Effects of fermentation by Lactobacillus rhamnosus GG on the antigenicity and allergenicity of four cows' milk proteins

In this study, the effects of fermentation by Lactobacillus rhamnosus GG on the antigenicity and Immunoglobulin E (IgE)-binding inhibitions of a-lactalbumin (LA), beta-lactoglobulin (LG), and alpha- caseins (CN) and beta-CN were investigated, using polyclonal antibodies and milk-allergic patient sera in competitive enzyme-linked immunosorbent assay (ELISA). Meanwhile, the proteolysis of milk proteins was detected by trinitrobenzene sulfonic acid (TNBS) assay and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). As a result, we found that fermentation by L. rhamnosus GG could significantly reduce the antigenicity and IgE binding of alpha-LA, beta-LG, alpha-CN and beta-CN in reconstituted milk. In addition, the antigenicity of four proteins decreased to a lower value at 12 h of fermentation and at 0.5 d of cold storage after fermentation. And the IgE-binding inhibitions of four milk proteins in fermented milk were reduced and ranged from 6.5 to over 70% compared to raw milk.