Effects of concentration factor and diafiltration on the protein recovery yield and the purity of peanut protein preparation by ultrafiltration

Abstract

This study focused on purification of peanut protein extract by using ultrafiltration technology. The peanut protein extract, adjusted to the pH 5, was ultrafiltered by 50 kDa membrane in dead – end model at the operating pressure of 6 bar. The higher the concentration factor was, the higher the removal of phytate and carbohydrate was. At the concentration factor of 2,5, the ratio of phytate and carbohydrate removal was 30% and 56%, respectively. In addition, discontinuous diafiltration was applied for improving purity degree of the protein preparation. With three dilution cycles, more than 90% of phytate and carbohydrate was rejected, and the recovery yield and the purity degree of the protein preparation was 89% and 92%, respectively. Ultrafiltration has been a potential solution to purification of peanut protein extract in practice.