Abstract
It is important to know the behavior of lipid peroxidation products in foods because lipid hydroperoxides are known to decrease food quality and safety. We have reported that the stability of linoleic acid hydroperoxide (hydroperoxyoctadecadienoic acid; HPOD) in the water system. Although the hydroperoxides have been believed to be so unstable at high temperature that they decomposed immediately, the stability of HPOD at high temperature has not been exactly provided. In this study, we examined HPOD decomposition in the oil system kinetically. In tri-n-caprine as the model of oil system, HPOD was lost completely within 1 h at 170°C, while only 20% was lost for 2 h at 100°C. Moreover,40% remained after 72 h at 50°C. Then, HPOD was stabler in oil than in water. According to activation energy, however, it was estimated that HPOD decomposition mechanism in oil was similar to that in water. Thus the homolytic cleavage of the hydroperoxy group to alkoxy and hydroxyl radicals was responsible for the decomposition of HPOD in both systems. Besides, butylated hydroxytoluene is such a strong radical scavenger that it could suppress the decomposition of HPOD.
