S.H. Abdel-Karim’s research while affiliated with High-Tech Institute and other places

Protein extracted from cold- and hot-defatted cottonseed flour was recovered by isoelectric coagulation, dialysis, isoelectric coagulation after dialysis and isoelectric coagulation followed by dialysis of the whey. Isoelectric precipitation resulted in poor protein recovery, but dialysis caused considerable improvement in protein recovery. Isoelectric precipitation followed by coagulation of the remaining protein in the whey by dialysis resulted in the highest protein recovery. Isoelectric coagulation, after dialysis of the extract, gave a low protein recovery compared to that obtained by dialysis, but higher than that obtained by isoelectric coagulation alone. The protein and gossypol contents of protein isolates obtained from hot-defatted cottonseed flour were determined. The protein content of isolates obtained by dialysis was markedly high (above 90%) and their free gossypol content was low compared to isolates obtained by isoelectric coagulation. Increase of solvent to flour ratio decreased both total and free gossypol contents of protein isolates obtained by both methods.