Contribution to the identification of the pigments responsible for the browning of anthocyanin-flavanol solutions

摘要: The formation of pigments responsible for the browning solutions pH 3.2 containing malvidin-3-monoglucoside (Mv3g) and (+)-catechin (cat), stored at 32  °C, was studied by liquid chromatography with double detection diode array spectrophotometry mass spectrometry. progressive accumulation yellowish pigments, λmax in visible region between 439 nm 458 nm, observed throughout assay period. results obtained allowed hypothesis that these result from anthocyanin-flavanol condensation to be discounted, instead suggested they derive cat involve products oxidation ethanol tartaric acid. Phloroglucinol, produced degradation Mv3g, seen participate one pigments. A colourless dimer resulting direct cat-Mv3g also found; this product stable did not evolve towards during period (90 days). Structures principal compounds detected were postulated, taking as a basis data their spectra.