Nutritional Content and Origin of Soy Protein Products

There are a number of soy protein products on the market today that allow you to be more versatile in your cooking and product selection. The starting point for all soy protein products is the whole soybean, which contains about 40 percent protein. As the proteins are processed and refined, each takes on different characteristics. Here's how the makeup of each soy protein product varies.

Isolated Soy Protein

Isolated soy protein comes from dehulled and defatted soybeans by removing most of the non-protein components such as carbohydrates. The result is an isolate containing 90 percent protein on a dry basis. Isolated soy protein contains all nine essential amino acids, no cholesterol and virtually no fat or carbohydrates.

The removal of carbohydrates yields an ingredient with a neutral flavor that can be incorporated into a variety of meat products, increasing protein content and lowering fat.

With more than 100 formulas of isolated soy protein available, processors can meet the exact needs and specifications of school foodservice professionals for applications from hot dogs to ground meat to pepperoni. Isolated soy protein is available in a variety of forms including powders, granules and structured fibers.

Soy Concentrates

Soy concentrates are prepared from dehulled by removing most of the water-soluble, non-protein components such as soluble carbohydrates. Because carbohydrates are removed, soy concentrates do not have a "bean-like" aroma.

Textured Soy Concentrates: Textured soy concentrate is processed to resemble a form of a food ingredient, such as fiber or chunk and is 70 percent protein. Dietary fiber ranges from 18-22 percent.

Functional Soy Concentrates: Functional concentrates are heat-treated by steam injection or jet cooking. This process increases solubility and functionality of the concentrate. Functional concentrates bind water and fat and also offer some adhesive properties available in isolated soy protein.

Soy Flours / Grits / Textured Vegetable Protein

Soy flours and grits are prepared by grinding and screening soybean flakes either before or after removal of oil. Their protein content ranges from 40-54 percent. They vary in fat content, particle size and the degree of heat treatment. Textured vegetable protein, unlike the newer concentrate products, contains soluble carbohydrates. Technically, it can be a variety of soy ingredients; however, it is commonly known as textured soy flour.