Molecular species of triacylglycerols in the seed coats of soybeans (glycine max L.) following microwave treatment

Soybeans (glycine max) were exposed to microwaves for 6 or 12 min at a frequency of 2450 MHz. The seed coats were then stripped from the soybeans and roasted in a microwave oven. Molecular species and fatty acid distributions of triacylglycerols (TAG), isolated from total lipids in the seed coats were analysed by a combination of argentation thin-layer chromatography (TLC) and gas chromatography (GC). Based on their different degrees of unsaturation and total chain-length of fatty acid groups, 15 molecular species of TAG were still detectable in the seed coats after the roasting treatment. However, roasting caused a significant decrease (P < 0.05), not only in molecular species containing more than four double bonds, but also in the amounts of diene and triene species present in a TAG. These results indicate that microwaves could (P < 0.05) affect TAG in the seed coats more signficantly than those in the other structural parts of soybeans. (C) 2000 Elsevier Science Ltd. All rights reserved.