A novel processing scheme for the production of rapeseed protein isolate was developed which includes extraction using aqueous sodium hexametaphosphate solution followed by activated-carbon treatment, ultrafiltration, diafiltration, and purification by ion-exchange. Aqueous sodium hexametaphosphate is an effective extraction agent for rapeseed proteins. The activated-carbon treatment removes glucosinolate hydrolysis products and color compounds. The membrane treatments reduce the concentration of soluble low-molecular-weight components to low levels. An anion exchange resin was used in the last step to remove phytate and residual hexametaphosphate. The process resulted in a protein isolate containing about 90% protein. Sixty-three per cent of the nitrogen in the meal was recovered as an isolate free of glucosinolates, low in phytates and fiber, light in color, and bland in taste.