Most convenience stores now carry “ready meals” catering to people on the go. These meals are often packed in disposable trays with multiple compartments to separate the main and side dishes. Also, they are often shelved with more common ready food such as buns, wraps or sandwiches. With the popularity of these food options increasingly growing, experts are continuously devising more effective packaging methods. Of course, all of these do not stay fresh for a long time.
There is a lot of ways to prolong the freshness of prepared food, and the easiest of which is refrigeration. One of the reasons for spoilage is the growth of microbes. Simple refrigeration slows down the growth of these microbes, thus extending the food’s shelf life. Other treatments can also be done such as using natural preservatives like salt, sugar or vinegar. Not all food can have any of these though, so non taste altering artificial preservatives can be added. These processes can store food for at least two weeks to one month without spoilage.
Nevertheless, keeping food fresh for more than a month sans the use of preservatives can be quite a challenge, and would involve a breakthrough technology. It’s a good thing that Modified Atmosphere Packaging (MAP) has been introduced and proven to do the job. MAP involves the substitution of natural gases inside a container with a protective gas mix to preserve the natural pH of prepared food. Oxygen, which causes oxidation or decay, is vacuumed out of the packaging. The mix of gases is carefully prepared in scaled proportions to significantly delay food degradation and inhibit oxidation. These proportions are based on the ingredients and the decay properties of each.
However, there are two downsides to packaging a product in a modified atmosphere. First, it necessitates a sophisticated machine to route out gases from the packaging for substitution with a predefined gas mixture. Another machine is required to ensure that proper gas weights are given, and to seal the container so as not to contaminate the food with unwanted gases. Second, there is a tendency for prepared food to suffer from odor due to confinement. This odor can result from the shortage of amino acids especially in case of proteins.
Another way to stretch the life prepared food is vacuum packing. This involves placing of food in an airtight container or pack, getting the air sucked out, and sealing the package for storage. Shrink film is the most used material since it can tightly fit any product. Recently, a leading packaging company has introduced advanced vacuum packs for manually prepared food. These packs feature an absorbent material that effectively captures odors, and markedly reduces growth of bacteria.
The main difference of MAP and vacuum packaging is the presentation. Obviously, MAP better showcases a product’s freshness given the natural setting. A vacuum pack, on the other hand, shrinks and forms itself around an object. If the product is not hard enough such as any vegetable, it can distort and collapse the shape.