Reduction of the antigenicity of powdered milk by gamma irradiation

The aim of this work was to examine the reduction in antigenicity of milk proteins in powdered milk by gamma irradiation which is increasingly used for food safety. Skim milk powder samples were exposed to irradiation doses of 1, 5, and 10 kGy. A greater reduction of alpha(S1)-casein and beta(A1)-casein was found than alpha(S0)-casein and beta(A2)-casein by capillary electrophoresis. Competitive indirect ELISA and passive cutaneous anaphylaxis tests using guinea pigs showed a reduction in antigenicity of powdered milk by 10 kGy gamma irradiation. These results indicated that gamma irradiation reduce allergenicity of milk proteins by structural changes of alpha(S1)-casein and beta(A1)-casein, and can be useful for dairy products.Y