Milk contains in the structure and delivers all vitamins of group B, A, D and calcium in our organism, not without reason it is recommended to include in the daily food allowance. Application of this product reduces risk of many diseases, including osteoporosis and diabetes. Before going on sale milk is exposed to heat treatment that considerably increases its period of storage and reduces quality of a product.
Ways of sterilization of milk
- Sterilization is a process at which milk heats up to 120-130 degrees. At such way of processing all useful properties of milk are lost, its initial taste changes.
- Ultrapasteurization is a more sparing sterilization with short-term heating of milk to 140 degrees with the subsequent instant cooling and instant packing. The product period of storage when processing increases these ways up to six months. - Pasteurization – a way at which there is a careful heating and a product isn't brought to the boil. Vitamins, minerals and taste of milk remain, and harmful microflora is destroyed. Period of storage of such product of only 10 days.
- Baked milk - previously pasteurized milk pining for three-four hours at a temperature of 95 degrees in the closed capacity. In difference from pasteurized in I am mute about 6% of fat, calcium, vitamin A and iron contain, but the amount of vitamins C also decreases Century. Period of storage of 10 days.
Additional methods for increase in a period of storage of milk
Except heat treatment of milk for increase in a period of storage on production there are several additional ways. Homogenization – alignment of consistence of milk. Molecules of fat break into small parts and from above in a package cream doesn't gather any more, it prevents process of rancidification of milk and increases a period of storage. Air promotes turning sour of milk therefore milk spreads in sterile packages in only a few seconds after pasteurization.
Packing is important for increase in a period of storage. So, the most popular packages from polyethylene pass air therefore the product is stored in them only two days. Very good packing - tetra pak, but expensive in production therefore milk in it is much more expensive, than in polyethylene. To spill milk in tetra pak, the sterile shop is necessary, packages arrive to the line in unassembled form and gather already on the conveyor. The period of storage in such packing increases from three to six months. One more type of packaging - the Swedish small jugs of Ecolean. These packages arrive on the conveyor in the soldered look, are opened with automatic machine, are filled with milk and are at once soldered. The contact with air is minimized. A period of storage of a fresh milk in such packing - up to ten days.