Quinone reactivity: Investigation of their contribution to nonenzymatic browning

Browning is a severe problem in the juice industry, which tremendously affected by quinone (Q) reactivity. Here, formation rate, electrophilicity, and oxidizing ability of different quinones were investigated. LC/MS was applied to monitor loss polyphenols model systems during storage. Mathematical modeling collected data conducted derive rate constants various reactions. Polyphenols containing catechol or pyrogallol groups are more susceptible oxidation. Periodic acid mediated oxidation faster than autoxidation polyphenols. Chlorogenic (CQA) 4-methylcatechol (4MC) only B ring can hardly contribute browning. They must combine with A form yellow polymers. Furthermore, electrophilicity order is: CQA-Q ≈ 4MC-Q > catechin (CAT-Q) epicatechin (EC-Q) gallic (GA-Q). It possible that CAT-Q EC-Q would undergo nucleophilic addition their rings GA-Q's extra hydroxyl group might electrons, resulting lower This work innovatively evaluated reactivity diverse quinones, attempting illustrate contributions nonenzymatic These findings provide new perspective restrain browning processing industry.