Effects of Hydroxyl Radical Oxidation on the Biochemical Characteristics and Emulsifying Properties of Myofibrillar Proteins from Sea Bass
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
The effect of hydroxyl radical oxidation on the biochemical characteristics and emulsifying properties of myofibrillar proteins were investigated by in vitro simulant oxidation experiments. The results showed that with increasing oxidation time, the carbonyl content, surface hydrophobicity, and average particle size of myofibrillar protein isolate from sea bass were increased, the content of total sulfhydryl group, active sulfhydryl group, and chromophore amino acids were decreased, and the content of tyrosine dimer reached a maximum value at 4 h. These indicators changed significantly when the H2O2 concentration was 1 mM. When the H2O2 concentrations were 5 and 10 mM, during the first 4 h, emulsifying activity and emulsifying stability were significantly decreased; the active sulfhydryl group content were decreased by 51.93% and 65.88%, respectively, compared to that in the control group; the average particle sizes of myofibrillar protein isolate were increased by 47.87% and 72.38%, respectively, compared to the control group. After 4 h, no significant changes were observed, but significant differences were detected among different oxidant concentrations. Sodium dodecyl sulfate polyacrylamide gel electrophoresis revealed that after hydroxyl radical oxidation, the proteins were cross-linked to form a large number of high-molecular-weight aggregates, which were accumulated in the region of over 200 ku. The content of myosin heavy chain was reduced. These results show that the hydroxyl radical oxidation system can change the structure of myofibrillar proteins in sea bass, leading to a decline in their emulsifying capacities.
