MAP - A Fresh Approach
In fact as long ago as the early 1930's shipments of beef and lamb carcasses were sent from New Zealand and Australia to the UK under carbon dioxide storage.Then MAP was largely confined to bulk storage and the transportation of food products. Today however MAP is used to package anything from fresh salads and meat products to snacks, ready made meals and bakery products.
What is MAP ( modified atmosphere packaging)
MAP is food packaging in which the earth's normal breathable atmosphere has been modified in some way. Usually combined with lower temperatures it is a highly effective method for extending the shelf life of food.Shelf life is extended in some applications simply by creating a vacuum in the package (vacuum packaging), and in this method there is almost a complete absence of gas.
Once a fruit,vegetable or animal product is harvested or slaughtered, it remains an ideal environment for bacteria, which continue to function using the available carbohydrate, protein, fats and nutrients. These continuing processes lead to degradation including undesirable colour changes, loss of flavour and poor texture. The action of enzymes also causes deterioration of foods.
MAP mainly involves the use of three gases (carbon dioxide, nitrogen and oxygen) Products are packed in a single gas or a combination of these gases, depending on the physical and chemical
properties of the food.
MAP Added Value
Food in all its natural, eye catching colour is what customers expect from the food industry. Modified Atmosphere Packaging technology most certainly does a lot to help the retailer to deliver this. Extended shelf life, greater choice and a reduction in food related hazards are some of the valuable benefits of MAP, but are not as apparent to the shopper as the presentation of the food itself. This is where MAP adds even more value for the retailer enabling food to look better and stay fresher longer.
Depending on the product, shelf life can be safely extended by between 50% & 500% using MAP techniques. This means that waste is minimal and re-stocking and ordering can become more flexible. This in turn ensures a far greater chance that the product will be sold and less chance of it being thrown away.
In a world which is becoming increasingly green in it's ideals, a world where more and more consumers are becoming watchdogs for the environment, there are points to be earned by the retailer and food producer who can get rid of as many additives in their product ranges as possible, and who can show that their food is basically fresh and natural. In many cases, MAP means that artificial preservatives are no longer required to achieve a reasonable shelf life.
Effects of Each Gas on Products
Carbon Dioxide (CO2)
Carbon dioxide inhibits the growth of most aerobic bacteria and moulds. Generally, the higher level of CO2, the longer the achievable shelf life. However CO2 is readily absorbed by fats and water, therefore most foods will absorb CO2. Excess levels of CO2 in MAP can cause flavour tainting, drip loss and pack collapse. It is important therefore, that a balance is found between the commercially desirable shelf life of a product and the degree to which negative effects can be tolerated. When CO2 is required to control bacteria and mould growth, it is generally accepted that a minimum of 20% is recommended.
Nitrogen is an inert gas and is used to exclude air in particular oxygen. It is also used as a balance gas (filler gas) to make up the difference in a gas mixture, to prevent the collapse of packs containing high moisture and fat containing foods, caused by the tendency of those foods to absorb carbon dioxide from the atmosphere. In dried snack products, 100% nitrogen is often used to prevent oxidative rancidity.
Oxygen causes oxidative deterioration of food and is required for the growth of aerobic micro-organisms. Generally, oxygen should be excluded, but there are often good reasons for it to be present in controlled quantities to maintain fresh natural colour in red meats, or to maintain respiration in fruit and vegetables. Oxygen also inhibits the growth of anaerobic organisms in some types of fish and vegetables.
MAP is an effective method of maximising the shelf life of most food products, but it is also critical to always practice safe food storage, handling and preparation. If this part of the operation is ignored, then any advantages gained through MAP packaging could be greatly reduced, or in fact eliminated if Best Food Handling Practices are not a top priority.
The three main areas to maximise safe food handling are:
- Personal Hygiene.
- Time & Temperature Control.
- Prevention of cross contamination.
D&L Packaging is in the business of supplying vacuum and MAP packaging systems, films and bags.
Machines For Modified Atmosphere Packaging includes and is all available through D&L Packaging.
- Vacuum Packaging (Chamber & Snorkel)
- Tray Sealers