FOOD SCIENCE ›› 2019, Vol. 40 ›› Issue (9): 23-28.doi: 10.7506/spkx1002-6630-20180405-057

• Basic Research • Previous Articles     Next Articles

Effect of Electron Beam Irradiation on the Activity and Conformational Unit of Endogenous Proteases from Hairtail Surimi

LUO Huabin, LIN Lu, GAO Xing, Lü Liangyu, LI Gaoshang, CHEN Yanting, ZHANG Jinjie, YANG Wenge*   

  1. Key Laboratory of Animal Protein Food Deep Processing Technology of Zhejiang Province, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, China
  • Online:2019-05-15 Published:2019-05-28

Abstract: Endogenous proteases in fish are one of the important causes of surimi gel degradation. In this study, to investigate the effect of electron beam (EB) irradiation on endogenous myofibril-bound serine proteinase (MBSP) and cathepsin L (Cat-L) in hairtail surimi, the activity and optimum temperature of both enzymes after being treated with different doses of EB irradiation were determined, and the secondary structure changes were studied by circular dichroism (CD) spectroscopy. The results indicated that the activity of endogenous MBSP and Cat-L decreased with the increase of irradiation dose; especially Cat-L activity decreased significantly at 9 kGy. The optimum temperature of both control and irradiated MBSP was 55 ℃, whereas the optimum temperature of Cat-L decreased from 55 ℃ to 45 ℃ after irradiation at 3 or 9 kGy. EB irradiation resulted in the transformation of secondary structure units in MBSP and Cat-L, thus leading to conformational change and weakening their ability to degrade myofibrillar protein. In conclusion, EB irradiation can affect the secondary structure and activity of endogenous MBSP and Cat-L from hairtail surimi. The appropriate dose of EB irradiation can effectively inhibit the activity of endogenous proteases in surimi, thereby weakening the degradation of myofibrillar protein and consequently facilitating the formation of surimi gel.

Key words: electron beam irradiation, hairtail surimi, myofibril-bound serine proteinase, cathepsin L, conformation unit

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