The aim of this study was to assess the effect of gamma-irradiation on the allergenicity of shrimp. Shrimp protein extracts and shrimp muscle was subjected to irradiation at different dose. The allergenicity of irradiated shrimp protein extracts and shrimp muscle was analyzed by immunoblotting and Ci-ELISA using pool sera from 15 patients with shrimp specific IgE. Results showed that irradiated shrimp protein extracts exhibited a decrease in allergenicity with the increase of irradiation dose. However irradiated shrimp muscle exhibited all increase of allergenicity before the irradiation dose reached to 5 kGy (10 kGy measured by ELISA), whereas it tended to decrease significantly when the dose exceeded 10 kGy. Therefore, gamma-irradiation might have an important effect on the allergenicity of shrimp. (c) 2006 Published by Elsevier Ltd.