Effect of gamma-irradiation on the physicochemical properties of porcine and bovine blood plasma proteins

To elucidate the effect of γ-irradiation on the physicochemical properties of blood plasma proteins, bovine and porcine blood, released from a slaughterhouse, was collected and plasma proteins were prepared. Physicochemical properties of blood plasma protein powders and solutions, such as molecular weight distribution, secondary structure, solubility, and viscosity, were examined after γ-irradiation at 1, 5, 7, and 10 kGy. Oxygen radicals, such as hydroxyl and superoxide anion radicals, generated by γ-irradiation, affected the physicochemical properties of the blood plasma protein solutions, but not the plasma protein powders. Circular dichroism and sodium dodecyl sulphate–polyacrylamide gel electrophoresis studies showed that an increase of γ-irradiation decreased the ordered structure of plasma protein solutions and caused initial fragmentation of the polypeptide chains and subsequent aggregation. However, solubility and viscosity of the irradiated plasma protein powders, as well as secondary structure and molecular weight profile, were not changed significantly with radiation dose.