Changes of digestive stability and potential allergenicity of high hydrostatic pressure-treated ovalbumin during in vitro digestion

Abstract

Food allergens are defined by their stability during digestion, with allergenicity largely influenced by resistance to enzymatic hydrolysis. Ovalbumin (OVA), a major egg protein, is a significant contributor to food allergies, particularly in children. Our previous work demonstrated that high hydrostatic pressure (HHP) treatment reduces OVA allergenicity by disrupting conformational epitopes and altering its structure. This study hypothesizes that HHP further influences OVA digestibility, allergenicity, and molecular structure during digestion. Results show that HHP treatment (600 MPa) reduced α-helix content by 16.1 % and increased β-sheet content by 38.4 %, enhancing free sulfhydryl groups and surface hydrophobicity. Hydrolysis and ELISA analyses confirmed that HHP accelerated enzymatic hydrolysis, significantly reducing OVA allergenicity. Molecular dynamics simulations revealed strengthened interactions between OVA and pepsin/trypsin, involving epitope residues. These findings indicate an association between HHP treatment and the modification of OVA's digestive stability and epitopes, suggesting its potential as a strategy for reducing allergenicity.