VALUTAZIONE DELL’EFFETTO DEL CONGELAMENTO SULLA CONTAMINAZIONE MICROBIOLOGICA DI MATRICI ALIMENTARI

Food safety and the protection of Public Health are the main objectives of the European Community Regulations. Within this framework, the low-temperature preservation (-18°C) of the samples to be analysed needs special attention in order to eventually obtain accurate analytical results. The objective of the present research has been to evaluate the variation of the analytical results during the processes of freezing and thawing in various typologies of food according to their physical state and to the time of frozen storage. The result showed that in minced meat, some microbial species are less sensitive to freezing storage. In fact the count of Enterobacteriaceae, Escherichia coli and L. monocytogenes remained within the range of uncertainty of measurement until, respectively, the 3rd, 31st and 90th day of preservation (66% of the samples). In all other cases, freezing leads to an undervaluation of the analytic results which would lose its value in terms of accuracy and food safety, for example in the case of assessment in relation to batches and production stocks