Packaging
Packaging has two main functions: to protect and preserve the product and to carry information about the product. There are many packaging systems, and the choice of which to use will depend on many factors including cost, the volume of product being handled and presentation. Some of the main methods used in the meat industry are described below. Shelf life varies considerably depending on the packaging used. The precise shelf life will also depend on the condition of the meat when packed, storage conditions and the quality of the packaging materials, so the details given below are only guides. Click here to order the leaflet Shelf Life of Fresh Meat.
Vacuum packing
Vacuum packing seals meat in plastic bags from which air has been expelled. The bags minimise both gas and moisture permeability; they act as a barrier to prevent both the meat surface coming into contact with external oxygen and the meat’s moisture from seeping out. The lack of oxygen inhibits the growth of bacteria which cause the meat to deteriorate. Vacuum packed primal cuts stored at 0°C should have a shelf life of 4-8 weeks. Meat held in vacuum pack for long-term storage must be kept at a temperature of 3°C or less.
		Vacuum packed beef steaks
		Source: MLC
Overwrapping
The meat is displayed on expanded polystyrene trays under light gauge PVC film. This film is permeable to external air enabling oxygenation of the meat to take place so that the meat retains its red ‘fresh meat’ colour. However, further oxidisation soon takes place to change the colour to dull brown. The shelf life of overwrapped meat is short, up to 3 days if stored at 0°C.
				Overwrapped lamb cuts
				Source: MLC
Modified Atmosphere Packaging (MAP)
UPVC or expanded polystyrene packs are formed to produce trays from a web of plastic. The air from the pack is expelled and then the pack is flushed with a modified atmosphere that contains higher levels of oxygen and carbon dioxide. The meat is then sealed under a top web of laminated, low permeable barrier film. The higher concentration of oxygen preserves the red colour of the meat, while the presence of carbon dioxide inhibits the growth of bacteria. If packs are kept at 0°C, they should have a shelf life of about one week.
			Pork roasting joint displayed in Modified Atmosphere Packaging
			Source: MLC
Frozen meat
Frozen meat can be stored for much longer times depending upon the packaging. Freezing of prime cuts of meat can have negative affect on meat quality, but is largely neutral in its effect on minced/diced product. The quality of the meat will also deteriorate depending on the length of storage time of the frozen product and is why, in general, fresh meat commands premiums over the frozen product.
For more information: Services, publications and websites Click here to order your copy of Extending the Shelf Life of Beef. BRC Global Standard on Packaging