WHAT IS SOYA PROTEIN ISOLATE 90%? Soya Protein Isolate 90% is a high quality protein powder, containing over 90 grams of protein per 100 grams, with less than 1 gram of fat. Protein contributes to the maintenance of muscle mass. Soya Protein Isolate 90% is derived from Soya Beans. Soya Protein Isolate 90% is a popular choice for Vegans who may be looking to increase the protein content of their diet. Also, for those allergic to dairy, Soya Protein Isolate 90% is an excellent alternative