The shelf life of a food product is defined as the period during which the product is considered acceptable for human consumption. The sensory characteristics of a food or beverage product are determined by the microbial, chemical, and physical aspects of it, and may become the basis for a consumer to accept or reject the product.
Shelf life is in most cases determined by a combination of raw material quality, product formulation, processing, packaging, and storage conditions. Storage conditions plays an important role as temperature and oxygen content may fasten or delay chemical reactions as well as microbial growth. The storage temperature also directly affects enzymes. Enzyme activity in food may result in a change of the chemical composition of the product, resulting in changes in flavor, odor, color, and texture. The amount of oxygen may gather chemical reactions and thus cause oxidation.
Thermal treatments are the most used methods to extend the shelf life of liquid foods by inactivation of microorganisms and enzymes, but thermal packaging does not work for every product. The application of nonthermal technologies or the combination of modified atmospheres and active packaging is a widely used alternative.
What are some types of modified atmosphere packaging?
Depending on the product and specifications, different MAP packaging technologies can be employed. Below are the most popular ones:
1. Gas flushing
One of the most popular active modified atmosphere packaging technologies for food and beverage products, gas flushing of packages is very common. Gas flush accomplishes three things:
1. Displacement of oxygen to delay oxidation
2. Decreasing the growth of aerobic spoilage organisms
3. Acting as a filler to maintain package conformity
During a gas flush process, a harmless gas, usually nitrogen is actively pumped into the packaging before sealing to displace ambient oxygen. This is done to decrease the amount of oxygen inside the package, which will in turn decrease the rate of spoilage, as oxygen is one of the top killers of freshness.
2. Barrier packaging material
Choosing specific packaging films that provide increased protection is an example of passive modified atmosphere packaging. This is accomplished by using barrier packaging materials that provide decreased permeability to moisture and oxygen, such as low-density polyethylene (LDPE), High-density polyethylene (HDPE) or polypropylene (PP). Oxidation prone products like sauces, also use multi-layer (upto six layers) packaging. The central layer in these multi-layer materials are mostly of EVOH. EVOH is a flexible, crystal clear, and glossy thermoplastic copolymer that has some of the best barrier properties to gases such as oxygen, nitrogen, and carbon dioxide making it especially well-suited for packaging of food, drugs, cosmetics, and other perishable or delicate products to extend shelf life.
3. Scavenger or desiccant packs
Another example of MAP packaging is the addition of an oxygen scavenger or desiccant pack to your packaging.
you have probably seen these inside pill bottles.
These small sachet type packages often contain a mixture of iron powder and ascorbic acid, and sometimes activated carbon. These ingredients act as catalysts or activators, absorbing ambient moisture and oxygen, thereby removing it from the interior of the packaging that houses the perishable product.
How does modified atmosphere packaging protect food?
Largely, modified atmosphere packaging technologies protect fresh food by decreasing its exposure to oxygen. Oxygen leads to oxidation, which can cause discoloration, spoilage, and off-flavors and textures. By decreasing or controlling the amount of oxygen present in a package, the food product remains fresher longer, gets an extended shelf life that ensures it remains attractive to consumers.
Modified Atmosphere Packaging became especially important during the COVID-19 outbreak of 2020. Consumers were instructed to social distance themselves and stay at homes as much as possible, so many began stocking up on food products with longer shelf lives. As a result, food producers and packagers saw enormous increases in demand for packaged food products that used MAP packaging technologies.
Want to know how you can extend the shelf life of your products? Write to us on firstname.lastname@example.org.