Rebalancing Flavor in Reduced-Calorie Beverages

It seems that Americans have finally accepted the fact that calories do counteven when they come from beverages. Our collective revelation has hit as our grab-and-go lifestyles have begun replacing the knife and fork with the straw, and the confluence of booming beverage consumption with caloric concern has shined a spotlight on reduced-calorie beverages. Beverage manufacturers have responded by reexamining their product lines for calorie-reduction opportunities. But, as any beverage developer knows, draining a drinks excess calories is only the first step in the reformulation processone that throws just about everything else we crave about a beverage out of whack. But, with the right flavors, alternative sweeteners and functional tricks, you can give even calorie-conscious consumers a reason to raise a glass to your formulation.

The sugar standard

The beverage medium leaves scant space for hiding flavor imbalances. This is doubly so in reduced-calorie formulas. By cutting sugar and fatthe main source of beverage calorieswe not only dramatically alter taste, but expose background flavors, upset sweet-acid balance, hamper flavor delivery and release, modify mouthfeel, and shift flavor intensity and duration, as well. All of which leaves major challenges for the developer in rebalancing these characteristics, according to a statement from the FONA International Beverage Technical Team, Geneva, IL.

Experts agree that much of the difficulty stems from matching the palatability and functionality of sugar, the classic beverage sweetener. Sugar is the standard by which we measure all other sweeteners, says Ron Deis, Ph.D., vice president, applications research & technical services, Corn Products U.S., Westchester, IL. Whenever a new sweetener is introduced, its unique characteristics are measured against sucrose at various sucrose equivalencies, and product development is shaped around reaching at least parity with a full-sugar product. But all sweeteners are not created equal. Each has its own taste profle, flavor and mouthfeel fingerprint, and to the extent that consumers have grown accustomed to any one, much of the reformulation task involves replicating it.

Sugar is very clean tasting, with a rapid onset, no off tastes, and limited lingering sweetness, says Greg Horn, senior director, sweetener technology, Wild Flavors, Inc., Erlanger, KY. Sucrose also adds mouthfeel to beverages because it can structure water and provide body to the beverage.

High-fructose corn syrup (HFCS), on the other hand, has its own profile. HFCS has a quicker sweetness onset and subsides faster than sucrose, allowing delicate flavors to come through, says Andrea Belford, food applications laboratory manager, Corn Products U.S.

The flavor of honey, which often appears in natural beverages, can vary by quality and flower source, adding an even more-complex flavor which can either augment or contradict the existing flavor profile, depending on what the flavor-type of the beverage is, Horn says. Add the changes that sugar undergoes courtesy of Maillard browning and caramelization reactions, and its a potent tool for building a beverages personality.

Body of evidence

Beverage experts give sugars effect on mouthfeel paramount consideration in any calorie-reduction effort. When you change the sugar blend, the one thing you really notice is the reduced mouthfeel that the sugar solids bring, says Tom Copeland, senior beverage technologist, Sensient Flavors, Inc., St. Louis. The bulk solids it contributes to a full-calorie beverage, plus its longer residence time on the tongue, substantially affect a drinks three-dimensional body. Manufacturers of reduced-calorie beverages have several options for replacing mouthfeel. Kimberly Ferruzzi, senior beverage technologist, Sensient Flavors, Inc., suggests increasing levels of those flavor components that lend themselves to mouthfeel, as well as sweetness. Maltol, vanillin and some of the fatty acids or lactones that would be present in your flavor are good candidates, she says. Another option rebuilds texture with alternative solids. Mouthfeel can be replaced somewhat using food gums, maltodextrin or corn-syrup solids, starches, and polyols such as maltitol or erythritol, or a combined effect to attempt to mimic the mouthfeel of sugar, Deis says. Andy Del-Rosal, beverage applications lead, Cargill Flavor Systems, Minneapolis, notes an added erythritol benefit. It has masking properties that mitigate the perceived negatives of noncaloric sweeteners, he says. Some viscosifiers arent without drawbacks. Certain hydrocolloids, due to their plant-source type, relatively high molecular weight and chemical modifications, can dramatically mask or diminish flavor impact, even at nominal use levels, says Jeff Foss, principal scientist, Wild Flavors, Inc. When used at high levels, some gums send mouthfeel overboard, rendering a beverage more spoonable than sippable. Fortunately, as Gregg Bromberg, manager of flavor creations, Virginia Dare, Brooklyn, NY, says, theres a difference between adding a non-sugar physical solid to give a beverage actual physical viscosity vs. adding a mouthfeel flavor, which is not giving any physical viscosity, but rather gives you the sensation of viscosity. Mouthfeel flavors play tricks with the palate. Theres a lot of scientific data saying that they hit receptors on your tongue and taste buds, coating them and tricking them into thinking that there are solids there that arent, says Bromberg. More specifically, mouthfeel modifiers are often emulsified flavors that, because of their small droplet size, coat the taste buds in a manner that restores lost body.

A different kind of sweetness

Perceptual trickery is at play in masking, or blocking, flavors, too. Maskers and blockers are used to cover up anything from a bitter aftertaste to too much astringency to metallic off notes, says Steve Wilbur, vice president of marketing, David Michael & Co., Philadelphia. Like mouthfeel flavors, they manipulate taste receptors. Theyre not chemically changing anything thats causing the off flavors, Bromberg says. Theyre blocking the sensation on your taste buds so you dont perceive it. Maskers are useful in formulas rife with functional and nutraceutical ingredients, but they really earn their keep in moderating the less-desirable aspects of alternative sweeteners. Such sweeteners are a fact of life in low-calorie beverages. While they may have revolutionized calorie reduction, theyve also heaped a new set of challenges on beverage formulators plates. All high-potency sweeteners have characteristic sweetness intensity and flavor profiles that do not exactly match those of sugar, says Deis. They dont function like sugar either, rarely participating in browning reactions, reacting differently to acidic and high-heat conditions, and, as is the case with sweeteners like aspartame, attenuating in potency over time. More than anything, alternative sweeteners throw a previously composed flavor profile into disarray. They typically display bitterness, astringency and lingering sweetness that give them a bad name with some consumers. Sugar substitutes dont yield sugars upfront mouthfeel, either. When youre dealing with things like aspartame and acesulfame K, says Bromberg, they give you a certain thinness. Some high-intensity sweeteners may actually accentuate some flavors. Because of their bitterness and astringency, Horn says, high-intensity sweeteners may enhance tea and herbal astringency. Most of them, though, just tip things out of balance. In my experience, aspartame has almost no upfront sweetness, says Mariano Gascon, vice president, research and development, Wixon, Inc., St. Francis, WI. Therefore, cherry flavors will have a delayed onset. On the other hand, sucralose tends to enhance the upfront notes. But due to lingering effects, he says, it will turn an orange flavor into a very sweet orangealmost like a Creamsicle. Alternative sweeteners can also cause acid balance to shift. It becomes a balancing act of acid, flavor and sweetener to find an acceptable taste profile says Shanyn Seiler, senior scientist, Wild Flavors, Inc. Its also important to push the sweetness forward, which will provide a fuller sweetness profile thats closer to sugar. Taste modifiers can bring things back in line, but because they modify both the high-intensity sweeteners sweetness profile, as well as the overall flavor of the beverage, Horn recommends developing the optimal base without the flavor first, and then modifying the flavor as needed. Gascon endorses a similar stepwise approach. Taste is a delicate balance, he says, and once one taste perception is modified, the other tastes may become unbalanced. Frequently, off flavors involve a combination of different factors, not one specific one. For off flavors that are intense and persistent, a lot of fine-tuning is required.

Meeting in the middle

When deciding between alternative sweeteners and sugar, formulators neednt treat the question as either/or. The availability of next-generation high-intensity natural sweeteners, like rebaudioside A, has been a game-changer. Moreover, beverage designers now know that the best way to reduce their products calories may not be to eliminate sugar, but rather reduce it. Reducingnot eliminatingthe sugar and replacing it partially with high-intensity sweeteners results in a superior-tasting product because the overall taste profile is closer to 100% sugar-sweetened products, Horn says. A beverage formulated to derive 10 to 20 caloriesrather than zerofrom sugar may evade many of the shortcomings associated with high-intensity sweeteners, including astringency and delayed sweetness onset. In cases where the products original sugar content is high, Deis encourages developers to consider a more-moderate approach to sugar and calorie reduction. If high-potency sweeteners are used, sugars such as sucrose, glucose and fructose combine well with these to moderate the intensity profile and aftertaste differences. Sweetener synergies ameliorate mouthfeel changes, too. Instead of going to zero viscosity where you have a drastic change, Bromberg says, youre meeting somewhere in the middle.

Cola case study

But all of this is so much academic speculation until you get to the bench and start playing around with beverage formulationsat which point you really experience how calorie reduction changes beverage flavor. Take a typical cola, for example. The platonic ideal would be a balance of citrus notes and spice or cola notes, says Laura Ennis, senior beverage innovation technologist, David Michael & Co. Citrus is the first flavor tasted, with the cola notes carrying through to the end. It is sweet upfront, with a slight lingering sweetness that is not overpowering. And there is an acidic, pungent taste that lasts throughoutbut again, this is not overpowering. The profile shifts when you switch sweeteners. Replace sugar with a high-intensity option, and citrus notes quickly drop off, Copeland says. Even without changing the flavor, when you change the sweetness, the balance will totally change. He suggests you stretch the flavor maybe 5% or 10% to compensate. That way, the brown spices will come down. And if you add a touch of citric acid, thatll help bring the citrus notes back up, he says. To end up with a nice, clean finish, Copeland turns to masking flavors to knock off some of the bitterness that you might see with stevia, or the metallic notes that youll find with acesulfame K. As for other alternative sweeteners, Bromberg thinks sucralose does a pretty good job of cleaning out, but it will linger a little bit. And he thinks aspartame can linger, too. Thats why he likes using blends. Blending the artificial sweeteners is a much better strategy than trying to use them as single notes, he says. The synergy that they bring with each other gives you an overall better flavor profile. Granted, sweetener blends cant replace a sugars mouthfeel, which, at the 10 to 11°Brix level of a typical soft drink, can be substantial. Employing flavor molecules used as sweetness enhancers can boost sweetness perception, Ennis says. This, in turn, makes the mouthfeel seem fuller, she says, noting the same is true for mouthfeel enhancers, which make the mouthfeel thicker or fuller without actually affecting the viscosity of the product.

Smoothie, saved

Matters of mouthfeel and body arise in low-cal juice smoothies, too. The restoration of solids is even more important considering the need for a certain amount of solids to make them freeze correctly, Copeland says. Starches and gums help rebuild body and bulk, but formulators should beware their effect on flavor. I do find that starches will sit on a flavor if they get too high in a smoothie, Copeland says. Thats why he likes working with xanthan. However, you have to watch the amount youre putting in, because itll get a slimy mouthfeel at high levels, he says, but its clean in flavor, its readily available, and its generally economic to use. Ive used it in conjunction with propylene glycol alginateyou can use them at very low percentages and you get a good synergy. Reducing sugar by reducing juice content also weakens and flattens the profile, says Sue Kidwell, manager of flavor creations, Wild Flavors, Inc. The degree will depend on the remaining juice content. Therefore, she says, the flavor needs to be rebalanced to help enhance sweetness, as well as replace any flavor impact from characterizing juices. What about sweet-acid balance? If youve got a good amount of juice, the acid generally doesnt become much of a problem, Copeland says. However, as you lower the juice percent in the product, acid does become a much more important factor, and you may have to rebalance the acid on a low-percentage-juice smoothie when youre replacing sugar with artificial sweeteners, he says.

A word about fat

Fat may be a marginal ingredient in most beveragesappearing mainly in dairy, soy and nut drinksbut its absence in a beverage can be conspicuous, as well. From a flavor standpoint, there are two issues, says Rajesh Potineni, application research scientist, Givaudan, Cincinnati. Most flavors are hydrophobic in nature. When fat is removed, the partitioning of these compounds is altered in the matrix, which directly influences the flavor release. This can lead to flavor imbalances, a shorter residence time in the mouth and decreased flavor intensity. The absence of fat will noticeably affect a beverages mouthfeel. Fat replacers help mimic textural effects, he says, but they do not help with the flavor partitioning into the fat, and subsequent flavor release in the beverage. This is a challenging food science aspect with respect to fat reduction. Without fat, beverage acidity rises to the foreground, and sweet notes diminish. This can become an issue in fruity milkshakes or yogurt smoothies. In fact, a peach flavor will become less fruity, because the nature of the flavor notes in peach is that theyre slower to dissolve in your mouth without fat; the residence time is shorter; and the peach perception becomes flat, Gascon says. Most citrus and tart berry flavors tend to stand out without fat, too, he adds, while stone fruits and pomes fade to the background. With exotics, grapes, melons and tropicals, the effect will vary depending on the specific fruit. Meanwhile, a low-sugar, low-fat chocolate milk presents an entirely different challenge. The ideal chocolate milk is made with 2% milknot whole milkgiving it a full mouthfeel that is smooth but not overpowering, Ennis says. The flavor is sweet, rich and chocolatey, and lingers all the way through to the end, leaving you wanting more. By removing both sugar and fat, she notes, youre essentially making brown water. The chocolate becomes chalky and bitter without the sweetness to carry it, she says, and an almost complete elimination of mouthfeel subverts our expectations of what chocolate milk should be. To bring everything back into balance, cream flavors help compensate for creamy notes that flee with the milkfat. Ennis recommends working with sweetness and mouthfeel enhancers, as well as fat replacers. If hydrocolloids or starches mask flavor intensity, she notes, try using a higher level of flavor. It is a matter of trial and error, she points out, along with experience. And isnt it always? As Gary Eck, chief flavorist, Wild Flavors, says, Both the flavorists and the application people must work hand-in-hand, understanding the goals for taste, processing, manufacturing, final use, packaging and appearance. Only then will all the flavor factors fall into place.

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].