Protein oxidation results in textural changes in sea cucumber (Apostichopus japonicus) during tenderization

• Published in: Food science & technology Vol. 144; p. 111231
• Main Authors: Xiong, Xin, Xie, Wancui, Xie, Jingwen, Qi, Hang, Yang, Xihong, Li, Hongyan, Che, Hongxia, Song, Lin, Dong, Xiufang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2021
• Subjects: Collagen fibers; Protein degradation; Protein oxidation; Sea cucumber (Apostichopus japonicus); Tenderization; Tenderization; Protein degradation; Protein oxidation; Collagen fibers; Sea cucumber (Apostichopus japonicus)
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.111231

Low-temperature tenderization is an important aspect in the processing of sea cucumber. Oxidative reactions induce protein aggregation or degradation during thermal treatment. However, whether protein oxidation occurs in sea cucumber during tenderization is unclear. Moreover, the effects of heat treatment on the protein structure in sea cucumber have not been well explored. In this study, Apostichopus japonicus body wall (AJBW) were tenderized at 37 °C and changes in the protein microstructure of AJBW and the relative indicators of oxidative reactions, including carbonyl, sulfhydryl, and amino constituents, were investigated. The findings indicated that the collagen fibers were depolymerized and the maximum denaturation temperature of collagen was significantly reduced after tenderization, suggesting that this process induced structural changes in collagen fibers. Furthermore, amino acid side-chain modifications and the formation of an unstable secondary and tertiary conformation indicated oxidation of the water-soluble proteins. The findings revealed that tenderization of AJBW caused the destruction of the collagen fiber structure and resulted in protein oxidation and degradation. Therefore, our study lays the foundation for subsequent research for determining the mechanism of tenderization. •Heating Apostichopus japonicus at 37 °C resulted in tenderization over time.•Collagen fibers were depolymerized and thermostability reduced after tenderization.•Carbonyl content increased and sulfhydryl content decreased after tenderization.•Unstable secondary and tertiary conformation changes were found after tenderization.