The Effect of Film Permeability on the Storage Life and Microbiology of Vacuum‐packed meat

Abstract

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.

Modified atmospheres and vacuum packaging

“…It is too easy to conc1ude that O2 limitation must be the key factor simply because a product is normally spoiled by aerobes, for example, the spoiling of refrigerated fresh meat by Pseudomonas (Newton and Rigg, 1979). However, in the case of Pseudomonas and the packaging of meat, it must be considered that all Pseudomonas species are very sensitive to CO 2 and significantly inhibited by a few per cent in the gas phase.…”

Modified Atmosphere Packaging of Meat, Poultry and Their Products

“…This depends in part on the composition of the microbial flora and the numbers of microbes initially present that are capable of growth in the MA [106].…”

“…For retail cuts of meat, where retention of bright red colour is desired, packages with a high oxygen transmission rate are used. However, for cuts of meat, where extended storage life is the primary concern, packages with low gas transmission rates are used [106,146]. When assessing information on the efficacy of MAP meat, the stage of development of gas-impermeable packages must be taken into account.…”

Effects of Whey, Whey-derived Lactic Acid and Sodium Lactate on the Surface Microbial Counts of Rainbow Trout Packed in Vacuum Pouches

“…Increasing film permeability causes higher growth rates and final counts of Pseudomonas spp. in meat (3). Vacuum-packed trout fillets have a longer microbiological shelf-life than fillets in oxygen with an over-wrap (4).…”