Impact of Quercetin on the Allergenic Potential of Peanut Protein Ara h 2 During pH-Shifting

The effects of pH-shifting combined with quercetin binding on peanut Ara h 2 were evaluated using multispectroscopy, cell models, molecular simulation, and correlation analysis. After dual treatment, Ara h 2 exhibited significant structural changes, as evidenced by decreased intrinsic fluorescence and converted α-helix into β-sheet, leading to reduced IgE-binding capacity and diminished ability of dendritic cells and T cells to differentiate toward the Th2 pathway due to the masking of epitopes. Moreover, the binding sites of quercetin gradually shifted toward the hydrophobic core of Ara h 2 with pH changes, which inhibited fluctuations in the aa50–70 region. Finally, according to the correlation analysis, pH-shifting combined with quercetin binding may reduce the allergenicity of Ara h 2 by the migration of many Trp and Tyr residues to the protein surface, which disrupted the conformational epitopes. Therefore, this study provides an approach for the development of hypoallergenic peanut products.