The Possibilities of Protein

The Possibilities of Protein
by Elizabeth Srejic

Proteins, a widely occurring class of natural polymer molecules, form the major structural components of cells and act as components of enzymes involved in cellular reactions. All protein molecules, which are the largest of all naturally-occurring molecules, are comprised of polypeptide chains, which include specific combinations of amino acids, 20 basic building blocks containing both amino and carboxylic acid functional groups. The number of amino acids in proteins may range from two to several thousand.

The primary structure of a protein refers to its specific sequence of amino acids, which determines the protein’s functionality. A protein’s secondary structure is defined as its specific geometric shape, produced by intramolecular and intermolecular hydrogen bonding of amide groups. Tertiary structure is the geometric shape assumed by a protein as determined by a variety of bonding interactions between the component amino acids. And a protein’s quaternary structure involves clustering of several individual peptide or protein chains into a final specific shape.

The two major categories of proteins with quaternary structure include fibrous and globular. Fibrous proteins include keratins found in hair, skin and nails, muscle fibers and clotting agents in the blood, and are composed of coiled alpha helical protein chains with a range of other coils analogous to those found in a rope. Globular proteins, comprising insulin, hemoglobin, and most enzymes, may consist of a combination of the above varieties of structures and are clumped into a spherical shape.

Beyond its basic and necessary utility as a building block of all tissue, protein is most valued as a functional food for its ability to produce satiety,^1,2 promote retention of lean body mass (especially during weight loss),^3,4,5,6 modulate postprandial blood glucose^7,8,9,10 and boost bone mineral density (BMD).^11,12,13 Protein ingredients commonly used in nutritional products and functional foods are primarily derived from soy, whey, casein, egg and fish, although newer ingredients such as colostrum and rice protein are gaining recognition in the marketplace. Each of these varieties has specific advantages and disadvantages determining their suitability for a range of applications.

One extremely popular protein source used in functional foods is soy protein, which provides a diverse portfolio of research-backed health benefits.

One of soy protein’s strongest attributes is its potential role in improving risk factors for cardiovascular disease, according to an American Heart Association (AHA) science advisory.¹⁴ For example, consumption of soy protein has been shown to lower cholesterol.^15,16,17,18 In fact, in October 1999, the Food and Drug Administration (FDA) approved a health claim for use on labels of soy protein-based foods to tout their heart-healthy benefits; the agency based its decision partially on evidence from 27 research studies indicating soy protein may lower serum levels of total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol.¹⁹ Another cardiovascular benefit afforded by soy protein is reduced blood pressure, according to various in vivo studies.^20,21,22,23 A recent study published in Nutrition showed intake of soy protein reduced several cardiovascular risk factors including TC and LDL cholesterol, blood pressure and Framingham risk assessment for coronary heart disease in postmenopausal women.24

Soy protein may also benefit bone health by inhibiting fracture or osteoporosis, or increasing BMD, according to numerous rodent and human studies. One such study, from the Vanderbilt University School of Medicine, Nashville, found an inverse relationship between consumption of soy foods and the risk of fracture among ²⁴,403 postmenopausal women who had no history of fracture or cancer.²⁵ Further, an Iranian study found soy protein consumption produced beneficial effects on bone metabolism indicators, leading the researchers to propose soy protein may have a preventive role in bone resorption, thereby preventing osteoporosis.²⁶ And a University of Illinois at Urbana-Champaign study conducted on 66 postmenopausal women found administration of high-isoflavone soy protein produced significant increases in BMD at the lumbar spine.²⁷

Soy protein has been shown to provide antioxidant advantages beyond those of its functional protein ingredient cousins.^28,29,30,31 These effects may be of particular benefit to athletes, who rely on protein supplementation as part of their training regimes and are at high risk for oxidative damage stemming from exercise. A study from Ohio State University, Columbus, compared the effect of consumption of soy and whey protein bars in athletes and found both the soy and whey groups showed a gain in lean body mass.³² However, the whey group, but not the soy group, showed a potentially deleterious posttraining effect on two antioxidant-related parameters, leading the researchers to conclude soy and whey protein bars both promoted exercise training-induced lean body mass gain, but the soy had the added benefit of preserving two aspects of antioxidant function. And a study on the impact of soy protein consumption versus whey protein intake on total antioxidant status of 20 healthy, athletic, college-aged males found supplementation with 40 g/d soy protein (as Supro®, from The Solae Co.) in conjunction with a strenuous training program produced an increase in total antioxidant status as well as reduced serum levels of myloperoxidase, an indicator of oxidative stress.³³

Soy protein’s antioxidant capabilities may also implicate the ingredient as an anti-cancer therapy. According to a recent metaanalysis from The Solae Co. published in the International Journal of Cancer, the results of two cohort and six case-control studies may indicate a role of soy protein consumption against prostate cancer.³⁴ And a 2006 study published in Cancer Research showed soy isoflavones inhibited markers of breast cancer in a postmenopausal primate model, leading researchers to conclude dietary soy isoflavones may alter estrogen receptor signaling and induce selective antagonistic effects in the breast.³⁵

Due to its heart-healthy, anti-osteoporotic and anti-breast cancer effects, use of soy protein may be ideal in functional foods aimed at women, who are at particular risk for health problems in these areas, especiallly during menopause. Soy protein may further benefit menopausal women due to its controversial ability to reduce hot flashes,³⁶ an effect possibly produced by the compound’s natural isoflavone content. Among men, however, soy protein may be a less popular protein source, in spite of the ingredient’s purported effects against prostate cancer; although soy protein’s isoflavone content functions as a selling point among women, it repels some male end users who fear soy isoflavones could cause estrogen-like effects. While not all soy proteins on the market contain isoflavones, soy protein also may be regarded as a woman’s protein by men because of the ingredient’s popularity among menopausal women.

In the realm of weight loss, soy protein may provide specific benefits beyond other protein sources. A study from the University of Kentucky, Lexington, comparing the efficacy of meal replacement beverages in producing weight loss, found a soy protein-based beverage produced greater weight loss over a 12-week period than a milk protein-based beverage did.³⁷ According to a recent study published in Atherosclerosis, such effects may be due to soy protein’s possible ability to increase endogenous production of adiponectin, an adipose-specific plasma protein with an inverse relationship to body weight, especially visceral adiposity.³⁸

Soy protein, which is extracted from soy bean cotyledons, is the ideal vegetable protein due to its comprehensive amino acid profile, according to Bob Rasmus, sales director with Archer Daniels Midland (ADM) Food Ingredients. “Of all vegetable protein sources, soy has the highest PDCAAS [protein digestibility corrected amino acid score], which rates the inclusiveness and ratios of a protein’s amino acid profile,” he said.

In general, the best applications for soy protein include crispy-type energy bars, where soy is delivered as a crisp, an ingredient available in different protein grades and manufactured by twin screw extrusion, a process originally developed for plastics in the toy industry, according to Grant Gengel, director of marketing with Nuvex. “That’s where the texture and shelf-life advantages are put to best use,” he said. However, he said soy protein crisps do not function well in all applications: “Generally, baking is not crisp-friendly. The crisps tend to hydrate and get soft and soggy.”

Another advantage soy protein has over other protein sources is its cost-effectiveness. According to Deborah Schulz, market development manager with Cargill Health & Food Technologies, soy protein is usually available at half the cost of whey protein. “Milk protein prices are at an all-time high,” she said. “We’re finding increasing numbers of customers are expressing interest in replacing other protein sources with soy protein.”

In spite of its health benefits and attractive cost, however, soy protein presents certain problems in formulation.For example, one wellknown drawback of soy protein use is the ingredient’s purported “beany” flavor. According to Gwen Bargetzi, marketing director with Hilmar Ingredients, this undesirable flavor note is detectable in certain formulations.“Soy’s notoriously beany taste is fine in some applications; however, a strong taste can be quite detrimental in others with a more transparent flavoring system,” she said.“Vanilla comes to mind as being particularly sensitive to any taste contributed by proteins.”

One solution to soy protein’s beany taste is the use of highly purified and concentrated soy protein isolates, which are largely tasteneutral. “Historically, some isolates continued to have flavor challenges,” said Schulz. “However, the technology to solve this problem has been developed over the years, and the soy protein isolates are now the ‘cleanest’ [most tasteneutral] proteins available.”

As with other protein isolates, soy protein isolates are useful for very high-protein applications as they consist of 90-percent or more protein, which allows flexibility for formulating other ingredients and can produce thick textures. According to Rasmus, soy protein isolates are available in a wide range of different grades, allowing for versatility in formulation. “Some are hydrophilic, some are hydrophobic, they all have different viscosities, and so forth,” he said. “These different attributes allow flexibility across a range of applications.” However, Rasmus noted the tendency of soy protein isolates to gel, or congeal, can preclude them from use in beverages. “While soy protein’s texture can be efficacious for meat and cheese analogues, the last thing you’d want to put in a sports drink is something with properties like Jell-O®,” he said. “Since soy protein isolates tend to gel, they must be kept within tight, specific parameters to work with specific machinery. In the case of extrusion, soy protein can gum up the machinery if it doesn’t contain the right ratios of protein and other components. In the case of bread manufacture, the dough is often pumped between machines; the addition of soy protein can make the dough too heavy and difficult to pump.”

Gengel added soy protein’s proclivity to congeal can also preclude the ingredient from use in energy bars; however, he further noted this problem is frequently solved by the use of soy protein crisps. “Soy protein crisp is used mainly because using soy protein isolate in its native state, along with other nutrients that you’d want to include in an energy bar, causes the protein to congeal, which makes the bar hard and shortens the shelf life dramatically,” he said. “However, when the protein is delivered as a crisp, the heat and the shear in the manufacturing process are sufficient to partially denature the protein, rendering it virtually inert, producing a soft texture and extending the shelf life.”

A limitation of soy protein crisp is its protein level, which, according to Gengel, normally cannot exceed approximately 80 percent. “Once you get past about 80 percent, the protein becomes un-extrudable because of the by-products of the protein denaturing process; it tends to clog up the equipment.”

According to Rasmus, another drawback of soy protein is its naturally occurring oils must be removed during processing, usually through use of a solvent. Once a solvent is used, the product can no longer be considered organic. Also, heat generated by the expeller pressing process used to remove the oil can negatively change the nature of the soy protein, causing it to lose its solubility, which limits the protein’s functionality. He added the quality of the finished product can hinge on how well the solubility of the soy protein was preserved during processing.

Rasmus further noted the functionality of soy protein is limited to non-liquid applications as the ingredient tends to precipitate out of solutions. A better choice for beverages is whey protein, he said, which is soluble across the pH range. “Soy is comprised of four major proteins, yielding an average isoelectric point of 4.5,” he said. “When you put it into an acidic state, that protein will become solid again and precipitate out. Whey, on the other hand, is easier to work with in an acid environment.”

Although soy protein does have certain limitations in formulation, its inclusive suite of health benefits still distinguishes it as an excellent choice among the protein sources, particularly its animal-based counterparts, according to Cathy Bloom, senior sales representative with DNP International. “As a pure vegetable soy protein, soy protein has fewer side-effects than animal protein,” she said. “It is lactose free and meets or exceeds the essential amino acid requirements for adults and children.”

Beyond the plant kingdom, dairy milk is a staple source for a wide range of protein ingredients, including whey and casein. “The nutritional value of milk proteins is nutritionally advanced to that of other protein sources,” said Margaret Greaney, marketing services manager with Kerry Dairy Proteins, which produces Ultranor™ TNT, a range of milk proteins designed to enhance textural and organoleptic properties of nutritional bars by preventing hardness during shelf-life. “The protein efficiency ratio (PER) of milk proteins is superior to other traditional protein delivery systems. Furthermore, our Ultranor milk proteins possess a clean milk color and flavor which requires no masking in the finished product.”

Dairy-derived whey protein is a widely used milk protein ingredient. As an isoflavone-free product, whey protein may be a more popular protein source among men than women. Further, as whey protein provides a rich source of branched-chain amino acids (BCAAs), it has been particularly popular among athletes and body builders. When combined with a resistance training program, whey protein has been shown to increase muscle mass and muscle strength,^39,40 enhance muscle glycogen uptake,⁴¹ heighten oxygen-carrying capacity of the blood, and encourage quicker recovery from muscle fatigue, promoting increased training efficiency.⁴² Whey protein’s BCAAs are particularly conducive to muscle growth and regeneration as they increase the rate of protein synthesis and decrease the rate of protein degradation in human muscle.^43,44,45

In the realm of weight loss, whey protein may provide benefits beyond soy protein- or carbohydrate-based diets, according to new research presented at the 2006 Experimental Biology meeting in San Francisco by researchers from the Beltsville Human Nutrition Research Center at the U.S. Department of Agriculture. In the study, 90 free-living, overweight and obese (BMI greater than 28 and less than 38) individuals were randomized to receive 60 g/d whey protein, soy protein or carbohydrate for six months. Test subjects who consumed supplemental whey protein for six months weighed less and had less body fat compared to individuals who consumed a supplement based on soy protein or carbohydrate. Further, while body weight did not differ between the whey and soy groups, the whey group lost more inches around the waist than the group consuming soy protein.

Whey protein may also boost immune response in athletes whose immunity has been compromised by strenuous, prolonged exercise.⁴⁶ Research indicates these benefits likely extend beyond athletes to benefit anyone with compromised immunity.^47,48,49,50

According to Bargetzi, whey protein is suitable for a wide range of applications. “Our whey proteins are quite dexterous and can be used in array of applications from nutritional bars and baked goods to dairy (e.g., yogurts, ice creams), savory and meat applications,” she said. “If I had to choose one specific area that maximized the contributions of whey protein, I’d choose a food bar [due to the texture whey provides].” One reason for whey’s broad functionality is its superior solubility across the pH range and ability to mimic the behavior of other protein sources, Bargetzi added. “[In contrast to acid-stable whey, other protein sources] are pH sensitive and will precipitate at the isoelectric point of pH 4.6,” she said. “Heat and acid stability are especially helpful in acid beverages, such as juice-based drinks, because other protein sources like caseinate are not stable and will flocculate or fall out of the system. [With regard to shared functionalities], whey proteins can be used as an alternative when egg or milk proteins are not desirable,” she said. Another benefit of whey’s functionality in lower-pH applications is its translucence in acidic beverages, added Simon Leitch, business manager, protein beverages, with Fonterra, which is developing high-protein shots and jelly drinks. “[In contrast to various other protein ingredients, whey protein maintains a] clear appearance at acidic pH’s,” he said.

Beyond its wide range of applications and texture, another major benefit of whey protein is its taste, which, according to Steve Dott, vice president of Grande Custom Ingredients, distinguishes this protein from its counterparts. “By far, whey protein provides the best taste of all the protein sources,” he said.

“Milk proteins definitely provide the best taste, making them a clear choice over other protein sources,” agreed Craig Air, technical services manager with Erie Foods.

However, optimal taste and wider functionality comes at a higher price; whey protein ingredients are often twice as expensive as soy ingredients, according to Gengel.

“The real drawback with whey protein, in spite of its many positives—it’s the best-tasting protein source out there, in my opinion—is the cost is very significant,” he said.“We’re charging about $4/lb for it, which really limits the applications; it could sink projects, economically.” Gengel said Nuvex Ingredients solves this problem with a soy- and wheat-protein hybrid, SuperSaver 60, a 60-percent protein soy protein crisp available at a significantly lower cost than most whey protein ingredients. “Normally, the combination of soy and wheat would be hard as buckshot, but we found a way to give it a crispy texture,” he said. “We’ve been hearing a lot from companies that wanted to introduce products like [whey protein-based] protein bars, but couldn’t find a high-protein crisp that fit their economic model,” he said. “With the introduction of the Super Saver 60 protein crisp, which is suitable for bars, breakfast cereals and baked goods, we expect to be able to provide the protein punch they’ve been looking for at a price that makes it all affordable.”

Gengel added another reason to avoid whey protein is that it is difficult to extrude. “It denatures at a fairly low temperature, so it’s constantly clogging the machinery,” he said.

Casein, a tasteless, odorless protein precipitated from milk by rennin, is another beneficial protein source. As it may improve cardiovascular training, decrease epididymal fat tissue and increase lean body mass,⁵¹ casein may promote positive results in resistance training programs. Further, casein produces similar increases as whey protein in muscle protein net balance and synthesis, despite different patterns of serum amino acid responses between the two ingredients.⁵² However, clinical trials comparing the efficacy of the two compounds have shown mixed results with regard to lean body mass and muscle glycogen uptake. One such trial, a randomized, prospective 12-week study on overweight policemen conducted at Brigham and Women’s Hospital, Boston, compared changes in body composition produced by supplementation with casein or whey protein plus exercise and a hypocaloric diet, and found test subjects supplemented with casein experienced greater gains in strength and lean body mass than individuals given whey.⁵³ The researchers concluded the disparity in results between groups was likely due to improved nitrogen retention and overall anti-catabolic effects produced by specific peptide components of the casein hydrolysate. Conversely, a Japanese study found whey protein superior to casein in promoting glycogen uptake in skeletal muscle of exercise-trained rats.⁵⁴

In comparison to soy protein, casein has shown better results in building lean muscle mass than its botanical cousin has in a handful of clinical trials. One such study, conducted at Maastricht University in the Netherlands, compared the efficacy of casein and soy protein with regard to the ingredients’ metabolic effects in healthy human subjects and found casein produced greater net protein synthesis in test subjects than soy; in addition, a significantly larger portion of soy protein than casein was degraded to toxic urea within the body.⁵⁵ Similarly, another study out of Maastricht University measuring net protein retention and amino acid and urea kinetics in gut, liver and muscle of pigs given casein or soy found casein promoted greater net protein synthesis than did soy, while soy protein produced higher levels of urea.⁵⁶

Other advantages of casein include its lower lactose content than whey protein, a boon to end users with lactose intolerance, as well as its slower absorption rate than soy or whey proteins, which could be beneficial to bodybuilders seeking a more sustained supply of amino acids.

With regard to casein’s facility in formulation, the ingredient can be further processed to produce a caseinate, which is more soluble than its predecessor, and can be manipulated to control viscosity. “We make the caseinate by adding an alkali, which makes the casein more soluble in liquid,” he said. “The ingredient can be processed to give it higher viscosity; a sodium caseinate has higher viscosity than a calcium caseinate, for example.” Air added that casein ingredients, such as sodium caseinate, generally have good emulsification properties and can be agglomerated and instantized to be more dispersible in a liquid.

Colostrum is a source of dairy-derived protein growing in popularity. Its main advantage over other protein sources is its content of antibodies, which have been shown to boost immunity, according to a number of clinical trials and reviews.^{57,58,59,60,61,62} “Although derived from a dairy source, colostrum is distinctly different from milk or casein or whey protein preparations, because of the high levels of these immune and growth factors present in colostrum,” said David Evans, technical director, and Barry Ritz, technical sales consultant - East coast, with La Belle Inc. “In many ways, colostrum can be considered nature’s first ‘functional food.’”

According to Evans and Ritz, La Belle’s bovine colostrum is processed by collecting excess bovine colostrum from Grade A dairies; the ingredient is then pooled, thermally treated by a proprietary lowtemperature process to protect the delicate protein fractions, concentrated, and gently spray-dried. Subsequently, all colostrum powder is analyzed for composition and purity, and assayed for bioactivity of immunoglobulins by radial immunodiffusion (RID) analysis. The ingredient is available in different grades of protein and immunoglobin content, and in special forms for markets with lactose and other dairy sensitivities. Evans and Ritz added the product is suitable for a wide range of applications as it has a balanced amino acid profile, and a prime target market is athletes, who require both extra dietary protein and immunity.

“When athletes are doing extra training to get ready for a competition, their immune systems tend to get depressed and it is not unusual for them to get sick; colostrum contains immunoglobulin proteins and cytokine fractions that support the immune system and help the body thrive,” they said. “La Belle produces Intact®, a powdered colostrum supplement for athletes with product-specific research on performance and recovery benefits.”

According to Evans and Ritz, colostrum has been available historically through a variety of delivery methods. “Traditionally, colostrum has been positioned in the human market as a capsule or chewable tablet,” they said. “Manufacturers have been including colostrum in the formulation of functional foods and nutrition/protein bars. There are also some powder mixes and liquids on the market. More recently, there has been a rise of consumers interested in powders in order to obtain higher doses of colostrum protein. We believe we are going to see more applications in the functional food markets and incorporation of colostrum proteins into more traditional health foods like orange juice and yogurt.”

One consideration in processing colostrum is heat treatment, which can be deleterious to the ingredient’s key components, they added. “Some processors treat colostrum proteins like milk proteins during production,” they said. “Exposing colostrum proteins to the harsh chemicals and temperature extremes of milk processing destroy a lot of their effectiveness.”

Beyond whey, soy, casein and colostrum, other typical protein ingredients are sourced from egg, fish and rice.

The avian egg is an important source of nutrients, containing all of the proteins, lipids, vitamins, minerals, and growth factors required by the developing embryo, as well as a number of defense factors to protect against bacterial and viral infection.⁶³ Further, several biological activities have been associated with egg components, including novel antimicrobial, anti-adhesive, immunomodulatory, anti-cancer, antihypertensive and antioxidant properties.⁶⁴ Before soy and milk-derived protein supplements and functional foods became widely available, eggs provided a standard source of protein for bodybuilders.⁶⁵ However, modern egg protein ingredients eliminate the fat and cholesterol naturally present in eggs to yield a highly purified, complete protein source. Further, according to Karen Moss, food scientist with Henningsen Foods, egg proteins may have anti-hypertensive properties.

“Chickens provide antibodies to the newborn chicks via the egg,” said Evans and Ritz. “La Belle is engaged in a tremendous amount of research and development to provide avian egg protein products that are enriched in specific antibodies (patents and licensures pending). These specialized proteins can then be used to supplement humans and animals to target specific immune challenges. Such products are currently being tested in calves and goats, and La Belle is on the verge of commencing a pre-clinical trial on the use of a specialized protein product to protect dogs from parvo virus.”

A delivery challenge associated with egg products is their sulfurous flavor. According to Moss, whose company produces EP-2, an egg white protein ingredient manufactured using a proprietary, controlled enzyme hydrolysis of egg white protein, hydrolysis can solve egg’s flavor challenges, if executed correctly, and can even increase bioavailability of the ingredient’s key components. “Very few protein products are hydrolyzed (broken down) due to the resulting off-flavors,” she said. “Most proteins are sold intact in powder form. However, the controlled hydrolysis used to manufacture EP-2 results in peptides with a mild, neutral flavor without the bitter taste usually associated with protein hydrolysates. Also, the hydrolysis of egg white protein results in greater bioavailability when compared to intact proteins, making the amino acids in EP-2 easily digested. While the idea of hydrolyzed egg whites is not a brand new concept, we believe EP-2 has found the correct balance between the benefits of hydrolysis and flavor.”

With regard to applications, Moss said the hydrolysis can prevent coagulation of proteins within egg protein ingredients, making them suitable for hot or cold beverages; further, the process makes rehydration easier than it can be with intact protein ingredients. Schultz added another good application for egg protein is baked goods due to the specific effects egg can provide, according to Schulz. “Eggs have specific functionality in the baking area,” she said. “They’re used frequently to provide aeration and whipping, which cannot be provided by other proteins such as whey or soy.”

However, although egg protein works well in baking applications, it is not suitable for extrusion due to the cost, Gengel noted. “We’ve done some experimental extrusion with egg and whey protein,” he said. “It made a wonderfully textured piece. Unfortunately, it was so expensive that it was just prohibitive.”

Fish protein, another complete protein source, is gradually gaining recognition as a protein ingredient. According to recent research, fish protein produces an extremely low postprandial glucose and insulin response. These effects could likely result in a more sustained supply of glucose as well as prolonged satiety. Researchers from Uppsala University in Uppsala, Sweden, administered three protein-rich meals based on soy protein, milk protein or fish protein to healthy test subjects.⁶⁶ The insulin-to-glucose ratio was lower after the cod protein meal compared to the milk and soy protein meals at 120 minutes. Similar results were obtained in a rat study out of Laval University, Ste-Foy, Quebec.⁶⁷ Male Wistar rats were fed for 28 days with isoenergetic diets containing either casein, soy protein, or cod protein. Cod protein- and soy protein-fed rats had lower fasting plasma glucose and insulin concentrations compared with casein-fed animals.

One hydrolyzed fish protein ingredient is Seacure®, a 99.8-percent cod and 0.2- percent rosemary extract ingredient from Proper Nutrition, produced utilizing a proprietary microorganism. According to Dee Eckert, director of operations for Proper Nutrition, fish protein provides a range of benefits beyond other protein ingredients. “Seacure provides so many benefits to the body because it is a highquality protein source,” she said. “Because Seacure is pre-digested during our manufacturing process, [its amino acid constituents are] immediately absorbed and assimilated by the body. In addition, recent research conducted in England indicates that the peptides found in Seacure have been shown to have healing properties.”

According to Eckert, fish protein can be delivered in numerous forms, such as powders or chewable tablets, and is suitable for a wide range of applications.

“Seacure may be incorporated into any finished product, unless [the end user] is allergic to cod,” she said. “There are no contra-indications in taking Seacure with any other dietary supplements, medications or vitamins.”

In spite of their wide applicability, one delivery challenge with fish ingredients is the issue of heavy metal content. However, Eckert said each batch of product can be independently assayed for content of mercury and other heavy metals, as is the case with her company. She added unpleasant fishy odors are another challenge common to fish protein ingredients. “Since Seacure is a fish protein concentrate, our product does have a fish odor,” she said. “This is a challenge that we have faced for over 11 years. After many failed attempts to mask the smell, we discovered that by chilling Seacure, which does not decrease the efficacy of the product, the smell dissipates.”

Rice protein, derived from the grain’s endosperm, is another protein source gaining momentum in the protein ingredient market. According to Gil Bakal, managing director of A & B Ingredients, the main benefit of rice protein is that the ingredient is hypoallergenic. “Rice protein is one of the only hypoallergenic protein sources known,” he said. “It is good for people who have allergies to soy, milk or meat proteins, or who don’t want to use these proteins.”

Bakal said the ingredient is processed by separating the carbohydrate and protein fractions from the endosperm; the protein is isolated and concentrated. The protein can also be treated with enzymes to improve its solubility, which in turn determines the different grades of product available, he added.

“Our standard protein is a concentrate, which is an insoluble product,” he said. “But we also offer hydrolysates, which are soluble. The degree of solubility determines the grade.”

Solubility can determine rice protein’s suitability for specific applications, Bakal added; ideal applications for rice protein include baked goods, often as a complementary protein source blended with other proteins. However, he noted rice protein does not function well in beverages as it tends to precipitate out of the solution: “We’re still working on ways to make the protein more soluble while retaining flavor and cost effectiveness.”

To select the appropriate protein for a functional food or beverage protein, manufacturers should consider issues such as functionality, delivery method, nutritional value, cost structure and target market to choose a protein ideally suited for the desired end product. In addition, consider the choice of supplier carefully, based on a supplier’s expertise, reliability, cost and specific benefits.

Since all proteins have different attributes, not all types of proteins can perform in all applications. Moreover, a major consideration in selecting a protein is the ingredient’s functionality, according to Bakal. “Different proteins have different functional properties,” he said. “They’ll bind different amounts of water, thicken or coagulate, all of which play a role in formulation. Milk proteins, for example, can get too dry, which can necessitate the combination of proteins, rather than milk protein alone, in formulation.”

To provide specific functionalities, most companies offer several grades of a protein product, each one suitable for particular applications, according to Schulz. “Often, use of more than one type of protein is necessary to achieve the desired functionality,” she said. “For example, in the case of Prolisse [Cargill’s line of soy protein ingredients], the membrane filtration process we use to manufacture the ingredient allows for several varieties with different attributes providing different types of functionality.”

According to Bargetzi, a good place to start is to ask for a supplier’s input on which protein ingredient best suits a proposed application. “There are many protein products available and a good supplier will provide technical support and advice to help shorten your development time,” she said. “Proteins are very different from each other; milk proteins are different than plant proteins. Even within the milk proteins, each has its own personality.”

Bakal agreed all proteins have different attributes that must be taken into consideration when choosing a protein ingredient for a particular application. “There are ‘cleaner’ proteins, but all of them have a flavor,” he said. “Soy proteins have a beany note; milk proteins have a dairy note; egg proteins have a sulfur note; rice protein has a grainy note. Each of them has their flavor—and color— considerations.”

The specific flavor notes of proteins often motivate manufacturers to blend varieties, rather than using an isolated protein source in formulation, according to Rasmus. “Proteins can work together in food systems,” he said. “You could pick just about any nutrition bar and see soy proteins and dairy proteins working side by side.”

However, not all grades of proteins will work together, necessitating formulation expertise, Rasmus cautioned. “The structures of various proteins determine how they fit together and act together in formulation; for example, solubility of various protein ingredients determines whether one will clump or separate from the others.”

One often overlooked consideration in selecting a protein source is the ingredient’s allergic potential, which can exclude certain target markets, according to Bakal.

“Almost all proteins are allergens,” he said. “Suppliers must help their customers select a protein that’s safe for a specific target market.”

Considerations in selecting a supplier include quality, price and reliability, as well as consistency between batches, according to Gengel.

According to Bargetzi, another consideration is the specific portfolio of expertise a supplier can provide. For example, she said Hilmar specializes in specific formulation issues including heat and acid stability, gelling, bar softening and texture improvement properties and molecular weight profiles for specific nutritional needs. “Always consider the competence and quality of support a supplier can provide,” she said. “It’s a measure of how much they are willing to invest in their product line and their customer. Look at application knowledge, timeliness of response, sampling, market awareness, customer service and company philosophy. Does this supplier treat us like a transaction or an investment?”

Certain suppliers provide services beyond formulation expertise and reliability, according to Schulz, whose company also helps its customers with marketing. “We can help a customer understand how trends in the consumer marketplace apply to the types of products Cargill brings to the table and how those products fit with our customers’ products. We also have branding programs that allow us to bring benefits to our customers.”

Further, Rasmus stressed the importance of flexibility. “A good vendor should be able to tweak a product to fit a specific process,” he said. “Customers have different needs; a supplier should be able to customize a product to fit a specific food program. In order to do this, a supplier should have extensive expertise across the range of proteins.”

The protein ingredients market boasts an expanding range of wellresearched offerings with a variety of different attributes and functionalities, and suppliers are transcending basic roles by providing manufacturers with various incentives, including formulation expertise, expanded product ranges and marketing assistance.

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