Changes in Structural and Gel Properties of Myofibrillar Proteins Induced by Sodium Chloride and Hydroxyl Radical

抄録

Protein oxidation can alter the structure of myofibrillar proteins (MPs), which further affect the MPs gelling properties. Ionic strength can influence MPs oxidation. The objective of the study was to evaluate changes in structure and gel properties of MPs induced by hydroxyl radicals (•OH) under certain ionic strength and pH. MPs were very susceptible to •OH attack under 0.5 M NaCl (pH 6.25) due to their swelling structure, resulting in higher protein oxidation level. Oxidative alternation of MPs structure had a significant influence on gel properties and microstructure. The maximum of storage modulus (G′) during the cooling stage was observed at 1.0 mM H₂O₂. Results of SEM confirmed that the gel had a more compact and dense structure at 1.0 mM H₂O₂. The results demonstrated that mild oxidative modification (H₂O₂ ≤ 1.0 mM) induced MPs aggregation, which was benefit to the formation of gel elastic network. However, further oxidative modification (2.5 mM ≤ H₂O₂ ≤ 10.0 mM) led to an excessively cross-linking of MPs, which made a negative effect on gel properties.