December 21, 2007
For the food technologist, protein is often more important than any component on the nutritional panel, as many proteins offer desirable functional and nutritional attributes. The industry has seen a number of new developments in protein to round-out tried-and-true sources.
Milk protein concentrate (MPC) has been available for a long time. Whats new is the increased domestic supply, says Sharon Gerdes, technical support consultant, Dairy Management, Inc. (DMI), Rosemont, IL. This is especially important for certain applications, such as yogurt, that require Grade A dairy ingredients. MPC can be used to increase viscosity and gel strength in smoothies and drinkable yogurts. MPC also improves foam stability and supports shape retention in frozen dairy products, thus allowing for lower stabilizer usage, she adds. In nutritional beverages, food manufacturers can increase protein and lower sugar content by incorporating MPC. We see a lot of interest in creating higher-protein beverages from the food industry, and food manufacturers can utilize either dried MPC or fluid UF milk that can be custom tailored to the desired protein level. Domestic MPC typically ranges in protein levels from 46% to 85%. Milk protein isolate is 90% protein.
Whey protein hydrolysates are being developed with improved flavor and specialized functionality. Traditionally, hydrolyzing whey proteins produced some bitter notes, says Gerdes. These were used extensively in chocolate and coffee formulation. By using proprietary technology, whey manufacturers are producing milder-flavored hydrolysates that work well in almost any beverage application, including vanilla and fruit flavors.
Whey protein hydrolysates allow beverage manufacturers to incorporate higher levels of protein into beverages and achieve greater heat stability. Specific degrees of hydrolysis can modify functional properties to include water binding, fat binding and emulsification.
Several U.S. manufacturers are selling whey fractions primarily for their nutritional and bioactive properties. According to Gerdes, glycomacropeptide (GMP) can be used to prepare specialty foods for individuals with phenylketonuria (PKU), who must severely limit their intake of the amino acid phenylananine. K. J. Burrington, whey applications program coordinator at the Wisconsin Center for Dairy Research, has worked on applications of GMP in a variety of food applications. These new foods add variety and improve palatability of the diet for this special population. At least one whey manufacturer is producing alpha-lactalbumin, which is used in infant formula, including special formulas for preterm infants with higher protein levels.
Some manufacturers are producing high-gelling whey protein concentrate (WPC). All whey proteins will gel when heated. These particular proteins have been modified so they will bind more water, says Gerdes. Some of them dont have to be heated, and some of them do. Theres a wide range of functional whey proteins on the market that can be used for water binding, fat replacement and emulsification.
WPC can partially replace eggs in baked goods, increase viscosity in yogurt or yogurt smoothies, and improve processed- cheese yield. High-gelling whey proteins find a lot of use in dips and spreads, where they contribute to the overall dairy flavor, says Gerdes. In meat applications, pregelatinized whey protein isolate (WPI) can improve cost economics. U.S. consumers prefer white-meat chicken, so most of the dark meat is exported.
A combination of whey protein concentrate and pregelatinized whey protein isolate can economically whiten chicken dark meat in ground and restructured chicken products such as chicken nuggets, says Gerdes. This new application was demonstrated in a presentation by Gitanjal Prabhu, Ph.D., partner and consultant, Ph.D. Technologies, Ames, IA, at the 2007 IFT Annual Meeting and Food Expo in Chicago. Most chicken nuggets are produced with white meat, but he showed a formula that incorporated 50% dark meat, 50% white meat, 4% WPC 80 and 20% of a gel made with pregelatinized WPI. A sensory study showed that consumers preferred the texture of the 50-50 white-dark nugget with whey protein, she says.
A totally new dairy ingredient is on the horizon: native whey protein. It is derived directly from milk, unlike whey protein, a byproduct of cheese-making. Because it skips the cheese-making process, it has not been affected by cheese cultures, enzymes, coloring and heat treatment, says Gerdes.
Whey protein has long been favored by athletes for muscle-building. However, research from Indiana University School of Medicine, Evansville, published in the Journal of Nutrition (2007,137:357-362) indicates that soy and whey are equally effective in building muscle in rats.
Nick Weber, public relations manager, The Solae Company, St. Louis, cites similar findings from Douglas Kalman, Ph.D., Miami Research Associates, published in the Journal of the International Society of Sports Nutrition (July 23, 2007; 4:4). The study found soy protein was just as effective as whey in its ability to help weightlifting males gain muscle, Weber says. Additional findings noted soy did not have any negative effects on male hormonal levels.
Solae offers isolated soy proteins with macronutrient profiles similar to nonfat dry milk and whole milk powder, Weber says. These proteins provide nutritional, functional and economic alternatives to dairy proteins. Some of their potential applications include beverage powders, frozen desserts, sauces and compound coatings.
Another innovation in the soy-protein category is a unique structuring technology that provides textural advantages in meat and meat-free products. It enables lower-fat meat products, improves the quality of lower-value meat products, and provides meatlike taste and texture characteristics in meat-free applications, says Weber.
Companies have improved meat analogues by developing soy chunks with improved chewing properties and mouthfeel. For example, Cargill Texturizing Solutions, Wayzata, MN, offers textured soy flours (TSF) that have 50% protein and closely match meats fibrous structure.
They are ideally suited for products with small meat pieces, like tacos or pulled pork. Our newest line of meatlike chunks comes in two shapes and three colors each, says Tom Katen, technical service specialist, meat. They can be used as meat replacement in formulas that allow it as a cost savings, texture improvement and nutritional benefit of soy proteins added.
Those who want to combine nonallergenicity and a vegetarian source might consider rice protein. Commercial ingredients are available at approximately 70% protein. The protein contains 19 amino acids, including all nine essential amino acids. Its mild flavor allows it to be used in sports and other beverages, bars, extruded products, baked goods, mealreplacement systems, and nutritional supplements.
Consumer interest in health and wellness is driving the market for vegetarian proteins. Solanic, a subsidiary of Avebe, Veendam, the Netherlands, manufactures potato-protein fractions containing 92% to 95% protein. These fractions are available with application-specific attributes, including heat stability, pH stability and lipophylic properties. Emulsifying fractions can be used in sauces, mayonnaise and dressings.
Gelling and structure-forming proteins can be used in processed meat. Potato protein is hypo allergenic and provides an alternative to egg or dairy proteins.
Roquette America, Inc., offers a pea protein that delivers protein as well as water- and fat-binding properties. The ingredient is derived from the yellow pea (Pisum sativum), contains 85% protein and is rich in many amino acids, including lysine, glutamine, and arginine, as well as the branched-chain amino acids isoleucine, leucine and valine. This slowly-digested protein source also has a positive impact on satiety.
Steak and eggs
As consumers become more conscious of reducing cholesterol and saturated fat in their diets, agricultural industries are paying attention.
Akaushi cattle, native to the Mt. Aso region of Japan, are now raised in Texas and marketed to consumers and upscale restaurants. What makes Akaushi beef unique from traditional domestic beef is its fatty-acid composition. Akaushi meat has extremely high amounts of marbling; however, this intramuscular fat is higher in monounsaturated fat. A 2-oz. portion of raw, 80% lean, 20% fat Akaushi ground beef has 10.62 grams protein, 3.66 grams saturated fatty acids (SFA), 0.35 grams polyunsaturated fatty acids (PUFA), 5.30 grams monounsaturated fatty acids (MUFA), a MUFA:SFA ratio of 1.45, and 4.30 grams oleic acid. This same serving size of 95% lean, 5% fat raw domestic ground beef has 11.99 grams protein, 1.26 grams SFA, 0.14 grams PUFA, 1.21 grams MUFA and a MUFA:SFA ratio of 0.96. Traditional ground beef does not contain oleic acid.
Omega-3 enriched eggs provide guilt-free consumption for those with cholesterol concerns. Compared to ordinary eggs, they contain approximately three times as much omega- 3 (100 mg omega-3 and 50 mg DHA, vs. 37 mg omega-3 and 18 mg DHA), nearly 20% less cholesterol, 25% more lutein and seven times more vitamin E. All eggs contain approximately 6.3 grams protein.
Even egg ingredients are getting a makeover. Foaming properties are supplied by egg-white proteins, says Glenn Froning, Ph.D., professor emeritus, University of Nebraska, Lincoln. Ovomucin helps stabilize the egg-white foams.
Globulins from egg white lower surface tension and promote bubble formation and a smooth texture. Ovalbumin and ovotransferrin contribute to the volume of the foam and provide heat-setting ability. Processors produce a foaming-type egg white, which can be used for formulations such as angel cakes. Some egg processors are producing a high-gelation egg white that possesses superior binding properties used in such products as surimi.
According to Froning, recent research by Canadian scientists (Journal of Agriculture and Food Chemistry, 2004; 52:1088- 1094) and European scientists (British Journal of Nutrition, 2005; 94:731-737), shows opportunities in enzymatic hydrolysis of egg white to produce various peptides. They indicate that these peptides lowered blood pressure of hypertensive rats. The peptides also show antioxidant activity and increased bacteriostatic activity, he says. These studies indicate that egg-white peptides have potential as a functional food. Their use in nutritional drinks may be a possibility.
Egg yolk provides emulsification. Lipoproteins and phospholipids in egg yolk are the main components in egg yolk producing the emulsifying characteristics, says Froning. Some processors are now marketing an enzyme-modified egg yolk phosphatidylcholine (lecithin), which is converted to lysophosphatidylcholine using an enzyme (phospholipase). This enzyme-modified egg yolk has superior emulsifying properties, producing a smoother and more viscous emulsion ideal for mayonnaise applications.
Cindy Hazen, a 20-year veteran of the food industry, is a freelance writer based in Memphis, TN. She can be reached at [email protected].
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