The effect of atmospheric cold plasma treatment on the antigenic properties of bovine milk casein and whey proteins

Casein, 0-lactoglobulin and alpha-lactalbumin are major milk protein allergens. In the present study, the structural modifications and antigenic response of these bovine milk allergens as induced by non-thermal treatment by atmospheric cold plasma were investigated. Spark discharge (SD) and glow discharge (GD), as previously characterized cold plasma systems, were used for protein treatments. Casein, beta-lactoglobulin and alpha-lactalbumin were analyzed before and after plasma treatment using SDS-PAGE, FTIR, UPLC-MS/MS and ELISA. SDS-PAGE results revealed a reduction in the casein and alpha-lactalbumin intensity bands after SD or GD treatments; however, the beta-lactoglobulin intensity band remained unchanged. FTIR studies revealed alterations in protein secondary structure induced by plasma, particularly contents of beta-sheet and beta-turn. The UPLC-MS/MS results showed that the amino acid compositions decreased after plasma treatments. ELISA of casein and alpha-lactalbumin showed a decrease in antigenicity post plasma treatment, whereas ELISA of beta-lactoglobulin showed an increase in antigenicity. The study indicates that atmospheric cold plasma can be tailored to mitigate the risk of bovine milk allergens in the dairy processing and ingredients sectors.

Automated summary

The study investigated the structural modifications and antigenic response of major milk protein allergens induced by non-thermal treatment using atmospheric cold plasma. Results showed a reduction in the intensity of casein and alpha-lactalbumin bands after plasma treatment, while beta-lactoglobulin intensity remained unchanged. Changes in protein secondary structure, amino acid compositions, and antigenicity were observed post plasma treatment.