Antioxidant activities of the water-soluble fractions of glandless and glanded cottonseed protein.

To promote application of cottonseed protein products in food industry, this work measured antioxidant activities of two water soluble protein samples (Gl-L and Gd-L) isolated in a lab scale from glandless and common glanded cottonseed meal, respectively, and one soluble protein samples (Gd-P) in a pilot scale from glanded cottonseed meal. SDS-gel electrophoresis showed that the distribution patterns of the peptide fragments in Gl-L and Gd-L were similar, but more fragments and higher molecular mass bands were observed in the Gd-P gel image. While Gd-P showed the highest activities, Gl-L and Gd-L exhibited comparable 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical-scavenging activities in most cases. In contrast, Gd-P showed lower capability of inhibition of linoleic acid autoxidation than Gl-L and Gd-L. It would be of great interest in further research on these protein fractions in food products and processes (such as roasting) involved in the protective effects of food spoilage. Published by Elsevier Ltd.