High hydrostatic pressure reducing allergenicity of soy protein isolate for infant formula evaluated by ELISA and proteomics via Chinese soy-allergic children's sera

Proteomics was used to confirm allergen subunit differences between control and high hydrostatic pressure (HHP)-treated soy protein isolate (SPI), which could support further understanding of reduced allergenicity associated with HHP. SPI solutions (0.75% protein weight/solvent volume, pH 6.8) were subjected to HHP treatment at 200, 300, 400, 500 MPa for 5, 10, 15, 20 min, respectively. Enzyme-linked immunoabsorbent assay was used to assess the allergenicity, using soy-allergic human sera as the probe and non-soy-allergic human sera as the negative control. Proteomics was performed to analyze allergen differences in a mixed protein sample. HHP reduced allergenicity by 45.5% at 300 MPa for 15 min. Western blotting and mass spectrometry indicated that HHP treatment altered the allergenicity of and ′ subunits of 7S globulin and A1 and A1a subunits of 11S globulin. This suggests HHP could improve the safe use of SPI in infant formula.