Inhibitory effect of trehalose on the autoxidation of unsaturated fatty acids by water/ethanol system

The antioxidative activity of trehalose on autoxidation of unsaturated fatty acid (UFA) were investigated by a water/ethanol system. The formation of hydroperoxide (HPOD) from linoleic acid (LA) was remarkably inhibited by trehalose. The inhibitory effect on the autoxidation was dependent on the amount of trehalose. Several other disaccharides, sucrose, maltose, and neotrehalose, showed negligible effect on the autoxidation, but maltitol was effective second to trehalose. Similarly to LA, the formation of HPOD from α-linolenic acid (LNA) was inhibited by trehalose and maltitol. On the other hand, when the degradation of LA-HPOD was tested under the same conditions of the autoxidation, it was found that the degradation was not influenced by the presence of all of the saccharides tested, including trehalose. Although volatile aldehydes generated from LA-HPOD was slightly reduced by trehalose and maltitol, the effect of both saccharides seemed to be weak, compared with their inhibitory effect on the autoxidation. Thus, it is clear that trehalose and maltitol inhibit the autoxidation of UFA, but negligibly supress the generation of volatile aldehydes from HPOD.