Hie effect of meat pH and package permeability on putrefaction and greening in vacuum packed beef

Summary Beef joints at three pH levels were vacuum packed and stored at 1°C in materials with different gas permeabilities. Dark‐cutting, high pH beef (pH 6.2–6.7) developed a green discoloration (greening) in all the packaging materials and had a putrid odour when the packs were opened after 9 weeks. the same type of spoilage occurred at pH 5.9–6.1 in materials of relatively high gas permeability (73 and 92 cm3 O2/m2‐day‐atm. O2 at 90%r.h.). Greening and putrefaction did not occur at pH 5.9‐6.1 in materials of very low gas permeability (25 and 23 cm3 O2/m2‐day‐atm. O2 at 90%r.h.) or in any packs of meat of normal pH (5.4‐5.5).