Reduced IgE/IgG binding capacities of bovine α-Lactalbumin by glycation after dynamic high-pressure microfluidization pretreatment evaluated by high resolution mass spectrometry

Dynamic high-pressure microfluidization (DHPM) pretreatment and glycation with lactose were employed to modify alpha-Lactalbumin (alpha-LA) with respect to the IgE/IgG binding capacities. No significant difference on incorporation ratio value of glycated alpha-LA was observed with and without DHPM pretreatment. However, IgE/IgG binding capacities of alpha-LA were decreased after glycation and DHPM pretreatment promoted the reduction. The lowest IgE/IgG binding capacities of glycated alpha-LA were obtained by DHPM pretreatment at 110 MPa. Native alpha-LA was mainly glycated at K62, K94, K98, whereas glycation sites and degree of substitution per peptide (DSP) were added after DHPM treatment. Therefore, the reduced IgE/IgG binding capacities of alpha-LA was attributed to the characteristics of glycated sites, including the amount, location, and DSP values. Interestingly, K98 played the most important role in decreasing IgE/IgG binding capacities of alpha-LA. The study revealed that glycation combined with DHPM was a promising way to decrease the allergenicity of proteins.