A Novel Processing Approach for Rapeseed and Mustard Seed-Removal of Undesirable Constituents by Methanol-Ammonia

An overview of a novel two-phase solvent-extraction system developed for treatment of rapeseed and mustard seed in our laboratories will be presented. In this process, the polar phase consisted of a lower alkanol containing 5% water (v/v) and 10% ammonia (w/w). The non-polar phase was hexane. Of the alkanols, methanol was the most effective, followed by ethanol. Isopropanol and t-butanol were of limited usefulness. A meal with a protein content of about 50% was obtained, and there was essentially no loss of protein material. Its glucosinolate content was reduced by an order of magnitude. Over 2/3 of the phenolics were removed by CH₃OH/NH₃/H₂O treatment; however, the phytates were not affected. The protein in the meal had lower solubility properties, but a very high fat absorption as compared with the protein in hexane-extracted meal. The oil obtained from this process was essentially free of phospholipids and may be considered as degummed.