Analysis of volatile compounds in Polished-graded wheat flours using headspace sorptive extraction

Headspace sorptive extraction method was used to determine the volatile flavor compounds of the Polished-graded wheat flours and commonly milled wheat flour (CW). The Polished-graded wheat flours of three fractions, C-1 (100-90%), C-5 (60-50%) and C-8 (30–0%), and CW obtained from a hard-type wheat cultivar ‘1CW’ (No. 1 Canada Western Red Spring) were used in the present study. A total of 48 volatile flavor compounds determined in all samples were common as in the wheat grain or flour. The major volatile compounds in C-1 included methoxybenzene (i.e. 1,4-dimethoxybenzene, 1,2,4-trimethoxybenzene, 1,2-dimethoxybenzene) associated with musty odors, and nitrogen compounds (i.e. trimethylamine, 3(4)-methyl pyridine, and 3-methoxy pyridine). The volatile flavor compounds identified in C-5 and C-8 were similar to those in CW. But, some compounds that have a connection with both oxidation products from unsaturated fatty acids and metabolites of a number of species associated with moldy grains, were more abundant in C-5 and C-8 than in CW. Furthermore, hexanal, methanol, ethanol, hexanol, 1-octen-3-ol, 3-octen-2-one, (E,Z)-3,5-octadien-2-one, (E,E)-3,5-octadien-2-one were considerably abundant in C-5 and C-8.