Irradiação gama na qualidade de carne bovina moída refrigerada embalada a vácuo

Abstract

The effects of gamma-irradiation and vacuum packaging on the reduction/elimination of Salmonella and of microbial load, and on color and lipid oxidation changes in ground meat were investigated. Samples inoculated with S. Typhimurium, were packaged under air or vacuum and irradiated at 0; 1.5; 2.5 and 3.5kGy. On second day of storage, S. Typhimurium reduction was dose-dependent. Reductions of 2.2, 3.7 e 4.5 log units were obtained by doses of 1.5; 2.5 and 3.5kGy, respectively, regardless of packaging. The number of Salmonella decreased with storage at 2ºC on irradiated samples, resulting in no survival cell being detected after 20 days of storage on samples irradiated at 3.5kGy. Higher reductions of microbial load were obtained in vacuum-packaged ground meat irradiated at 3.5kGy. Irradiation and storage time reduced a* values and increased TBARs values. Better color and lipid oxidation stability is obtained under vacuum. Irradiation of vacuumpackaged ground meat produced a reduction on microbial load and a more stable (color and rancidity) product.