A canola protein isolate consisting predominantly of 2S canola protein and
having improved solubility properties, has an increased proportion of 2S
canola protein and a decreased proportion of 7S canola protein. The
canola protein isolate is formed by heat treatment of aqueous supernatant
from canola protein micelle formation and precipitation, to effect
precipitation of 7S protein which is sedimented and removed.
Alternatively, the canola protein isolate may be derived from a selective
membrane procedure in which an aqueous canola protein solution containing
12S, 7S and 2S canola proteins is subjected to a first selective membrane
technique to retain 12S and 7S canola proteins in a retentate, which is
dried to provide a canola protein isolate consisting predominantly of 7S
canola protein, and to permit 2S canola protein to pass through the
membrane, the permeate is subjected to a second selective membrane
technique to retain 2S canola protein and to permit low molecular weight
contaminants to pass through the membrane, and the retentate from the
latter membrane technique is dried.