Roughly 50 million American adults are currently watching their carbohydrate intake, according to the Natural Marketing Institutes (NMI) Health and Wellness Trends Database (HWTD). NMI figures suggest consumers who have tried to manage weight by eating fewer carbohydrates in the past year comprise 24 percent of the American general population, a figure that is projected to grow to 32 percent of Americans by 2006. The low carb phenomenon has been covered by mainstream media such as The New York Times and TIME magazine, and visitors to the recent Natural Products Expo in California were overwhelmed by the array of low carb options. Beyond bars and powders, protein is taking center stage in the processed food arena.
Protein is critical to human health. It is a part of every cell in the body, and is used for cellular growth and development, immune function and overall cellular energy. The cells of the muscles, tendons and ligaments are all maintained with protein.
Some 20 different amino acids serve as the building blocks for protein. Nine cannot be synthesized by the body; these essential amino acids must come from the diet. While animal-based foods are the best source of complete protein, containing all nine essential amino acids, some plant sourceslike soyalso contribute these important components.
Studies have shown the importance of protein for heart health, immune function, sports performance and weight management. The largest study to date on protein intake and cardiovascular health found over a 14-year period women who ate approximately 110 g/d of protein were 25-percent less likely to have a heart attack or die of heart disease than women who ate the least amount of protein (around 68 g/d).1 Whether the protein came from animal or vegetable sourcesor whether it was part of a low-fat or high-fat dietdidnt seem to matter. And a research review from Pennsylvania State University, University Park, reported, As part of a low-saturated fat diet, animal and/or soy protein intake at or above the recommended intake level of 15 percent of total calories lowers plasma cholesterol levels, reduces blood pressure and potentially facilitates healthy weight management.2
In the immune arena, specific protein fractions have the best support for their role in human health. For example, whey protein concentrate was shown in an animal model to stimulate humoral immune responses to a range of antigens, demonstrated through enhanced serum antibody levels.3 And Canadian researchers found high levels of isoflavones from soy protein affect immunity, possibly explaining enhanced immune response to certain cancers.4
Until recently, protein was of the most interest in the natural products industry for its performance enhancement abilities. Researchers have found amino acid intake combined with exercise has an additive effect on muscle protein synthesis.5 Casein has been shown to specifically increase strength in the chest, shoulders and legs;6 soy (as Solae soy protein) was shown in studies to protect against muscle tissue breakdown and inflammatory oxidant stress in exercising humans;7 and whey was found to lead to improvements in peak torque and lean tissue mass.8
Protein is currently seeing a great deal of research in weight management. Comparative studies now support the theories of Robert Atkins, M.D.that low carbohydrate/high protein diets can help people lose and maintain weight in a healthy way. One recent study of 20 adults assigned to low carb or high carb energy-restricted diets found both diets reduced total cholesterol and body weight, but the low carb dieters were more satisfied and reported less hunger.9 Another study examined the role of low fat diets with differing carbohydrate levels in subjects with hyperinsulinemia, and reported both diets achieved net weight loss and improvements in cardiovascular risk factors.10
Even former skeptics are being forced to reconsider low carb living. The American Heart Association (AHA) said in a recent issue of the Journal of the American College of Cardiology that while such diets can be seriously deficient in micronutrients and fiber, they show benefits on weight loss and cardiovascular health, including reducing LDL cholesterol levels.11
Such reports are driving consumer and manufacturer interest. Increased knowledge from the general public about the nutritional value of specific proteins as well as the value of proteins in general as a macronutrient are increasing interest in the protein area, said Benoit Turpin, national sales director/technical director for Wapakoneta, Wis.- based Euro Proteins. The next step is to decide what path to take. Formulators have to identify the functionality and nutritional targets they are shooting for, Turpin added.
There are many considerations when selecting a protein source. In the dairy arena, there are two primary protein optionscasein and whey. Casein makes up approximately 80 percent of the protein in milk and is heat stable; it is separated from whey during the cheese-making process. It has been commercially marketed since the early 1900s, and today is a common additive to many processed foods. Whey, once just a milk byproduct, is filtered to separate whey from lactose and any remaining fat, and is then concentrated and purified. Whey protein is available as concentrate (WPC) and isolate (WPI); isolates are more pure and concentrated, offering more than 90 percent protein by weight with very little fat or lactose. WPC contains between 30 percent and 90 percent protein, depending on the product.
Whey protein is made up of a host of individual proteins, each contributing to human health. Beta-lactoglobulin, for example, comprises approximately 60 percent of the protein in whey and is the fraction richest in branched chain amino acids (BCAAs). Alphalactalbumin makes up 20 percent of whey protein and is a rich source of tryptophan, a serotonin precursor. Other proteins include glycomacropeptide, bovine serum albumin, lactoferrin and lactoperoxidase.
Whey is a very high quality protein that can be very functional, said Grace Harris, manager of dairy applications and business development for Proliant Dairy Ingredients in Ames, Iowa. Most protein suppliers are looking at making more functional proteins so they can be used across the board.
Whey protein is the focus of many current studies, which cover a range of benefits. Many bioactive components derived from whey are under study for their ability to offer specific health benefits, wrote researchers from Functional Ingredients Research Inc., Twin Falls, Idaho, in the Journal of Nutritional Biochemistry.12 The capacity of these compounds to modulate adiposity and to enhance immune function and antioxidant activity presents new applications potentially suited to the needs of those individuals with active lifestyles.
One reason whey performs well in muscle applications is its high concentration of BCAAsleucine, isoleucine and valine. BCAA supplementation is being studied for its ability to support long-term muscle development and growth, and avoid muscle fatigue and oxidative damage. Beyond the BCAA content, whey protein is absorbed quickly in the gastrointestinal tract, meaning consumers have an immediate protein source to rebuild muscle following exertion.
Casein can also serve a critical role in performance nutrition. A recent study on micellar casein (an undenatured casein) conducted for Burlington, N.J.-based American Casein Co. found whole body protein breakdown was inhibited by 34 percent after casein ingestion following muscle stress. According to the lead researcher, Yves Boire, the casein produced a prolonged plateau of increased plasma amino acids, producing high nitrogen retention and utilization.
There are several issues to consider in formulating with dairy protein. Whey products are extremely versatile, said Mike Kothbauer, director of sales/marketing with Land OLakes. They have solubility over a wide pH range, which is critical for fruit flavor or blended products. The flavor impact is also the least of all protein supplements available on the market. He added the digestibility of the protein is also a positive for whey.
When determining whether to use isolates or concentrates, the deciding factors are the percentage of protein desired and whether the presence of other macronutrients would impact the finished item. Also, because isolates require more processing, they are generally more expensive than concentrates, impacting the products price point.
Another consideration is processing temperatures. Several of the beneficial components in whey are extremely heat sensitive. Proteins can aggregate in high-heat conditions, denaturing the protein and influencing its health effects. WPI produced in high-heat environments, or exposed to high heat in processing, can lose the beneficial health effects associated with some of the fractions. Suppliers are addressing this concern; Proliant Dairy Ingredients, for example, developed a proprietary microfiltration process to manufacture its Iso-Chill WPI. The product delivers less than 3 percent denatured protein, with 97 percent or more intact. If those fractions are not denatured, theyre still bioactive for the consumer, Harris said.
The other main protein source in the market is soy. Soybeans contain 38-percent protein, with the remainder consisting of carbohydrate (including fiber), oil and moisture. They are the only legumes that contain all nine essential amino acids in the correct proportion for human health. When soybeans are processed, they are first made into flakes, then the oil is removed. Defatted material serves as the basis of soy flour, protein concentrations and isolates.
Soy protein isolate is basically a highly refined and concentrated soy protein, which is lower in fat and generally has less beany notes than whole soy protein. It is prepared through a water extraction process and is nearly carbohydrate free, resulting in a product with more than 90 percent protein by dry weight. Major processors offer specialty soy isolates, including ADMs NutriSoy, Cargill Soy Proteins Prolisse and Solaes Solae protein and isolate.
Studies on soy's health benefits have been particularly focused in the heart health arena. In fact, the studies were convincing enough that when St. Louis-based Solae Co. submitted a petition showing more than 50 independent, published studies supporting this health benefit, the Food and Drug Administration (FDA) authorized a health claim linking soy protein with lowering heart disease risk. In the May/June 2000 issue of FDA Consumer magazine, author John Henkel wrote, Scientists agree that foods rich in soy protein can have considerable value to heart health, a fact backed by dozens of controlled clinical studies. A year-long review of the available human studies in 1999 prompted FDA to allow a health claim on food labels stating that a daily diet containing 25 grams of soy protein, also low in saturated fat and cholesterol, may reduce the risk of heart disease.
Ongoing studies strengthen the link. Consumption of soy protein with isoflavones appears to significantly reduce blood pressure and total cholesterol,13 improve plasma lipid levels14 and reduce LDL oxidation.15 Researchers studying the effects of soy protein with high and low levels of isoflavones found both diets reduced the risk of coronary heart disease (CHD), because of both modest reductions in blood lipids and reductions in oxidized LDL, homocysteine and blood pressure.16 And recent data from the Shanghai Womens Health Study of 75,000 Chinese women aged 40 to 70 years found a clear dose-response relationship between soyfood intake and risk of coronary heart disease.17
Some concerns have been raised about the isoflavone content in soy protein causing androgenic effects; however, comparative studies using generations of rats have shown only minor negative effects, including accelerated puberty in female rats.18 The researchers, from University of Arkansas for Medical Sciences, Little Rock, noted they did not expect the results to be mirrored in humans, as humans dont eat an isolated diet of soy protein throughout their lives, and population studies have not found such effects. Instead, the long-term health consequence implications of early diet exposure ... such as reduced breast cancer incidence, are likely to be very positive.
Soy protein suppliers report market trends are favorable for business. The FDA health claim stimulated product development with soy protein, but the low carbohydrate diet trends have accelerated the use of soy protein in mainstream foods, said Russ Egbert, director of protein research with ADM Natural Health & Nutrition in Decatur, Ill. It appears the low carb trend will have a significant impact on the inclusion of soy protein in our diets.
Given the options in the market, manufacturers have an array of willing suppliers that are available to assist in product development and formulation, and help determine the right protein source for a given product. There are a number of new applications, particularly in the high protein/low carbohydrate processed food area, said Gary Brenner, marketing director with Solbar Industries, a supplier of soy proteins and isoflavones. Formulators have to look at the functionality of a protein in the finished product in addition to nutritional health requirements and cost benefits.
Understanding formulation considerations means working closely with a supplier to find the right mix. We encourage formulators to try several different products to see which works best in a specific formula, said Cliff Lang, general sales manager with American Casein Co. It is good to send several samples and let the customer evaluate which works best in a specific formula.
The increasing interest means suppliers are working on new application options. Kothbauer said there is interest in such products as protein-fortified candies, breath films, cookies and frozen desserts. Similarly, Nuvex Ingredients developed soy and whey NuChews, chewy snack shapes with 25-percent protein that come in a wide variety of flavors (e.g., marshmallow, strawberry) and shapes to use as inclusions or finished products.
Besides offering assistance in formulation, protein suppliers are helping drive consumer interest in the protein category. ADMs NutriSoy, for example, is one of the national presenting sponsors of the American Heart Associations Heart Walk. Solae rolled out a multimillion dollar national television advertising campaign earlier this year entitled, Protein in Unexpected Places. Reaching out to consumers is a critical component to building an ingredient brand, said Todd Sutton, global marketing director for Solae brand protein. We want to educate consumers that if they purchase products containing Solae soy protein, theyre choosing great-tasting, better-for-you foods and beverages that are easily incorporated into everyday life.
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|Enzymes Enhance Functionality|
While millions of Americans modify their diets to up their protein intake while decreasing carbs (including those from fruits and vegetables in some cases), a common complaint can be digestibility.
Protein takes longer than fats or carbohydrates for the human body to digestone reason high protein diets have a higher satiety value.
However, that slow digestion can pose a problem, and enzymes might be the answer.
With the growing popularity of high protein diets, it is important to supplement with digestive proteases, since most undigested protein ends up in the colon and is fermented by bacteria to release toxins, explained Rohit Medhekar, Ph.D., director of research and development with National Enzyme Co., based in Forsyth, Mo.
While the body naturally produces digestive enzymes, production decreases over time. Recent research done in the field of enzymes and digestion indicates the body may not produce enough endogenous enzymes to digest all the food we eat, said Mark Anderson, Ph.D., director of research and development for Wayne, N.J.-based Triarco Industries. And with the trend toward a high protein diet, it is more likely the endogenous enzymes will be saturated.
Formulators do have options, however. Supplemental enzymes can be incorporated into some food systems to aid in digestion, although there are limitations inherent to enzymes. Dry blended enzymes can be used in dry systems, such as powdered protein drinks. When water is added, the enzymes are activated and begin acting on their substrate.
This moisture issue means great care must be taken when adding enzymes to other foods; also, temperature changes (e.g., heat deactivates enzyme activity) can affect whether the enzyme is available in the final consumer product.
Formulators should consider the optimum pH and temperature conditions that the enzymes work on, and which substrate is used in the test protocols, said Chris Conn, sales manager with American Laboratories in Omaha, Neb. Conn noted enzymes can be wet granulated, but the moisture and heat used in the process can activate or deteriorate the enzyme activity; therefore, working with an experienced formulator is important.
Proteases are the specific enzyme class that acts on proteins, and most suppliers have developed specialty items to focus their activity.
Certain proteases are better at digesting soy protein and some are better at breaking down whey, Medhekar said. To formulate an effective product, it is necessary to know what protein is the intended target.
Triarco developed a specialty enzyme system designed to aid consumers on a high protein diet. Its Aminogen product has been shown in pre-clinical trials to consistently increase blood levels of free amino acids by as much as 50 percent over controls. Aminogen is GRAS (generally recognized as safe) and can be used in both supplements and in food products such as bars and beverage powders.
Two other protein sources are gaining interest in the nutritional industry. While not as well known, rice protein and fish protein each have health benefits, and can be used in different applications.
Rice protein is similar in amino acid profile to human breast milk. It has a protein efficiency ratio (PER) of around 2.75 and is easily digested. A 2003 review on the status of rice protein noted while rice is only 7 percent to 9 percent protein by weight, 380 million tons of rice are produced annually.19 Rice proteins are recognized as nutritional, hypoallergenic and healthy for human consumption, and rice protein products have been in demand in recent years, wrote F.F. Shih, a New Orleansbased researcher working with the U.S. Department of Agricultures (USDA) Agricultural Research Service (ARS), in Nahrung.
His assessment is shared by suppliers in the area. Protein demand has been very strong due to the low carb trend, said Gil Bakal, managing director of Fairfield, N.J.-based A&B Ingredients, supplier of Remypro rice protein concentrate. Rice protein can be used as a hypoallergenic protein source in bars and baked goods. He added rice protein does not impart viscosity nor bind water in a formula.
Fish protein is used less in food applications than dietary supplements, and is primarily used for the highly bioavailable protein fractions which aid gastrointestinal and immune health. The primary supplier is Reading, Pa.-based Proper Nutrition, which supplies hydrolyzed white fish under the brand Seacure. Barry Ritz, sales director, said the company has seen a great increase in interest in its fish protein, which contains bioactive peptides that support the health of the gut lining.
We have spent a good deal of time researching the role of bioactive dietary peptides in protein nutrition, and it is clear that peptides are absorbed more effectively than free amino acids, Ritz said. While Seacure is a unique source of peptides, the extensive production process makes it more expensive than other protein sources, so it is currently used primarily for specific nutritional applications. Ritz added the company is encouraging more research and development on different application possibilities.