Simultaneous alleviation of acrylamide and methylimidazole accumulation in cookies by Rhizoma kaempferiae and kaempferol and potential mechanism revealed by density functional theory

The simultaneous alleviating effect of Rhizoma kaempferiae and kaempferol on accumulation of acrylamide and methylimidazole in cookies was explored. Electron paramagnetic resonance (EPR) and density functional theory (DFT) were used to investigate the potential mechanism relating to the quenching of free radicals and elimination of carbonyl intermediates. The maximum inhibition rates for acrylamide and methylimidazole were 52% and 70% (15 g/kg RK). EPR experiments showed that the HO· and carbon-centered free radicals, critical for the production of acrylamide and methylimidazole, were reduced by RK and kaempferol in a dose-dependent manner. DFT indicated that the 1-OH group of kaempferol was the most important and quenched HO· mainly via H-atom Transfer. The active carbonyl intermediates, acrylaldehyde, glyoxal, and methylglyoxal can also be reduced by RK and kaempferol, which may result from the quenching of free radicals. On the basis of these results, we suggested that RK and kaempferol exerts simultaneous alleviating effect for accumulation of acrylamide and methylimidazole by blocking free radicals-centered path and reducing active carbonyl intermediate.