| Summary: | Lately, an increasing number of hyperbaric storage (HS) studies has been observed, since HS could become an alternative or a complement to refrigeration (RF) due to the promising results for food preservation. This work aimed to study the HS methodology up to 60 days, for raw fresh meat preservation, pork and bovine (minced and in pieces), at a room like temperature and at a temperature below it in order to be used as an alternative to RF or a complement to it, respectively, being for that the results compared to the traditional RF. Throughout the work it was possible to observe the HS feasibility for microbial growth control at RT from 75 MPa and at 10 °C from 50 MPa, both for 60 days of storage. Moreover, it was verified that generally not only microbial growth was inhibited but also microorganisms could be inactivated over time. Regarding inoculated Escherichia coli and Listeria innocua, HS was also capable to inhibit its growth, and additionally led to its inactivation over storage. Several physicochemical parameters were studied, being generally not affected by HS or affected in a similar way as samples stored at RF. For instance, pH was better maintained at HS conditions than in RF, as well as colour differences were similar between HS and RF. It was also observed for the higher pressure levels used, mainly 100 MPa at variable RT a tendency of lower and higher moisture and drip loss values, respectively, over storage. The thiobarbituric acid reactive substances (TBARS) results demonstrated that HS could potentiate the increase of secondary lipid oxidation products, however when HS was coupled to low temperatures, in this case 60 MPa/10 °C, the results obtained were very similar to the ones obtained in RF. The fatty acid and volatile organic compounds profiles were also studied being observed that although 75 MPa/25 °C preserved better the initial profiles than RF, 60 MPa/10 °C revealed to be the best storage condition since the initial values could be better maintained than in RF. Moreover, when samples were analysed regarding enzymes activity, generally pork meat in pieces revealed a decrease of enzymes activity alike RF over storage, while minced bovine meat presented higher activity values for HS conditions than for RF, not being observed differences between both HS conditions. Although minor differences were observed on texture of cooked meat preserved by HS and RF for the same storage period, 60 MPa/10 °C demonstrated an equal to better meat preservation characteristics compared to the initial sample. The scanning electron microscopy images revealed that 75 MPa/25 °C could lead to smother muscular fibres and a less individualized organization.
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