Two-dimensional gel analysis to investigate the effect of hydroxyl radical oxidation on freshness indicator protein of Coregonus peled during 4 °C storage.

The present study investigates the freshness indicator protein of Coregonus peled and the effects of oxidation on the quality of fish during 4 °C storage. Samples were stored at 4 °C after oxidation treatment and analyzed for changes in proteins, using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS). A total of 382 differential proteins were identified, of which 20 proteins were quantified and studied including 12 proteins related to oxidation. The analysis of differential proteins was related to quality postmortem. Moreover, creatine kinase, malate dehydrogenase, and glyceraldehyde 3-phosphate dehydrogenase were identified as potential biomarkers for protein oxidative damage. Actin can be used to represent the softening of fish in postmortem storage. Pearson correlation analysis indicated that the changes in protein structure and biomarkers were influenced by oxidation. Bioinformatics suggested that differentially expressed proteins participated in the metabolic pathway via oxidation during 4 °C storage. The results of this study can contribute to a further understanding of the changes in fish quality during storage and the use of differential proteins as indicators of fish freshness. • In total, 382 differential proteins were identified in oxidative C. peled muscle. • 20 proteins were selected as freshness indicator proteins of oxidative C. peled. • Analysis on oxidative proteins in C. peled highlighted energy metabolism pathways. • Energy metabolism and proteolysis were prominent with increasing in storage time. [ABSTRACT FROM AUTHOR]