Effects of Gamma Irradiation on Residual Nitrite, Lipid Oxidation, Total Volatile Nitrogen and Color in Meat Products with Various Meat Contents

Gamma irradiation has been shown as an effective technology to decrease or eliminate microbial contamination in raw and cooked meat products. However, irradiation-induced physicochemical changes are important to accept the technology by meat industries and consumers. The objective of this study was to assess effects of gamma irradiation (0, 2, 4, 6 and 8 kGy) on nitrite residue, lipid oxidation, total volatile nitrogen and color in two heated meat products (sausages) during refrigerated storage at 4 ºC for 28 days.

Two groups of emulsion meat products with various proportions of meat (40 and 65%) were irradiated at 2, 4, 6 and 8 kGy doses. Residual nitrite and TVN tests were carried out on Weeks 0, 7, 14, 21 and 28. The color test was carried out using the Hunter Lab system on Weeks 0 and 4 of storage.

Radiation at 8 kGy doses resulted in a significant decrease in nitrite in both groups (P < 0.05). The TVN value in radiated samples was significantly lower than that in non-irradiated samples (controls). Furthermore, high-dose radiation (doses of 6 and 8 kGy) in the two food products significantly decreased the red index (a-value) and significantly increased the TBA value (P <0.05).

Based on the results from chemical properties of the radiated products, irradiation is suggested at 2 and 4 kGy doses as appropriate doses.