Soy foods can be an excellent source of dietary protein, depending on both the amount present and the quality used. Soy foods are made with one or more of a number these ingredients, which further are low in saturated fat.
With the increased interest in healthy eating and the tendency for many of us to read nutrition facts panels and ingredient lists on the foods we buy, understanding what those ingredients are has become more important than ever. For anyone interested in adding soy to your diet, it can be beneficial to understand the different proteins used. The three most commonly used ingredients are soy flour, soy protein concentrate, and soy protein isolate.
- Soy Flour… Soy flour is the least processed of the three main ingredients and is made by grinding soybeans into a fine powder and can be full-fat, low-fat or defatted. Soy flour typically is about 50% protein and is a versatile ingredient commonly used in baked goods to boost protein intake as well as to enhance taste and texture.
- Soy Protein Concentrate… Soy protein concentrate is a higher protein ingredient than soy flour and is typically about 70% protein and 23% dietary fiber. Soy protein concentrate is prepared by removing the water-soluble carbohydrates from defatted soybeans. Soy protein concentrate tends to take on the flavor of the foods it enhances. Additionally, this ingredient tends to improve the overall quality of many protein foods, because it helps to retain moisture and hold flavor through multiple cooking processes, while boosting protein levels and reducing fat levels.
- Soy Protein Isolate… Soy protein isolate is the most refined ingredient and contains the highest amount of protein, typically about 90%. Soy protein isolate is made by removing nearly all of the fats and carbohydrates from defatted soy flour, leaving a product that generally has a very neutral flavor and the flexibility needed for use in numerous protein foods. Because soy protein isolate is generally in a fine powder, it can be easily added as an ingredient in home recipes to boost nutritional value. In the food industry, soy protein isolate is typically used in high protein foods like meal replacement bars and shakes as well as in snacks, cereal, and baked goods.
All three of these soy ingredients are used to make high protein foods, because they are concentrated sources. Additionally, these are excellent ingredients for the development of various protein foods, because soy provides the full complement of essential amino acids for human nutrition and is generally lower in saturated fat than other protein sources.