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

• Published in: Food chemistry 2021-04, Vol.342, p.128283, Article 128283
• Main Authors: Ng, Sing Wei, Lu, Peng, Rulikowska, Aleksandra, Boehm, Daniela, O'Neill, Graham, Bourke, Paula
• Format: Article
• Language: English
• Subjects: Allergen; Allergens - chemistry; Allergens - immunology; Animals; Atmosphere - chemistry; Atmospheric cold plasma; Casein; Caseins - chemistry; Caseins - immunology; Cattle; Glow discharge; Milk; Milk - chemistry; Milk - immunology; Plasma Gases - chemistry; Spark discharge; Whey; Whey Proteins - chemistry; Whey Proteins - immunology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.128283

•Bovine milk protein responses to tunable cold plasma were characterised.•Cold plasma reduced the antigenicity of bovine casein and α-lactalbumin.•Antigenicity change was due to amino acid composition and secondary structure changes.•Milk protein features and antigenicity can be modulated using air based cold plasma. Casein, β-lactoglobulin and α-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, β-lactoglobulin and α-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 α-lactalbumin intensity bands after SD or GD treatments; however, the β-lactoglobulin intensity band remained unchanged. FTIR studies revealed alterations in protein secondary structure induced by plasma, particularly contents of β-sheet and β-turn. The UPLC-MS/MS results showed that the amino acid compositions decreased after plasma treatments. ELISA of casein and α-lactalbumin showed a decrease in antigenicity post plasma treatment, whereas ELISA of β-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.