Biochemical changes of Coregonus peled myofibrillar proteins isolates as affected by HRGS oxidation system

The objective of the study was to research the effect of protein oxidation on the biochemical properties of Coregonus peled muscle proteins. Myofibrillar proteins (MP) prepared from C. peled back muscle was oxidized using a hydroxyl radical-generating system (HRGS: 0.1 mM FeCl₃ , 0.1 mM ascorbic acid (Asc) and 1-20 mM H₂ O₂ ). In the HRGS oxidizing system, the carbonyls, dityrosine content, and the surface hydrophobicity of C. peled MP (p < 0.05) increased with the increasing of H₂ O₂ concentration and oxidation time, while the total sulfhydryl, free amino groups and the Ca-ATPase activity decreased (p < 0.05). The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) pattern reflected the formation of protein polymers and protein degradation. The results indicate that protein oxidation and the increasing levels of biochemical alterations of C. peled MP have influence on the quality of C. peled muscle protein. PRACTICAL APPLICATIONS: Protein oxidation plays a major role in the meat quality deterioration of C. peled, which always leads to a change in protein physical and chemical properties. In this study, the biochemical change of MP isolates as affected by HRGS oxidation system was proposed. Such chemical modification leads to loss of protein amino groups, shift in the isoelectric point of the protein, loss of solubility and functionality. Additionally, protein carbonyls have been found to be potentially toxic to humans, and relevant measurement of dityrosine as those have been found to cause health problems after oral administration. So such modifications are of technological and nutritional relevance.