Shelf Life Evaluation of Sheep Cheese in Modified Atmosphere Packaging.

cheese is the product of Sardinian dairy industry most exposed to microbial post-process contamination. Due to its technological characteristics, intrinsic parameters, pH (6.10-6.80) and water activity (0.974-0.991), it represents an excellent substrate for the growth of spoilage and pathogenic microorganisms, which are usually resident in cheese-making plants environments. Generally, has a shelf life of 5-7 days. For this reason, at industrial level, modified atmosphere packaging (MAP) is used to extend the durability of the product. However, few investigations have been conducted to validate the use of MAP in The aim of this work is to evaluate the shelf life of under MAP. A total of 108 samples were collected from three Sardinian industrial cheese-making plants and analysed within 24 h after packaging and after 7, 14 and 21 days of refrigerated storage. Aerobic mesophilic bacteria, mesophilic and thermophilic cocci and lactobacilli, and spp, , yeasts and moulds, and the chemical-physical parameters and composition of the product were determined. At the end of the shelf life, spp. and reached high concentrations, 5 to 7 and 3 to 6 log colony forming unit g, respectively. The presence of environmental contaminants indicates that the use of MAP without the appropriate implementation of prerequisite programmes is not sufficient to extend the durability of Gas mixture and packaging material should be selected only on the basis of scientific evidence of their effectiveness.