CORRELATION BETWEEN OXIDATIVE DETERIORATION OF UNSATURATED LIPID AND NORMAL-HEXANAL DURING STORAGE OF BROWN RICE

n-Hexanal in the headspace over cooked brown rice stored at 5.degree. C and 35.degree. C for 0, 4, 8 and 12 months was determined by a gas chromatographic method usng modified direct vapor injection. The off-flavors of stored brown rice were evaluated by n-hexanal and oxidized linoleic acid analysis. The amount of n-hexanal was found to be linearly proportional to the amount of oxidized linoleic acid (correlation coefficient, 0.99). Therefore, the simple and rapid method of vapor injection gas chromatography can be used for determining n-hexanal in the headspace vapor over cooked brown rice. Thus, the off-flavor of the stored brown rice resulting from lipid oxidation can be detected indirectly.