a monoethenoid acid that is the cis isomer of brassidic acid and makes up 40 to 50% of the total fatty acid in rapeseed, wallflower seed, and mustard seed; crystallizes as needles from alcohol solution, insoluble in water, soluble in ethanol and methanol, an unsaturated fatty acid, cis-isomer of brassic acid, having the formula C22H42O2, existing as a glyceride in oil of rape seed and of mustard, rüpsi- ja rapsiseemnete õlis sisalduv, inimestele ja loomadele kahjulik aine