Effect of cold plasma treatment on the allergenicity of hazelnut proteins in a BALB/c mouse model

Hazelnut is a major food allergen, and hypoallergenic processing methods remain limited. This study evaluated whether cold plasma (CP) treatment can reduce the allergenicity of hazelnut protein (HNP) in a BALB/c mouse model. Mice were sensitized with untreated HNP or CP-treated HNP for 10 min (CP10) or 30 min (CP30) (operating parameters: 120 kV, 50 Hz, 200 mA, atmospheric air), with PBS-sensitized mice as negative controls. Untreated HNP induced a robust allergic response, whereas mice sensitized with CP10- or CP30-treated HNP exhibited reduced allergic symptoms and intestinal inflammation. Allergic responses were evaluated through symptom scores, serum antibodies (IgE, IgG, IgG1, IgG2a), histamine, and cytokine profiles (IFN-γ, IL-4, IL-13, IL-6, IL-35, IL-10). Mechanistically, mice sensitized with CP30-treated HNP exhibited a rebalanced immune response. It attenuated the pro-allergic Th2 phenotype, evidenced by decreased levels of IgE (27.26%), IgG1 (30.05%), IL-4 (57.2%), and IL-13 (56.2%), while promoting a protective Th1 state through a significant increase in IFN-γ (from 105.31 to 250.22 pg/mL). These findings indicate that CP treatment, particularly for 30 min, reduces the allergenicity of HNP in a mouse model by rebalancing the Th1/Th2 immune response toward a more balanced state. This suggests that CP is a promising technology for developing hypoallergenic hazelnut products.