Preparation of canola protein isolate involving isoelectric precipitation

A process of preparing a canola protein isolate, which comprises:

• (a) extracting a canola oil seed meal to cause solubilization of canola protein in the canola oil seed meal and to form an aqueous protein solution having a pH of about 5 to about 6.8;
• (b) separating the aqueous protein solution from residual canola oil seed meal;
• (c) acidifying the aqueous protein solution to a pH of about 3 to about 4 to precipitate therefrom a canola protein isolate having a protein content of at least about 90 wt % (N×6.25) and comprising predominantly 7S canola protein;
• (d) separating the precipitated canola protein isolate from supernatant;
• and
• (e) processing the supernatant to recover therefrom additional canola protein isolate having a protein content of at least about 90 wt % (N×6.25) comprising predominantly 2S canola protein, said processing including heat-treating said supernatant to precipitate 7S and any 12S protein from the supernatant and separating the degraded 7S/12S protein from the heat-treated supernatant, wherein the pH of said supernatant is adjusted to the range of about 5 to about 6.8 prior to said heat treatment step.