Consumers are still focusing on protein as a daily need and increasingly turning to beverage formats for the important macronutrient. To put it in perspective, a just-released report by Straits Research forecasts global sales in the Ready-to-Drink (RTD) protein beverage market to reach $2.65 billion by 2030, following a CAGR of 8.1%.

Protein is a key and vital nutrient, necessary not only for maintaining muscles and other tissues but for production of key components of the body’s operating systems—virtually every metabolic function relies on the protein structures known as enzymes. For decades consumers were reminded that daily needs in US and other developed countries are rarely unmet.

However, a “protein boom” began in the 1990s as research revealed certain benefits to increasing protein in the diet for some consumers, especially athletic and otherwise active ones. Protein’s high satiety also brought it into play for those consumers focusing on weight management.

As with any trend with such long growth, differentiation is vital. The world of protein has some new applications in flavor, texture and functionality in a beverages. Currently, the most popular proteins used in a beverage applications are whey protein concentrate, whey protein isolate, whey protein hydrolysate, casein, soy protein, pea protein and brown rice protein.

The Milky Way

Whey protein is made from the liquid byproduct of cheese production. It’s used in protein beverages and as an additive in processed foods like breads, crackers and infant formula. Whey is a preferred protein source for many athletes because it contains more branched-chain amino acids (BCAAs)—including leucine, which is an important amino acid in signaling muscle protein synthesis—than other types of protein. 

Whey concentrate also is rich in vitamins and minerals, and highly bioavailable, being rapidly digested and metabolized. In fact, whey helps to increase muscle growth by stimulating synthesis within the first few hours of consumption to support recovery.

Whey protein isolate is whey protein concentrate that has been further processed to remove most of the lactose and fat. The vast majority of whey protein isolate will be made up of at least 90% protein. Whey protein isolate also has low viscosity is overwhelmingly seen as the preferred option to whey protein concentrate in many beverage formulations.

A step further in the breakdown of protein is whey hydrolysate is a pre-digested protein composed predominantly of di- and tripeptides, which are absorbed more rapidly than free-form amino acids and much more rapidly than non-hydrolyzed (i.e. intact) proteins. However, whey protein hydrolysate has a distinct brothy, malty flavor profile reminiscent of potatoes, plus can also give off bitter back notes. This is another reason whey protein isolate might be a better choice for a beverage product, as it has a clean, slight milky flavor with a faint fruity aftertaste.

Casein is another dairy protein used in beverages, especially sports and energy beverages. As a major component of milk, cheese, and yogurt, it also is commonly added to ice cream, coffee creamers, protein powders, shakes, infant formula, and other products both to enhance the protein profile and to control texture.

Casein is a popular ingredient in recovery beverages for athletes because it contains all nine essential amino acids and is slow digesting—much slower than whey. This proffers another advantage, that of having very high satiety. Casein has a bland flavor profile and a texture smoother and creamier than whey. It makes up the majority of the protein in milk—about 80%—yet it also is often more expensive than whey. Moreover, whey tends to mix and blend much better than casein in formulation.

Rice and Beans

Soy protein is made from soybean meal that has been dehulled and defatted. It’s the most common form of plant protein in use, and its history as an animal protein replacer goes back centuries. In beverages, it’s a veritable workhorse among milk alternatives, sports and energy shakes, protein powders, and infant formulas. Soy protein has a nutty profile but can also deliver a “beany” or bitter aftertaste, and if a soy beverage is not formulated correctly, a chalky texture.

Pea protein is experiencing significant growth, largely due to the demand for plant-based products that are non-GMO allergen-free. It’s extracted from split peas—typically the mild-flavored yellow peas—and is used in products such as meat alternatives, vegan cheeses, yogurts, milks and snack bars. It’s also commonly used to boost protein content, when developing products like nut milks. Pea protein has an astringent, grassy, earthy flavor and a chalky or gritty texture, and pea protein hydrolysates can even be noticeably bitter.

One of the fastest growing plant protein sources is the chickpea. It has many advantages in beverages. As a dairy milk alternative, it has a high protein profile, comparable to soy and cow’s milk, and is rich in other nutrients. Recent technology has allowed for the removal of bitter and beany flavors, as well as an enhanced creaminess that gives it advantages in beverages such as shakes and functional milks.

Brown rice protein is made by treating brown rice with select enzymes that cause the carbohydrates and protein to separate. It’s primarily used as a vegan, allergen-free alternative to whey, casein, and soy in sports nutrition beverages and beverage powders and shakes. Brown rice protein is hypoallergenic and thus safe for consumers with lactose, gluten, nut, and legume allergies.

As with casein, brown rice protein is slowly digested and contains all the necessary amino acids (although it’s low in lysine). It’s also high in fiber and B vitamins. Brown rice protein has a subtle slightly sweet flavor with a very strong and bitter taste with a dry chalky texture.

Brown rice has potential to be a great source of protein but lacks lysine and needs to be combined with another lysine-containing protein such as collagen. But this is where pea protein can also come into play: Mixing brown rice protein with pea protein makes up a complete amino acid profile.

Seeing Clearly

Clear beverages, especially carbonated ones, were not typical carriers of protein until relatively recently, due to the propensity of protein to cloud and separate. But ingredient technology overcame those challenges and gave a considerable boost to the multibillion-dollar RTD sports beverage industry. In fact, according to Innova Market Research, some 90% of RTD sports drinks launched make protein claims.

Carbonated protein beverages have commonly turned to whey protein hydrolysate. Usually carbonating protein would create foam and cloud not preferable in a carbonated drink, but whey hydrolysate avoids this. Whey protein hydrolysate allows beverage processors to add protein to carbonated drinks more easily and without the occurrence of foam or cloudiness.

Developers of still waters and fruit-based drinks often turn to whey protein isolate because it has a milder, fruiter flavor profile and also remains clear. Mixing whey proteins with fruit juices may have some development issues due to the higher acidic environment, however, so adding ingredients such as high methoxyl pectin help to protect the protein at a low pH and extend shelf-life.

With beverages one of the more ready vehicles to use for boosting nutrition in the daily diet, often without excess calories, and health foremost in the mind of many consumers, the opportunities offered by beverages to act as vehicles for nutrients such as protein remain impressive. The variety and quality of RTD protein beverages can give the category plenty of room to grow in the near future.

Bridgette Love-Shaw is R&D Manager for product development company Victus Ars in Chicago. With degrees in chemistry and biology, as well as an MBA for good measure, she has nearly 20 years of experience in the food and beverage industry covering R&D in beverages, confections, bakery and ingredient development and manufacturing.  She has specialized in fruit juices, teas, and electrolyte and protein beverages, as well as alcohol beverages. She can be reached at bridgette.love-shaw@victusars.com.