For the past years physical methods - among them rheological investigations - have been widely applied in the field of agricultural and food industry. Rheological methods can be successfully used for the detection of irradiation in the case of treated foodstuffs. We investigated the rheological properties of protein- containing food-industrial ingredients (milk protein concentrate powder and whole egg powder) as a function of absorbed γ-dose (max. 20 kGy), using rotational viscometers. Our investigations form part of complex examination for comparing the above results with those of thermoluminescence, chemiluminescence and electron spin resonance methods applied for the study of irradiated foodstuffs. It was found that the rheological method was suitable for significant detection of irradiation in the case of protein-containing foodstuffs, even after a longer storage.