A Watched Pot: Soups Go Low-Sodium

June 14, 2012

20 Min Read
A Watched Pot: Soups Go Low-Sodium

By Kimberly J. Decker, Contributing Editor

In early 2010, The Campbell Soup Company announced to great fanfare that it would lower the sodium content across more than half of its condensed canned soup line by as much as 45%in some cases dropping totals from an eye-popping 800 mg of sodium per serving to a relatively modest 480 mg. The initiative earned widespread praise from constituencies ranging from public health advocates and government officials to members of the medical community.

But consumers were conspicuous in their silence. It turns out that, despite their vocal handwringing, most consumers had grown to like those salty soups. Which may be why less than a year and a half after its original announcement, Campbell's management, facing flagging sales of its reformulated products, reversed course and brought the salt back.

One could read the story as an object lesson in the perils of doing well by doing good. But the more constructive interpretation may be to take it as a sign of the difficulty of reducing sodium in soups, where a salty taste has become a defining characteristic. Yet difficult though it may be, ingredient suppliers and product developers are putting salt savvy to work in making low-sodium soups not just possible, but profitable.

Recommendations versus reality

Kevin McDermott, technical sales, Savoury Systems International, Inc., Branchburg, NJ, recalls when the sodium situation first hit him. I think I understood the real seriousness of the salt-intake concern when, in March 2009, I read of a study in the Journal of Nutrition on how medical researchers had observed high sodium intake affecting nitric oxide synthase enzyme activitywhich, in short, slows down the regulation of blood flow by slowing the signal to muscles around the blood vessel to relax. It is a real scientific linkage to cause and effect."

But you dont have to read the scientific journals to know that Americans get more sodium than they need. The Centers for Disease Control and Prevention (CDC), in its February 2012 report, Food Categories Contributing the Most to Sodium ConsumptionUnited States, 2007-2008,"  notes that 9 out of 10 Americans exceed sodium recommendations by 40%, seeing the current ceiling of 2,300 mg per day1,500 mg for at-risk groups like non-Hispanic blacks, people ages 51 and older, and those suffering from hypertension diabetes and chronic kidney diseaseand raising it to 3,266 mg, excluding what we add at the table.

And that exclusion speaks volumes, the gist of which is that most of the sodium consumers get comes from processed and packaged foods (two-thirds) and foodservice (one quarter), according to the CDC. If we in industry were to cut the sodium content by 25% in the top-10 sodium sources, all of which Americans largely purchase outside the home, CDC says we could reduce total dietary sodium by over 10%, prevent an estimated 28,000 deaths and save $7 billion in healthcare costs annually.

Soup in the crosshairs

When CDC ranked those top-10 sources, the leading five were, in descending order, breads and rolls, cold cuts and cured meats, pizza, fresh and processed poultry, and soups. To anyone whos ever skimmed the numbers on the nutrition facts label, the only surprise is that soups didnt rank higher.

According to Emil Shemer, director, food solutions, Sensient Flavors LLC, Indianapolis, Sodium levels in retail soup products vary across different brands and product lines, but in general can range from a high of over 900 mg sodium per serving to a low of 140 mg of sodium per serving."

What consumers consider a serving size, however, can be a problem. Although an individual serving may have 600 mg of sodium, if you eat the whole can of soup, which may be two servings, you end up eating 1,200 mg of sodiumalmost an entire days worth," notes Meredith Bishop, principal development scientist, Spicetec Flavors & Seasonings, Cranbury, NJ.

The miracle mineral

Tthe presence of so much sodium in soups is no sinister plot, nor is it a matter of careless formulation. Sodium is a miracle mineral. Sodium brings a lot to food," Bishop says, including preservation and microbiologic, textural and flavor functions." Most importantly, its taste is like nothing else on earth.

As far as ingredients go, salt is the main source of that inimitable taste, as well as most of the sodium in soups. Salt gives enhancement to the broths and ingredients used in soup by making flavors brighter and letting them come alive in your mouth," Bishop says. It enhances mouthfeel and the body of food while balancing flavors and toning down bitterness."

And, adds Shemer, because canned soups see harsh processing conditions, added salt provides overall flavor enhancement" to make up for notes that processing may attenuate.

But as a source of sodium in soups, salts got help. Flavor enhancers like hydrolyzed vegetable protein (HVP) and monosodium glutamate (MSG) carry a sodium load of their own. For example, MSG contains 12.3% sodium, compared to salts 39.3%, and appears in soup at levels ranging from 0.2% to 1.0%, according to Joseph A. Formanek, Ph.D., associate director, business development and application innovation, Ajinomoto North America, Chicago. Therefore, at 0.4% delivered"not unusual in soups, he saysthe sodium level is 49.2 mg per 100 grams of product, or 110.7 mg per cup." Thats not insubstantial, but its still less than if salt were used at the same level, in which case the sodium content would rise to 157.2 mg per 100 grams, or 353.7 mg per cup. Meanwhile," he says, MSG delivers that delicious umami flavor that is a critical contributor to the overall complete flavor of the product."

Other contributors of sodium include sodium salts used for texture, preservation and other functions, as well as seemingly innocuous ingredients like meats, grains and vegetables can. All of which is why Bishop advises companies to consider sodiums broad range of functional properties in a formula, so they can identify alternatives" to replace it effectively.

Cracking the sodium code

Soup companies have been taking those considerations into account as they try cracking the sodium code. Campbells pullback notwithstanding, many manufacturers have voluntarily and publicly stated their intent to reduce the salt and/or sodium levels significantly in their processed soups in stepwise programs," says Esmond Joseph, Ph.D., R&D director, Mizkan Americas, Inc., Mt. Prospect, IL. In some soup categories, a typical serving size three years ago had as much as 1,100 mg sodium. Today, in that same category you can find sodium levels around 480 mg per serving, if not lower."

Thats not to say its been easy. The two major challenges of sodium reduction are pricing and stability, McDermott notes. Salt, he says, is an inexpensive way to add both a lot of flavor and stability to food, making food taste better and safer to eat. It is the cheapest flavor on the market, and its easy to access."

And though were only beginning to understand the science behind salt perception, one thing we know for sure: We like it. Humans seem to have an innate response to salt," Bishop says. We just like that taste." And that makes its removal all the more difficult. Moreover, the more salt we eat, the more we seem to want.

, explains, The problem with sodium receptors is that they become desensitized," says Rich Davidson, Hagelin Flavor Technologies, Branchburg, NJ. Nevertheless, people want to do the right thing," he says. That holds true for consumers aiming to consume less sodium and for the food manufacturers who can help them reach their goals. But, while manufacturers may find the first 5% reduction, maybe even the first 10%, painless, he say, go beyond 10%, and all of a sudden, the customer says, Wait a minute, this doesnt taste right. It tastes bland, it tastes wrong, it doesnt have that pop. They dont get the umami. They dont get the flavor release. They dont get the mouthfeel they really crave."

And the soup medium itself poses unique challenges, because of the way its processed and delivered," Bishop says. When cutting salt, companies must maintain flavor integrity while controlling for the taste and flavor changes that occur during packaging or retort," she says. And once the soup gets to the consumers kitchen or office microwave, any manufacturer control over quality goes out the window. Yet, because its such an obvious source of sodium, salt is an easy target," she says. "What is not so easy is mimicking the flavor and body that salt brings to soups."

No silver bullet

Historically, product developers have turned to salt replacers, like potassium chloride (KCl), and flavor enhancers made from a combination of hydrolyzed proteinssoy, wheat, corn, yeastplus sodium-containing components like MSG to restore savory flavor and balance to low-sodium formulations. But, no single ingredient will replace the flavor of salt,"  says Joseph. "Thus, this can be a painstaking exercise, and the resulting product will likely be more expensive to formulate while still not entirely matching the original product in overall sensory characteristics."

Each of the standard solutions has its drawbacks. Consumer skepticism and labeling issues dog MSG. KCl is economical, but is notorious for its bitter aftertaste. , Manufacturers are still looking at these replacers as options," notes Barbara Zatto, director of culinary and sales manager, West, food ingredients division, Mizkan. But, given their weaknesses, the manufacturer then typically needs to add another replacer to mask the chemical aftertaste," she says.

Flavor enhancers are no silver bullet, either. As Sam Rao, Ph.D., vice president and chief innovation officer, Nu-Tek Salt, Minnetonka, MN, points out, Flavor enhancers tend to be a more costly solution, and one of the problems companies have experienced while using them in low-fat and low-solid soups is that flavor enhancers dont survive processing."

The 21st-century toolkit

Suppliers are bringing these ingredients into the 21st century with advances that augur greater success in soups. Take KCL.Nu-Tek Salt has patented a technology for producing what Rao calls an advanced formula, single-crystal potassium chloride which allows for sodium reduction without the bitterness associated with potassium chloride." The ingredient is already seeing action in high-solids, high-fat applications such as cream-based soups, where it improves upon traditional KCl and offers a cost-effective solution," he says.

Ajinomoto offers a new yeast extract designed for enhanced umami impact. Unlike most other high-umami yeast extracts," Formanek says, the ingredient delivers high levels of glutamates, making the product suggested for use in applications where label restrictions would, unfortunately, not allow the use of MSG."

As for flavor enhancers like HVP, they too are getting an upgrade. One common complaint about HVPs concerns the not-insignificant dose of sodium they deliver themselvesmaking their use as sodium-reduction agents something of a two-steps-forward, one-step-back proposition. But for soup manufacturers who include it in their toolkit, -Innova, Lombard, IL, developed a line of low-sodium HVPs.

Dafne Diez de Medina, Ph.D., vice president of innovation, research and development, Innova, emphasizes that these HVPs are not sodium-reduction ingredients in themselves, but rather help lower the sodium that HPV contributes. Switching to a reduced-sodium version of the same HVP, she says, reduces "the salt content to 35% without diminishing the flavor. It provides a comparable ingredient and a comparable flavor enhancement, but with lower salt."

The extent of the sodium reduction will depend on the HVP chosen, as well as its formulation level. But Diez de Medina notes that with options made from corn, soy, wheat and combinations thereof, theres plenty of opportunity to fine-tune a choice for a soup. And, because of the high enhancement," she adds, sometimes you can even decrease the amount of HVP itself, using less and delivering the same flavor profile." Even better for the cash-strapped consumer, the HVPs allow for at least partial replacement of more costly ingredients like autolyzed yeasts or meat powders," she says.

The big picture

Obviously, choosing ingredients to compensate for salt is a necessary aspect of sodium reduction. But its not sufficient. Product developers have to examine where else sodium lurks, and how it works, taking into account the bigger picture. In the past, product developers had added ingredients to solve for flavor challenges, versus stepping back and evaluating the whole product," Bishop says. With each sodium-reduction project, our customers and our technologists have gained hands-on experience that gives us the knowledge to greatly improve reduced-sodium formulation," she says.

For example, Spicetec unbundles recipe formulation, identifies key components and locates sodium sources," Bishop says. "Then we use ingredient and applications expertise to find effective, functional and economical strategies to achieve sodium-reduction goals, taste and product performance." That may mean tapping into combinations of Maillard reaction flavors, yeast extracts, MSG, disodium inosinate and disodium guanylate (I+G), mineral salts, acids, fermented ingredients, vegetable concentrates, spices, high-intensity sweeteners, bitter maskers and blockers and flavor top notes to come up with a comprehensive solution. And if that sounds pricey, it can be. But it neednt be prohibitively so. Replacing salt is not a low-cost venture," she concedes, but you can achieve measurable results without a great deal of added expense."

Sensient uses improved sensory profiling" to draw a finer bead on the profile of the ideal finished soup. By understanding these sensory attributes," Shemer explains, we can determine how a certain level of sodium reduction affects the overall profile. Then its possible to change, build back and/or compensate for any notes that become enhanced or reduced with the reduction in salt." So, when using flavor enhancers in a reduced-sodium tomato soup, they may play with acid, spice and herb notes, along with the fundamental tomato flavor. They may lower or mask sweetness. Manipulating the entire formulation and not just compensating for the reduction in salt," he says, results in a successful reformulation project for sodium reduction."

Work in progress

Figuring out how the bigger picture affects saltiness perception remains a work in progress, as the approach to starch and mouth-coating ingredients illustrates. On one hand, some formulators believe dairy and starch thickeners create the need for more salt. On the other, Rao and others believe that, in general, starchy and creamy textures are helpful in replacing sodium in soups," he says. "These textures act as a solid ingredient and enhance the viscosity of the soup. Adding purified ingredients, such as starches, fats and proteins, is another way to replace sodium in soups."

Whos right? For his part, Ody Maningat, Ph.D., vice president of applications technology and technical services, MGP Ingredients, Inc., Atchison, KS, splits the baby: In a high-salt food matrix such as soups, we have a theory that the type of modified starch used in the broth may impact perception of saltiness." Hydroxypropyl wheat distarch phosphate, used as a thickener, has a short, smooth mouthfeel with quick release from the palate," he says. Faster release triggers a more intense flavor sensation. As a result of the absence of flavor masking," he adds, the salt level, as well as use levels of other flavors in soups can be reduced, leading to saltand sodiumreduction and cost savings."

Stealth sodium

Salt may contribute the lions share of sodium to soups, but Yan Huang, Ph.D., technical applications specialist, meat, seafood and poultry, Innophos, Cranbury, NJ, reminds us that we dont just add sodium to the liquid soup base, but to the solid components, as well. And this, she says, might give us a new direction in how we can lower the overall sodium in soups: by cutting both the salt added directly to the water phase, as well as in the solids."

For example, diced chicken may use sodium lactate as a preservative, or sodium phosphate to bind water. Because both functional ingredients add sodium, alternatives to these ingredients might help to lower the sodium in the solids phase and, thus, lower sodium overall," Huang says.

Yet, Bishop points out that some soup ingredients can suffer for a reduction in sodium. Salt affects meat texture by helping muscle fibers bind," she explains. Reduced-salt meats tear more easily during slicing because the meat doesnt hold together as well. Messy slices make portioning hard and can further increase costs if you have to add more pieces to a soup."

Innophos offers several phosphate-based products that improve the sodium-reduction picture. One is a direct substitute for sodium tripolyphosphate (STPP), considered a workhorse of the meat, seafood and poultry industry," says Huang. A combination of potassium and sodium phosphate with 2% sodium compared to STPPs 31%, it can effectively reduce sodium content by 10% to 30%" in the finished meat product, depending on the formulation, she says. Another phosphate blend improves binding in lower-salt meat products. It is particularly helpful in directly lowering the salt content from 15% to 25% in processed meats without affecting the texture of the product," she says.

Playing with the brain

Other companies are taking a more physiological approach to sodium reduction, aiming at how the brain perceives salty taste. If you look at the neurobiology of the taste receptor," Davidson says, how it takes up sodium, travels down the ion channels, goes into the cell, triggers the signal of the neurotransmitter to say to the brain, Hey, theres salt here," you have a mechanism whose manipulation can alter our perception of salt.

Hagelin Flavor Technology offers ingredient technology that actually tricks the receptor into thinking theres more sodium there than there is," Davidson says. So you almost get a stronger response from the cell." The ingredient comprises a wide range of materials, including non-KCl salt enhancers and flavor ingredients whose precise composition reflects the formulation of the soup. Itll depend on water activity, the chemistry of the matrix, the other ionic products in there, phosphates, nitrates," he says, because those will all have an effect on the taste receptors on the tongue, as well."

Because each flavor system is unique to each soup, the ingredient is no one-size-fits-all solution. One version of the product at 0.05% in a beef broth may deliver a really, really good effect and a 15% to 20% reduction in sodium," Davidson says. But put the same product at the same level in a chicken noodle soup and the effect is not nearly as strong."

Minor tweaking to find the right match requires close collaboration with the supplierand a degree of disclosure not all product developers feel comfortable making. But they should. We want to work with customers who are willing to collaborate that way, because if you just lob the system over the fence into products, people will think it doesnt work," Davidson says. But thats because we havent been able to get our hands on the product and understand its chemistry."

Back to basics

Advanced technologies like these are impressive, but they may just be souped-up versions of tools that savvy cooks have been deploying for years. As Zatto says: Lets get back to basics. Building flavor profiles that provide complexity, balance and interest is keydeveloping flavor by paying attention to secondary characteristics and nuances in food."

For example, dont just settle for a beef flavor. Roasted, caramelized and grilled notes need to come through in that flavor, too," Zatto says. "Sweet notes, light or heavy, can also appeal to the palate. Vegetables, sautéed or roasted, can add to the flavor without adding additional salt." And, when they have intriguing textures and piece identity, she continues, theyre even more effective. Vinegars, wine and citrus notes from orange, lime or lemon can help make up for lost salt, as can herbs like rosemary, thyme, basil, tarragon and mint.

Bishop recommends leveraging umami-rich ingredients, which create what she calls a universal taste" that aids sodium reduction. Japanese ramen soups are an example of an ethnic soup that uses umami-rich ingredients like miso to create big flavor," she says. "Thai tom yum, with its sour and spicy components, is another great example of an ethnic soup that creates perceptions of more flavor and dimension without relying on excess sodium."

And though we associate umami principally with the flavors of Asia, the concept knows no boundaries. There are many foods that are rich in umami character," Bishop says, including cheese, tomatoes, meat, fish and mushrooms. Their inherent glutamate and ribonucleotides provide a savory enhancement to enrich the profile," she says. "These products are a hidden secret, too, because they occur naturally in the development stage."

With global cuisines so popular, why not take advantage of what they bring to sodium reduction? Indian daal soups can be flavorful without adding a lot of salt," Zatto says. And dont forget the condiments. Fresh salsas, chutneys, hot sauces and sambals provide a huge pop of flavor without adding a lot of sodium," she adds.

Shemer also appreciates how international cuisines can teach us about sodium reduction. The great thing about global ethnic cuisines is the abundance of unique and flavorful spices, herbs and flavor profiles," he says. The combination of interesting, bold flavors, acid, spices and herbs provides a flavorful option for building a profile thats stimulating to various sensory sites in such a way that the lower-sodium soup is still very pleasing to the palate."

Take it easy

Butas developers at Campbell's would likely advisetake things slowly, both when introducing global profiles and when cutting sodium. Companies lowered the levels of sodium in their products too fast and lost ground with consumers," Bishop points out. Big jumps can shock a customer who is familiar with a food, so an immediate drop in sodium, which affects flavor, can be offsetting."

Managing these shifts can prove tricky. But, says Bishop, thats where a flavor company can help control the taste differences that come with those changes, like helping maintain a roasted-chicken flavor that retort decreased without adding excess sodium. Gradual reduction of sodium over time, slowly and steadily reducing sodium 5% or so each year, has given consumers the chance to adjust to the taste."

Kimberly J. Decker, a California-based technical writer, has a B.S. in consumer food science with a minor in English from the University of California, Davis. She lives in the San Francisco Bay Area, where she enjoys eating and writing about food. You can reach her at [email protected].

Lower Sodium, But Don't Brag About It

This might explain the Campbell Soup experience. According to a study published in the March 2012 Public Health Nutrition (dx.doi.org/10.1017/S136898001200064X), foods highlighting sodium reduction can negatively affect taste perception and salt use.

Researchers at Deakin University, Australia, and Unilever R&D, the Netherlands, investigated the effect of nutrient labels and health logos on expected and perceived liking and salt intensity of sodium-reduced soups. Of 50 participants, more than half stated that health labels affect their food choices. They looked at commercial chicken noodle soup with the same ingredients, but three different sodium levels: no sodium reduction; 15% sodium-reduced soup; and 30% sodium-reduced soup. Each of the soup products was labeled with one of three labels: no health label; a label stating Now reduced in salt, great taste"; or the check" health logo.

For all types of soup, more participants added table salt when the soup carried the reduced-salt label compared to when the same soup carried either the health logo or no label. Those who did add salt, also added more salt when soups carried the reduced-salt label, independent of the actual sodium content of the soup. When 30% sodium-reduced soup was labeled with a reduced-salt label, participants over-compensated the reduction in sodium by adding table salt beyond benchmark levels.

Exposure to the reduced-salt label resulted in lower expectations and lower actual taste experience of the soups in terms of liking and saltiness. The perceived saltiness of the soups with a salt-reduction label was lower than would be expected based on the actual amount of salt in the soup. Providing the health logo or no label did not influence taste perception.

The Editors

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