Joints of beef were stored in packaging films with oxygen permeabilities ranging from 0–920 ml/m224 h/atm at 25 °C and 100% r.h. The storage life of the ‘vacuum‐packaged’ meat, as assessed by discolouration and the development of putrefactive odours, was inversely related to film permeability; the best results were obtained with meat which received ‘zero oxygen’ treatment. The growth rates and final counts of Pseudomonas spp. increased with increasing film permeability; the storage life of the meat corresponded with the time taken for the counts of the organism to reach ca. 106/cm2 for putrefactive odours to be produced. Although their growth rate was unaffected, the final counts of Brochothrix thermosphacta also increased with increasing film permeability. These results are discussed in terms of the influence of film permeability on the inhibitory effects of Lactobacillus spp., whose numbers were unaffected by the permeability of the film used, and the substrates in the meat available to the bacteria.

Modifications to the American Society for Testing and Materials standard method (D1434) for the determination of film oxygen permeability are described. The method gives results consistent with published data and allows the measurement of permeability under likely food storage humidity conditions. It is recommended that the permeability of hydrophilic materials used for meat packaging should be measured at 100% relative humidity (RH) to permit adequate comparison with other films.