It's salt. (formal) Saline itself is one of the best preservatives. Although it depends entirely on the nature of the thing you are trying to preserve.
The last post pretty much summed it up- it depends on what the nature of the product you are attempting to preserve. If you would like more information on preserving foods you should take a look at "cook books" specifically targeted for preserving for advice. As for the science (chemistry/biology) behind preservation, you might want to take a look at food science books- particularly those that specialize in preserving.
As far as primary research on food preservation you may want to try the Journal of Food Processing and Preservation (Wiely-Blackwell) [I cannot comment on this particular journal as I am unfamiliar with it]. As far as regulation of food preservation you will want to check out the Food and Drug Administration (FDA) or USDA or other similar regulating agency [I am assuming you reside in the USA].