Pour it on: texturizing dairy beverages
The right texture can yield sensory benefits that differentiate a dairy beverage from its competitors.
You’ve got to be pretty quick to keep up with the changing dairy beverage space these days. Dairy brands are looking for new ways to compete not only with sodas — which are finally starting to cede market share to better-for-you options — but also with a growing array of better-for-you beverage options.
To do that and to stand out to consumers in crowded beverage cases, dairy brands have to innovate. And that’s exactly what they’re doing.
“Traditionally, most consumers thought of dairy beverages as either chocolate milk or conventional white milk,” noted Christine Addington, senior dairy technical service specialist, Cargill, Minneapolis. “That’s no longer the case. Consumers are open to trying new flavors and products, and now recognize all the great health and sensory benefits available in dairy.”
Chief among those sensory benefits is texture, which “can make or break the sensory experience of a dairy beverage,” she noted. And as dairy developers entertain new strategies for innovation, they’re increasingly looking to texture as a means to differentiation. Still, dairy brands must choose ingredients that provide the appropriate texture for each dairy beverage application.
Dairy is diversifying
Those applications aren’t what they used to be.
“Over the last decade, consumers have opened their minds and their mouths to new tastes, textures, colors, aromas and packaging that they may not have considered in the past,” said Barbara Chinn, senior manager, food applications and research and development, CP Kelco, San Diego.
Their explorations have led them to “delicious and innovative dairy beverages,” including fermented milk drinks, acidified low-pH dairy drinks, fruit-protein smoothies, milk-juice drinks, drinkable yogurts, flavored milks and more, Chinn said.
As the number of dairy drinks multiplies, so, too, do consumers’ demands for “healthier and more nutritious options,” Chinn added. But the opportunities here are plentiful. After all, formulators can fortify with novel protein sources, probiotics, fibers and nutrient-delivery options, all while leaning on texturizers “to accommodate the use of these added wellness components and ensure the desired texture in the finished product,” Chinn said.
What’s texture got to do with it?
Despite the fact that “in most people’s minds, texture comes after flavor in the enjoyment of drinkable products,” the two sensations are inextricably linked, said Jon Hopkinson Ph.D., senior applications scientist, DuPont Nutrition & Health, New Century, Kan.
That’s true not only for consumers, but for developers, too, who have to consider texture as much as they do taste when formulating dairy beverages.
“With texture, the palette available to product innovators is quite wide,” Hopkinson said. “Often, it’s the combination of all the colors on the palette that produces the best product. But like an artist’s palette, improperly mixed colors can become muddy and unappetizing.”
Even a properly developed texture can muddy those waters if it doesn’t meet people’s expectations.
“Consumers know what they like,” Chinn noted, “and their preferences vary widely by region and country across the globe. What seems ‘too thick’ in consistency in the U.K. may seem thin and watery to someone in the U.S.”
And these textural effects stand out even more starkly in dairy relative to nondairy beverages such as juices, sodas and teas, added Nesha Zalesny, technical sales manager, Fiberstar Inc., River Falls, Wis. A beverage’s mouthfeel “correlates to how fast the consumed mass dissipates in the mouth,” she explained, and variations in the viscosity of something as simple — yet familiar — as chocolate milk “can mean the difference between a refreshing post-workout beverage and a treat of melted ice cream,” she noted.
Hopkinson pointed to the texture that results from particulates as another position on the texture palette. Consider the bubbles in a bubble tea or the pearls of tapioca in a pudding, he suggested — or on a smaller scale, the unique texture provided by the particle size of cocoa. This textural effect, too, needs managing.
But for the most part, the core texture in dairy drinks largely boils down to classic creamy with “good mouth-coating characteristics,” Addington concluded. Thus, a drinkable yogurt needs a thick viscosity “so consumers can feel like they’re actually drinking a yogurt beverage versus thin white milk.”
Striking the right textural balance in dairy drinks might sound easy. And it’s true that there are few textures that today’s ingredients can’t achieve. But the nature of the dairy environment means that even “smart” texturizers have their work cut out for them.
“Dairy beverages are sometimes more challenging to texturize because there can be many components in the formula, including milk proteins that can be very unstable,” Addington explained. Because whey proteins are heat-labile, high-temperature treatments such as ultra-high-temperature processing “run the risk of denaturing the proteins, causing a sandy or gritty texture,” she said, or leaving a mass of congealed protein settled out at the base of the bottle.
Contrast this with the relatively sedate environment of a fruit or juice beverage, for which processors need not worry about changing the inherent pH or stabilizing proteins. It becomes easier to achieve a smoother texture and mouthfeel, Addington said. What’s more, consumers don’t expect a thick, creamy texture in a fruit juice anyway.
In fortified and shelf-stable dairy drinks with shelf lives topping six months to a year, textural challenges are “magnified” further still, Chinn added.
“Ingredients like insoluble calcium, fiber and cocoa must remain suspended throughout the product’s shelf life to ensure consumers will receive the intended nutritional impact and consumption experience,” she said. And in an era when low-sugar — and, to some extent, low-fat — formulations are gaining traction, the need to “build back the desired mouthfeel” in these products is even more critical.
But no need to let texture intimidation set in.
“In general, it’s not hard to change the texture of any dairy beverage,” Hopkinson said. “Knowing the rheology of the original and that of the desired product is the first step toward achieving your goal.”
“With the introduction of new texturizing ingredients like starches, gums and fibers, dairy beverage production has become more efficient and consistent. We now have options that allow manufacturers to add texture to products more quickly while also maintaining flavor and keeping costs in check,” she said.
Use levels are often low, Addington noted, and in addition to improving mouth-coating and texture, today’s options also help provide effective homogenization and avert phase separation and protein precipitation.
But what’s funny is that many of these “new” ingredients aren’t all that new — at least not fundamentally — and it’s quite striking how consistently some texturizers show up in dairy beverage formulations year in and out. Take, for instance, pectin — the go-to texture choice in acidified dairy drinks.
“Without pectin, dairy protein begins to stick together, forming large clumps,” explained Paige Ties, senior technical service specialist, research and development for Cargill.
At a low pH, the normally net-negative charge on the dairy protein casein creeps closer to zero, allowing aggregates to form. In a low-pH milk system stabilized with pectin, Ties said, “the negative pectin molecules electrostatically stick to the positive areas on the casein while avoiding the negative areas,” forming what she calls a “protective net” that maintains the overall negative charge on the casein/pectin complex. Thanks to that net negative charge, “the proteins continue to repel each other” rather than clump together and settle at the container base or produce the gritty texture that sometimes plagues low-pH protein beverages.
While pectin has been around for generations, processors’ ability to extract it from citrus “has advanced by leaps and bounds in the last 10 years,” noted Jamie Underwood, senior technical service representative for Cargill.
“We’re now able to manipulate pectin’s structure better to target stability and gelling,” Underwood said.
That’s allowed for the stabilization of drinkable yogurts, milk-juice blends and low-pH dairy beverages.
“Thanks to our enhanced pectin products, yogurt drinks are now one of the hottest dairy beverage segments,” she added.
Noting that some pectins can be “highly processed” — as is carboxymethylcellulose (CMC), its common accompaniment in dairy texturizing systems — Zalesny offers her company’s natural citrus fiber, Citri-Fi, as a “clean-label alternative” to both ingredients in acidified dairy and smoothies. The fiber is water-washed and physically processed to “open up the fiber” before it’s dried and milled, she explained, and its high levels of native pectin, cellulose and hemicellulose help it extend pectin and add mouthfeel to the point of nearly replacing pectin or CMC. She recommended a grind size of 30 mesh for bringing pulpiness to smoothies, and 200 mesh “for creamy-type beverages.”
Though not unique to low-pH dairy beverages, the phenomenon of age gelation, or the clumping of milk proteins over time, also requires a solution from today’s texturizing arsenal. Phil a’Becket, market research analyst, TIC Gums, White Marsh, Md., noted that when age gelation occurs, the product can look unappealing and even spoiled.
“It can limit a brand’s or even an individual product’s footprint,” he said. “And if a dairy product appears to be clumping, the consumer automatically assumes it’s unsafe to eat.”
His company developed a stabilizer blend, Ticaloid PRO 192 AGD, which not only stabilizes proteins to suppress age gelation, but also emulsifies the beverage to allow the removal of other ingredients not meeting clean-label parameters.
If pectin is the standard bearer for texture creation in low-pH dairy drinks, neutral-pH products such as chocolate milk traditionally achieve their stability and textural appeal courtesy of carrageenan. Its ace in the hole is its charge density, which helps it keep particles such as potassium, calcium, magnesium, proteins and — yes — cocoa in suspension.
“Electrostatic interactions enable carrageenan to entrap insoluble particles such as cocoa or calcium salts used to fortify dairy, as well as lower-density constituents such as fat globules,” said Brian Surratt, project manager at Cargill Texturizing Solutions. “And in neutral-pH beverages containing protein and electrolytes, carrageenan can stabilize proteins and provide properties such as thickness, viscosity, fat mimetic or creaminess aspects to a finished beverage.”
Use levels can be low —0.025 to 0.04%, Zalesny noted.
Carrageenan “interacts synergistically with milk proteins and ions naturally occurring in milk,” she said. “And it has a nice low viscosity, which makes carrageenan-stabilized chocolate milk refreshing rather than overpowering.”
But it’s not perfect — at least not as far as some consumers are concerned.
“The North American market is going through another ‘carrageenan is toxic’ cycle because of questionable information and science,” Zalesny lamented.
Formulators need effective substitutes, and blends, including gellan gum and a shorter-chain hydrocolloid like locust bean gum, come in handy. High acyl gellan gum forms a high-yield stress fluid gel network, suspending the cocoa well at low use levels — 0.02 to 0.03% — but still resulting in a low drinking viscosity.
But she cautioned that the fluid gel network will tighten up over time, resulting in syneresis. Thus, gum blenders recommend the inclusion of locust bean gum or gum acacia to help stabilize the network.
Zalesny also praised the performance of a carrageenan replacement system — comprising gellan gum and her company’s natural citrus fiber — in sports nutrition and nondairy nut-based beverages. With 0.3% Citri-Fi 100M40 and 0.03% gellan, the system “can replace 100% carrageenan while maintaining superior mouthfeel and oil and protein stabilization over shelf life,” she said.
It works because of the fiber’s “unique composition of insoluble and soluble fiber — mostly native pectin — protein and lipids. The high surface area and native pectin provide the natural emulsification stabilization needed in certain beverages,” she said.
It’s only natural for texturizer suppliers to focus on texturizing ingredients. But Hopkinson points out that texture also can be modified using unconventional means when appropriate.
“Protein can be hydrolyzed, starches broken into smaller segments, sugars polymerized,” he said. “All these can be achieved using technologies now available and becoming available to dairy developers.”
Ivan Gonzales, marketing director, dairy for Westchester, Ill.-based Ingredion Incorporated, added that new ingredient technologies and processing conditions offer ways to functionalize milk’s inherent components to manipulate the texture in the final products.
“Thus, we have cultures that use lactose, processing conditions like UF and heat treatments to make proteins more functional, but also new texturizers and gums that let us create new beverages,” he said.
In other words, we have options — as do dairy drink consumers. And that should encourage us all.
“Be open to new and interesting concepts, unique textures and new processes,” Hopkinson said. “They’re not difficult to achieve, and the consuming public is eager for new and interesting offerings. Remember, the most successful products rarely, if ever, come from incremental changes to existing products.”
All photos courtesy of Cargill