Freezer burn

As freezer burn is defined as the occurrence of dried outer layers in frozen foods. They are usually white to gray - brown. Freezer burn forms primarily in areas that are exposed to fresh air, mainly caused by a leaking package. The name comes from the resemblance actually burned areas.

The main cause temperature fluctuations throughout the frozen chain which can hardly be avoided. If the temperature of refrigerated products to light, water starts to evaporate from its surface layers. This condensed or frozen again at decreasing temperature then added to water droplets and ice crystals on the cooling material and the package. The product dries out so. Since it comes in the course of a frozen product life to numerous variations in temperature, occurs in nearly all high water content foods on freezer burn.

Also goes by sublimation of water from the food in the surrounding atmosphere is lost and the food is excessively dry. The water resublimated at other points of the food and the packaging as snow-like crystals. This process occurs even at very low temperatures, without the cold chain is interrupted.

You can prevent the formation of freezer burn by a possible tight and vapor-tight packaging, by avoiding extreme temperature fluctuations and glazing products (meat, fish) with water, forming a thin protective layer of ice forms on the product. The discoloration occurs by the sublimation of the ice crystals in the outer layers of the products. In doing so voids that scatter the incident light diffusely and let the surface usually appear lighter form. Furthermore, it is by the extreme dehydration to a denaturation of proteins and oxidation of fats and other food ingredients. Thus, the digestibility and palatability, as well as the taste of the affected areas is severely impaired, the food is spoiled in part.

In the microbiological sense, the product does not automatically tainted by a freezer burn, but usually inedible. Often it is sufficient to cut out the affected area.