Effect of laccase-catalyzed cross-linking on the structure and allergenicity of Paralichthys olivaceus parvalbumin mediated by propyl gallate

The aim of the present study was to evaluate Paralichthys olivaceus parvalbumin (PV) following treatment by laccase (LAC) in the presence of propyl gallate (PG) on the structure and potential allergenicity. The structure of LAC+PG treated PV was analyzed through SDS-PAGE, CD, fluorescence, and allergenicity was analyzed by immunological and cell model. Our results showed that LAC + PG treatment can induce structural changes through PV cross-linking. Western blotting and indirect ELISA analysis revealed the decrease in IgG binding capacity of PV, corresponding with the structural changes. The results of in vitro digestion illustrate that LAC + PG treated PV showed more resistance to gastrointestinal digestion compared to untreated PV. The release rate of beta-hexosaminidase and histamine decreased by 35.6% and 66.9%, respectively, with LAC + PG treatment by RBL-2H3 cell assay. Considering the wide utilization of LAC in food industry, our treatment reveals its potential for creation of hypoallergenic fish products under mild reaction conditions.