Salt (sodium chloride)

Salt, scientifically known as sodium chloride (NaCl), is a crystalline mineral commonly used as a seasoning and preservative in food. It is composed of 40% sodium and 60% chloride by weight. Salt is essential for human life, playing a critical role in maintaining cellular function, fluid balance, and nerve transmission.

Origin

Salt can be of both natural and artificial origin. Naturally, it is harvested from evaporated seawater or mined from salt deposits formed by ancient bodies of water. The two primary sources of natural table salt are sea salt and rock salt (halite). Artificially, it can be produced through the evaporation of brine from salt lakes or through industrial processes.

Characteristics

Table salt is used in food for several reasons:

• Flavour Enhancement: Enhances the taste of food by activating taste buds and balancing other flavours.
• Preservation: Inhibits the growth of bacteria and fungi, extending the shelf life of food.
• Texture Improvement: Helps in retaining moisture and improving the texture of food products.
• Fermentation Control: Regulates the fermentation process in foods like bread and cheese.
• Nutrient Delivery: Provides an essential source of sodium and chloride, important for bodily functions.

Uses in Ultra‑Processed Foods

In ultra‑processed foods, table salt is utilized extensively due to its versatile properties:

• Flavouring Agent: Salt enhances the palatability of processed foods, making them more appealing to consumers.
• Preservative: It extends the shelf life of products by preventing microbial growth, which is crucial for the mass production and distribution of food.
• Texture and Binding Agent: Salt helps in maintaining the structural integrity of processed meats, cheeses, and other food products by binding proteins and retaining moisture.
• Fermentation Inhibitor: In products like bread, salt regulates the activity of yeast and bacteria, ensuring consistent quality and preventing spoilage.
• Colour Enhancement: In processed meats, salt interacts with myoglobin to stabilize the pink colour, which consumers associate with freshness.
• Economic Efficiency: The use of salt as a preservative and flavour enhancer allows manufacturers to produce large quantities of food that remain stable and palatable over long periods, reducing waste and costs.

Health Considerations

While salt is necessary for health, excessive consumption can lead to several health issues:

• Hypertension: High sodium intake is linked to increased blood pressure, a risk factor for heart disease and stroke.
• Cardiovascular Disease: Excessive salt consumption is associated with a higher risk of cardiovascular diseases.
• Kidney Damage: High sodium levels can strain the kidneys, leading to impaired function and chronic kidney disease.
• Osteoporosis: Excessive sodium can lead to calcium loss through urine, potentially weakening bones over time.
• Gastric Cancer: Some studies suggest a correlation between high salt intake and an increased risk of stomach cancer.
• Water Retention: High salt intake can cause the body to retain water, leading to bloating and edema.

References

1. He, F. J., & MacGregor, G. A. (2009). A comprehensive review on salt and health and current experience of worldwide salt reduction programmes. Journal of Human Hypertension, 23(6), 363‑384.
2. Strazzullo, P., D'Elia, L., Kandala, N. B., & Cappuccio, F. P. (2009). Salt intake, stroke, and cardiovascular disease: meta‑analysis of prospective studies. BMJ, 339, b4567.
3. World Health Organization. (2012). Sodium intake for adults and children. WHO Guidelines Approved by the Guidelines Review Committee.
4. Campbell, N. R. C., Johnson, J. A., & Campbell, T. S. (2012). Sodium consumption: an individual's choice? International Journal of Hypertension, 2012, 860954.