Effect of PPs on weever myofibrillar sulfhydryl contentsduring frozen storage The sulfhydryl contents in the Mf decreased during frozen stor-age for up to 90 days for all samples (Fig. 2). For the control group, the sulfhydryl content sharply decreased to 0.06 nmol/g pro-tein after the first 45 days of frozen storage. In the case of the PPs containing group, sulfhydryl contents in weever Mf decreased gradually, but consistently higher than that in the control group during the entire frozen storage. Sulfhydryl contents in the weever myofibrillar protein also increased with increasing PPs addition.The decrease in sulfhydryl content during frozen storage could be due to the formation of disulfide bonds by the oxidation of sulfhydryl groups,