Food matrixes play a key role in the distribution of contaminants of lipid origin: A case study of malondialdehyde formation in vegetable oils during deep-frying.

Vegetable oils are increasingly replacing animal fats in diets, but malondialdehyde (MDA), a peroxidation product of these oils, has been regarded as toxic; this necessitated investigation of MDA formation during consumption. This study investigated MDA formation in four vegetable oils during frying French fries (FF) and fried chicken breast meat (FCBM) at 180 °C for 7 h. Results showed that MDA contents were lower in oils used for frying foods than in control oils, mainly because MDA was incorporated into the foods. MDA content was lower in FF, but higher in FCBM, due to the different food components. Model oil and food system analyses yielded similar results. MDA bound the hydrophobic helical structure in starch-based FF, but was exhibited greater reactivity with nucleophilic groups in protein-based FCBM, resulting in stronger interaction with FCBM than with FF. Our results indicated the existence of distinct mechanisms underlying MDA migration in different food matrixes.