Variation of Terpenoid Flavor Odorants in Bran of Some Black and White Rice Varieties Analyzed by GC×GC-MS

Abstract

Among the total of 146 volatiles extracted by SPME from the headspace of some black and white rice bran samples, twenty-eight terpenoid odorants were acculately identified. Most of these terpenoids possess good aroma character and are varied among three groups of Thai rice; black glutinous, black non-glutinous, and white non-glutinous. Of these three groups, black non-glutinous rice contains the greater number of these monoterpenoids. However, the content of the major terpenoid odorants, which are limonene, trans-β-ocimene, β-cymene, and linalool, is the highest in the bran of white Thai jasmine rice, Khao Dawk Mali 105 (KDML 105). An herbaceous odorant, myrcene, occurs in the bran of all black rice varieties but not in the bran of white rice. The flavor type of rice bran using these rice bran terpenoids was successfully classified using the chemometric principle component analysis method.