Ask a Dietitian

MODIFIED ATMOSPHERE PACKAGING

AGING
Aging beef is not something you can do in your own refrigerator safely. Aging is the process where by naturally occurring enzymes within the meat slowly break down the connective tissue that contributes to toughness. Aging is done under a controlled temperature and humidity in a safe environment. Beef is aged between 3-21 days. A tender beef should be aged a minimum of 10-14 days.

COLOUR
In Canada there is no artificial colour added to meat. When beef is first cut the colour of the meat is dark red/purple. Upon exposure to air, the O2 reacts with the iron causing the meat to turn bright red. When you look at a package of ground beef you can often see a darker purple/red on the inside of the mound of meat and the outer surface will be bright red. A well aged meat may be darker in colour. The colour is not the best indicator of freshness. Although after prolonged storage a meat may begin to turn slightly brown due to oxidation, typically, the best indicator of freshness is the best before date or date packaged. To prolong freshness a method called modified atmosphere packaging is used.

MODIFIED ATMOSPHERE PACKAGING
Modified Atmosphere Packaging involves using packaging material that allows for removal of air from around the food (creating a vacuum) and replacing it with a mixture of inert gases. These gases modify the atmosphere inside the package to:
– inhibit the growth of organisms such as moulds, yeast and bacteria
– prevent browning that occurs with oxidation
– keep food fresher longer. Traditionally, ground meat should be kept only one day in the refrigerator. MAP packaging prolongs the “best before” period up to about a week.

With MAP, busy consumers who shop just once a week are able to buy their ground meat on the weekend and use it up to a week later without having to freeze it.

Although you may not have seen MAP meat packages until recently, MAP has been around for many years. It can be used for fresh fish, poultry, sausages, entrées, baked goods, pasta, pizza, fruit and vegetables. The mixed salad greens you see in bags are a typical example of MAP technology prolonging the time foods stays fresh in the refrigerator.

DISPELLING THE MYTHS
Contrary to some media reports:
– MAP does not involve injecting the meat
– Carbon monoxide is not used in the process in Canada
– Canadian regulations stipulate that only gases that can be used are those found naturally in the air we breathe – oxygen, nitrogen and carbon dioxide – in combinations that will retard spoilage bacteria. This applies to all foods, including beef.
To learn more about keeping all foods safe during the summer months, viewers can order or download the booklet “Food Safety at Home … You’re in Control” from the website www.beefinfo.org or by calling the toll-free number 1-888-248-beef. In that booklet it does recommend that ground meats should be stored only one day in the refrigerator, but with MAP packaged meats you can use the longer “best before” date on the package.