Impact of γ-Radiation on Antigenic Properties of Cow's Milk β-Lactoglobulin

Abstract

This study evaluated the effects of γ-radiation on the antigenic properties of β-lactoglobulin in cow's milk. Liquid and lyophilized samples of cow's milk and whey were irradiated with γ-cells (60Co) at dose levels of 3, 5, and 10 kGy, at room temperature in the presence of air. Effects of treatment on proteins were monitored by Lowry's method, sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and enzyme-linked immunosorbent assay. Radiation did not affect the molecular-weight distributions of proteins, but it did reduce their solubility. Furthermore, results showed that irradiation at 10 kGy increased the recognition of milk and whey powders by anti–β-lactoglobulin (β-Lg) rabbit immunoglobulin G, with the other samples remaining antigenically stable. These results indicate that γ-rays do not reduce cow's milk β-lactoglobulin antigenicity.