Gas atmosphere treatments

Gas atmospheres in packages can be varied in several ways. Controlled atmosphere (CA) techniques are not normally applicable to packages unless the atmosphere of the room or shipping container is physically controlled. 

Modified atmosphere packaging (MAP) is used in a multiplicity of forms. When used for fresh horticultural produce the aim is to reduce the respiration rate whereas with other foods the aim can be to minimise degradation involving oxygen, to kill insects and their larvae or to modify microbial populations (Brody, 1989). 

MAP has been defined as packaging in which there is an initial alteration of the gas composition followed by time-based alteration stemming from product respiration, microbiological action, gas transmission, etc. , whereas vacuum packaging is removal of air from the package with no gas replacement (Brody, 1988). 

1 Vacuum packaging. Fresh, chilled beef and other low pH meat has been successfully vacuum packed since the 1960s due to control of hygiene, storage temperature and packaging material permeability to 

Recent interest in chilled shipment of whole carcasses and centralised butchering of meat has led to the assessment of the suitability of vacuum packaging for distribution. The success with primal cuts where a five-fold increase in storage life is achieved compared with that in air (Seman et al., 1988) is not reflected in small cuts where only a two-fold increase is found (Gill, 1990). 

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