Cereal Chem 54:865 - 873.  |  VIEW ARTICLE
Large-Scale Laboratory Soxhlet Extraction of Wheat Flours, and of Intact and Cracked Grains.

R. L. Clements. Copyright 1977 by the American Association of Cereal Chemists, Inc. 

Flours and cracked wheat (5-6 kg) were extracted with hexane on a large-scale Soxhlet extractor, and extracts were sampled at intervals, analyzed for total lipid, and chromatographed by thin-layer chromatography (TLC). About 95% of hexane-extractable lipid was extracted in the first 8 hr. TLC showed no qualitative differences among extracts from different stages of extraction. Hexane-extraction yielded 1.07-1.15, 1.01-1.05, and 0.95-0.97% lipid (dry basis) from soft red (SR), soft white (SW), and hard winter (HW) wheat flours, respectively. Extraction with acetone or chloroform yielded about 20% more lipid than hexane. Hexane-extracted lipid averaged 1.07% (dry basis) from cracked hard wheat and 1.32% from SR and SW wheats. Lipid averaged 0.12, 0.23, and 0.30% from intact hard red (HR), SR, and SW kernels, respectively. Yields from hexane extraction of intact and cracked rye were comparable to yields from wheats, but oat groats gave 3.63% lipid (56% of the lipid from cracked groats). Small amounts of lipids from intact grains appeared to be from the cuticle, but the results suggest little lipid is extracted from unbroken kernels, and lipid yield may be an index of kernel damage.