Food preservation is one of the ancient technologies that individuals use, and people will always differ on which are the best techniques of food preservation. In common people want safe, nourishing foods that are measured good quality, taking into account freshness, wholesomeness, nutritional value, aroma, color, texture and flavour.
Usually, food is measured safe if there is no danger from naturally occurring toxins, pathogenic microbes, or other possibly harmful chemicals. Food that is sanitary comprises no bacteria; if it is not sterilized and sealed it does contain bacteria. Milk, for instance has bacteria naturally living in it and will spoil in two or three hours if left out at room temperature. However, by putting it in the refrigerator bacteria is slowed down to such an extent that it will stay fresh for a week or two, even though bacteria are still present. You can also visit http://www.top10fooddehydrators.com/ for tips on Storing & Rehydrating Dehydrated Foods.
Food preservation includes treating and handling food to either greatly slows down or stops decomposition that caused or accelerated by micro-organisms. Protection normally includes preventing the growth of fungi, bacteria and other micro-organisms, as well as the oxidation of fats which the cause rancidity.
There are many procedures of preserving food comprising freezing, freeze drying, spray drying, food irradiation, sugar crystallization, adding preservatives, preserving in syrup, canning and vacuum-packing.