RESUMEN
The effects of high hydrostatic pressure (HHP) processing (600 MPa, 8 min, 16 °C) and storage temperature (4 °C and 18 °C) on experimentally inoculated Listeria monocytogenes (L. monocytogenes), mesophilic aerobic plate counts (APC) and yeast and mould (YM) populations in Iberian dry-cured "salchichón" (DCS) and dry-cured loin (DCL) during 120 days of storage were studied. Tocopherol contents, fatty acid profile, instrumental colour and lipid and protein oxidation were evaluated. HHP treatment reduced L. monocytogenes population by >3 log10 in both DCS and DCL. HHP and storage temperature affected APC differently in both products, whereas YM were significantly decreased by HHP, mostly at 18 °C. Lipid and protein oxidation were promoted, mainly in DCS, and the colour was affected in a minor extent. Despite these effects on oxidation, these results suggest that HHP treatment at 600 MPa for 8 min in both products allowed to control L. monocytogenes below the microbiological limit established by the food safety regulations.
Asunto(s)
Conservación de Alimentos/métodos , Presión Hidrostática , Listeria monocytogenes/crecimiento & desarrollo , Productos de la Carne/microbiología , Animales , Recuento de Colonia Microbiana , Microbiología de Alimentos , Productos de la Carne/análisis , Oxidación-Reducción , Porcinos , TemperaturaRESUMEN
Four batches of Iberian dry-cured loins were manufactured with reduced ingoing amounts of both nitrate and nitrite: 150â¯mg/kg, 75â¯mg/kg, 37.5â¯mg/kg and 0â¯mg/kg. The effect of reducing or removing nitrate and nitrite and time of drying on physicochemical parameters (moisture, pH, water activity, chloride and residual nitrate and nitrite contents), instrumental colour and nitrosylmyoglobin content, lipid and protein oxidation and on microbiological counts (L. monocytogenes, aerobic mesophilic bacteria and moulds and yeast counts) were investigated. Lipid oxidation increased during the drying process being higher for non-added NO3-/NO2-, meanwhile protein oxidation affected also those with 37.5 and 75â¯mg/kg of NO3-/NO2- added. The removal of these additives affected instrumental colour coordinates and total colour changes showing that the variation of coloration would be perceptible by the consumer. Nitrosylmyoglobin content was significantly higher for NO3-/NO2- added loins. Reduced levels of these additives up to 37.5â¯mg/kg did not show significant effects on their physico-chemical, microbiological and colour.