Antioxidant activity of Maillard reaction products (MRPs) in a lipid-rich model system

Ribose-lysine (RL), ribose-glycine (RG), fructose-lysine (FL) and fructose-glycine (FG) Maillard models (whole mixture (WM) pH 4 and 9) were heated at 60, 80, 121 degrees C for 30, 60, 120 min, and dialysed into low (LMW) and high molecular weight (HMW) fractions. Reducing power (RP), DPPH and peroxyl radical scavenging (PRS) evaluated indirect antioxidant activity (AA). Direct AA in a water-in-oil emulsion was evaluated through peroxide value (PV), p-anisidine, TBARs inhibition and oxidative stability (OS). PRS and RP increased significantly with temperature and time from FL < FG < RL < RG and LMW < WM < HMW for all pHs. MRPs showed higher PRS and RP than BHA. DPPH decreased (p < 0.05) with temperature and time from LMW > WM > HMW. With DPPH, only MRPs at 121 degrees C exhibited higher AA than BHA. MRPs exhibited low PV, p-anisidine and inhibited the formation of TBARs. BHA showed the highest OS, with p-anisidine, PV and inhibition of TBARS similar to that of MRPs. (C) 2016 Elsevier Ltd. All rights reserved.