Proportions of C18∶1n−7 and C18∶1n−9 fatty acids in canola seedcoat surface and internal lipids

Lipids of canola seedcoats ( Brassica napus L. and B. rapa L.) were prepared by surface washing and by complete extraction of seed coats with toluene. The major fatty acyl‐containing triacylglycerols, wax esters and free fatty acids were separated by thin‐layer chromatography prior to transesterification and analysis by gas‐liquid chromatography. The proportion of C18∶1n−7 to C18∶1n−9 was higher in the extracted lipids than in the surface‐washed lipids for all three classes.