Proteins perform a myriad of functions in the human body and are a vital nutrient to sustain life. In fact, proteins are the second-most plentiful substance in the body after water. Proteins are essential for proper functioning of the immune and digestive systems; DNA replication; promoting muscle tissue growth and repair following exercise; assisting in nutrient transport in the bloodstream; and catalyzing a variety of metabolic reactions. Protein also appears to have a growing role in weight management, promoting satiety better than carbohydrates or fats.
The Institute of Medicine (IOM) recommends adults consume 0.8g of protein per kg of body weight daily. The Recommended Dietary Allowances (RDA) translates this number into 46g of protein/day for women and 56g of protein/day for men (ages 19-70+). According to the Centers for Disease Control and Prevention (CDC), 10-35% of daily calories should come from protein sources.
Consumers increasingly demand products that contain plant-derived proteins. They also have become more aware that such protein sources must offer similar or superior functional properties to animal-based proteins.
However, acceptable sensory properties—especially taste and aroma—still are key to successful penetration of plant protein ingredients into applications. This is especially true when plant proteins are designed to replace items or categories typically dominated by animal proteins, as well as with the development of new applications.
Global 2015 animal protein ingredient sales are projected to be 61.25% compared with plant protein at 13.8%. And, as of 2013, dairy proteins still took the lion’s share of sales within the sports ingredient market, at 59.3%, with plant protein at 22%, according to global research group Frost & Sullivan. Sales of animal-based protein combination products were more than $126 million, as of February this year, but increased only 6.8% over the prior year.
Although sales of plant-based protein combination products amounted to just under $10 million during the same period, this amount represents a huge 92.1% increase over last year, according to market research firm SPINS LLC. And, soy is still king of the plant proteins.
In 2014, soy protein products accounted for 38% of the global protein product market, compared with 26% for all other non-soy plant protein products. Protein products formulated with pea protein accounted for just under 5% in 2014, according to Frost & Sullivan.
Sales of products labeled both “vegan” and “vegetarian” topped more than $47 million during 2014, an increase of 23% from the previous year. Refrigerated dairy alternatives, such as almond milk and hemp milk, garnered the highest revenue at $11.5 million, according to SPINS. Three drivers have inspired consumers to change their dietary habits and reduce their intake of animal and animal byproducts: animal welfare, concern for the environment, and a renewed focus on personal health and sustainable living.
Proteins contribute a variety of functionality in food formulations, including water binding, gelation, emulsification, aeration, foam stabilization, viscosity, film formation and texture. Plant proteins are by no means new.
Soy, barley, beans and nuts are examples of vegetarian protein sources with legacies going back to the dawn of history.
However, emerging protein sources, such as quinoa, rice, oat, flax, lupin, chia, canola and even algae, offer promise for creating the same great food products but with increased protein content. Their other advantages include allowing for potentially less allergenicity and low or lower fat levels—plus labeling that, under certification, can display the kosher, non-GMO, all-natural and gluten-free cachet.
Research by Datamonitor conducted in 2013 shows increases in protein label claims for different food and beverage categories. The fastest increases in “high protein” claims are in the frozen yogurt, ice cream and non-dairy/dairy beverage sectors.
The building blocks of proteins are amino acids. There are 20 primary amino acids—with nine considered essential—meaning the human body does not synthesize them, and they must be consumed from the diet.
Complete proteins are those containing all of the essential amino acids, in amounts that meet human requirements to prevent deficiency.
An incomplete protein is too low in one or more of the essential amino acids. Milk, eggs, cheese and meat all are considered complete proteins, as they contain all of the essential amino acids.
The essential amino acids are lysine (which plays a role in growth and bone health); branched-chain amino acids (isoleucine, leucine and valine), which help maintain muscle protein; sulfur-containing amino acids (methionine), which is involved in protein and nucleic acid synthesis; and phenylalanine, histidine, threonine and tryptophan (a precursor to serotonin, the a hormone that promotes a positive mood).
Complementary proteins proteins that, when combined together, result in a complete protein.
The most common example in food is beans and rice: Legumes are generally low in methionine and high in lysine, while grains are the opposite. Thus, the two ingredients complement each other to form a complete protein source when consumed together.
Protein quality is measured by a number of methods. Examples include Biological Value (BV), Protein Efficiency Ratio (PER) and Protein Digestibility Corrected Amino Acid Score (PDCAAS). Egg white has a biological value of 100, which means that all the nitrogen from eggs can be used by the body. Plant proteins usually have lower BV scores (e.g., 70 for corn).
PDCAAS is an internationally used measurement that accounts for a protein’s ability to supply the essential amino acid requirements of humans, corrected for its digestibility. (This is the amount of protein actually absorbed and its ability to supply the FAO/WHO amino acid requirements for 2-to-5-year-olds).
The PDCAAS is calculated based on the essential amino acid present in the lowest quantity; the highest PDCAAS score is 1.0. Soy protein concentrate and soy protein isolate are complete proteins with PDCAAS scores of 0.99 and 0.92, respectively. (See chart, “Product Categories Showing the Greatest Change in Protein Claims,” page 108, for a list of protein content from various vegetarian-based sources.)
Joy of Soy
Soybean is the largest plant-based protein source, and soy protein commonly is available in isolate, concentrate and textured forms. A health claim is allowed in the US for soy protein, where 25g/day of soy protein may reduce the risk of heart disease. Soy protein’s allergenicity, however, can be an issue.
Depending on the product and its composition, soy protein also can have a slight off-flavor (sometimes described as grassy or bitter) due to the activity of the enzyme lipoxygenase, saponin compounds and/or isoflavones). Soy protein is a good emulsifier and film former, however, and it has favorable gelation properties in many applications.
Soy protein is used as a functional or nutritional ingredient in a variety of foods, such as infant formulas, soups, meat analogs, cheeses, salad dressings, frozen desserts, baked goods, breakfast cereals and pastas.
Soy protein isolates are not only used to improve the texture of meat products, but also to increase protein content, to enhance moisture retention and as emulsifiers.
According to the “Soy Protein Ingredients Market,” by Markets and Markets research, the global market for soy protein ingredients, in terms of revenue, was estimated to be worth $6.4 billion in 2012 and is expected to reach $9.2 billion by 2018, growing at a compound annual growth rate (CAGR) of 6.3% from 2013-2018.
In 2012, North America dominated the global soy protein ingredients market. Because of rapid advancement and increasing demand from key countries such as China and India, Asia-Pacific is expected to be the fastest growing market in the near future.
Soy protein isolate has been developed for enhanced functionality in either clear, low-pH beverages or for neutral pH applications, such as soymilk, meal-replacement drinks or smoothies. In the latter product, up to 10g of protein can be comfortably formulated.
Soy protein isolate contains 90% protein, and soy protein concentrate contains a minimum of 70% protein (both on a dry-weight basis), along with soluble fiber. Soy tends to be less expensive than milk-based proteins or hydrolysates and can be used at levels between 0.5-5.0% in beverages.
(It should be noted that flavor level, solubility and other characteristics depend on the exact protein product used.)
Enzymatically hydrolyzed soy proteins can be formed using a low level of hydrolysis; these are used for emulsification and to increase viscosity in a beverage. However, when soy proteins encounter low pH levels, bitterness results. Vanilla or certain fruit flavors can help mask that bitterness, as well as soy’s notorious “beany” notes.
If a beverage can be processed under high-shear conditions, a decreased particle size can help stabilize the emulsion, as well as contribute a creamier mouthfeel.
Not by Bread Alone
Wheat protein, one of the gluten-containing grains, is the second-largest plant-based protein used, after soy. Wheat protein is low in lysine and its PDCAAS is 0.43, which is roughly half that of soy protein. Wheat is comprised of gliadin and glutenin proteins.
Wheat protein also has poor water solubility, foaming and emulsification properties. However, wheat protein does have excellent viscoelastic, thermosetting and water-holding properties. It has a good flavor profile and also is low in price.
Seitan, prepared from wheat gluten, is used as a binder and texturizing agent in vegetarian meat analogs such as meatballs, burgers and nuggets. Seitan is high in protein and can take on many different flavors to suit the formulation and consumer expectations.
To prepare seitan, water is first added to wheat flour to form a dough. This dough is then kneaded and rinsed under running water to remove the wheat starch. After about 20-30 minutes of kneading and rinsing, the resulting stretchy gluten is evident. At this point, the gluten should simmer in broth for no less than one hour (and up to two or more) to develop its flavor.
There also are different forms of wheat that can be used to craft artisanal breads. “Unlike whole-wheat flour, which is basically a form of entire wheat kernels that have been milled into a fine powder, organic cracked whole wheat is a wheat kernel that has been broken into large raw pieces,” says Dan Letchinger, product manager for Dave’s Killer Bread LLC. “It adds great texture to breads and to hot cereals.”
Letchinger explains that cultured whole wheat is used to extend the shelflife of breads by locking in the moisture. “The wheat is cultured by adding an organic yeast starter culture to a small amount of organic whole-wheat flour,” he says.
This combination ferments over time to produce a small amount of vinegar, he notes, which acts as an antimicrobial. Whole flax seeds can also be ground to increase the protein content of breads, as well as adding extra omega-3 fatty acids. “Our breads contain protein ranging from 3-5g and up to 700mg omega-3 fatty acids per slice,” informs Letchinger.
Flax has other beneficial properties. It can function as a guar gum replacement in gluten-free baked products and provides water-holding capacity, viscosity and crumb structure. It also adds omega-3 fatty acids and a nutty taste to breads.
Natural Ovens Bakery Inc. is another processor delivering value-added breads to consumers. The company’s breads use either flax seed or ground flax seed, vital wheat gluten, and a combination of other seeds and flours (i.e., whole rice flour, whole sorghum flour, amaranth flour and whole quinoa) to deliver between 4-6g protein per slice.
Peas Porridge Hot
Due to consumer demand, pea protein has moved from a niche to a mainstream product. Pea protein from Pisum sativum (yellow pea), is non-GMO, not known to be allergenic and is gluten-free—all big buzzwords with today’s consumers.
Christopher Shanahan, global program manager, food and agriculture, at Frost & Sullivan, predicts an 11.3% CAGR for pea protein through 2020. He further estimates that pea protein sales could even reach as high as 15-20%.
In agriculture, the low-water usage and nitrogen-fixation properties of peas and other pulse crops make them more sustainable than some other protein crops. This also has become a big attraction for consumers. Peas are low in cysteine and methionine but high in lysine, resulting in a PDCAAS of approximately 0.65.
Pea protein properties and applications depend on the method used for isolation. Methodology can determine albumin, vicilin and legumin ratios in the final ingredient. This likely explains the differences in behavior between various pea protein products on the market and those described in the literature.
Generally, pea proteins show good water-binding, gelation and emulsification properties—but lesser foaming properties. According to the USA Dry Pea & Lentil Council, pea and egg proteins have similar emulsification capabilities.
Pea protein also has a foam stability comparable to egg albumin. Independent, controlled baking tests found pea isolates and concentrates can perform better than, equal to, or only slightly less functionally than eggs in cookies, cakes, muffins or waffles.
High protein content is king in the sports nutrition industry. Pea protein has a comparable amino acid profile with soy protein for all but one of the essential amino acids: methionine. Whey protein contains higher levels of most essential amino acids, but overall differences are not that dramatic. PDCAAS scores for pea protein closely correspond with values for whey or casein.
Another health benefit from pea protein is its digestion speed. Pea protein has a longer digestion window than whey. This can be ideal for endurance athletes, who would benefit from a steady, long-lasting source of protein for activity; or for senior citizens, to help avoid sarcopenia, the gradual loss of muscle mass which has gained attention as a key health issue for women.
Pea protein can be fairly viscous, so suppliers may dilute it with some coarser rice protein, which also can help balance its textural characteristics. As with soy, pea protein also can have issues with taste and aroma. Combining pea with rice protein avoids some of these taste issues. Another advantage of this combination is that a more complete protein is created with an enhanced PDCAAS score.
Richer flavors, such as chocolate, work well with pea protein in a fitness or meal-replacement smoothie, ready-to-drink (RTD) beverage or an energy shot. Vanilla and/or other masking agents also can be used to improve the upfront flavor profile and smooth out any objectionable background flavor notes.
With value-added, high-protein baked goods, such as denser nutritional bars and granolas, flavors like cinnamon and nutmeg also help in taste-masking any off-flavors from the use of pea protein.
Pea protein is highly functional in a variety of meat-replication applications, including hot dogs, bologna, coarse ground sausage and chicken nuggets, due to its excellent water-binding and emulsification capabilities.
Each percent of pea protein used can emulsify up to 10% fat in meat applications. The million dollar question is: Could these non-GMO, plant-based proteins perform equally well on taste and texture as meat from animals? As it turns out, the answer is a resounding “yes.”
Soy protein, pea protein and rice flour have teamed up along with other ingredients to make different forms of plant-based meat analogs, such as grilled chicken strips, chicken nuggets, burgers, meatballs and beef crumbles.
For example, Beyond Meat Inc.’s products deliver up to 20g of complete protein per 3oz serving, comparable to the protein level in chicken breast. The company’s slogan, “The future of protein” might even need updating, since success of such products demonstrates that the future is apparently now.
“Our protein is sustainable, contains no cholesterol, hormones, antibiotics, animal fat or gluten, and is vegan. Even the chicken and beef flavors are plant-derived,” says Ethan Brown, founder and CEO of Beyond Meat. “These plant-protein items work just as well in salads, wraps, fajitas, tacos and other applications as any animal-based product,” he concludes.
Rice is Nice
The results from a recent 2013 double-blind study at the University of Tampa proved for the first time that plant-based rice protein has identical benefits to dairy-based whey protein. The study followed a tightly controlled population of seasoned body-builders and how they built muscle mass and experienced the same rates of repair and soreness.
Rice protein is isolated from whole-grain brown rice using a unique, hexane-free fractionating process.
“In the past, studies have shown that the combination of resistance exercise with consumption of animal-derived protein—such as whey, casein, eggs and meat—has had a different effect on muscle growth than when resistance exercise was paired with plant proteins, such as soy,” says study co-author, Ralf Jaeger, PhD. “The results of this study show, for the first time, this notion has changed.”
The objective of the study, “Rice Protein Increases Lean Body Mass, Muscle Hypertrophy, Power and Strength Comparable to Whey Protein Following Resistance Exercise,” was to determine if high doses of rice protein isolate could increase recovery and elicit adequate changes in body composition compared to whey protein isolate, if given following periodic resistance-training.
The study determined that rice protein isolate administration, post-resistance exercise, decreases fat-mass and increases lean body mass, skeletal muscle hypertrophy, and power and strength comparable to whey protein isolate.
Results further showed there were no significant differences in the ratings between the groups supplemented with rice vs. whey for recovery. Both groups experienced significant changes in body composition, strength and power from week 0 to week 8. Specifically, muscle mass, strength and power increased, while body fat decreased.
Brown rice protein, with its non-GMO, hypoallergenic and gluten-free status, has been commercialized for more than a decade. Protein levels are high and can vary between 70-95%; however, rice is still deficient in lysine. The US Pharmacopeia Convention currently is developing a monograph standard for rice protein. One supplier has developed a grit-free rice protein with good suspension properties specifically for beverage applications.
Newly available sources of protein are being derived from ingredients commonly used for other nutrients. Protein from potatoes, mushrooms and fruits have fairly burst onto the scene in just the past few years.
One ingredient maker has developed methods to economically produce a canola protein isolate with a balanced amino acid profile that contains all essential amino acids. These isolates are also high in sulfur-containing amino acids (methionine and cysteine), as compared with other vegetable proteins; have low levels of anti-nutritional factors; and are free of phytoestrogens.
Canola protein isolate is well-suited for use in acidic beverages, including soft drinks, sports drinks, energy drinks, fortified waters and juices. As with pea protein, canola protein isolate is heat-stable at low pHs. This permits thermal processing of RTD acidic beverages, such as hot-fill drinks, without a loss of clarity or a notable change in viscosity.
Another recent market entry into the emerging protein space is lupin protein. Lupinus is a genus of flowering plants of the legume family and grows in North America. This genus includes more than 200 species and exists as far as South America and the Mediterranean.
Seeds of various species of lupins have been used as food for more than 6,000 years, but they have never been accorded the same status as soybeans or other pulse crops. Lupin is gluten-free, can act as a prebiotic, and is non-GMO and high in protein content (approximately 40%).
Deriving protein from fruits is a difficult proposition, with a substance that often is 80% water and .5% or less protein. But the ability to do so has become more practical, with the advent of new technology.
One supplier applied state-of-the-art technology that “targets and evaporates water molecules” without disturbing the antioxidants, vitamins or minerals in the original material.
Freshly picked produce is rapidly converted to a fine powder that retains the entire nutrition profile intact and has full flavor aroma and color. The protein easily can then be separated out for use in beverages and other formulations.
While nuts long have been recognized for high protein and other nutrition benefits, such as vitamins, minerals and healthful fats, other plants that offer consumers value-added protein benefits include grains and seeds. For example, quinoa has a complete amino acid profile and is non-allergenic, non-GMO and gluten-free. Oats are low in gluten and high in beta-glucan soluble dietary fiber.
Flax has been a hit for its omega oils and fiber, but it also deserves recognition as a protein source. Flax seed is nearly as rich as most nuts and beans and has a versatility that allowed flax milk to increase markedly in popularity in recent years.
Some manufacturers, such as Good Karma Foods Inc., enrich flax milk with added pea protein isolate to boost the protein level to 5g of high-quality, vegan protein per serving.
Good Karma’s flax milk uses cold-pressed, unrefined flax seed and delivers a balanced source of both omega-3 and omega-6 fatty acids at 1,200mg per serving.
Hemp is a variety of the Cannabis plant and has been used for paper, biodegradable plastics, rope and textiles. Hemp has been cultivated by many civilizations for more than 10,000 years. In more modern times, George Washington and other US presidents were known to have farmed hemp, and farmers in World War II were encouraged to grow hemp for rope manufacturing for the war effort.
Hemp seeds contain 37% protein, 45% fat (providing essential fatty acids), as well as a variety of minerals. The amino acid profile of hemp seeds is comparable to other protein sources, such as meat, milk, eggs and soy, and hemp is a good source of the branched-chain amino acids prized by athletes. Hemp protein is an allergen-friendly replacement for soy and whey protein and can be produced by a solvent-free process. Hemp protein and seeds have been used in cereals, granolas, waffles, ice cream, RTD beverage and nuts.
Plukenetia volubilis, commonly known as the Inca peanut or sacha inchi, is derived from star-shaped pods and native to much of tropical South America, as well as some Caribbean islands. It has been cultivated by indigenous peoples in the Amazon rainforests of Peru for centuries and is emerging as a relatively new protein source in the US. It is produced as a defatted protein meal and obtained via a mechanical, solvent-free, cold-press process.
The seeds of sacha inchi have a high protein (27%) and oil (35-60%) content. Unlike other protein sources, sacha inchi contains the exact proportions of omega-3, -6 and -9 fatty acids the human body needs. Once the seeds are cold-pressed, the protein level is concentrated to between 60-65%, and the oil level remains small, at 5-10%. Sacha inchi has a shelflife of about two years and is not heat-sensitive, so it will work well in bakery applications, such as bars, and also in nutritional beverages. Sacha inchi seeds also can be lightly dry-roasted to enhance their nutty flavor.
One company at the forefront of emerging proteins is VMG Partners’ Vega, recently acquired by White Wave. The company has a line of bars, as well as nutritional and performance-enhanced powdered beverage mixes.
The bars contain chia, hemp and sacha inchi seeds, while the nutritional shakes contain pea protein, sacha inchi, alfalfa protein and sprouted whole-grain brown rice protein, which adds texture and is easily digestible.
While the bars deliver 5g protein per serving, the nutritional shakes deliver 20g protein per serving and also include six servings of greens. The performance-enhanced beverage mixes give consumers 25g protein per serving, which includes 5g branched-chain amino acids and 5g glutamine (to help with muscle fatigue recovery).
“Pea protein can be very beany to quite bitter, depending on the source,” says Julie Daoust, PhD, R&D manager for Vega. “Since the taste of pea protein varies widely from one supplier to the next, choosing the right pea protein for the product you are formulating is a key to success. Also, having other protein sources in your protein blend may balance out the taste of the pea protein.”
Daoust concludes, “Sachi incha is generally quite nutty and can help give the product a more neutral taste; but again, product taste may vary depending on the supplier that is used.”
More Tiny Titans
One company, Mamma Chia Corp., has recently pioneered a brand new category of beverages containing the tiny, but powerful, chia seed. “While our squeezable products deliver 2g of protein, 4g of fiber and 1,200mg omega-3s, our RTD beverage lines boast 4g of protein, 6g fiber and 2,500mg omega-3s.
Chia seeds are a complete protein and contain all nine of the essential amino acids. Unlike flax seed, chia seeds do not have a hard shell and do not need to be ground in order to benefit from the nutrients. Chia seeds are also a wonderful source of antioxidants,” says Janie Hoffman, founder and CEO at Mamma Chia.
Several renewable plant-based ingredients manufactured from microalgae made their debut in 2014. Whole algal flour significantly improves the nutritional qualities of recipes (i.e., reduces fat, optimizes lipid profile), while preserving taste and texture, and chlorella also is a whole food ingredient rich in proteins, antioxidants, vitamins and minerals.
Both of these ingredients can improve the softness and nutritional profile of baked goods; provide detoxifying properties and a wealth of nutrients to smoothies; and enrich soups. In addition to these two plant-based ingredients, an innovative whole-algal protein is currently under development which also is GMO-free, kosher and vegan.
Another newcomer to the plant protein stage is derived from the Wolffia genus (known as duckweed). This plant is part of the Lemnaceae vegetable family and is a wetland plant found floating on water surfaces. Advances in hydroponic technology allow one company to produce this eco-friendly, non-GMO, pure vegan protein year-round and without the use of pesticides. The proprietary system also ensures the ingredient is free from contaminants.
When conditions are ideal, in terms of water temperature, pH, incident light and nutrient concentrations, duckweed species compete in terms of biomass production with the most vigorous photosynthetic terrestrial plants and can double their biomass in anywhere from 16 hours to two days, depending on conditions.
This plant source has extraordinary nutritional value and provides a complete protein on par with beef, egg and soy (PDCAAS 1.0). It also is rich in vitamins and minerals.
The pure powder derived from the Wolffia is at least 45% protein, 25% carbohydrate and 7% fat on a dry-weight basis. It has a mild taste, which is not overpowering like its green algae cousins (such as spirulina) and is ideal for baked goods.
While this proprietary Wolffia powder does impart a green color to formulations similar to spinach powder, it still works well in RTD beverages and smoothies using darker fruits or specifically marketed for their green color (think kale).
According to Lux Research Inc. and Frost & Sullivan Inc., global protein consumption will reach 943 million metric tons (MMT) by 2054, rising at an 8.6% CAGR from the current 473 MMT. Whole protein sources must pick up the slack of the slowing and unsustainable meat and seafood growth.
These sources could claim as much as 33% of total protein supply by 2054. Protein is, and will continue to be, the most important revenue-generating nutrient in the food space.
Proteins are the only energy-providing nutrients that do not have a negative association with consumers in terms of human health (the other two being carbs and fats).
The big challenge will be finding sustainable sources of protein for future generations, and plant-derived proteins are more than able to meet that challenge.