Modification of bovine β-lactoglobulin by glycation in a powdered state or in aqueous solution: adsorption at the air-water interface

摘要

The adsorption at the air-water interface of native and various glycated forms of β-Lactoglobulin B (β-LG), prepared under two different experimental conditions, was investigated by ellipsometry, surface tension and shear elastic constant measurements. The measurements were performed in 0.1 M phosphate buffer, 0.1 M NaCl, pH 6.8. It was found that the interfacial properties of β-LG were more affected when the glycation was performed in solution than in the dry-way system. Dry-way glycated β-LG, despite a higher glycation extent, affected slightly its interfacial behaviour. solution glycated β-LG exhibited a higher adsorption and more rigid interface as expressed by shear elastic constant measurement at saturation (16.5 mN/m against 8.7 and 11.5 mN/m for native and control treated β-LG, respectively). These results were sattributed to the specific molecular species induced during glycation in solution, which includes monomers and unfolded covalent homodimers of β-LG molecules with a high tendency to self-association via non-covalent interactions.