关键词: 鳝鱼, 冷藏, 货架期, 理化性质, 蛋白质

Abstract: The purpose of this study was to investigate the quality changes of cold stored Monopterus albus during shelf life. The results showed that the shelf life of Monopterus albus was 4 days during cold storage as determined by measuring total volatile basic nitrogen (TVB-N) content, K value (freshness index) and thiobarbituric acid reactive substances (TBARS). pH decreased firstly and then increased with storage time, color turned from bright red to brown red, and water-holding capacity decreased continuously. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and trichloroacetic acid (TCA)-soluble nitrogen measurement showed that myosin and actin were degraded gradually during storage. Chemical analysis indicated that ionic bonds and hydrogen bonds decreased, whereas disulfide bonds and hydrophobic interactions showed a gradually increasing trend. Fourier transform infrared spectroscopy analysis indicated that amide A band moved to high wavenumber, which was consistent with the changes of hydrogen bonds. Curve fitting of amide ? band indicated that interconversion between β-sheet and β-turn was dominant during the early storage period, and then the protein structural components were transformed to α-helix and random coil, indicating increased structural disorderliness. Overall, these results showed that hydrogen bonds and ionic bonds may be the major forces to maintain the secondary structure of protein during the early storage period. The destruction of hydrogen bonds and ionic bonds can cause changes in protein conformation.

Key words: Monopterus albus, cold storage, shelf life, physicochemical properties, protein