Boosting Protein Content

Of the major food components—carbohydrates, fat and protein—only protein has an unblemished reputation. Carbohydrates and fats have been maligned by diet faddists, but it seems no one can find fault with protein.

Indeed, it is the basis of all bodily needs, from hair development to muscle mass. It’s critical to life and, within the body, it’s second only to water in abundance.

A food developer often thinks about protein in terms of the ingredient declaration or the nutritional panel, but that’s the smallest part of the story. Protein is multifunctional. Choosing the right protein for a particular application requires an understanding of all the ways a product might be impacted, from labeling to shelf life.

Soy options

Linda Beck, global product/process development manager for soy, Cargill, Minneapolis, notes that soy protein is typically added to beverages and bars for protein fortification. “Even though you’re adding it for protein, you have to be very aware of the functionality,” she says. “All proteins are going to affect functionality. Depending on what textural and manufacturing parameters you have to meet, that’s going to dictate what protein you’re going to need.”

Soy is making an entrance into beverages that were once classically dairy drinks. In general, a beverage containing soy protein is going to be more viscous than a comparable dairy product. “Soy protein is not going to have as high a solubility as dairy proteins,” Beck says.

Soy flavor, even if mild, is a consideration when formulating for a dairy market. “In North America and Canada, we are a dairy-based culture,” Beck cautions. “This is not the case when you go to Asia and other parts of the world, or if you’re servicing different ethnic populations within the United States.”

In making beverages, use of an isolate vs. other soy ingredients is more typical because of the higher protein content. When choosing a protein ingredient, “the formulator also has to be aware of how much room you have in the formula,” says Beck. Isolates have 90% protein, concentrates are around 65% to 70%, and flours are in the 50% range. “So, if you’re delivering a targeted protein amount, say 10 grams of protein in 8 oz., you’re going to have to use a lot more concentrate or flour,” she says. “That’s going to have an effect on your formula—and, based on the other ingredients in there, do you physically have room? That alone can dictate your choice.”

Cost is another important consideration. “If you’re delivering protein, it’s not the cost per pound of the ingredient,” explains Beck. “It’s the cost per pound of your protein. With today’s escalating prices of dairy, formulators should start looking at combining protein.” She recommends adding soy protein isolate to a dairy-based beverage to reduce cost. If labeling allows, the key is finding the level of soy that will not affect flavor, but will cut costs.

Soy protein isolates and soy protein concentrates are typically used in North America. “That’s not true of everywhere,” says Beck. “For example, our European division makes full-fat soy flour that is used in beverages.”

Soymilks can be made from different processes. In one case, manufacturers grind the bean and remove the insoluble materials from the soluble materials. The soluble material is composed of the protein, the soluble sugars and fat. That product is shipped to soymilk processors who then add flavor.

In the second type of soymilk production, manufacturers crush the soybeans, then remove the oil, so only the protein, the soluble carbohydrates and the insoluble carbohydrates remain. Depending on how it’s ground and treated, “you could have soybean meal for animals, you could have soy flour or textured soy flour,” says Beck. “There is more than one type of soy flour. You can remove the soluble carbohydrates, and now you have a concentrate. Remove all the carbohydrates, now you have an isolate.” Some companies might buy soy isolate, buy a vegetable oil and buy a sugar source, but that’s not necessary. “Put all the parts back together, and they, too, are soymilk,” she explains. “In Europe, there are several companies that make full-fat soy flour. You’ve got the fat, you’ve got the protein and you still have all the carbohydrates. You have a nice powder to work with instead of shipping liquids all over. Soy flour is used in beverages—we just don’t see it much in the United States.”

In cereals and bars, textured soy flour could provide crunch and texture, similar to an oat, but it would contain more protein. Beck suggests using regular soy flour to boost protein in cereal flakes. “And, using soy flour would be a more-economical choice than a concentrate or an isolate,” she says. “Soy flour contains protein and insoluble carbohydrates, i.e., dietary fiber, and it’s still less than 1% fat.”

According to Beck, more cereal and bar companies should consider incorporating soy flour, which will allow them to “back off on some of their cereal grains. They’re going to get more protein and have a label that’s going to read better for the consumer,” as well as provide a better balance between protein, carbohydrates and fats.

Historically, soy flour has served as an egg replacer in cookies and muffins. Because it can repulse fat, in the doughnut industry it helps prevent fat absorption during the frying process.

When using soy, it’s important to remember that, in general, some soy proteins tend to bind more water than other proteins. Some soy proteins do not. Beck encourages formulators to talk with their soy supplier and discuss their parameters. “Soy products are manufactured with different viscosities and different end products in mind,” she says. “The more the formulator is willing to share with the soy manufacturer, the better they can target which soy product to send.”

Rice possibilities

“In recent years, rice proteins have become more and more popular in food and beverage applications worldwide,” says Gil Bakal, managing director, A&B Ingredients, Fairfield, NJ. One reason for their popularity is they are hypoallergenic.

Nutritional-grade rice protein has a minimum of 70% protein. “You can use rice proteins in high-protein breakfast cereals, cereal bars, meat coatings, rice and pasta applications,” says Bakal. In gluten-free pasta and bakery applications, and in cereal and energy bars, rice protein can increase nutritional values. “In meat coatings, rice protein can enhance the crunchiness after frying,” he continues. “In batters, we know that 2% enhances the crunchiness.”

Another rice-protein application is in breakfast cereals, where it can increase bowl life by reducing sogginess. “This phenomenon is visible with a dosage of 10%, and you can go up to 30% without noticeably changing taste and expansion,” Bakal says.

Depending on the application, rice protein can be added at 2% to 60% of the formula. Generally, in nutritional cereal bars, breads and cookies, a formula may contain up to 10% rice protein. “In the United Kingdom, we have a customer making protein breakfast cereals using up to 60%,” says Bakal. Rice protein has a slight rice flavor, but no bitterness. The disadvantages are that it is not soluble, and rice supplies are tight, potentially limiting future availability, he says.

Investigating pea protein

Pea proteins range from 85% to 90% protein on a dry-weight basis. According to Carl Jaundoo, Ph.D., associate program coordinator, Roquette America, Inc., Keokuk, IA: “Pea proteins are high-quality proteins with digestibility comparable to the best animal proteins. Pea proteins also have an excellent amino-acid balance and low allergenicity, and are not listed on the U.S. and EU major allergen lists.”

Pea proteins can work well in applications where soy proteins are currently used, such as beverages, snacks, sauces, dressings, pasta, cereals, baked goods and nutrition bars. “Pea proteins can be used at varying levels up to about 75%, depending upon the application,” Jaundoo says. “In extruded snacks, pea proteins have been used to provide a snack with 65% protein. In other applications, such as beverages and bakery snacks, the desired finished protein content determines the use level of protein incorporated. In sweet snacks such as cookies, pea proteins can be added at about 3%.”

In vegetarian foods, pea protein provides an alternative to soy. According to Bakal: “In formulation, pea protein varies between 6% in weight-control shakes to 14% in sport-nutritional shakes. Within protein bars, levels can be up to 17%.”

Pea protein has a slight vegetable taste, but a minimal impact on the final flavor. Depending on the application and the product used, the effect on texture is low to medium. Unit cost-related factors are similar to that of rice protein.

Jaundoo notes that the solubility, viscosity, fat and water-binding capacity of pea protein are comparable to other vegetable proteins. “There is a range of commercial pea protein products available that provide varying physical and functional properties,” he says.

Working with wheat protein

Wheat protein works well in a wide range of products, especially in applications with flour as the primary source of protein. “Wheat protein complements other proteins,” says Steve Ham, director of marketing, specialty ingredients, MGP Ingredients, Atchison, KS. “In certain cases, this combination can help create a more-balanced amino-acid profile, as well as provide diverse functional properties. Consumers, as well as manufacturers, are recognizing the nutritional benefits of elevated protein levels.”

While wheat gluten, with 75% protein, is generally considered a cost-effective ingredient, Ham notes that, in some formulations, it can affect dough handling. “Our wheat-protein isolates are beneficial when formulations require high levels of protein,” he says. “Because of their extensible nature, these isolates allow for greater consistency in dough handling and finished product qualities.”