Effect of ionizing radiation on microbiological safety and activity of antioxidant enzymes in minced meat

Abstract

A number of studies have shown the effectiveness of meat irradiation at doses of 2-6 kGy to extend its shelf life when stored in vacuum packaging. It is known that the radiation treatment of meat can lead to a decrease in the content of natural antioxidants. Furthermore, the intensity of oxidative processes is significantly higher in meat products with a high fat content (20% or more). At the same time, the optimal modes of minced meat irradiation, which make it possible to ensure safety for the population and to increase the shelf life, have not yet been established. The purpose of the research was to study the effect of various doses of ionizing radiation on the content of aerobic, facultative anaerobic microorganisms and radiolysis products, and the activity of antioxidant enzymes in chilled minced meat during storage. Material and methods. The object of the study was minced meat, consisting of beef and pork (1 : 1) with 20% mass fraction of fat. The experimental samples were irradiated on an electron accelerator UELR-10-15-S-60-1 with an electron energy of 5-10 MeV at doses of 2, 2.5 and 3 kGy. The control sample of minced meat was not subjected to radiation treatment. Determination of the total count of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM) (CFU/kg) in control and experimental samples was determined on days 0, 7, 15 and 22. Methods for evaluating antioxidant activity included spectrophotometric determining the content of active radiolysis products that react with 2-thiobarbituric acid (TBA-AP) according to the Brajet method, total antioxidant capacity (TAOC) and activity of antioxidant enzymes in minced meat: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx). Results. Radiation treatment of minced meat at a dose of 2.0 kGy provided a normalized level of QMAFAnM in chilled minced meat for 22 days. It has been established that the treatment of minced meat with ionizing radiation in doses of 2.0-3.0 kGy leads to a dose-dependent decrease in its TAOC and the activity of antioxidant enzymes (SOD, CAT, GPx), as well as to an increase in TBA-AP content (р<0,05). Conclusion. The dose of ionizing radiation of 2.0 kGy helps to maintain the microbiological safety of minced meat for 22 days in terms of QMAFAnM with minimal changes in TAOC values, SOD, CAT and GPx activity and TBA-AP content.