The reduction in the immunoglobulin G and immunoglobulin E binding capacity of β-lactoglobulin via spray-drying...

Bovine β-lactoglobulin (β-LG) is the major allergen in milk powder. The IgG/IgE binding capacity and structural characteristics of β-LG after spray drying in the presence or absence of α-lactose at 120 and 180°C were investigated by ELISA and mass spectrometry. At a drying temperature of 120°C, no change was found in the IgG/IgE binding capacity of β-LG and no change was observed in free amino group content, fluorescence intensity, or detectable glycation. At a drying temperature of 180°C, aggregation of β-LG occurred, leading to a decrease in the IgG/IgE binding capacity. When α-lactose was also present, 7 lysine side-chains in β-LG were modified by glycation and the IgG/IgE binding capacity was further decreased. Therefore, the glycation and structural changes in β-LG were responsible for the reduction in the IgG/IgE binding capacity during high temperature (180°C) spray drying.