Salt (food ingredient)

Description
Food-grade salt is composed mainly of sodium chloride (NaCl), an essential mineral for human physiology and one of the most widely used ingredients worldwide. It can come from evaporation of seawater (sea salt), crystallisation of brines, or mining of underground deposits (rock salt/halite), followed by purification. It appears as white crystals, regular or irregular, with variable particle size (fine, medium, coarse). Salt is used to provide savouriness, preserve foods, influence texture, support fermentations and enable numerous technological processes. On land, salt is extracted from mines in the form of rock salt and then processed.

Sea salt is salt obtained from seawater, collected in tanks and evaporated in the sun.

Then there is iodized salt, which is a common sea salt to which iodine or potassium, elements that the human body needs, have been added.

There is also diet salt, with a lower percentage of sodium and then a large amount of salt from the most diverse parts of the gobo, Himalayan pink salt, South Africa, China etc.

Indicative nutritional values per 100 g

• Energy: 0 kcal

• Water: 0–2 g (residual moisture)

• Carbohydrates: 0 g

• Protein: 0 g

• Total fat: 0 g

  • SFA: 0 g

  • MUFA: 0 g

  • PUFA: 0 g

• Fibre: 0 g

• Sodium: 38–40 g

• Chloride: ≈ 60 g

• Trace minerals (calcium, magnesium, potassium), especially in less-refined sea salt

Key constituents

• Sodium chloride (NaCl) → main component (typically 97–99%).

• Traces of chlorides and sulphates of magnesium, calcium and potassium (more evident in unrefined sea salt).

• Authorised anti-caking agents in packaged table salt.

• Iodine (in iodised salt), usually as potassium iodide or iodate according to legislation.

Production process

Sea salt

• Collection of seawater in saltpans.

• Natural evaporation by sun and wind.

• Crystallisation of NaCl.

• Harvesting, washing and drying of crystals.

• Particle-size grading and, if required, iodisation.

• Packaging for food use.

Rock salt (halite)

• Extraction from underground deposits (mining or solution mining + recrystallisation).

• Crushing, purification and grading.

• Iodisation where required by law or market.

• Packaging for food use (clearly distinguished from technical salt).

Physical properties

• White, odourless crystals, fully soluble in water.

• Variable bulk density depending on particle size.

• High melting point (around 801 °C; relevant mainly for technical uses).

• Hygroscopic: tends to absorb moisture and form lumps.

• Crystal habit: cubic in pure NaCl; grains may appear irregular after crushing.

Sensory and technological properties

• Taste: intensely salty, clean, without off-flavours in quality products.

• Enhances flavours and sweetness, and can mask or reduce bitterness.

• Key technological roles:

  • Osmosis (brines, partial dehydration, osmotic balance in fermentation).

  • Fermentation support (bread dough, vegetable fermentations).

  • Preservation (reduces water activity and inhibits microbial growth).

  • Texture modulation (meat products, cheeses, baked goods).

Food applications

• Direct seasoning in home and professional cooking.

• Preparation of brines for cheeses, olives, pickled vegetables and cured meats.

• Curing of meats and fish (e.g. hams, bacon, cod).

• Bread and bakery products, snacks, processed meats, cheeses and canned foods.

• Salt-crust baking of fish and meat.

• Numerous industrial applications in preservation and processing.

Nutrition & health

• Salt is the main dietary source of sodium, essential for:

  • Fluid and electrolyte balance.

  • Nerve transmission.

  • Muscle contraction.

• However, excessive intake is associated with:

  • Hypertension.

  • Increased cardiovascular risk.

  • Possible kidney overload in susceptible individuals.

• Health guidelines typically recommend less than 5 g of salt per day for adults (all sources combined).

• Iodised salt contributes to iodine intake, important for thyroid function, especially in areas with low natural iodine.

Portion note
The recommended daily intake is below 5 g of salt per adult, including both added salt and salt contained in processed foods.

Allergens and intolerances

• Salt does not contain EU-listed major allergens.

• It may need to be reduced or restricted in individuals with:

  • Hypertension.

  • Kidney disease.

  • Heart failure or certain endocrine disorders.

• Sensitivity to iodine in iodised salt may be relevant for specific medical conditions (follow medical advice).

Storage and shelf-life

• Store in a cool, dry place, away from humidity and strong odours.

• Keep the container tightly closed to prevent clumping and odour absorption.

• Salt has a very long shelf-life (often several years); for iodised salt, the limiting factor is mainly iodine stability, not spoilage of the salt itself.

Safety and regulatory aspects

• Must comply with EU and national requirements for:

  • NaCl purity.

  • Heavy metals and insoluble impurities.

  • Permitted additives.

  • Iodisation levels (for iodised salt).

• Production must follow GMP and HACCP systems.

• Food-grade salt must be clearly separated from technical/industrial salt along the supply chain.

Labelling

• Sales name: edible salt, sea salt, rock salt, etc., depending on origin and processing.

• Clear indication if iodised (with the iodine source specified).

• List of ingredients: salt, authorised anti-caking agents, iodide/iodate where present.

• Net weight, lot code, best-before date.

• Name and address of the responsible food business operator.

• Instructions for use or specific warnings where relevant.

Troubleshooting

• Lumping/caking → excessive humidity; improve sealing and storage conditions.

• Foreign odours → salt has absorbed environmental smells; always store away from detergents, strong spices, etc.

• Abnormal colour → impurities or contamination; check source and quality.

• Slow dissolution → very coarse crystals or partially hydrated/caked salt; grinding before use can help.

Sustainability and supply chain

• Solar sea-salt production has relatively low energy demand, though it requires large saltpan areas and careful ecosystem management.

• Rock-salt mining has a higher and more variable environmental impact, depending on extraction technologies and site management.

• Well-managed saltpans can act as valuable habitats for birds and other wildlife.

• Packaging (paper, cardboard, plastic) is often recyclable; selecting more sustainable materials reduces environmental footprint.

• Transparent supply chains distinguish food-grade salt from technical salt and support quality and safety.

Main INCI functions (cosmetics)
In cosmetic formulations, salt (e.g. Sodium Chloride, Maris Sal) is commonly used as:

• Viscosity regulator in shampoos and liquid cleansers.

• Astringent and toning agent in bath and spa products.

• Mechanical exfoliant in body scrubs and foot soaks.

• Stabilising agent in certain surfactant systems.

• Component of bath salts and wellness products for osmotic and sensory effects.

Conclusion
Salt is a fundamental food ingredient, indispensable for flavour, preservation and many technological functions in both domestic and industrial food preparation. Although it is essentially just sodium and chloride, it plays a crucial role in human physiology and in food processing. Conscious use, adherence to intake recommendations, proper storage and a well-controlled supply chain ensure quality, safety and a reasonable environmental impact.

Mini-glossary

• SFA – Saturated fatty acids (absent in salt; relevant to overall diet and cardiovascular risk).

• MUFA – Monounsaturated fatty acids (absent in salt; generally beneficial for lipid profile).

• PUFA – Polyunsaturated fatty acids (absent in salt; important for cell membranes and anti-inflammatory functions).

• GMP – Good Manufacturing Practices; industrial rules ensuring hygienic, correct production.

• HACCP – Hazard Analysis and Critical Control Points; preventive system for managing food-safety hazards.

• MRL – Maximum Residue Level; legal limit for contaminants/residues where applicable.

• BOD/COD – Biochemical/Chemical Oxygen Demand; indicators of organic load in wastewater used to assess environmental impact.

Studies

It is recommended to reduce salt consumption as it may cause damage to the cardiovascular system and increase the values of harmful LDL-cholesterol and cause hypertension, obesity and other serious diseases, but there is also diet salt on the market, with a lower percentage of sodium. 

'Salt killer'. This was the title of a well-known and authoritative American newspaper some time ago, explaining in detail the reasons why the overuse of common table salt could cause serious damage to health. In fact, salt is found naturally in almost all foods, so we absorb it daily, but heavy consumption can damage the human body. 

Hypertension: The relationship between salt and hypertension is unequivocal (1), and especially for the elderly, consumption must be reduced (2). For young people, the problems may be minor, but still exist (3). 

Obesity : High salt consumption is associated with overweight and obesity (4). 

Drinks and chips : The amount of salt in drinks, crisps etc. should be controlled, as the combination of salt and sugar (as not only sugar is included, but fructose, dextrose and others) can increase the risk associated with high salt consumption (5). 

Osteoporosis: In this study, despite press campaigns to advise against salt consumption, the results proved rather disappointing (6). The title of the article sums it up well: Important element, but invisible threat. 

So, to summarise, salt is an indispensable element, but one must be very careful not to abuse it. 

Salt is used as a food preservative

Cosmetics

In cosmetics, sodium chloride has the function of increasing the moisturising efficacy of ageing skin, is a thickener in shampoos and conditioners, but is also a co-factor in the eye irritation experienced with most shampoos and can cause dryness and itching of the scalp (7). Skin sodium is a pathophysiological feature of psoriasis (8), a chronic inflammatory skin disease, so high concentrations of sodium chloride should not be present in cosmetic products.

Medical

Sodium chloride is used in numerous medical and pharmaceutical applications: preservative, hypertonic salt solution in conjunction with dextran, production of interleukin-4, antibacterial with biocidal effect against Staphylococcus aureus (9).

Human epidermal stem cells can be stored in anhydrous sodium chloride at room temperature for months as well as some resident immune cells and skin fibroblasts (10).

In the following link you will find the best studies on salt and its health profile.

Salt studies

Sale ed obesità (italian)

Controllare il consumo del sale (italian)

Typical commercial product characteristics Sodium Chloride

Appearance	White powder
Boiling Point	1461 ºC
Melting Point	801°C(lit.)
Flash Point	1413°C
Density	2.165      1.199 g/mL at 20 °C
Refraction Index	n20/D 1.378
Water Solubility	360 g/L (20 ºC)
Storage	+15C to +30C
Potassium Iodate	35±15(20-50) mg/kg
Potassium ferrocyanide	≤10.0
Pb	≤1.0
As	≤0.5
F	≤5.0
Fe	≤0.0002
Ferrous cyanide	≤0.0001
Ba	≤15
Nitrogen	≤0.001
Sulfate	≤0.002
Nitrite	0
Safety

• Molecular Formula  NaCl    ClNa
• Molecular Weight     58.44
• Exact Mass    57.958622
• CAS  7647-14-5
• UNII    451W47IQ8X
• EC Number   231-598-3
• DSSTox Substance ID    DTXSID3021271    DTXSID6040379    DTXSID501033754
• IUPAC  sodium;chloride
• InChI=1S/ClH.Na/h1H;/q;+1/p-1
• InChl Key      FAPWRFPIFSIZLT-UHFFFAOYSA-M
• SMILES   [Na+].[Cl-]
• MDL number  MFCD00003477
• PubChem Substance ID    329824637
• ChEBI  26710
• RXCUI    9863  
• NSC   77364
• RTECS   VZ4725000
• NCI   C29974    C821
• Beilstein    3534976
• NACRES NA.21

Synonyms

• Sodium chloride
• Salt

References__________________________________________________________

(1) Patience S. Understanding the relationship between salt intake and hypertension. Nurs Stand. 2013 Jan 2-8;27(18):45-7. doi: 10.7748/ns2013.01.27.18.45.c9487. 

Abstract. Hypertension is a public health problem that contributes significantly to the non-communicable disease burden. A review of the epidemiological literature demonstrates that the relationship between salt and hypertension is unequivocal. The Department of Health has reported some success promoting awareness of the need to reduce salt consumption, but more work needs to be done in this area.

(2) Borghi C, Tartagni E. The older patient with hypertension: care and cure. Ther Adv Chronic Dis. 2012 Sep;3(5):231-6. doi: 10.1177/2040622312452189. 

Abstract. Hypertension is one of the most important clinical conditions affecting older people. Its prevalence in this group of subjects is above 60% and continues to grow. Isolated systolic hypertension accounts for the majority of cases as systolic blood pressure increases with advancing age, while diastolic blood pressure remains unchanged or even decreases. Nowadays hypertension is a well established risk factor for stroke and cardiovascular disease among older people and its treatment is considered mandatory. The general recommended blood pressure goal in uncomplicated hypertension is less than 140/90 mmHg, even if this target in older people is based mainly on expert opinion. All patients should receive nonpharmacological treatment, in particular reduction in excess body weight when body mass index is greater than 26 kg/m(2) and dietary salt restriction. Older patients with hypertension may also benefit from smoking cessation, physical activity and alcohol restriction. In relation to drug therapy, a low-dose thiazide diuretic could be a good first step. Other first-line drugs are long-acting calcium channel blockers, generally dihydropyridines, and angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. The HYVET study showed a specific protective effect of indapamide with or without perindopril in people older than 80 years. Since monotherapy normalizes blood pressure in only 40-50% of cases, a combination of two or more drugs is often required. Moreover the addiction of a second drug may reduce the dose-related adverse effects of the first one. Finally, compliance with treatment should always be achieved by giving complete information to patients and simplifying the drug regimen as much as possible.

He FJ, Campbell NR, MacGregor GA. Reducing salt intake to prevent hypertension and cardiovascular disease. Rev Panam Salud Publica. 2012 Oct;32(4):293-300. doi: 10.1590/s1020-49892012001000008.

Abstract. There is compelling evidence that dietary salt intake is the major cause of raised blood pressure (BP) and that a reduction in salt intake from the current level of ≈ 9 - 12 g/day in most countries to the recommended level of < 5 g/day lowers BP. A further reduction to 3 - 4 g/day has a greater effect and there needs to be ongoing consideration of lower targets for population salt intake. Cohort studies and outcome trials have demonstrated that a lower salt intake is related to a reduced risk of cardiovascular disease. Salt reduction is one of the most cost-effective measures to improve public health worldwide. In the Americas, a salt intake of > 9 g/day is highly prevalent. Sources of salt in the diet vary hugely among countries; in developed countries, 75% of salt comes from processed foods, whereas in developing countries such as parts of Brazil, 70% comes from salt added during cooking or at the table. To reduce population salt intake, the food industry needs to implement a gradual and sustained reduction in the amount of salt added to foods in developed countries. In developing countries, a public health campaign plays a more important role in encouraging consumers to use less salt coupled with widespread replacement of salt with substitutes that are low in sodium and high in potassium. Numerous countries in the Americas have started salt reduction programs. The challenge now is to engage other countries. A reduction in population salt intake will result in a major improvement in public health along with major health-related cost savings.

(3) Campagnoli T, Gonzalez L, Santa Cruz F. Salt intake and blood pressure in the University of Asuncion-Paraguay youths: a preliminary study. J Bras Nefrol. 2012 Oct-Dec;34(4):361-8. doi: 10.5935/0101-2800.20120026. 

Abstract. Introduction: High salt intake is a major risk factor related to many cardiovascular and renal diseases. World Action on Salt and Health is a newly formed coalition of heath professionals whose goal is to implement changes in salt consumption in their respective countries for the goal of reducing blood pressure. In the same vein, we have decided to study the amount of salt intake in Paraguay to determine if a relationship exists between salt intake and blood pressure. Objective: A preliminary study was undertaken to determine salt intake in Paraguay and its relationship with blood pressure, in order to implement a national program to combat hypertension.... Conclusion: Salt intake and blood pressure were found to be significantly elevated in young adults in Paraguay and argues for the importance of instituting a national campaign to reduce salt intake in this society.

(4) Woodruff SJ, Fryer K, Campbell T, Cole M. Associations among blood pressure, salt consumption and body weight status of students from south-western Ontario. Public Health Nutr. 2014 May;17(5):1114-9. doi: 10.1017/S1368980013000335.

Abstract. Objective: The purpose was to examine the associations among body weight status, blood pressure and daily Na intake among grade 7 students from south-western Ontario, Canada. Design: Cross-sectional. Data were collected using the Food Behaviour Questionnaire, including a 24 h diet recall. Measured height and weight were used to determine BMI. Blood pressure was taken manually using mercury sphygmomanometers.... Conclusions: High intakes of Na, coupled with high SBP and DBP, were associated with overweight and obesity status among the grade 7 sample from south-western Ontario, Canada.

(5) Grimes CA, Riddell LJ, Campbell KJ, Nowson CA. Dietary salt intake, sugar-sweetened beverage consumption, and obesity risk. Pediatrics. 2013 Jan;131(1):14-21. doi: 10.1542/peds.2012-1628.

Abstract. Objective: To determine the association among dietary salt, fluid, and sugar-sweetened beverage (SSB) consumption and weight status in a nationally representative sample of Australian children aged 2 to 16 years....Conclusions: Dietary salt intake predicted total fluid consumption and SSB consumption within consumers of SSBs. Furthermore, SSB consumption was associated with obesity risk. In addition to the known benefits of lowering blood pressure, salt reduction strategies may be useful in childhood obesity prevention efforts.

(6) Wick JY. Salt: important element, invisible menace. Consult Pharm. 2012 Nov;27(11):756-62. doi: 10.4140/TCP.n.2012.756.

(7) Staszak K, Wieczorek D, Michocka K. Effect of Sodium Chloride on the Surface and Wetting Properties of Aqueous Solutions of Cocamidopropyl Betaine. J Surfactants Deterg. 2015;18(2):321-328. doi: 10.1007/s11743-014-1644-8.

Abstract. Surfactants are important ingredients of personal care products and household products. The main characteristic of these compounds is to decrease the surface tension of solvent and resulting many properties such as contact angle, foam properties etc. The coexistence of other ingredients in the product may affect the properties of surfactants. One of the main components contained in almost every personal care and household product is sodium chloride. The main aim of this work was to determine the effect of this salt on some surface and usage properties of cocamidopropyl betaine (