Cold Storage & Food freezing
Freezing, by reducing temperature and water activity, inhibits a variety of chemical reactions, thus delaying food spoilage. The faster the cooling rate is, the ice crystals formed by the water molecules in the food.
But even in food processing, the "quick freeze" process can not freeze enough ice crystals, and the structure of the cell membranes in food is destroyed by larger ice crystals. For this reason, frozen foods and fresh foods taste worse than they do.
Frozen ice crystals do not hurt bacteria because they are very small. Once the food is thawed, the bacteria recover from hibernation and begin to multiply.
When thawed, the temperature and water activity of the food gradually increased, and the fluidity of the cell fluid in the food was also increased. As food cell membranes are punctured by ice crystals during freezing, these cells flow out of the body, further attracting bacteria to eat and speeding up bacterial growth.
The two freeze will make the bacteria live better, and after the food is thawed, many people will have to put it back in the freezer and continue to freeze.
However, from the first to the second freeze thaw also need a period of time, a large number of ingot thaw in the resurrection of breeding bacteria also take advantage of this opportunity to continue to expand, when the number of frozen food, bacteria has a lot more times than when thawed.
For meat, seafood, ahead of time will be removed from the freezer, freezer, frozen until slightly soft, it can be used for cooking. If you do not have time to put the meat in advance in freezer, frozen meat will research into the salt water thawing.
The defrosting method of quick-frozen food is that the package is firstly communicated and packaged, and the frozen room is moved to the refrigerating chamber for thawing at low temperature, and the frozen food can be communicated with the packaging bag to be soaked in the sealed state and thawed in cold water.