Correlating changes that occur in chemical properties with the generation of antioxidant capacity in different sugar-amino acid Maillard reaction models.

UNLABELLED: We investigated the development of antioxidant activity relative to the change of pH, fluorescent intensity, ultraviolet (UV) absorbance (A294), browning (A420), and alpha-dicarbonyl compounds in sugar-amino acid Maillard reaction (MR) model systems comprising fructose, glucose, or ribose each with glycine (Fru-Gly, Glu-Gly, and Rib-Gly) or lysine (Fru-Lys, Glu-Lys, and Rib-Lys), respectively, which were heated at 121 °C for 5 to 90 min. For hexose models, the change in pH was shown to fit a second-order polynomial regression with A294 and A420. Antioxidant activity was significantly and positively correlated with UV absorbance (r = 0.905, P < 0.001) and browning products (r = 0.893, P < 0.001) rather than with fluorescent products or the alpha-dicarbonyl compounds. Type of sugar was most important in evoking a change in UV absorbance, browning, alpha-dicarbonyl compounds, and antioxidant activity of MR products (MRPs). In conclusion, the antioxidant activity of MRPs in six model systems was more closely associated with products derived at the intermediate-to-late stages of the reaction and influenced mostly by the type of sugar. PRACTICAL APPLICATION: We report on the different factors and their interactions that are important for understanding the functional attributes of food components that comprise the generation of Maillard browning products and the associated antioxidant activities generated during high-temperature food processing.