Packaging conditions for extended storage of chilled dark, firm, dry beef.

Normal-pH (5·5-5·7) and high-pH (> 6·0) beef cuts of 500g were vacuum packaged in polyvinylidene chloride (PVDC), metalized polyester or aluminium foil laminates, or in foil laminate packs inflated with 1 litre of CO(2). During storage at + 1°C. vacuum packaged cuts developed spoilage floras of lactobacilli and enterobacteria; cuts stored under CO(2) developed floras of lactobacilli alone. Floras on all high-pH vacuum packaged cuts approached maximum numbers after 6 weeks' storage. At this time, cuts in PVDC laminate showed early symptoms of spoilage, but such symptoms did not develop in other vacuum packaged high-pH cuts until 9 or more weeks. Similarly, normal-pH cuts in PVDC film showed spoilage symptoms at 12 weeks, but such symptoms did not develop in other vacuum packaged normal-pH cuts until 15 weeks. Both normal- and high-pH cuts packaged under CO(2) were unspoiled at 15 weeks.