PREPARATION OF RAPESEED PROTEIN ISOLATES: A STUDY OF RAPESEED PROTEIN ISOLATES BY MOLECULAR SIEVE CHROMATOGRAPHY

Extraction of defatted rapeseed meal at alkaline pH followed by neutralization of the extract gives a protein isolate in a low yield. This material was found to be rich in acidic proteins and to contain all of the high molecular weight proteins. Quantitative recovery of the extracted proteins was achieved by adding ananionic polymer to the extract prior to acidification. Both methods were found to give protein isolates with a chemical score of 100. The isolates contained proteins with a variety of isoelectric points. A soluble complex between rapeseed proteins and CMC was shown to exist at pH 11.