Improving the microbiological quality and safety of prepared meals consumed in Greece by low dose irradiation

The proposed research of this CRP will address the use of low-dose-gamma irradiation (< 3 kGy) to extend the shelf-life and ensure the microbiological safety of prepared meals, marketed as refrigerated products. Such products are recently of increasing demand in Greece. Prepared meals will include salad meals that are very popular in Greece i.e. (eggplant salad, yoghurt/garlic salad), traditional sausage products, smoked trout etc. The first part of the proposed project will focus on the effect of low dose irradiation on shelf-life extension of above products. Assessment will include microbiological, chemical, and sensory parameters. Chemical parameters will include: pH, TBA (degree of lipid oxidation), TVB-N, TMA-N, vitamin and biogenic amines content. Microbiological parameters will include: Total viable counts, Enterobacteriaceae, Pseudomonas spp., Yeasts/Molds, Clostridium spp., Listeria spp. and Salmonella spp. Sensory assessment of non- and irradiated meals will include: evaluation of appearance (color, texture), taste, and odor. In the second part of the proposed project, a series of challenge experiments will be conducted regarding the microbiological safety of prepared meals. Food products will be inoculated with pathogens i.e. Listeria monocytogenes and their survival will be monitored as a function of irradiation dose and storage time. Experiments will be carried out at two different temperatures i.e. 4 and 10 deg. C