The beneficial effects of rutin on myofibrillar protein gel properties and related changes in protein conformation

Effects of different levels of rutin (0, 10, 50, 100 and 200 mu mol/g protein) on the conformational changes and gel properties of myofibrillar protein (MP) were investigated. Rutin at 200 mu mol/g caused the greatest carbonyl content. The incorporation of rutin caused the losses of thiol, free amine and a-helix contents, reduction in tryptophan intrinsic fluorescence intensity, and enhanced exposure of hydrophobic groups and protein cross-linking. When compared with control, the MP gels with 10, 50 and 100 mu mol/g rutin had higher gel strength but slight lower water-holding capacity; the gels appeared to have compact microstructure with few visible pores. However, 200 mu mol/g rutin was detrimental to gel properties. All the gels with rutin presented higher final storage modulus and converted to elasticity-dominant gel types. The results indicate that a slightly high concentration of rutin could improve MP gel properties which are related to the protein conformational changes induced by rutin.