Effect of hydroxyl radicals on biochemical and functional characteristics of myofibrillar protein from large yellow croaker (Pseudosciaena crocea). Issue 1 (23rd October 2019)

• Record Type: Journal Article
• Authors: Li, Xuepeng; Liu, Cikun; Wang, Jinxiang; Zhou, Kai; Yi, Shumin; Zhu, Wenhui; Xu, Yongxia; Lin, Hong; Li, Jianrong
• Is Part Of: Journal of food biochemistry. Volume 44:Issue 1(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-10-23
• Subjects: hydroxyl radicals -- myofibrillar protein -- protein oxidation -- Pseudosciaena crocea; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; Biochemistry -- Periodicals; 664.024
• DOI: 10.1111/jfbc.13084
• Languages: English
• ISSNs: 0145-8884

Abstract

Abstract: The oxidative modification effect of hydroxyl radicals generated by an H2 O2 oxidative solution on the biochemical and functional characteristics of myofibrillar protein (MP) from large yellow croaker ( Pseudosciaena crocea ) was investigated. The results showed that MP of large yellow croakers was vulnerable to hydroxyl radicals. Incubation of MP with increased concentration of H2 O2 led to the gradual formation of carbonyl derivatives, disulphide bonds and dityrosine, and loss of available lysine, sulphydryl, and free ammonia. Surface hydrophobicity increased, while tryptophan residues decreased, indicating a conformational transition of MP. SDS–PAGE demonstrated that both disulphide and nondisulphide bonds were involved in MP aggregation. The MP functionalities were also affected by hydroxyl radicals, including reduced solubility, gelling, and emulsifying properties. Mild oxidation (0.1 mM H2 O2 ) slightly improved MP gel strength and water‐holding capacity, while excessive oxidation caused a reduction in gel properties. The results suggested that the MP oxidation should be controlled. Practical applications: Protein oxidation mediated by hydroxyl radicals is one of the most crucial reasons affecting the quality of large yellow croaker during processing and storage. Additionally, it is well known that the quality of protein in fish systems directly determines the quality stability and nutritional value of the fish products. Hence, the study explored how the hydroxyl radicals influenced the physicochemical and functional properties of fish MP. The changes in amino acid residues (carbonyl, available lysine, sulphydryl, free ammonia, tryptophan residues, etc.) of MP and its gelling and emulsifying properties after oxidation not only benefit the awareness of quality deterioration and quality control of large yellow croaker, but also provide a basis for the understanding of protein oxidation on the nutritional value of aquatic products and human health. Abstract : Hydroxyl radicals induced the oxidative modifications of myofibrillar protein of large yellow croakers, including the formation of carbonyl derivatives, disulphide bonds and dityrosine, and loss of available lysine, sulphydryl, and free ammonia. The oxidation caused the conformational changes, protein cross‐linking, aggregation and fragmentation. The solubility, gelling, and emulsifying properties of myofibrillar protein were also affected by hydroxyl radicals.