ISP is the most highly refined soy protein. It is made by separating, or isolating, the protein portion of the soybean from the rest of the bean. The result is a dry, white powder that is over 90 percent protein. By comparison, soy protein concentrate is 70 percent protein, and textured vegetable protein is 50 percent protein. Normally, ISP is not very high in isoflavones, but certain manufacturing processes can increase the concentration of this nutrient.
Some manufacturers list the concentration on their labels.
Several different ISP products I checked indicated between 5 and 10 mg isoflavones in one tablespoon. As good as it is, however, you cannot cook up a batch of ISP for supper because it is a food ingredient, a very good food ingredient. In addition to boosting protein, ISP improves appearance, juiciness, texture and holding conditions of food products. It is tasteless and odorless. Some common foods that use ISP as an ingredient include luncheon meats, hot dogs, ground meats, pepperoni, breads and bakery goods, and meat alternatives, such as veggie burgers.