Effects of lipid peroxide on the structure and gel properties of ovalbumin

Protein oxidation can influence the quality of food during processing and storage. In the present study, the sensitivity of ovalbumin (OVA) to oxidize radicals produced by peroxyl radical-generating system was investigated. Meanwhile, both structural and gel properties of OVA were evaluated. With increasingAAPH concentrations, the protein carbonyl content increased (P < 0.05), while free sulfhydryl, total disulfide, protein solubility, enthalpy (Delta H) and denaturation temperature (Td) decreased (P < 0.05). Circular dichroism spectra, differential scanning calorimeter and fluorescence spectrum analysis indicated that exposure of OVA to AAPH caused destabilization of protein structure. Then the results of electrophoresis and particle size distribution revealed protein aggregation in oxidized OVA, and also covalent cross-linking by the former method. Moderate oxidizing conditions can enhance the gel strength of OVA, high-intensity oxidation decreased gel strength and water holding capacity. Overall, OVA are susceptible to free radical attack. In addition, oxidative stress had detrimental influence on structural and gel properties of OVA. (C) 2017 Elsevier Ltd. All rights reserved.