Evaluation of the effect of catechin on the Maillard reaction based on model systems: a chemical insight

The Maillard reaction (MR) strongly affects food quality and sensory properties by generating desirable and undesirable products. Herein, catechin reactivity toward reducing sugars and amino acids was systematically investigated under conditions mimicking thermal food processing to assess its impact on early-stage MR. Catechin effectively reduced browning and suppressed furosine-associated signal formation through the formation of covalent catechin-sugar adducts identified by LC-UV-MS and NMR analysis. Antioxidant capacity of the reaction mixtures exceeded the theoretical value calculated based on the amount of residual catechin, indicating a contribution from catechin-derived products. Reduced browning and enhanced antioxidant properties were observed even in complex food systems (e.g., milk, egg white, flour) when catechin was present. Similar effects were observed using polyphenol-rich apple samples in place of catechin. Overall, these results highlight the dual role of natural polyphenols in modulating MR progression and enhancing antioxidant properties in food systems.