摘要 : Osmotically dehydrated and air dried berry fruits are used as ingredients for the production of yoghurts, chocolates, cereal bars and mixes, ice creams and cakes and these fruits are often subjected to mild thermal treatments only... 展开 Osmotically dehydrated and air dried berry fruits are used as ingredients for the production of yoghurts, chocolates, cereal bars and mixes, ice creams and cakes and these fruits are often subjected to mild thermal treatments only, posing questions around their microbiological safety. As osmotic dehydration methods and parameters vary considerably within the industry and minimally processed high quality fruits are increasingly sought, the scope of this study was to determine which temperatures are required for the inactivation of relevant bacteria and viruses during osmotic dehydration of berries, using blueberries as a model berry in a thawed state to mimic common industrial practices. Additionally, we studied the inactivation of osmotic dehydration at 23 degrees C, sometimes referred to "cold infusion" followed by air drying at 100 degrees C to determine the microbiological safety achieved by this combined treatment. Four pathogens (Salmonella enterica, Escherichia coli O157:H7, Listeria monocytogenes and hepatitis A virus (HAV)) and five surrogates (Enterococcus faecium, Escherichia coli P1, Listeria innocua, murine Norovirus (MNV) and bacteriophage MS2) were inoculated on blueberries and reductions were measured after different treatment combinations. After osmotic dehydration of bacterial strains at 40 degrees C no survivors were detected on blueberries, with the exception of E. faecium. Inactivation of the viruses at 45 degrees C showed no survivors for MS2 and mean reductions of 1.5 and 3.4 log(10) median tissue culture infectious dose (TCID50)/g for HAV and MNV, respectively. Similarly, in the sugar solution at 40 degrees C, no survivors were observed, with the exception of E. faecium and the three viruses. The combined process (osmotic dehydration at 23 degrees C followed by air-drying at 100 degrees C) achieved an> 6 log reduction of all tested bacterial strains and MS2. For HAV and MNV, 2.6 and> 3.4 log(10) TCID50/g were measured. In summary, the present study shows that osmotic dehydration appears an efficient control measure for the control of L. monocytogenes, S. enterica and E. coli O157:H7 if carried out at 40 degrees C or at 23 degrees C and followed by air-drying at 100 degrees C. Based on the results generated with MNV, the combined treatment is also expected to reduce human Norovirus (NoV) but does not appear to be sufficient to fully control HAV. The results contribute to a better management of the microbial safety of osmotically dehydrated and dried berries and especially the results generated for the viruses emphasize that within a robust food safety management system, safety must be assured through the entire food supply chain and therefore must start at primary production with the implementation of Good Agricultural Practices (GAP). 收起