Sulfur content of rapessed oils

Sulfur contents in rapeseed oils were determined by reduction with Raney nickel, acidification, and titration of released H 2 S with mercuric acetate. The sulfur contents decreased with successive steps of industrial processing, i.e., crude oil, 17–31 ppm S; degummed, 16 ppm; alkali refined, 4–9 ppm; bleached, 3–5 ppm; and deodorized, <1 ppm. Laboratory‐extracted oil from sound seed contained no detectable sulfur, regardless of the glucosinolate content of the seed. Heating of the seed or addition of water to the seed prior to extraction increased the sulfur in the oil‐less, however, for low‐glucosinolate seed than for high‐glucosinolate seed. Laboratory‐extracted oils from green, frost‐damaged, and bin‐heated seed contained appreciable amounts of sulfur.