For preserving foods can be done several good technique which uses high technology and simple technology. The trick also vary with different levels of difficulty, but the core of food preservation is an attempt to restrain the rate of growth of micro-organisms in food. Here are a few standard techniques that have been known in general by the wider community of the world.

1. Refrigeration
This technique is most famous for his technique often used by the general public in the village and the town. Concepts and theories of the refrigeration system is to put food on the place or room temperature is very low. To cool food or drinks can be put into the refrigerator or refrigerator, or it could also put in the container that contains ice.
Fishermen usually use a container that contains ice to preserve fish catch. In the houses typically use a refrigerator to preserve vegetables, fruits, meat, sausages, eggs, and so forth. Temperature is usually normal food to cool temperate 15 degrees celsius. Whereas for durability are usually stored at the site of the temperature from 0 to -4 degrees Celsius.

2. Fumigation
How to fumigation is to put food in the box and then smoked from below.
Fumigation technique does not actually make the food to be durable in the long term, because the necessary combination of salting and drying techniques.

3. Canning
This one is entering the system of food into aluminum cans or other metal materials, and given as a preservative chemicals such as salt, acid, sugar and so forth. Materials are usually canned vegetables, meat, fish, fruits, milk, coffee, and more stuff. Canning techniques include alloy chemistry and physics techniques. Chemical engineering is to provide preservatives, while physics because canned in the vacuum.

4. Drying
Micro-organism like a damp or wet places containing water. So drying technique to make a dry food with water content as low as possible while dried, baked, heated, and so forth. The more moisture in the food, it will be easy to process food spoilage.

5. Sweetened
Sweetened foods is by placing or putting food on the medium containing glucose with a concentration of 40% to reduce levels of microorganisms. If dyed at 70% concentrations, it can prevent damage to food. Examples of sweetened food is like candied fruit, milk, jelly, jelly, and so forth.

6. Curing
This last way of using NaCl or materials that we know as table salt to preserve food. This technique is called also referred to as salting. Table salt has properties that inhibit the development and growth of food spoilage microorganisms or destroyer. Examples such as salted fish as a combination of salting with drying.

 

source:
Organisasi.Org Online Indonesian Community & Library