Effects of moderate dielectric barrier discharge (DBD) plasma treatment on the structure, antigenicity, and digestibility of casein

Abstract

Casein is the primary allergen in the dairy products. This study investigated the effects of moderate dielectric barrier discharge (DBD) plasma treatment on the structure, antigenicity, and digestibility of casein. The results showed that exposure to moderate DBD plasma for 4 min decreased the antigenicity, digestibility, total amino acid content, α-helix content, surface hydrophobicity, and total free sulfhydryl (SH) groups of casein by 18.2%, 9.5%, 42.2%, 4.5%, 51.0%, and 50.9%, respectively. The amino acid side chains of casein were oxidized, but cleavage was not observed on the peptide bone. Moderate DBD plasma treatment induced structural modification and oxidation of the amino acid side chains, which disrupted both the conformational and linear epitopes of casein, resulting in a reduction of its antigenicity. The modification of amino acid may have also disrupted the enzymatic cleavage site of casein, leading to a decrease in its digestibility. This study provides evidence that moderate DBD plasma treatment can decrease the antigenicity of casein, potentially broadening the application of dairy products in the food industry.