The anthocyanins are present in the grapes as monomers, but aged red wines have only linked anthocyanins in the different polymers. One of the possible reaction of red wine colourant is the forming of linkage between the anthocyanins and flavanols by (CH2CH) bridge of acetaldehyde. The formation of coloured products between malvidin 3-glucoside, acetaldehyde and (-)epicatechin, its dimer B2 and oligomers was analysed by liquid chromatography (HPLC). These polymeric compounds were hydrolyzed in the presence of toluen-α-thiol (thiolysis) for the determination the linkage place of anthocyanins with flavanols. The model studies showed, that the procyanidins were linked by "top molecule" across of aldehyde bridge with malvidine, because the coloured toluen-α-thiol derivatives were obtained. The spectrum of these compounds had the maximum at 240 nm corresponding to toluen-α-thiol molecule and other maximum in visible region had shift to longer wavelength. This is characteristic for the polymers of anthocyanins with flavanols. In the red wine after thiolysis, the compounds were identified by the HPLC method with the same retention time as in the model solution, but only in the presence of acetyladehyde being previously added.
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