FOOD SCIENCE ›› 2019, Vol. 40 ›› Issue (21): 107-114.doi: 10.7506/spkx1002-6630-20190304-036

• Food Engineering • Previous Articles     Next Articles

Allergenicity Reduction of Shrimp Tropomyosin by High Hydrostatic Pressure Treatment Combined with Enzymatic Hydrolysis and Its Linear Epitope Residues

HU Zhihe, WANG Lijuan, XUE Lu, LIU Ping, JIA Ying, LU Dingqiang   

  1. (Tianjin Key Laboratory of Food Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin 300134, China)
  • Online:2019-11-15 Published:2019-12-02

Abstract: The objective of this work was to compare the differences in the allergenicity and linear epitope residues of trypsin hydrolysates of tropomyosin (TM) prepared under normal and high pressure conditions and to discuss the reason why allergenicity reduction of hydrolyzed TM is enhanced under high pressure. The allergenicity was detected by indirect enzyme-linked immunosorbent assay (iELISA), and the secondary and tertiary structures were investigated by infrared and fluorescence spectroscopies. Optimal hydrolysis conditions under normal and high pressure were determined based on the binding capacity of hydrolysate to antibody (OD492 nm). Mass spectrometry (MS) was used for detecting the amino acid sequences of hydrolytic fragments. The results showed that trypsin activity was enhanced after treatment for 30 min under 200 MPa at 40 ℃. The allergenicity of high-pressure treated TM decreased with increasing pressure from 100 to 600 MPa, and it was related to changes in the relative content of β-turn structure and in tertiary structure. The allergenicity of TM was reduced by 89% and 98% after 30 min hydrolysis with 3 000 U/g of trypsin at 40 ℃ under normal pressure and 200 MPa, respectively. The percentage of fragments containing 8–16 amino acid residues in the hydrolysates was 76.8% and 93.3%, respectively, and the linear epitopes were reduced by 60.0%–66.7% and 88.9%–90.0%, respectively. Therefore, high pressure treatment could promote the enzymatic hydrolysis of TM, facilitating the elimination of linear epitopes and reducing the allergenicity of hydrolyzed products.

Key words: tropomyosin, high hydrostatic pressure, trypsin, allergenicity, linear epitope

CLC Number: