The storage life of beef and pork packaged in an atmosphere with low carbon monoxide and high carbon dioxide

Ground beef, beef loin steaks and pork chops were packaged in modified atmo spheres of 0.4% CO/60% CO2/40% N-2 and 70% O-2/30% CO2. In addition ground beef was packaged in clipped chub packs. beef loin steaks Were vacuum packa ged, and pork chops were packaged in an atmosphere of 60% CO2/40% N-2 With each pack containing an O-2 absorber. The packs were stored in the dark at 4 or 8 degrees C for up to 21 days. Meat in 0.4% CO/60% CO2/40% N-2 had a s table bright red colour that lasted beyond the time of spoilage. The storag e lives in this gas mixture at 4 degrees C, as limited by off-odours, were 11, 14 and 21 days for ground beef, beef loin steaks and pork chops, respec tively. The 70% O-2/30% CO2 atmosphere resulted in an initially bright red to red colour of the meat, but the colour was unstable and off-odours devel oped rapidly. The off-odours probably were caused by Brochothrix thermospha cta, which grew in all meat types, or by pseudomonads in ground beef. Meat stored in chub packs, vacuum packs or 60% CO2/40% N-2 with an O-2 absorber developed off-odours and microflora similar to those of meat in 0.4% CO/60% CO2/40% N-2, but with less acceptable appearances. These results show that a low CO/high CO2 atmosphere is effective for preserving retail-ready meat . (C) 1999 Elsevier Science Ltd. All rights reserved.