Although per capita consumption of fluid milk has been declining for more than 40 years, the use of dairy ingredients in all types of beverages continues to grow. This is in part due to dairy’s healthful halo, as many of the ingredients contribute protein and essential vitamins and minerals, most notably calcium.
Depending on the beverage and the production process, either fresh fluid dairy, such as milk and cream, or concentrated dry dairy ingredients may be used. The benefit to using the latter is the beverage may typically be produced in a non-Grade-A fluid dairy manufacturing plant. Such facilities are a requirement for the processing of raw fluid milk.
The Grade-A plants necessitate a license to process milk. They also must be compliant with the Pasteurized Milk Ordinance (P.M.O.), which is published by the Food and Drug Administration. The P.M.O. provides minimum standards and requirements to ensure the quality and safety of all fluid milk products that are shipped interstate.
When dry dairy ingredients are used instead of raw fluid milk or cream, neither a license nor P.M.O. compliance is required. As with any rule, there are exceptions. If a beverage is formulated to contain more than 65% milk ingredients and 2% protein, then it is regulated under the P.M.O. There are some products excluded from the regulation, including infant formula, dietary products such as meal replacement shakes, and coffee and tea-based beverages.
Some marketers pride themselves on using fresh dairy in their beverages and will even tout inclusion with such packaging claims as “made with real milk.” Other marketers find dry dairy ingredients are easier to transport and store, as compared to fresh milk and cream. The dried forms provide year-round availability and consistency and are produced to specification. They are designed for easy hydration, with blenders usually willing to combine multiple dry beverage ingredients to simplify the manufacturing process and eliminate human error.
Understanding ingredient variations
Dry dairy ingredients vary in their protein (casein and whey), carbohydrate, fat and mineral composition, and this influences their functional and nutritional contribution to beverages. They may be divided into three groups: milk, casein and whey.
“Caseins and whey proteins have very different structures and physical properties,” said Kimberlee Burrington, dairy ingredient applications coordinator, Center for Dairy Research, University of Wisconsin-Madison. “Processing techniques have been developed to modify the composition of milk according to the unique characteristics of its components. These processes have given the dairy industry the ability to make a wide variety of dairy ingredients manufactured from milk. Some of these processes involve the use of filtration methods that can separate milk according to the molecular weight of its components.”
Dry milk ingredients are made from fresh fluid milk. They contain casein and whey proteins in the same ratio as fluid milk, which is 80% casein and 20% whey proteins. What varies is the concentration of non-protein solids. The category includes nonfat dry milk, whole milk powder, dried cream, milk protein concentrates and milk protein isolates. With many of these dried ingredients, lactose-free versions are available.
Nonfat dry milk is the most basic dry milk ingredient available to formulators. As the name suggests, it is nonfat milk, also known as skim, which has been dried into a powder. Whole milk powder and dried cream contain milkfat and provide a richness that is not possible with nonfat dry milk.
Milk protein concentrates and milk protein isolates are both relatively new ingredients made possible through the use of ultrafiltration. The technology concentrates the protein, yielding ingredients with protein contents up to 90%
Casein vs. whey
The category of casein ingredients include caseinates, casein hydrolysates and micellar casein. Their primary use in beverages historically has been to assist with foaming and emulsification, as well as to add protein. Most casein-based ingredients cannot be used in acidic beverages because casein will precipitate at pH
4.5 to 5.5.
Whey ingredients include whey protein concentrates, whey protein isolates, whey powders and whey protein hydrolysates. Whey ingredients tend to be stable over a wide range of pH.
Unlike whey proteins, which are separated from milk during cheese manufacturing, and then made into ingredients, casein ingredients must be physically separated from milk. This may be an expensive process and for long, was not common in the United States. In fact, most casein ingredients historically have been imported into the states, rendering them cost prohibitive for applications other than those intended for the body builder market.
This has changed with the advent of microfiltration.
“Microfiltration enables the fractionation of caseins and whey proteins from milk,” Ms. Burrington said. “Caseins are larger in molecular weight than the majority of whey proteins. They are retained in the membrane and referred to as the ‘retentate.’ The smaller molecules that pass through the membrane become the ‘permeate.’”
The retentate fraction contains casein and commonly is referred to as micellar casein, while the permeate fraction contains whey proteins. To differentiate from whey obtained via cheesemaking, whey proteins obtained via microfiltration of milk are often referred to as native whey, serum proteins or milk-derived whey.
“Manufacture of micellar casein concentrates produces a range of compositions depending on the amount of milk-derived whey protein removed,” Ms. Burrington said. “Further concentration and diafiltration can increase the total protein and decrease the amount of lactose in the final ingredient. Micellar casein concentrates provide notable nutritional benefits and are an excellent source of all essential amino acids and calcium.”
They may also withstand the high temperatures encountered during retort beverage processing.
One of the most significant differences between milk-derived whey protein ingredients and those derived from cheese whey is the fat content.
“The microfiltration process retains milkfat in the retentate, yielding a whey ingredient that is essentially free of fat,” Ms. Burrington said.
Alternatively, cheese-whey-derived ingredients contain up to 7% fat. The lack of fat in milk-derived whey proteins impacts functionality, flavor and appearance, and all in a positive way in regards to use in beverages.
Because whey and casein have different but complementary effects on the body — both are excellent sources of the essential amino acids, but whey is a fast-digesting protein and casein is a slow-digesting protein — many formulators want to include both in functional beverages. Both micellular casein and milk-derived whey are rather new ingredients and have opened the door to innovative beverage applications.
Recent beverage innovations
Beverage manufacturers are embracing both fluid and dry dairy ingredients, sometimes in the same product.
For example, Starbucks Corp., Seattle, is growing its Doubleshot line with Coffee & Protein. Each 11-oz can provides 20 grams of protein that comes from reduced-fat milk, skim milk, milk protein concentrate and calcium caseinate. It comes in coffee, dark chocolate and vanilla bean varieties.
Some products are blending proteins. Starbucks’ Evolution Fresh line of cold-pressed juices includes Protein Power, a blend of orange juice, apple juice and mango puree with whey protein concentrate and soy protein isolate. Like all Evolution Fresh beverages, the variety is made using high-pressure processing instead of pasteurization, which helps preserve the flavor and nutrition of the fruit ingredients and ensure protein integrity.
Less than a year ago, Campbell Soup Co., Camden, N.J, entered the protein beverage category with V8 Protein Shakes. The iconic vegetable juice brand strayed from its vegan image by including milk protein concentrate in the protein blend, which also includes soy protein isolate, pea protein isolate, whole grain brown rice protein concentrate and quinoa flour.
Others prefer fresh milk ingredients. For example, WhiteWave Foods, Boulder, Colo., is introducing International Delight Chai Tea Latte. Available in caramel chai and vanilla chai varieties, the lattes start with a base of brewed black tea to which fluid skim milk and cream are added.
The Hain Celestial Group Inc., Lake Success, N.Y., also is entering the ready-to-drink chai latte category. The company just started rolling out four on-trend flavors of shelf-stable Celestial Lattes. Made with 2% milk, Celestial Lattes provide barista-quality beverages brimming with the healthfulness of brewed tea.
There are four varieties. Dirty chai is chai spiked with espresso. The Godfather builds on the formulation through the addition of a layer of cocoa flavor. Mountain chai is simply a traditional chai featuring the flavors of ginger, cardamom and cloves, while matcha green is a smooth blend of brewed green tea and traditional matcha.
Nestle USA Inc., Glendale, Calif., is all about the use of fluid milk in its Skinny Cow Creamy Iced Coffee Drink line. Described as “rich, expertly roasted coffee folded into creamy, velvety dairy heaven and then whipped, not once, not twice but three times to deliver a uniquely thick and indulgent smooth coffee beverage,” the new line comes in three flavors: creamy cappuccino, mocha latte and vanilla latte. Reduced-fat milk is the No. 1 ingredient in the shelf-stable beverage.
Dairy ingredients are even making their way into energy drinks. Rockstar Inc., Las Vegas, introduced a non-carbonated Rockstar Energy Horchata Dairy Beverage. Made with whole milk and nonfat milk, the drink gets energized from the brand’s proprietary energy blend of caffeine, ginseng, guarana, inositol,
L-carnitine and taurine.
As the dairy industry refines and identifies technologies to make more functional and nutritional dairy ingredients, it is likely that new beverage concepts will enter the marketplace.