Product Admission Conditions
One of the main factors determining the period of storage of chilled product is its condition at the entrance to die store. Cooling only slows down the natural aging process, product, which comes with bruises, with the skin is broken or damaged, it will be bad shelf life. In this state, the majority of products of resistance to invasion by microorganisms has been compromised. Consequently, the products are exposed to fast damage, and is not a good candidate for storage. Similarly, the shelf life of ripe fruits and vegetables is a very short, even with the best storage conditions. These products should be addressed directly to the market to avoid excessive losses during storage.
Packaging Products
Appropriate packaging reduces the speed of dehydration, which is one of the main factors limiting term storage of frozen products. Unpackaged products are subject to serious losses of moisture not only during the freezing process, but also during the period of storage. When stored, without frozen food packaging continue to lose moisture of air by the method of sublimation.
Sublimation is the process by which the moisture in the product as ice state changes directly in pairs, and whenever its vapour pressure exceeds the environment. This is a common phenomenon in the freezer and eventually causes a condition known as a freezer, a bum. Freezer burn independent of the corresponding product white, leathery appearance. This is usually followed by oxidation, compromising taste and vitamin content of the affected food. To avoid these problems, most of the products are packaged before getting in frozen storage.
To ensure adequate protection against moisture loss and oxidation, packaging material, used for frozen food must prevent the transfer of vapor (water) and gas (air). It should also be applied in a manner that results in tight fence around a food product to minimize the amount of air remaining in the package. This provision reduces the amount of oxidation that may arise in the package, and the reduction of the insulating air space within die package. These unwanted air pockets to reduce the speed of freezing of the product, increase the size of the ice crystals that form in the cells, and increase the cost of freezing the product.
The fact diat frozen products in competition with products preserved by other methods introduced several factors that must be considered when choosing packaging materials. When the product will be sold directly to the consumer package must be attractive and convenient to use in order to stimulate sales. In terms of cost, the package must be relatively inexpensive and design that allows you to efficiently process, to reduce processing costs. It should also be biodegradable or recyclable minimizing their impact on the environment. Some of packaging materials, widely used aluminum foil, cans, impregnated cardboard, carton, cardboard, boxes, wrapped with vaporproof wrapper, wax paper, cellophane, polyethylene and other formed sheet plastics...
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Food refrigeration and freezing