High pressure processing at subzero temperature: Effect on spoilage microbiota of poultry

Mechanically recovered poultry meat (MRPM) was treated at 350 and 450 MPa for 5 and 15 min at -20°C and then stored at 2°C. Counts of mesophilic, psychrotrophic and lactic acid bacteria were determined at 1, 4 and 15 days of storage. Initial counts were ca. 7 log CFU/g for the three populations. High pressure induced lethalities of ca. 1.5 log CFU/g for mesophiles and psychrotrophs and, in some cases, ca. 2.5 log CFU/g for lactic acid bacteria. At 4 days, counts in pressurized samples increased less for mesophiles and psychrotrophs (<0.5 CFU/g) than for lactic acid bacteria (>1 log CFU/g). At 15 days, counts of the three populations were ca. 9 log CFU/g in all samples. High pressure processing at subzero temperature does not extend shelf-life of MRPM.