in foods, icluding acidic or organic extraction as well as solid phase extraction. This study deals with the comparison of two different exctraction methods applied to tomato-based products very popular in italian alimentary habits. In particular, homogenization and matrix solid phase dispersion (MSPD) have been compared for quantitative determination of 8 non-volatile (putrescine, cadaverine, histamine, tyramine, tryptamine, serotonine, spermidine and spermine) bioactive amines in commercial samples. In both cases perchloric acid has been used for analytes extraction. The influence of different parameters have been evaluated. More precisely: 1. Homogenization: perchloric acid concentration (0.2, 0.4 and 0.6 N); 2. MSPD: perchloric acid concentration (0.2, 0.4 and 0.6 N) and final elution volume (5, 10, 15 and 20 ml). After a derivatization process with dansyl-chloride, samples were analyzed for amines quantitative determination on a C18-RP-HPLC-UV system, water/acetonitrile gradient and detected by UV absorption at l=254 nm with a total run time of 30 minutes. Method performances were tested and good results for linearity, repeatability and recoveries were obtained for all the 8 amines analyzed. Results have shown that putrescine is the most abundant amine, followed by tyramine, spermidine and tryptamine.