SOME MINOR FATTY-ACIDS OF RAPESEED OILS

A number of minor unsaturated fatty acids of rapeseed oil (from Brassica napus or campestris) have been isolated by combinations of distillation preparatve gas liquid chromatography and silver nitrate thin layer chromatography, and were further identified by oxidative fission in BF3-MeOH. Among the shorter chain, all-cis polyunsaturated fatty acids described are 16:3ω3, 16:2ω6 and 14:2ω6. A ubiquitous minor component in unproceessed oils was found to be cis-9, cis-12, trans-15-octadecatrienoic acid, with lesser proportions of the trans-9, cis-12, cis-15 isomer. Among others identified were cis-14:1ω9 and 15:1ω10, the latter accompanied by half as much trans-15:1ω10. Particular attention was paid to the proportions of the minor monoethylenic fatty acids of the ω7 series relative to the longer chain major ω9 monoethylenic fatty acids which have been reduced by plant breeding. © 1979 The American Oil Chemists' Society.