Characterization of the Reduced IgE Binding Capacity in Boiled and Autoclaved Soybeans through Proteomic Approaches

Influence of Fermentation by Lactobacillus helveticus on the Immunoreactivity of Atlantic Cod Allergens

Fermentation techniques may induce alterations in fish allergen immunoreactivity. In this study, the influence of fermentation with three different strains of Lactobacillus helveticus (Lh187926, Lh191404, and Lh187926) on the immunoreactivity of Atlantic cod allergens was investigated via several methods. Gradually reduced protein composition and band intensity due to the fermentation by strain Lh191404 were found in SDS-PAGE analysis, and decreased immunoreactivity of fish allergens was confirmed by Western blotting and ELISA analysis due to the fermentation of strain Lh191404. Additionally, results from nLC-MS/MS and immunoinformatics tools analysis demonstrated that the protein polypeptide and allergen composition of Atlantic cod showed evident alterations after fermentation, with the epitopes of the main fish allergens being heavily exposed and destroyed. These results indicated that the fermentation of L. helveticus Lh191404 could destroy the structure and linear epitopes of the allergens from Atlantic cod and may have considerable potential in mitigating the allergenicity of fish.

Investigation of the differences in the effect of (-)-epigallocatechin gallate and proanthocyanidins on the functionality and allergenicity of soybean protein isolate

In this study, the differences in effects of (-)-epigallocatechin gallate (EGCG) and proanthocyanidins (PC) on the functionality and allergenicity of soybean protein isolate (SPI) were studied. SDS-PAGE demonstrated that SPI-PC conjugates exhibited more high-molecular-weight polymers (>180 kDa) than SPI-EGCG conjugates. Structural analysis showed that SPI-PC conjugates exhibited more disordered structures and protein-unfolding, improving the accessibility of PC to modify SPI, compared to SPI-EGCG conjugates. LC/MS-MS demonstrated that PC caused more modification of SPI and major soybean allergens than EGCG, resulting in a lower abundance of epitopes. The successful attachment of EGCG and PC to SPI significantly increased antioxidant capacity in conjugates. Furthermore, SPI-PC conjugates exhibited greater emulsifying activity and lower immunoglobulin E (IgE) binding capacity than SPI-EGCG conjugates, which was attributed to more disordered structure and protein-unfolding in SPI-PC conjugates. It is implied that proanthocyanidins may be promising compounds to interact with soybean proteins to produce functional and hypoallergenic foods.