Effect of natural antioxidants on kinetic behavior of acrylamide formation and elimination in low-moisture asparagine-glucose model system

The present study investigated the effect of two natural antioxidants, i.e. antioxidant of bamboo leaves (AOB) and extract of green tea (EGT), on the mitigation and the kinetic behavior of acrylamide in an equimolar asparagine-glucose model system (pH 6.80). The substrates with addition of AOB or EGT were oven-heated at 180 degrees C under low-moisture conditions and the acrylamide content in final reaction products was quantified by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Results of mitigation effect on the generation of acrylamide showed that both AOB and EGT could effectively reduce the formation of acrylamide and achieve a maximum reduction rate (74.4% for the use of AOB and 74.3% for the use of EGT) when the addition levels of AOB and EGT were both 10(-4) mg. Such mitigation effect in the model system was further confirmed by addition of homoorientin. and epigallocatechin gallate (EGCG), the representative components in AOB and EGT. To describe the kinetic behavior of acrylamide, a logistic-exponential model was selected among three kinetic model candidates while relative kinetic rate constants were calculated by the Marquardt non-linear regression method. Results indicated that there were significant differences on kinetic parameters (k(g) and t(cg)) between AOB/EGT-spiked and non-spiked model system studies, which suggested that addition of AOB or EGT could reduce the formation of acrylamide during the formation-predominant kinetic stage and prolong the formation progress of acrylamide in the low-moisture reaction system. However, such addition method was not able to reduce the acrylamide content during the elimination-predominant kinetic stage of acrylamide. (C) 2007 Elsevier Ltd. All rights reserved.