Effect and mechanism of pyridoxamine on the lipid peroxidation and stability of polyunsaturated fatty acids in beef patties

BACKGROUND: Little is known about how vitamins can affect the peroxidation and stability of polyunsaturated fatty acids in cooked foods. Thus the effects of 15 vitamins on toxic malondialdehyde (MDA) formation in cooked beef patties were examined with the application of solid phase extraction and thiobarbituric acid (TBA) analysis by HPLC-DAD. The polyunsaturated fatty acid profiles in cooked beef patties treated with some vitamins were further compared with that of control sample (no vitamin addition) by GC-MS analysis. RESULTS: Pyridoxamine, pyridoxine, retinoic acid, alpha-tocopherol and L-ascorbic acid exhibited significant effects lowering the amount of MDA. It was further discovered that retinoic acid, alpha-tocopherol and L-ascorbic acid could help preserve polyunsaturated fatty acids, while pyridoxamine addition actually showed no effect upon the retention of most of the tested polyunsaturated fatty acids, even lowering the content of arachidonic acid. Further LC-MS analysis demonstrated that pyridoxamine could directly react with MDA via an addition reaction. The reaction involves a nucleophilic attack of pyridoxamine's free amine group on one of the aldehyde functional groups of MDA to form a new adduct, and may accelerate lipid peroxidation with the loss of more polyunsaturated fatty acids. CONCLUSION: Some vitamins may directly participate in lipid peroxidation and affect food quality. (C) 2015 Society of Chemical Industry