The method of sugar and salt preservation of food is basically done in the same way, chemically speaking, in that water withdrawal is the main result, although the way this comes about is different. The type of food preserved is usually of a different variety, also. Sugar is the best preservative for fruits, along with that of drying and freezing.
Salt works best with meat and fish and a few vegetable varieties. The famous Virginia ham is one example of how meat can be cured’ and there’s kraut, a vegetable, cabbage, that been preserved in salt for centuries.
Preservatives protect food from decay and fermentation and from four main type of food spoilers, enzymes, molds, yeast, and bacteria (a) enzymes are produced by living cells; (b) molds are formed when moisture is allowed to collect on top of jellies, jams; (c) yeast are single-celled fungus that reproduces itself by budding; (d) bacteria are disease producing microscopic animals.
Salt has been used in preserving meat for centuries. It works by incorporating its crystals among the tissue cells of meat and dries up the water, making it impossible for bacteria to grow while also protecting from yeast and mold which need water to grow.
Sugar prohibits growth of bacteria by the process of diffusion. This method of preservation works by drawing the water out of the fruit or other food by high levels of sugar content. The water removed is in proportion to the level of sugar added.
As already mentioned, salt and sugar works to preserve food in much the same way in that water is removed, but there are differences. Sugar does away with the water and salt only binds the water in its method. A salt cured ham, as an example, can be reconstituted.
Some types of molds that grow on foods are dangerous. There are documentations of epidemics of frenzy caused by notorious examples of hallucinogenic delusions caused by people eating rye bread contaminated with the fungus ergot.
Preservation works because all living organisms, helpful to humanity or not helpful to humanity, must have certain conditions to live. They either thrive with excess sweetness, or they are overcome by it. The same with salt. The neutral point of acidity and sweetness is the number seven. All below this measures the level of acidity, (6.99 being minutely acid) and all above the number seven (ph.7) measuring the sweetness level.
The dreaded organism, clostridium botulism, is the culprit all food preservers work to rid. On the news frequently we hear of outbreaks of food poisoning where several persons have either died or been ill from eating contaminated food.
And again, some commercial food from time to time is removed from shelves when it has been discovered that some mistake in handling has resulted in contamination, or the possibility of contamination.
Thus salt and sugar plays a much more important role in our diet than simply being a pleasure sensation for our taste buds. Often times a little sugar and little salt go a long way in keeping ourselves healthy, especially when a few wise words are spoken, or are thought, or read. When in doubt, throw it out.
http://www.essays.cc/free-essays/rok224.shtml
http://www.faia.org/uk/preserve.php
http://www.cfsan.fda.gov/~dms/qa-sto5.htm
