'Microwave heating of oil seeds (peanut, sesame and soybean) was
conducted to study the influence of heating on their oil constituents. Each seed
sample was microwave heated for certain heating intervals avoiding charring and any
damage of. its components. Acid value, oxidation parameters (represented by
peroxide and para-anisidine value and the calculated total oxidation value) and
conjugation of polyunsaturated fatty acids have been followed during the course of
microwave heating. Fatty acids, as their methylesters, and tocopherols, as their
trimethylsilyl (TMS) derivatives, were determined by GLC. Total tocopherols, isolated
by preparative TLC from the unsaponifiable matter, were quantitatively determined. It was found that acid value, oxidation Parameters and fatty acid conjugation showed
considerable changes during microwave heating. It was also found that unsaturated fatty .acids were decreased as a result of the
formation of the primary arid secondary oxidation products. Meanwhile, individual
tocopherols of sesame and peanut oils showed slight decrease during microwave
heating, however marked decrease in individual tocopherols was observed in case of
soybean oil, In conclusion 2m in heating of seeds is more reasonable for obtaining high quali!y oils from seeds probably having some acceptable taste characteristics .