Gelation properties of myofibrillar protein under malondialdehyde-induced oxidative stress

BACKGROUND: The structure of myofibrillar protein (MP) can be readily altered by oxidation, leading to the unfolding of MP structure, which further promotes protein–protein interactions, and thus influences the MP gelling properties. The objective of the study was to investigate the effect of malondialdehyde-induced oxidative stress on the gelation properties of myofibrillar protein (MP). Structural changes of the oxidised MPs were evaluated by the contents of carbonyl and total sulfhydryls, surface hydrophobicity, SDS-PAGE and Fourier transform infrared spectroscopy. The oxidative stability of the MP gels as indicated by lipid hydroperoxide was also determined. RESULTS: With the addition of an MDA concentration less than 10 mmol L, the MP gels showed an improved elasticity, gel strength, water holding capacity, and oxidative stability. Nevertheless, higher MDA concentration (25–50 mmol L) significantly reduced the gel quality, probably due to the formation of excessive covalent bonds in the system. CONCLUSION: Results suggested that protein aggregation occurred in the oxidised system. Myosin was involved in gel formation through non-disulfide covalent bond