A canola protein isolate having a protein content of at least about 90 wt
% (N.times.6.25), preferably at least about 100 wt %, and consisting
predominantly of the 2S protein and substantially free from the 7S and
12S proteins is prepared. In one aspect, canola oil seed meal is
extracted with aqueous protein solution at an elevated temperature to
preferentially extract 2S protein from the meal to produce a canola
protein solution containing predominantly 2S protein. The 2S canola
protein is recovered as an isolate. In another aspect, canola oil seed
meal is initially extracted with water to preferentially extract 7S and
12S canola proteins followed by extraction of the canola oil seed meal
with aqueous saline solution to extract 2S protein from the meal. 2S
canola protein isolate is recovered from the saline extract. In another
aspect, the canola oil seed meal is extracted with aqueous saline
solution to extract 2S, 7S and 12S proteins from the meal. The aqueous
protein extract solution is heat treated at an elevated temperature to
precipitate 7S and 12S proteins and leave a 2S protein solution from
which the isolate may be recovered. In a further aspect, the aqueous
protein solution is concentrated prior to the heat treatment.