mechanics of refrigeration in foods preservation?

Answer 1

generally, for every 10 degree increase in temperature, a chemical reaction will double in terms of its rate, including spoliation of food by bacteria, etc. so, the cooler the environment, the slower the food degradation.

Answer 2

The basic idea behind all forms of food preservation is either:
To slow down the activity of disease-causing bacteria
To kill the bacteria altogether
In certain cases, a preservation technique may also destroy enzymes naturally found in a food that cause it to spoil or discolor quickly. An enzyme is a special protein that acts as a catalyst for a chemical reaction, and enzymes are fairly fragile. By increasing the temperature of food to about 150 degrees Fahrenheit (66 degrees Celsius), enzymes are destroyed.
A food that is sterile contains no bacteria. Unless sterilized and sealed, all food contains bacteria. For example, bacteria naturally living in milk will spoil the milk in two or three hours if the milk is left out on the kitchen counter at room temperature. By putting the milk in the refrigerator you don't eliminate the bacteria already there, but you do slow down the bacteria enough that the milk will stay fresh for a week or two.

Answer 3

below 4 degree celcius the replication of most bacteria almost stops.
below -18 degree celcius it is almost completely stopped for all bacteria

oxidisation slows, improving flavour retention.

However in processed or cooked meat, amines are formed and some people are allergic to these regardless of refrigeration. For these people fresh is the only option

Answer 4

PV=nRT

Compress gas, it gets hot... run it through a radiator and cool it down. Decompress, it gets cold. Run it though another radiator and blow air across that. Voila! Cold air. Refrigerators and air conditioners work on that principle.

It is correct to state that bacteria reproduce at a much slower rate when cold, if at all.

Answer 5

Keeps food cold
Foods won't mold

End of mechanics.

Answer 6

Chemical reactions slow down when the temperature drops. So, as your meatloaf decays, it will decay slower when the temperature drops.