Regional Characterization of Tocopherols and Distribution of Fatty Acids Within Soybean Seeds (Glycine Max L.)

Seed coat, embryonic axis and sections of cotyledons in four soybean cultivars were analyzed by high‐performance liquid chromatography for tocopherols, and by gas–liquid chromatography for acyl lipids and their fatty acid profiles. Tocopherols were predominantly detected in axis, followed by cotyledons and seed coat. With a few exceptions, dominant components were γ‐ and δ‐tocopherols, with much smaller amounts of α‐ and β‐tocopherols. However, α‐tocopherol was present in higher (P < 0.05) amounts in axis than in other tissues. Triacylglycerols were the major component of total lipids, respresenting 92.0% of cotyledons and 70.0% of axis or seed coat. Regardless of the soybean cultivar, phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI) were the major phospholipids in all tissues; PC was present in highest concentration followed by PE and PI. These results indicate that the differences in soybean cultivars can be predicted by determining the regional distribution of tocopherols and fatty acids within soybean component parts.