Salt tastes sweet at low concentrations, suppresses bitterness and gives fullness/ thickness in foods. Preference for salt is not hereditary, and the environment has a strong influence on the preference, which is determined by the salt concentration in the foods people consume.

It is well documented that people consume too much salt in their diet. Processed foods are responsible for at least 75% of daily salt intake among the populations of most countries. In addition, cross-epidemiological studies have shown populations with higher salt intakes have higher levels of blood pressure.

As a response to this, the industry has been working hard to reduce the levels of salt in processed food products. To replace the sodium chloride in foods, salt replacers, such as potassium chloride, potassium lactate and magnesium sulphate, are applied--with potassium chloride still being the most widely and commonly used.

The global market for low-salt foods is worth an estimated $50 billion, of which the U.S. accounts for 40%. Foods claiming no salt, where salt replacers or alternative seasonings are used, are worth approximately $16 billion, according to the 2010 market report, "Salt Reduction--A market and technical review of global initiatives, actions and challenges for the food industry," by Leatherhead Food Research.

Another widely used option to reduce levels of salt, but one which is generally not advertised to consumers, is the use of a gradual reduction of salt (stealth). This approach is being applauded by organizations, such as the UK Food Standards Agency and World Action on Salt and Health (WASH). Using this approach, consumers' palates will adapt to the lower level of salt, as the salt is very gradually reduced. This approach will depend on brand loyalty, ensuring that consumers do not switch to brands containing higher levels; thus, an industry-wide approach would be required for some products. The rate by which to reduce salt is uncertain. Many companies have successfully used a stepwise reduction rate of 5%, but the specific approach will be dependent on food type and initial salt level (products with higher initial salt content are likely to achieve higher reduction levels).

Some examples of brands reducing salt content include:
* Heinz Baked Beans and Heinz canned pasta, claimed to reduce salt by around one third and children's pasta ranges by 59%.
* Unilever has removed 3,640 tons of sodium from their portfolio with, for example, 10-15% reduction in powdered soups in Europe & South America since 2005, and 25% across Knorr recipe kits in South Africa.
* Campbell Soup Company has quadrupled the number of its lower-sodium products in the past five years. Campbell claims it is dedicated to seeking new solutions to reduce sodium, without compromising on taste.
* Arla Foods has committed up to a 50% salt reduction in its soft cheese range and has already achieved a reduction of 15% in butter.
* Kellogg has committed to the salt-reduction campaign and has vowed to reduce the amount of salt in Kellogg's Rice Krispies and Kellogg's Corn Flakes by 30%.

Although there are many examples of salt-reduced products, the level of salt reduction by brands may vary extensively, according to the country where it is sold.

Consumer preference for salty taste depends on the individual's habitual salt intake and can change across the consumer age span. Preference for salt is not hereditary, and the environment has a strong influence on the preference, which is influenced by the salt concentration in the foods people consume. This also shows the difficulty in reducing salt of products in different countries; consumer liking towards salt is dependent on the levels present in products within the specific countries. In addition, it may also be dependent on their liking towards salt replacers, which could also be influenced by their level of exposure to these materials.

A current trend in salt replacement is pointing towards the use of sea salt, which benefits from its perception of being a "natural" product and associations with the "clean label" and "provenance" trends. To highlight this, several product launches with sea salt as an ingredient have been seen recently on the market, particularly in some premium brands, as well as an expected continuation of sales increases of sea salt itself at retailers.

Salt Perception
Salt (sodium chloride) has its own familiar taste and is classified as one of the five basic tastes (sweet, salt, sour, bitter and umami). Although other chemicals can also give a salty taste, sodium chloride is generally recognized as a pure salty taste.

Salt enhances flavors, particularly in savory foods, but also in sweet foods, such as chocolate. Removal of salt may make foods bland and unappetizing. Monosodium glutamate (MSG), which gives an umami taste, can be used to enhance flavor. Salt also tastes sweet at low concentrations, suppresses bitterness, gives fullness/ thickness in foods and, in some products, is used for its visual, crystal-like appearance.

Salt requires dissolution, before it can be perceived. Salt in liquid products is thus more readily perceived than salt in solid products. Solid foods need to be properly chewed and mixed with saliva, in order for the salt to reach the taste buds and to prevent the salt from being swallowed without being tasted.

Masticatory behavior is important for the level of salt released and, thus, perceived in solid foods, with variability in people, due to physiological and chewing behavior. The quantity of salt released varies significantly between products, and large proportions of salt can be swallowed, without consumers even perceiving it.

The rate at which salt dilutes also alters salt perception. The dissolution rate can be amended by changing the sodium availability, which includes the particle size or type of sodium and the positioning of the sodium chloride in the product. Quicker salt perceptions are generally perceived as saltier, while a combination of quick and slower release of sodium chloride seems to be preferred for some products by consumers.

Although great achievements have been made by the industry, further reductions are still required to meet the targets of healthy salt consumption levels, and manufacturers are investigating the possibilities to reduce levels further, without compromising food safety, consumer perception and processing.pf

References: 

* Angus F, et al. 2005. Salt in processed foods collaborative research group, Leatherhead Food International.
* AWASH, 2009 survey.
* Cobcroft, et al. 2009. Salt reduction--a technical overview, Food New Zealand. 9: (6), 29-31.
* Leatherhead Food Research, 2010, "Salt reduction, a market and technical review of global initiatives, actions and challenges for the food industry," collaborative report, Leatherhead Food Research.
* Phan VA, et al. 2008. In vivo sodium release related to salty perception during eating model cheeses of different texture. International Dairy Journal. 18:956-63.