Unraveling inhibitory effects of Alpinia officinarum Hance and curcumin on methylimidazole and acrylamide in cookies and possible pathways revealed by electron paramagnetic resonance.

ABSTRACT

The synchronous mitigative effects of Alpinia officinarum Hance (AOH) and curcumin on the generation of methylimidazole and acrylamide in cookies were investigated. Possible mechanisms related to quenching free radicals, reducing lipid oxidation and eliminating carbonyl intermediates were explored by electron paramagnetic resonance (EPR) and HPLC. The total methylimidazole and acrylamide contents raised with an increase in heating temperature and time, and reached a maximum at 200 °C for 11 min. AOH and curcumin reduced methylimidazole and acrylamide simultaneously; the maximum inhibition rates for methylimidazole and acrylamide were 51.55% (0.015% curcumin) and 73.66% (1.5% AOH). Alkyl free radicals and HO· were proved to be the critical free radicals for methylimidazole and acrylamide, AOH and curcumin quenched these radicals in a dose-dependent manner. The lipid oxidation, active carbonyl intermediates glyoxal, methylglyoxal, and acrylaldehyde were also reduced by AOH and curcumin simultaneously, which may be resulted from the quenching of free radicals.