One of America's Favorites - Salt

Salt

Salt, also known as table salt, or rock salt, is a crystalline mineral that is composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of ionic salts. It is essential for animal life in small quantities, but is harmful to animals and plants in excess. Salt is one of the oldest, most ubiquitous food seasonings and salting is an important method of food preservation. The taste of salt (saltiness) is one of the basic human tastes.
Salt for human consumption is produced in different forms: unrefined salt (such as sea salt), refined salt (table salt), and iodized salt. It is a crystalline solid, white, pale pink or light gray in color, normally obtained from sea water or rock deposits. Edible rock salts may be slightly grayish in color because of mineral content.

Salt for human consumption is produced in different forms: unrefined salt (such as sea salt), refined salt (table salt), and iodized salt. It is a crystalline solid, white, pale pink or light gray in color, normally obtained from sea water or rock deposits. Edible rock salts may be slightly grayish in color because of mineral content.
Chloride and sodium ions, the two major components of salt, are needed by all known living creatures in small quantities. Salt is involved in regulating the water content (fluid balance) of the body. The sodium ion itself is used for electrical signaling in the nervous system. Because of its importance to survival, salt has often been considered a valuable commodity during human history. However, as salt consumption has increased during modern times, scientists have become aware of the health risks associated with high salt intake, including high blood pressure in sensitive individuals. Therefore, some health authorities have recommended limitations of dietary sodium, although others state the risk is minimal for typical western diets. The United States Department of Health and Human Services recommends that individuals consume no more than 1500–2300 mg of sodium (3750–5750 mg of salt) per day depending on age.

While people have used canning and artificial refrigeration to preserve food for the last hundred years or so, salt has been the best-known food preservative, especially for meat, for many thousands of years. A very ancient saltworks operation has been discovered at the Poiana Slatinei archaeological site next to a salt spring in Lunca, Neamţ County, Romania. Evidence indicates that Neolithic people of the Precucuteni Culture were boiling the salt-laden spring water through the process of briquetage to extract the salt as far back as 6050 BC. The salt extracted from this operation may have had a direct correlation to the rapid growth of this society's population soon after its initial production began. The harvest of salt from the surface of Xiechi Lake near Yuncheng in Shanxi, China dates back to at least 6000 BC, making it one of the oldest verifiable saltworks.

The salt works north of Pondicherry, India.

Salt was included among funereal offerings found in ancient Egyptian tombs from the third millennium BC, as were salted birds and salt fish. From about 2800 BC, the Egyptians began exporting salt fish to the Phoenicians in return for Lebanon cedar, glass, and the dye Tyrian purple; the Phoenicians traded Egyptian salt fish and salt from North Africa throughout their Mediterranean trade empire.
Along the Sahara, the Tuareg maintain routes especially for the transport of salt by Azalai (salt caravans). In 1960, the caravans still transported some 15,000 tons of salt, but this trade has now declined to roughly a third of this figure.

Salzburg, Hallstatt, and Hallein lie on the river Salzach in central Austria, within a radius of no more than 17 kilometers. Salzach literally means "salt water" and Salzburg "salt city", both taking their names from the German word for salt, Salz.
Hallstatt gave its name to the Celtic archaeological culture that began mining for salt in the area in around 800 BC. Around 400 BC, the Hallstatt Celts, who had heretofore mined for salt, began open pan salt making. During the first millennium BC, Celtic communities grew rich trading salt and salted meat to Ancient Greece and Ancient Rome in exchange for wine and other luxuries.
The word salary originates from Latin: salarium which referred to the money paid to the Roman Army's soldiers for the purchase of salt. The word salad literally means "salted", and comes from the ancient Roman practice of salting leaf vegetables.
Mahatma Gandhi led at least 100,000 people on the "Dandi March" or "Salt Satyagraha", in which protesters made their own salt from the sea, which was illegal under British rule, as it avoided paying the "salt tax". This civil disobedience inspired millions of common people, and elevated the Indian independence movement from an elitist struggle to a national struggle.

Sea salt harvesting in Pak Thale, Phetchaburi, Thailand

Forms of salt

Unrefined salt

Different natural salts have different mineralities, giving each one a unique flavor. Fleur de sel, a natural sea salt from the surface of evaporating brine in salt pans, has a unique flavor varying from region to region. In traditional Korean cuisine, so-called "bamboo salt" is prepared by roasting salt in a bamboo container plugged with mud at both ends. This product absorbs minerals from the bamboo and the mud, and has been claimed to increase the anticlastogenic and antimutagenic properties of doenjang.
Unrefined sea salt contains small amounts of magnesium and calcium halides and sulfates, traces of algal products, salt-resistant bacteria, and sediment particles. The calcium/magnesium salts make unrefined sea salt hygroscopic(i.e.,it gradually absorbs moisture from air if stored uncovered) and confer a faintly bitter overtone. Algal products contribute mildly "fishy" and "sea-air" odors, the latter from organobromine compounds. Sediments, whose proportion varies with the source, give the salt a dull gray appearance. McGee  points out that since taste and aroma compounds are often detectable in minute concentrations, sea salt might have a more complex flavor than pure sodium chloride when sprinkled on top of food, though when added during cooking these flavors would be overwhelmed by those of the food ingredients.
The refined salt industry cites scientific studies saying that raw sea and rock salts do not contain enough iodine salts to prevent iodine deficiency diseases.
Unrefined sea salts are also commonly used as ingredients in bathing additives and cosmetic products. One example is bath salts, which uses sea salt as its main ingredient and combined with other ingredients is used for its alleged healing and therapeutic effects.

Refined salt

Refined salt, which is most widely used presently, is mainly sodium chloride. Food grade salt accounts for only a small part of salt production in industrialized countries (3 percent in Europe) although worldwide, food uses account for 17.5 percent of salt production. The majority is sold for industrial use. Salt has great commercial value because it is a necessary ingredient in many manufacturing processes. A few common examples include: the production of pulp and paper, setting dyes in textiles and fabrics, and the making of soaps and detergents.
The manufacture and use of salt is one of the oldest chemical industries. Salt can be obtained by evaporation of sea water, usually in shallow basins warmed by sunlight; salt so obtained was formerly called bay salt, and is now often called sea salt or solar salt. Rock salt deposits are formed by the evaporation of ancient salt lakes, and may be mined conventionally or through the injection of water. Injected water dissolves the salt, and the brine solution can be pumped to the surface where the salt is collected.

After the raw salt is obtained, it is refined to purify it and improve its storage and handling characteristics. Purification usually involves recrystallization. In recrystallization, a brine solution is treated with chemicals that precipitate most impurities (largely magnesium and calcium salts). Multiple stages of evaporation are then used to collect pure sodium chloride crystals, which are kiln-dried.

Table salt

In Western cuisine, salt is used in cooking, and is often found in salt shakers on diners' eating tables for their personal use on their food.
Table salt is refined salt, which contains about 97 to 99 percent sodium chloride. It usually contains substances that make it free-flowing (anticaking agents) such as sodium aluminosilicate or magnesium carbonate. Some people also add a desiccant, such as a few grains of uncooked rice, or a saltine cracker in salt shakers to absorb extra moisture and help break up clumps when anticaking agents are not enough. Table salt has a particle density of 2.165 g/cm3, and a bulk density (dry, ASTM D 632 gradation) of about 1.154 g/cm3.

In many East Asian cultures, salt is not traditionally used as a condiment. In its place, condiments such as soy sauce, fish sauce and oyster sauce tend to have a high sodium content and fill a similar role to table salt in western cultures. They are most often used for cooking rather than as table condiments.

Acute effects

Too much or too little salt in the diet can lead to muscle cramps, dizziness, or electrolyte disturbance, which can cause neurological problems, or death. Drinking too much water, with insufficient salt intake, puts a person at risk of water intoxication (hyponatremia). Salt is sometimes used as a health aid, such as in treatment of dysautonomia.
Death can occur by ingestion of large amounts of salt in a short time (about 1 g per kg of body weight). Deaths have also resulted from attempted use of salt solutions as emetics, forced salt intake, and accidental confusion of salt with sugar in child food.

Long-term effects

The effect of salt consumption on long term health outcomes is controversial. The effects of salt reduction appears to have an unclear effect on mortality and its effect on morbidity is contentious.

Recommended intakes of salt are usually expressed in terms of sodium intake. Salt (as sodium chloride) contains 39.3 percent of sodium by weight.(wiki)