Structural and gelation properties of five polyphenols-modified pork myofibrillar protein exposed to hydroxyl radicals

In this study, five phenolic compounds, including quercetin, rutin, caffeic acid, cyanidin-3-O-glucoside, and cyanidin-3-O-rutinoside, were added into myofibrillar protein (MP) suspensions to study their effects on the structural and gelation properties of protein when exposed hydroxyl radicals. Results showed that phenols delayed the changes of MP structure during of MP oxidation, including carbonylation, conversion of sulfhydryl to disulfide bond, and reduction of ϵ-NH2 group, thus changing the gelation behavior of MP. Most phenols can effectively weaken the sensitivity of MP to hydroxyl radicals and improve the gel properties of MP after oxidation. Among all samples, the quercetin-modified MP gel exhibited a dense and uniform microstructure, even better than the non-oxidized MP gel. However, perhaps due to the excessive unfold of MP structure, the gel strength, water holding capacity (WHC) and elastic modulus (G ′) of MP decreased significantly after caffeic acid modification, and the gel microstructure was also collapsed.