PREPARATION OF RAPESEED PROTE.lN ISOLATES. Dissolution and Precipitation Behavior of Rapeseed Proteins.

Abstract

ABSTRACT The dissolution of nitrogen and phosphorus containing substances from defatted rapeseed, and the subsequent precipitation of these substances by acid was studied. The dissolution of the substances of interest was found to vary in a complicated manner with the pH of extraction. This was especially true for the dissolution of inositol hexaphosphoric acid (phytic acid) and the other phosphorus containing substances. The presence of phytic acid in the protein extracts strongly affected the nitrogen recovery, the useful pH range for precipitation and the dry matter content of the precipitates. These effects were different with extracts prepared at different pH values. With an extract prepared at pH 11.1, addition of sodium phytate increased the yield from about 35 to 75% of the extracted nitrogen and the dry substance content of the precipitate from 16 to 33%.