Effect of high pressure on the microbiological quality of cooked chicken during storage at normal and abuse refrigeration temperatures

Vaccum-packaged cooked poultry meat was treated at a range of pressures(400-600 MPa) and hold times (1, 2 and 10 min), followed by storage at 4 degrees, 8 degrees or 12 degrees C for up to 35 days. Weissella viridescens was found to be the dominant microorganism in the pressure-treated meat, constituting 100% of the microflora identified at 500 and 600 MPa None of the pressure-treated samples had obvious signs of spoilage during the 35 day storage period, even when the Weissella count was >7 log(10) cfu/g Studies oil a typical W viridescens isolate showed it to be relatively pressure-resistant In poultry meat, with <1 log reduction in numbers after a treatment of 2 min at 600 MPa Agar diffusion assays showed that the isolate also caused the inhibition of a number of Gram-positive and Gram-negative pathogens, including strains of Clostridium botulinum, Listeria monocytogenes, Bacillus cereus and Escherichia coli The selection of a pressure-resistant organism, such as this Weissella sp could be advantageous in extending the shelf-life, and also microbiological safety, of the cooked meat, as it could give protection in addition to the pressure treatment itself (C) 2009 Elsevier Ltd All rights reserved