Reducing sodium intake is a global health priority. In processed foods, salt serves as a flavoring agent, preservative and texturant. Consequently, food manufacturers are facing extensive challenges in reducing the salt content of their food while still maintaining the desired taste attributes and functional properties of their products. In this article, we will explore why sodium reduction is such a challenge, what solutions exist today and where research and innovation are still needed.
Taste Is Complex
As humans, we experience taste through receptor buds, called papillae. While the traditional view is that distinct parts of our tongue experience five basic tastes—salt, sweet, sour, bitter and umami—more recent research suggests that our individual buds can be receptive to more than one taste at a time. The artistry of flavor creation in our food must therefore create the perfect balance of taste, acting to enhance those attributes we want to experience and suppress those we don’t.
Salty taste is experienced when Na+ ions in the oral cavity enter taste receptor cells through epithelial sodium channels (ENaC). These receptors are usually opened and when foods are ingested with salt concentrations, sodium flows into the cell leading to membrane depolarization. This change in membrane potential opens voltage-gated sodium and calcium channels. The increased calcium influx causes the release of serotonin which acts on the afferent taste axon. This response translates to our brains as a taste enhancer. At low concentrations it will reduce bitterness to increase sweet perception and boost overall flavor—and if introduced at higher concentrations it is perceived salty, enhancing the overall savory flavor profile and balance umami.
To make things more complex, research shows that even in our gut there are neurological stimuli for the perception of taste. A U.S. study found the brain cells of mice are able to be activated or deactivated to control what they were tasting from a sweet or salty perspective. By silencing specific regions of the brain, the scientists were able to control what the mice tasted, irrespective of what they were eating.
The experiment shows that our basic sense of taste—recognizing sweet or saltiness—is hardwired, and not something that is learned or built through experience. A challenge when looking at reducing salt arises because our brains are not easily tricked as alternative solutions cannot trigger the signal to the same degree. We then need to stimulate a cross-modal reaction in order to compensate for the physiological response with reduced sodium levels.
The Sodium Reduction Challenge
Sodium performs multiple roles within processed food and beverages, including amplifying taste, preservation and texture—three essential roles that come with minimum cost impact.
Taking the first challenge as an example, reducing salt has clear physiological challenges as well as taste perception challanges. It suppresses the overall saltiness of the food and distorts the balance of the overall savory taste. This includes characterizing tonalities decrease, sourness and bitterness increase, and umami intensity is negatively impacted. Some solutions include mineral salts, e.g., potassium chloride, yeast extracts and flavors that stimulate cross modal answers.
Food safety must be guaranteed, and spoilage must be addressed to maintain shelf life. Salt keeps the water activity in foods low, which limits microbial growth. When salt is removed, alternative ingredients that have preservative effects must be used to limit pathogen and spoilage organism growth.
Many traditionally used preservative ingredients contribute sodium, such as sodium nitrite, sodium lactate and even buffered vinegar (often buffered with sodium-based ingredients). Their direct potassium-based replacements can bring challenges of their own with taste and hygroscopicity.
Texture is another challenge that can arise when salt is reduced, especially into processed meat and bakery. NaCl plays an integral role in meat processing and when it is reduced there are negative impacts on water holding capacity, protein binding functions and fat binding functions. The increase of binding characteristics improves texture and corresponds to decreased cooking loss and therefore improved stability in some meat products. In bakery products, salt reduction will change water absorption, dough development, length and intensity of kneading and stability of dough. Gluten development and its viscoelastic properties are affected.
How Is the Industry Responding?
Hence, the challenge of salt reduction is clearly a complex one that will remain a priority for governments and manufacturers in the coming years. This provides an exciting opportunity for the industry to innovate and offer truly sustainable nutrition that tastes good.
A few common solutions used today include stealth reduction, mineral salts, MSG and ribotides, yeast extracts and salt perception flavors. Everything comes with its own price.
The most common alterative for sodium reduction is potassium chloride (KCl). Potassium chloride is a naturally occurring salt derived from the ground or sea. Food manufacturers use KCl to reduce the presence of sodium chloride by as much as 50 percent. So, what’s the problem? Well, this ingredient provides metallic taste and bitterness which needs to be masked. Most consumers complain about the metallic taste of potassium chloride. And so, it begins—a delicate balancing act of salt perception, and re-balancing of taste and flavor intensity to try and re-configure complex signaling pathways to re-create consumer acceptable taste.
Let’s look at a snack seasoning as an example. When you remove salt from a snack seasoning, the overall taste becomes unbalanced. How would your salt and vinegar chips taste if we reformulated with reduced salt? To rebalance the taste, you must have a strong understanding of the interplay of all elements of the snack seasoning. What is your snack base? How much salt can be reduced by stealth? What is the target Na in the final recipe? What other ingredients are contributing to Na content other than salt? Working with a trusted partner that offers a holistic approach to solve taste, nutrition and functionality requires not only application expertise but a deep technical toolbox to pull solutions from.
Offerings and Innovations
Sodium reduction requires a comprehensive approach. Balanced taste must be built back into foods. Salt alternatives, like potassium chloride, often bring their own taste challenges. Flavors that recover salt perception and “umami” yeast extracts are other possible solutions that can build back some of the balanced taste and mouthfeel seen at full sodium levels or mask off-notes from sodium alternatives.
By leveraging our fermentation, extraction and cooking expertise, Kerry has developed a toolbox of alternative solutions which stimulate cross-modal reaction in order to compensate for the physiological response with reduced sodium levels. Our approach looks to rebalance taste, namely through the application of our Tastesense Salt and Authentic Savory solutions which deliver a great eating experience rather than just replacing salt. Tastesense Salt can reduce salt on average by 50 percent and can be applied across a variety of foods including snacks, processed meat, prepared meals, soups, sauces, bakery and savory spreads. They are also flexible across applications including vegetarian and vegan.
Many consumers do not want to see artificial preservatives in their food, adding another challenge to sodium reduction. Kerry has a whole line of no and low-sodium preservative solutions across conventional and clean label ingredients built specifically to solve these challenges in meat and meals. Our clean label ingredients leverage fermentation, extracts, vinegars, flavor systems and innovative drying methods to deliver shelf life without compromise. With meat being the highest value category in food waste, Kerry’s Provian conventional preservation systems, IsoAge vinegars, DuraFresh fermentates and Nourishield clean label multifunctional systems are invaluable to ensuring food safety and preservation in reduced sodium processed meat.
Kerry offers manufacturers a holistic approach to solve for taste, nutrition and functionality when it comes to salt reduction. With our unique footprint of portfolio, in-house ingredients and end to end process expertise through to the final application, we embrace the challenge. NIE
Hugo Leclercq is Global Portfolio Director for salt reduction at Kerry. He holds a master’s degree in food engineering. Through his 12 years of experience in food industry in Asia Pacific, Leclercq gained strong industrial technical background with a record in managing successfully disruptive sustainable technology, based on yeast extracts, dedicated to salt reduction for regional markets. He also brings extensive knowledge in marketing and business development by understanding technical customers’ taste and nutritional needs. Over the past years, he anticipated and acted on various food segments trends (snacks, processed meat, meat analogues, sauces …) with the research development and application teams to offer tailor-made salt reduction solutions while rebalancing the taste.
