FOOD SCIENCE ›› 2020, Vol. 41 ›› Issue (6): 1-7.doi: 10.7506/spkx1002-6630-20190411-143

• Food Chemistry •     Next Articles

Effect of Malondialdehyde-Induced Protein Oxidation on Structural Properties of Myofibrillar Protein from Silver Carp (Hypophthalmichthys molitrix)

JIANG Yiren, LI Tao, LIU Youming, XIONG Shanbai   

  1. (1. College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; 2. National R & D Branch Center for Conventional Freshwater Fish Processing, Wuhan 430070, China)
  • Online:2020-03-25 Published:2020-03-23

Abstract: The impact of secondary products from lipid oxidation on structure and functional characteristics of silver carp myofibrillar protein were studied by using malondialdehyde (MDA) oxidizing systems (0–1.00 mmol/L). The results showed that the contents of carbonyl and free amino groups content changed slightly with increasing MDA concentration from 0.05 to 0.50 mmol/L. The active thiol contents and surface hydrophobicity were enhanced as the malondiadehyde concentration was increased to 0.25 mmol/L, but dityrosine content decreased somewhat; Ca2+-ATPase activity initially decreased and then increased, whereas the opposite trend was observed for its solubility. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that oxidation promoted the crosslinking and aggregation of myofibrillar protein molecules mainly through disulfide bonds. The increasing MDA concentration resulted in a reduction in α-helix content and an increase in β-sheet content. The results implicate that in the proper concentration range, MDA as a representative of the secondary products of lipid oxidation led to mild oxidation of myofibrillar protein, and the mild oxidation of myofibrillar protein at MDA concentration of 0.25 mmol/L promoted partial unfolding of myofibrillar protein, resulting in exposure of more active sites and consequently protein cross-linking, which might contribute to the formation of surimi gel.

Key words: silver carp, myofibrillar protein, malondialdehyde, protein oxidation, mild oxidation

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