Reduction of antigenicity and emulsibility improvement of ovalbumin by dielectric-barrier discharge plasma treatment induced structure modification

Abstract

The effects of Dielectric-Barrier Discharge (DBD) plasma treatment (40 kV, 1–4 min) on the structure, antigenicity and emulsibility of ovalbumin (OVA) were investigated. Plasma-induced structural changes of OVA were determined by SDS-PAGE, multi-spectroscopic, and LC-MS/MS analysis. Meanwhile, the reduction in antigenicity of OVA was evaluated by western blotting (WB) and enzyme-linked immunosorbent assay (ELISA) analysis. The results indicated effective elimination of the antigenicity of OVA was achieved after 4 min of plasma treatment. The immunoglobulin E (IgE) binding capacity of OVA was notably reduced by 90.80%, as evidenced by WB and ELISA analysis. Plasma-mediated oxidation led to the unfolding of OVA's structure, resulting in alterations to its conformational epitope, and the partial destruction of linear epitopes through polypeptide chain cleavage, thus contributing to the reduction in antigenicity. These findings were supported by the results of SDS-PAGE, multi-spectroscopic, and LC-MS/MS analysis. Furthermore, a significant increase (53%) in emulsifying ability and a one-fold improvement in emulsifying stability of OVA were achieved after 4 min of plasma treatment. The current study confirms that DBD plasma treatment not only reduces the allergenicity of OVA but also enhance its emulsibility through structural modification.