Investigation of the mechanism underlying the influence of mild glycation on the digestibility and IgG/IgE-binding abilities of β-lactoglobulin and its digests through LC orbitrap MS/MS

This study aimed to investigate the mechanism underlying the influence of mild glycation on the digestibility and anaphylactic effect of beta-lactoglobulin (beta LG) and its digests through LC Orbitrap MS/MS. Three glycated sites were discovered after glycation with fructose, whereas only lysine47 (K47) was glycated with maltose. After digestion, the intrinsic fluorescence intensity decreased and red shifted, and the degree of hydrolysis (DH) values showed no significant difference among digests. beta LG glycated with Fru showed the lowest IgG and IgE-binding abilities. Meanwhile, the IgG and IgE-binding abilities further decreased and showed no apparent difference among digests. These results were attributed to the proximity to the IgG-binding epitope, the high glycation degree of K47, and mild glycation. Therefore, mild glycation could reduce the anaphylaxis of proteins before digestion, but did not influence the anaphylactic effect of the digests.