Modified Atmosphere Packaging of Raw Red Meat

Extending the shelf-life of raw red meat products

Red meat is reddish in color due to the high amounts of myoglobulin, a protein in meat that holds oxygen in the muscle. Though not all red meat can be identified solely by its color. Pork, for example, is typically considered red meat even though it is light in color after cooking. According to the latest Dietary Guidelines for Americans, red meat includes all forms of:

• Beef
• Pork
• Lamb
• Rabbit
• Veal
• Goat
• Non-bird game, like venison, bison, wild boar, and elk

As part of an overall healthy diet, red meat is a valuable, nutrient-dense food as it contains protein, as well as heme iron, which is the more easily absorbed type of iron. Heme iron is particularly important for children and women who are or may become pregnant, as well as important vitamins and minerals like B12 and zinc.

Packaging fresh meat such as beef, pork in modified atmosphere packaging (MAP) is a real challenge because you need to consider not only prolonging the shelf-life of raw fresh meat, but also retaining the red color and texture to make the packages more attractive to consumers and the tastes stay natural, which is why you need MAP packaging rather than simple vacuum packaging. For red meat such as beef, one of the main problems of storage is ensuring that the meat retains its attractive red colour: in the open-air, meat tends to turn brown.

The two principal spoilage mechanisms affecting the shelf-life of raw red meats are microbial growth and oxidation of the red oxymyoglobin pigment. When red meat is kept under proper chilled conditions, the controlling influence on the shelf-life of the product is the rate of oxidation of the red oxymyoglobin pigment to its brown oxidized form, metmyoglobin. For this reason, high concentrations of O2 are necessary for the MAP Modified Atmosphere Packaging of red meats in order to maintain the desirable bright red colour for a longer period. Highly pigmented meats, such as beef, require higher oxygen concentrations than meats with low pigmentation levels such as pork.

Aerobic spoilage bacteria, such as Pseudomonas species, which are normally predominant on red meats are inhibited by CO2. Both objectives – attractive appearance and a slow rate of spoilage, can be achieved by gas mixtures containing 20-30% CO2 and 70-80% O2, this gas mixture is recommended for extending the chilled shelf-life of red meats from 2-4 days to 5-8 days and even longer. A gas/product ratio of 2:1 is often recommended. The maintenance of recommended chilled temperatures +3.33°C (37.99℉) and good hygiene and handling throughout the butchery, MAP, distribution and retailing chain is also very important in ensuring the safety and extended shelf-life of red meat products.

General Information for Modified Atmosphere Packaging of Raw Red Meat