High yield production of cyanidin-derived pyranoanthocyanins using 4-vinylphenol and 4-vinylguaiacol as cofactors

Pyranoanthocyanins are anthocyanin-derived pigments with vivid colors and enhanced stability, making them promising food colorants. We evaluated two 4-vinylphenols, decarboxylated p-coumaric (pCA) and ferulic acid (FA), as cofactors for pyranoanthocyanin formation. Cyanidin-3-glycosides from saponified black carrot were incubated with 4-vinylphenol or 4-vinylguaiacol in different anthocyanin-to-cofactor molar ratios (1:1-1:30) to form pyranoanthocyanins. Formation efficiency (45 degrees C, & LE;96 h) was compared to their respective precursors at a 1:30 ratio. Composition changes were monitored using uHPLC-PDA-ESI-MS/MS. Pyranoanthocyanin yields with 4-vinylphenol (13.8-33.4%) were-12x higher than with pCA and yields with 4-vinylguaiacol (8.1-31.0%) were-6.5x higher than with FA. Molar ratios of 1:5 and 1:10 yielded significantly more pyranoanthocyanins. Pyranoanthocyanin formation with 4-vinylphenols followed first-order kinetics, whereas formation with hydroxycinnamic acids followed zero-order kinetics. Detection of intermediate compounds was consistent with a nucleophilic addition and aromatization formation mechanism. Overall, pyranoanthocyanin formation with 4vinylphenols was more efficient than with hydroxycinnamic acids.

Automated summary

This study evaluated two vinylphenols as cofactors for the formation of pyranoanthocyanins in food colorants. The results showed that the synthesis efficiency was highest when the molar ratio of vinylphenols to precursors was 1:5 or 1:10. The formation process followed a nucleophilic addition and aromatization mechanism. Overall, vinylphenols were more efficient than hydroxycinnamic acids in pyranoanthocyanin formation.