Polysaccharide biodegradable hydrogels had been developed to be used for the controlled delivery of pharmaceutically active protein. Also, food hydrogels having biodegradability are used to prepare new materials required for packaging by the food industry. In this paper two common food hydrogels were submitted to ionizing radiation. Gelatin and carrageenan solutions alone as well as ternary water-gelatin-carrageenan systems (97.5:1.0:1.5) were Co-60-irradiated with different radiation doses (0-20 kGy). The comparison of viscosity versus dose patterns of previous and irradiated resulting systems showed an anomalous rheological behavior produced by radiation suggesting the formation of a protein-polysaccharide complex.