Potential allergenicity and hydrolysis assessment of bovine casein and β‐casein by treatment with lactic acid bacteria

Casein is one of the main allergens in cow's milk, accounting for 80% of cow's milk proteins. The ability of hydrolyzing proteins by bacteria is also different. In this study, the capacity of lactic acid bacteria to hydrolyze casein or β-casein and the IgG/IgE-binding capacity of hydrolysates were evaluated. The intensity of casein and β-casein degradation was analyzed by SDS-PAGE and RP-HPLC. The hydrolysates were tested for their capacity to inhibit IgG and IgE binding by ELISA. The peptides in the hydrolysate were also analyzed by LC-MS/MS. In these strains, Lactobacillus rhamnosus (CICC No. 22175) had the strongest hydrolysis of casein and β-casein. The hydrolysate of Lactobacillus rhamnosus (CICC No. 22175) showed the lowest antigenicity and potential allergenicity. It also hydrolyzed major allergen IgE epitopes and preserved T cell epitopes. Thereore Lactobacillus rhamnosus (CICC No. 22175) could be used for developing hypoallergenic dairy products and the development of tolerance. PRACTICAL APPLICATIONS: By the study, it obtained that a strain of Lactobacillus rhamnosus could effectively degrade casein and reduced the potential allergenicity of casein. At the same time, some major allergic epitopes were hydrolyzed and T cell epitopes were preserved. Therefore, it is very valuable for the application and development of lactic acid bacteria. The hydrolysate can also be used in a new hypoallergenic dairy formula with specific health benefits and promoting oral tolerance.