The salt is possibly the oldest and more used seasoning in food, and one of the main milestones in every kitchen and culture in the world.
Some culinary authors mention that the cooking art is probably to be able to get to know exactly when to apply salt to food, to get to know the exact amount of salt and to get to know the most recommended type of salt depending on the circumstances. At this point it is when we find the salt experts: selmeliers.
There is another food using an important amount of salt as main ingredient in the receipt: bread. Salt is used in patisserie thanks to its enhancing flavour effect, specially in sweets, so this is the reason why it is found in small amounts among the doughs of cakes. It is also used when manufacturing sodas.
The discovery of salt as a preservative might have been done by chance when noting that a forgotten food amongst salt lasted longer than one in fresh air. It is very possible that such remarks led to the production of salting foods such as meat and its derivates (cold meats, hams, salami, etc.). The salting offered the possibility to take food to further places. That is the case of fish, that could be eaten in distant places from the sea. The business of salting has been a very profitable business upon the arrival of the refrigerating systems (qv. History of salt). In the case of canned foods, like the canned veggies, salty solutions are used to preserve the original colours of vegetables.
Many foods have a high salt level due to its treatments in salting with the aim of making cured processes. This treatment gives a particular character to some foods. Some examples are the caviar from Slavonic countries, the salty cod traditional from some Atlantic cultures, and the herring, the anchovies and the sardines.
Other cultures, like the Chinese cuisine, have saltings based on eggs, like duck salty eggs or the very popular century egg. In some cases, the salt is mixed with some different spices so that the cured process of foods has a final aromatic flavour. Likewise, some foods are made with big amounts of salt to enhance their useful life and to extend their utility. Some examples are ham (typical in Spain, and very popular in other Celtic cultures) and cheese.
The saltings have the aim of drying the food until the activity of the bacteria responsible for the rotting is stopped. The sodium and chlorine ions make the cellular membranes to stop the biological processes, including the rotting process. One of the foods using big amounts of salt are instant soups or the bouillon cubes (with salt amounts that can exceed the 3%). Other similar salt used to preserve meats since the XIX century is the potassium nitrate (KNO3) that also has the property of giving a brilliant red colour to the meat fibers, so it is a preservative widely used in ham. The potassium nitrate is often called “nitro salt”.
It is known worldwide the use of salt in the production of cheese. It is a dairy product that has the ability to last thanks to its saline concentration amongst other properties. The needed concentration of salt to preserve the cheese is about 2% of its own weight (this quantity can vary depending on the place and the process of elaboration of the place where it is made). When boiling vegetables, the salt helps making colours more brilliant.