Effect of G-radiation dose on quality and microbiological safety of meat during postradiation storage

One of the ways to prolong shelf life of chilled meat is to use radiation technology for reducing the total number of the vegetative forms of spoilage microorganisms. g-radiation not only kills microorganisms in meat products, but also induces formation of radiolysis and lipid peroxidation products in biological material, which affect its quality and duration of the shelf life. The purpose of the work was to select the optimal irradiation parameters, which allowed minimizing formation of radiolysis and lipid peroxidation by-products in the meat, as well as slowing the microbial growth during the storage. The study subject was minced meat, the most problematic meat product, because it consisted undesirable microflora both on the surface and throughout the product due to the specifics in mince meat technology. Samples were packaged in polymer film in modified atmosphere of the gases mixture of O2/CO2 (3:1). For irradiation of the packed minced meat samples the unit GU-200M (NIITFA, Moscow) was used. The dose rate - 1 Gy/s. The integral absorbed doses to the product were 0.5, 1.5, 3.0 and 6.0 kGy. The condition of irradiated samples was tested in 0, 5, 12 and 20 days after exposure to the lowest radiation dose of 0.5 kGy. No radiolysis species were found, physico-chemical properties and sensory attributes of irradiated samples were unchanged. It was possible to conclude that the shelf life of the irradiated minced meat samples could be 1.5 times longer with consideration for the reserve ratio. After exposure to higher radiation doses, 1.5, 3.0 and 6.0 kGy, the presence of radiolytic products and changes in the sensory attributes were registered; with that, microbiological safety of the irradiated samples was within the norm and remained unchanged during 20-day storage following the exposure to radiation. Results of the study allowed us to make the following conclusion: it was possible to extend the shelf life of the product by using radiation doses below 1.5 kGy. In order to preserve the irradiated meat product antioxidants should be added.