Effect of ultrasound treatment on structure and antigenicity of β- lactoglobulin

In order to study the effect of ultrasound treatment on structure and antigenicity of β- lactoglobulin( β-Lg),SDS-PAGE,circular dichroism spectra,fluorescence spectrum and indirect competitive enzyme- linked immunosorbent assay were used to measure the structure and antigenicity,respectively. The molecular weight ofβ- Lg was not significant change,free sulfhydryl groups decreased,the content of β- sheet and surface hydrophobicity firstly increased and then decreased with the increasing of ultrasonic power.The content of β- sheet and surface hydrophobicity reached the maximum with 400 W ultrasound treatment. It was indicated that β- Lg could be unfolded and spacial structure was destroyed by ultrasound treatment. Meanwhile,the antigenicity ofβ- Lg was also firstly increased and then decreased. When it was treated at 400 W for 25 min,the antigenicity ofβ- Lg increased up to 2540.20 μg / m L,showing an increase by 133%. The results indicated that the unfolding ofβ- Lg might result in the allergic epitope exposed.Therefore,the antigenicity change of β- Lg was probably related to its spacial structural alteration induced by ultrasound treatment.