Composition, nutritional, and functional properties, and quality criteria of soy protein concentrates and soy protein isolates

The available commercial soy protein concentrates and soy protein isolates afford the food processor concentrated sources of protein with some interesting and varied functional properties. Each class of products is mild to bland in flavor and light in color. The concentrates contain at least 70% protein and the isolates 90%. The nutritional quality of the proteins is fair to good and can be excellent either by supplementation with 1.5% methionine or by appropriate blending with other sources of proteins. The concentrates provide the food manufacturer with products where a high protein content for unit of volume or wt is needed. The isolates are available for uses where the functional properties reside solely in the protein and the nonprotein components may interfere. The adaptability of the proteins to modification by controlled processing conditions has made it possible for the manufacturers to produce a diversity of products that should be of interest to practically all food formulators.