Innovation in dairy beverages seems to fuel significant growth surges at specific junctures — who can forget the revolutionary Milk Chugs which forever changed the world of single-serve milks? The most recent development of this nature is the explosive growth being exhibited in smoothie-type beverages.

Most major dairy manufacturers have by now introduced some version of a smoothie beverage, and smaller dairy manufacturers are also starting to get into the game with smoothie product lines. At the same time, new iterations of smoothies are expanding the available variations and segmentation of this category. New formulations include ingredients that often boost the protein content or enhance the nutritional profile.

Right now, it seems the sky is the limit on how willingly consumers are embracing smoothies, which makes this category a perfect playground for upping the ante with nutritional ingredients and innovative formulations. Manufacturers will continue to benefit by capitalizing upon the astronomical growth curve and by understanding where innovation is taking the category and how the newest formulations are being created.

The surprise golden child of the dairy industry in this millennium is the smoothie. Over the past three years, growth in the smoothie category has exceeded all expectations. Part of the reason for this overwhelming growth is because the definition of a smoothie remains overarching and amorphous — without a standard of identity for a smoothie product, such beverages include yogurt versions, soy versions, soy and milk versions, milk and juice combinations or any variation upon this theme. All such types are included in the smoothie category and factor into the growth curve calculation.

Then, there are significant market factors contributing to the popularity of smoothies. First, consumers have learned that dairy products are inherently healthy. But convenience is the biggest driver for the smoothie category growth; like the Chug transformed milk into a grab-and-go beverage, the single-serve packaging of the smoothie has turned dairy into a nutritional package that can be consumed anywhere.

“Any way that you can have a delicious meal that fits into a car cup holder for the consumer on the go, there is real, live market pull for those types of products,” says Alan Reed, vice president of business development at Dairy Management Inc. (DMI), Rosemont, Ill. “Smoothie products are those products of today — they meet all those criteria of being healthy, convenient, tasty and versatile for any meal occasion, ideal for breakfast, lunch, snacking or for dinner.”

Dairy manufacturers have realized that health plus convenience together is an unstoppable duo. If not already a player in the market, dairy companies are hurrying to introduce variations upon the smoothie theme. “Watching the dairy industry, we saw that drinkable dairy beverages was a category with growth that was substantial and sustained year after year, so we thought we should capitalize upon this trend,” says Jay Allison, vice president of sales and marketing at Tillamook County Creamery Association, Tillamook, Ore. “We introduced a line of five smoothies this month, products targeting the convenience factor. Our decision to enter the market was driven by observing that America is a society on the go, and consumers are looking for that perfect, healthy, convenient snack.”

Various ingredients are being included in smoothie products to deliver amplified nutritional profiles. Many of the smoothies boast live and active cultures on the label. Stonyfield Farm includes a true probiotic ingredient in their smoothie product, although consumers are still unclear on the health benefits of probiotic bacteria. Other innovative ingredients include various fortification nutrients.

“Our SunActive iron ingredient is being used to fortify various smoothie drinks, as well as our Sunfiber and even our matcha powder,” says Bill Driessen, technical sales manager at Taiyo International, Minneapolis. “Matcha powder is made from green tea leaves and, as an ingredient, it delivers the naturally occurring levels of the nutrients in green tea. All of these ingredients are desirable as fortification elements because of their health benefits.”

For example, consumers have learned that green tea is healthy due to its antioxidant properties. When “contains green tea” appears on a smoothie label, consumers correlate the green tea fortification with an improved nutritional profile. Iron is a common fortification ingredient because women are frequent consumers of yogurts and smoothie products, and women have learned that iron is particularly important to their health. In particular, pregnant and nursing mothers often seek iron fortification due to its role in healthy natal development.

And then there is magic of fiber — fiber has become a buzzword in the food industry since the newly released Dietary Guidelines and revised Food Guide Pyramid highlighted fiber for heart health.

“Now there is an FDA-approved health claim for fiber and its ability to enhance cardiovascular health, which has increased the demand for fiber fortification in the market,” says Driessen. “In response, the fiber ingredients that are available in the industry have improved and become easier to use in formulation, delivering the desired viscosity and solubility.”

For example, SunFiber is a partially hydrolyzed guar gum that is completely soluble in solution, is tasteless, odorless and does not affect the viscosity of smoothie beverages. Iron is typically difficult to use in dairy applications due to metallic off-flavors and shelf life issues where products with iron can eventually discolor and precipitate.

“SunActive iron is microencapsulated to protect this mineral from interacting with other components of a dairy formulation, so it can be used in milk and smoothie drinks,” says Driessen. “And we use cryogenic grinding for our matcha powder which yields an extremely fine particle size and also preserves the vivid color of green tea. The existence of this natural green color is an indicator that healthy high levels of the anti-oxidants, vitamins and amino acids in green tea have not been lost in the manufacturing process, which is desirable for use in the smoothie products.”

The biggest ground-breaking ingredient making its way into smoothie products is whey, which is used to boost the protein content of the smoothie drink and provide a significantly enhanced nutrition profile.

“A lot of manufacturers are interested in adding nutrient density to foods in general, and beverages are included in that trend. One way to improve the nutritional offering of a beverage is to add protein, and using whey protein is easier that using other types of proteins because of technical hurdles in terms of flavor and functionality,” says K.J. Burrington, dairy ingredient applications coordinator at the Wisconsin Center for Dairy Research at the University of Wisconsin-Madison. “Plus, what these other proteins don’t bring with them that whey does offer is that whey protein is a very high quality protein, with essential amino acids that contribute to increasing lean body mass and have other health benefits.”

Whey proteins work well in smoothie beverages because they are soluble in the pH typical of yogurt, they don’t contribute any off-flavors, have a smooth texture and are easy to work with in dairy-based drinks. Whereas a typical yogurt smoothie might contain 10 grams of protein, a smoothie enhanced with whey protein isolate can achieve 20 grams of protein. Tropicana offers a smoothie with a yogurt base and also includes whey protein isolate to increase the overall protein content.

Two shelf stable smoothie products, which are not quite mainstream yet, incorporate a significant portion of whey ingredients to boost protein levels. From Next Proteins, a shelf-stable smoothie within the Designer Whey Protein brand uses a combination of whey protein isolate, whey concentrate and hydrolyzed whey protein to deliver 20 grams of protein. Slim-Fast has a smoothie that includes a similar whey combination to also yield a high protein count, and both are packaged in an ESL aseptic packaging. “Both of these products are currently targeted toward the fitness-oriented or weight-conscious consumer, but we expect them to become mainstream in the near future,” says Burrington. “A result of the low-carbohydrate movement is that consumers are still seeking high protein, and the whey ingredients in both of these smoothies boost their nutritional profile and their protein load.”

When using whey protein ingredients in smoothie formulations, often a stabilizer like pectin is used to help protect the protein during heat processing if the pH range is low — 3.4 to 4.5 — where the dairy proteins are close to their isoelectric point and can be unstable. The pectin helps keep the whey proteins soluble and hold the drink’s emulsion so that the smoothie beverage doesn’t separate.

“If using a stabilizer in a smoothie application, it is usually recommended to homogenize the drink before heat treatment because the homogenization allows the pectin to interact properly with the whey protein efficiently,” says Burrington. “Homogenization after heat treatment is sometimes done, but this is more of a ‘Band-Aid’ approach because aggregation may have already formed during heat treatment. Although homogenization will break up that aggregation, this doesn’t provide the ideal environment for the protein’s performance.”

Other considerations include allowing sufficient time for the whey ingredient to hydrate before putting it through the rest of the processing steps, which usually means a half hour of hydration in the formula water and constant, slow aggravation. This allows the whey protein to withstand the ensuing heat processes.

“Without proper hydration, whey proteins lose heat stability and this causes more issues with the protein aggregating and precipitating to create sludge at the bottom of the smoothie drink,” says Burrington. “Although folks who are accustomed to using dry dairy ingredients know to hydrate whey proteins, as we see more beverage manufacturers enter the market with new dairy drinks this will become more of a hurdle.”

Finally, an issue with using whey proteins to create a higher protein load in smoothie-type beverages is that increased protein typically requires increased flavor ingredients to maintain the overall flavor of the beverage throughout the product’s shelf life. Protein tends to “suck up” flavor over time and diminish product taste, so increasing the flavor load is important to offset this unwanted effect. “It’s also important to select flavors that do not contain large amounts of acid or alcohol, which can interact with milk proteins. And the use of flavors in the milk/juice combination smoothies can compensate for the limitations of certain juices,” says Phyllis Williams, manager of flavor applications at Robertet Flavors, Piscataway, N.J. “The high-acid juices such as orange and lemon or lime can cause problems due to the isoelectric point of milk proteins. So citrus and tropical flavors can be added to these formulations to replace the reduced juice content without sacrificing a juicy flavor profile.”

One outgrowth of the whey protein enhancement of smoothie beverages is that whey protein isolates are starting to appear in other types of grab-and-go beverages. Gatorade test marketed a product last year called Gatorade GSlide Smoothie, which was a whey protein-enhanced beverage positioned as “uniquely designed” for growing athletes. And Accelerade introduced a whey protein fortified isotonic this year.

“Isotonics that include whey protein are just starting to generate buzz, but we expect to see much excitement in this realm in the near future. DMI showed an isotonic at IFT with 10 grams of whey protein isolate per serving,” says Reed. “Whey protein isolate can remain clear in the low pH environment of isotonics, and the ability of whey protein to build muscle is a perfect complement to these types of formulations.”

Meanwhile, smoothie drinks are in store for a bright future as their nutritional profile continues to be amplified and the smoothie field continues to expand. “We are going to see more and more segmentation based upon age and lifestyle, and see segmentation based on particular benefits and needs. For example, Slim Fast has an Optima line for weight loss, and I think we will see smoothies for energy or muscle building or more specific occasions,” says Reed. “Nouriche Light now has a breakfast smoothie in its line, and we will see fortification ingredients like fiber appear in more of these products.”

These latest developments indicate that smoothies will be designed for specific target audiences, day parts and nutritional benefits. “This segmenting is a reflection of what’s going on with consumer products in general,” says Suzanne Niekrasz, director of marketing communications at Robertet Flavors Inc. “Examples include refrigerated smoothies that are great for snacking, yogurt smoothies that offer the added bonus of active cultures, traditional meal replacement beverages, nutritional energy shakes and high protein drinks. Milk protein beverages have become highly diversified, with distinctive market positions.”