Inhibition of lipoxygenase by Maillard reaction products from glucose and glycine

The Maillard reaction products ( MRPs) were prepared from glucose and glycine.The inhibitory effect of MRPs on purified soybean lipoxygenase ( LOX) was studied.The results showed that as the glycine concentration, initial pH, reaction time and temperature increased, the final pH decreased, the browning of the reaction system deepened and the inhibitory activity enhanced. When the glycine concentration was over 0.6mol /L, the initial pH was over 8.0, the reaction temperature was over 110℃ and the reaction time exceeded 3h, the inhibition rate of MRPs reached a stable level ( 80% ~100%) . Meanwhile, Glu /Gly- MRPs extended the lag time of the enzymatic reaction considerably.The Lineweaver-Burk plots showed that Glu /Gly-MRPs were mixed-type inhibitor of LOX.