Understanding these interactions provides insight into the ways in which food composition influences our sensory experience.
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Salty taste linked to food composition and sensory perception

Understanding these interactions provides insight into the ways in which food composition influences our sensory experience.

The salty taste is one of the basic flavours usually linked to sodium, which can be found in table salt or sodium chloride. Although adding sodium to food enhances characteristics like texture and conservation, its excessive consumption is associated with the development and prevalence of chronic diseases.

The World Health Organisation recommends a maximum daily sodium intake of 2000 milligrams, equivalent to 5 grams of salt. Excessive consumption of sodium comes not solely from salt in foods but also from sodium in other product formulations.

Food composition or the method of adding salt can affect the content of salt in the food and alter the perception of salty flavour, either reducing or enhancing it.

Verónica Fonseca Bustos

Credit. Author

What can be done to reduce sodium in processed foods?

Various strategies have been employed to reduce the amount of sodium in food without compromising taste. Modifying the particle size of salt crystals has proven effective in enhancing their salty taste. This change increases the dissolution velocity of the salt, making sodium more readily perceivable in the mouth. Likewise, incorporating salt in a heterogeneous form, allowing spaces without salt in the food, shows similar effects.

When implementing these strategies, it is important to maintain the structural integrity of the salt. Foods with high moisture content pose a challenge as they can dissolve or alter salt crystals. To address this, distributing salt on the surface of dry products or coating salt with fat to limit its solubility can ensure the effectiveness of these strategies.

Products such as meat hamburgers, pizza crusts, chips, and bread are often high in sodium. These strategies to reduce sodium have been useful in these products.

Salt substitutes and alternative taste combinations have been used to reduce the sodium content of food without compromising customer acceptance. While the umami taste provided by monosodium glutamate has been proposed, it has not been effective in all cases. Although potassium chloride, a widely used salt substitute, has a similar salty capacity to regular salt, its bitter or metallic aftertaste limits its appeal.

Food composition also affects the salty taste

Foods consist of different components, including proteins, fat, carbohydrates, water, and minerals. These components possess distinct characteristics that influence the salty taste. Sodium, an ion with a positive charge, can interact with negatively charged molecules or ions in food. Components in foods have positive, negative, or both charges. These components can alter sodium mobility. For instance, if sodium is added to a negatively charged molecule, its mobility decreases.

Proteins are one example of these charged components. Depending on their conformation, they can be positively or negatively charged. When a protein has more negatively charged amino acids, it can interact with the sodium, affecting mobility. This interaction can either enhance or reduce saltiness perception, depending on the case. For instance, in foods with high water content, salt solubility tends to decrease. On the contrary, lower moisture levels increase salt solubility, accelerating salty perception.

Additionally, increasing the speed of dissolution plays a crucial role in reducing sodium consumption, as it promotes the release of sodium from the food before it is swallowed, thus enhancing flavour perception. This principle applies to both salts included in the food matrix and on its surface.

How can we evaluate the salty flavour in food?

There are several ways to assess the saltiness of food, with tasting being the most common. Usually, a person can detect if one food is saltier than another, but in some cases, the differences are so subtle that specific tests are required to detect them.

There are tests designed to evaluate if a modification to the salt incorporation accelerates the perception of salty taste. Due to their complexity, only trained panellists are suitable to conduct these tests. One such example is the Time Intensity Scale, in which, after tasting a product, the velocity and intensity of the perception of salty taste are recorded.

Tests like preference or scaling are employed to evaluate preferences or the ability to detect variations in salty levels.

Sensitivity to salty taste varies among individuals

Individual characteristics can influence the detection of salty flavour. For instance, habitual salt consumption can affect sensitivity. Individuals who consume high quantities of salt may need more salt to perceive food as “salty”. Also, age-related changes can affect flavour detection, and older adults may perceive salty foods differently than children.

Considering these factors, salty flavour is not solely dependent on the added salt in the food. Several options are available to reduce the amount of sodium derived from food consumption. It is crucial to consider the target population and the intrinsic characteristics of the food, as these factors play a key role in modifying the flavour.

So, how can all of this be applied to reduce sodium consumption?

First, it is a factor that enhances the taste of salt by reducing added salt. So, if the product to elaborate on is dry food, incorporating the salt in particles with smaller or hollow shapes on the surface is an option.

If the salt is going to be part of the ingredients (mixed), using proteins or gums to adhere the sodium may have an enhancing effect, always looking to accelerate the sodium dissolution speed.

Conclusions

Considering that sodium is not only used to give a salty taste but also to prevent the growth of microorganisms, applying alternative techniques, like lowering the moisture content, can be an option to reduce the use of sodium that is not too flavourful.

Lastly, promoting knowledge of the content of sodium and salt in foods, resalting the fact that not only the added salt is the source of ingested sodium, may be of help in the promotion of healthy and conscious decision-making when eating food.

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Journal reference

Fonseca-Bustos, V., Madera-Santana, T. J., Martínez-Núñez, Y. Y., Robles-Ozuna, L. E., & Montoya-Ballesteros, L. D. C. (2024). Techniques of incorporation of salty compounds, food matrix, and sodium behaviour and its effect over saltiness perception: an overview. Journal of Food Science and Technology61(5), 861-869. https://doi.org/10.1007/s13197-023-05861-6

Ms Verónica Fonseca Bustos is currently pursuing her PhD at CIAD A.C. Her research focuses on enhancing and evaluating food products with added benefits. She is particularly interested in evaluating the sensory, physical, and biochemical aspects of food production processes, composition, and ingredients. Additionally, she explores the use of different local ingredients or by-products to maximise their potential benefits and apply them in food products.

Dra. Luz del Carmen Montoya B. is a senior research professor at CIAD A.C. and a member of the National System of Researchers Level I of CONACYT. Dr Montoya's research focuses on developing new products and adapting processes to extend the shelf life of fruits and vegetables. This helps to preserve their bioactive compounds to maximise the health benefits to consumers. Dr Montoya also works on utilising the by-products generated from these foods and supports the food industry in production processes and product quality. Additionally, she contributes to training future researchers and their development in the food industry.