Comparative degradation pathways of malvidin 3,5-diglucoside after enzymatic and thermal treatments

Bioconversion of anthocyanin glycosides by Bifidobacteria and Lactobacillus

“…As they had most probably been formed transistorily, their detection was not possible (Fig. 3) since aglycones are quite unstable in neutral media, where the reactive carbinol or pseudobase may be transformed into its corresponding chalcone which later undergoes a rapid ring fission producing the corresponding phenolic acid and phloroglucinol aldehyde (Piffaut, Kader, Girardin, & Metche, 1994). In accordance with this latter hypothesis we found the chalcone of malvidin-3-glucoside in most of the analysed samples at a retention time of 9.9 min.…”

Effect of water activity on anthocyanin degradation and browning kinetics at high temperatures (100–140°C)

“…Relatively little is known about the mechanisms of anthocyanin thermal degradation, except that degradation is primarily caused by oxidation and cleavage of covalent bonds (Patras, Brunton, O'Donnell, & Tiwari, 2010). Adams (1973) proposed that the hydrolysis of the sugar moiety and the formation of aglycone are the initial steps of cyanidin 3-glucoside degradation in an acidified aqueous solution at 100°C; Piffaut, Kader, Girardin, and Metche (1994) also suggested that thermal degradation of malvidin 3,5-diglucoside at 100°C starts by the hydrolysis of glucosidic bonds, which destabilizes aglycone and leads to opening of the pyrilium ring and subsequent chalcone formation (Piffaut et al, 1994). Because thermal degradation is assumed to be a hydrolytic reaction, water availability is thought to be essential for anthocyanin degradation (Erlandson & Wrolstad, 1972).…”

Waste grape skins thermal dehydration: potential release of colour, phenolic and aroma compounds into wine

“…Anthocyanin concentration was significantly damaged by the dehydration temperatures of the raw material as observed in DWGS-solutions. Piffaut, Kader, Girardin, & Metche (1994) suggested that thermal dehydration at 1008C influence anthocyanin equilibrium by shifting the flavylium form (coloured) towards the chalcone form (non-coloured). These degradation products may be responsible for the lower red component detected by UV-vis analysis in thermal DWGS solutions.…”