What gives burgers a leaner profile and boosts juiciness in marinated chicken breasts? Adds texture to meatballs and binds water in frankfurters? Becomes a protein-packed extender for school-cafeteria sloppy Joes and stands in for sausage in meatless entrées?

Pat yourself on the back if you said “soy proteins,” the culinary chameleons of the modern world. Produced through the removal of soybean oil and carbohydrate components from naturally protein-packed soybeans, soy proteins not only enhance and extend meat products, but also provide a number of health benefits when consumed in sufficient quantities.

Most soy proteins used in meat and poultry products are produced from defatted soy flakes, says Larry Hand, Ph.D., regional director, applied technology for The Solae Co. in St. Louis. Soy proteins can be divided into three basic categories based on protein content: soy flours, soy protein concentrates, and soy protein isolates. The protein content is calculated on a dry-weight basis.

Soy flours are at least 50 percent but less than 65 percent protein, says Hand, while soy protein concentrates are at least 65 percent but less than 90 percent protein. Soy protein isolates pack the most protein, boasting a content of 90 percent or more.

“Textured soy proteins may be based on flours, concentrates, or isolates,” says Hand. “However, textured soy protein concentrates and textured soy flours are most common.”

Each class of soy protein works its own kind of magic on meat to improve textural and/or functional characteristics.

“Textured soy protein concentrates are better suited to precooked items that will undergo subsequent reheating than are textured soy flours, which tend to lose their texture if subjected to more than one cooking process,” notes Hand. “Additionally, textured soy protein concentrates typically have a cleaner flavor than textured soy flours, which still contain both soluble and insoluble carbohydrate fractions.”

According to Russ Egbert, director of protein research for Decatur, IL-based Archer Daniels Midland Co. (ADM), “Isolated soy proteins and soy protein concentrates help maintain firm meat-like eating qualities in finished products. They also reduce purge, improve freeze/thaw stability, and help to retain a moist, succulent texture.”

Although all classes of soy proteins can be used in all meat products, says Hand, a number of factors must be considered before deciding on a product — or before choosing soy at all. Such factors include “meat product characteristics, market segment, economic and regulatory constraints, equipment and process capabilities,” he says, as well as a clearly defined objective for the product.

“The objective may be moisture retention through cooking, reheating, and freeze/thaw cycles; firmer texture; a specific nutritional profile; improved economics; or any combination of a variety of specific objectives,” says Hand.

Today’s soy-enhanced meats have little in common with the beany-tasting blobs passed off as hamburgers in yesteryear’s school cafeterias.

“The flavor characteristics of soy have improved immensely,” says Egbert. “The improvements go beyond flavor addition. We have changed things in the manufacturing process and gotten much of the beany flavor out.”

The grassy or beany flavors that have slowed the acceptance of soy-based foods have been blamed, in part, on the hexane-based extraction process traditionally used by many of the large vegetable oil processors, says Rob Kirby, vice president of marketing for Springfield, IL-based Spectrum Foods Inc. However, many soy ingredients, including the company’s Nexsoy® brand of soy ingredients, now are produced through solvent-free methods that alleviate historic ­flavor issues.

“The Nexsoy processing method is entirely mechanical and requires no chemicals such as hexane,” says Kirby. “The result is very bland, naturally produced soy ingredients that can be used by food manufacturers in high inclusion rates without negatively impacting the ­flavor.”

Cedar Falls, IA-based Nutriant, a Kerry company, also uses a natural processing method to produce its soy concentrates and isolates, says Terry Gieseke, director of business development. “These soy ingredients have both a uniquely clean
flavor and remarkable physical properties in analog and blend applications,” she says, “and they are the only [types of] soy concentrates and isolates that can be certified organic.”

Research linking soy consumption with cardiovascular and other health benefits also is boosting the appeal of these ingredients. The U.S. Food and Drug Administration (FDA) authorized the use of coronary-heart-disease-related health claims on certain soy- containing products. Although most soy-enhanced meat and poultry products do not contain enough soy protein to qualify for an FDA health claim, a little soy here and there still can add up.

“Consumers are looking for ways to include soy protein in their diets via foods that are familiar favorites,” says Hand. “Therefore, meat products with soy protein are a key component of a diet that achieves the recommended daily intake of 25 grams of soy protein.”

Meat processors must consider the application, the type of soy protein to be used, and any regulatory issues in determining appropriate soy-to-meat ratios.

“In very general terms”, says Kirby, “a twenty-percent inclusion is normally undetectable from a taste/mouthfeel perspective. With increased inclusion, additional flavor systems can effectively be used to compensate for a natural dilution in flavor as the percentage increases. Flavor houses have developed very good beef and chicken flavors and even such ­flavors as ’grilled,’” he adds.

The type of soy protein used and the flavor profile of the meat work together to influence overall product flavor, notes Hand. “Generally speaking, soy protein isolates have the cleanest flavor, ­followed by the soy protein concentrates and then soy flours,” he says. “Meat products with comparatively mild flavor profiles such as minimally seasoned boneless chicken breasts will be more sensitive to soy protein flavors than highly seasoned products.”

Because the newest soy proteins have such a clean flavor profile, regulatory constraints typically will have a greater impact than flavor considerations on inclusion rates.

“The level of inclusion is limited by standards of identity,” says Gieseke. “However, should pro­cessors choose to market meat products with names that are non-standard, there is significant opportunity. USDA has indicated a willingness to work with processors in labeling these potentially great-tasting and healthy meat-inclusive products.”

High-moisture soy protein extrusion potentially could allow processors to combine meats and analogs in very familiar forms, says Gieseke. Slices from a formed piece made of 70 percent soy protein and 30 percent beef could look and taste very much like brisket, she adds.

Spectrum Foods’ Kirby agrees that the outlook for these types of products is bright. “I believe there is enormous opportunity for processors to take a more middle-of-the-road approach … to provide a product that decreases saturated fat while still providing the protein necessary for a nutritious diet,” he says.

Today’s soy protein suppliers not only offer the highest-quality soy protein ingredients, but also possess the requisite knowledge and expertise to guide processors in product selection.

“Naturally processed textured soy concentrate from Nutriant has eliminated both the beany flavor and the need for masking,” says Gieseke. The company drove this point home when it added textured pieces of its soy protein concentrate to a vegetarian chili destined for last year’s IFT Annual Meeting and Food Expo in Chicago. The chili was microwaved from the frozen state at the show, and then simmered all day in a crock-pot.

“At the end of the day, the textures retained an excellent ’meat-like’ bite and chew,” says Gieseke — and an “outstanding” flavor, according to visitors to the booth.

Spectrum Foods’ Nexsoy textured soy protein products “hydrate instantly” and exhibit “excellent water-binding properties,” says Kirby, making them appropriate additions for coarsely chopped meat or poultry ingredients to “provide a vegetable-based protein source, reduce saturated fat content, and add moisture.” The blended products, he says, “have a consistency and mouthfeel consistent with unblended products, but have a more balanced nutritional content.”

In addition to soy-derived ingredients for processed meats such as sausages and hot dogs, ADM supplies soy protein and concentrates “that further increase tenderness and juiciness when infused into marinated chicken breasts, pot roast, roast beef, and ham,” says Egbert. “In ground meat applications, we also supply soy isolates, concentrates, and textured vegetable protein (TVP®).”

The Solae Co. has a wide range of isolated soy proteins, soy protein concentrates, soy flours, and textured soy proteins, says Hand. Within each protein class, he adds, are products that provide a “broad range of functional characteristics that can bind fat and water, contribute texture, improve nutritional profile, and achieve economic objectives.”