Antioxidant and chelating capacity of Maillard reaction products in amino acid‐sugar model systems: applications for food processing

BACKGROUND Maillard reaction products (MRP) have gained increasing interest owing to their both positive and negative effects on human health. Aqueous amino acid‐sugar model systems were studied in order to evaluate the antioxidant and chelating activity of MRP under conditions similar to those of food processing. Amino acids (cysteine, glycine, isoleucine and lysine) combined with different sugars (fructose or glucose) were heated to 100 and 130 °C for 30, 60 and 90 min. Antioxidant capacity was evaluated via ABTS and DPPH free radical scavenging assays, in addition to Fe2+ and Cu2+ ion chelating capacity. RESULTS In the ABTS assay, the cysteine‐fructose model system presented the highest antioxidant activity at 7.05 µmol mL−1 (130 °C, 60 min), expressed in Trolox equivalents. In the DPPH assay, the cysteine‐glucose system presented the highest antioxidant activity at 3.79 µmol mL−1 (100 °C, 90 min). The maximum rate of chelation of Fe2+ and Cu2+ was 96.31 and 59.44% respectively in the lysine‐fructose and cysteine‐glucose systems (100 °C, 30 min). CONCLUSION The model systems presented antioxidant and chelating activity under the analyzed temperatures and heating times, which are similar to the processing conditions of some foods. © 2017 Society of Chemical Industry