Proteins and Fats

Two other materials are commonly found in sauces and have some influence on their texture. Flour is about 10% protein by weight, and much of this fraction is insoluble gluten. Gluten aggregations probably get caught in the starch network and so slightly increase the viscosity of the solution, though the pure starches are generally more powerful thickeners overall. Sauces based on concentrated meat stocks also contain a good deal of gelatin, but gelatin and starch seem not to affect each other’s behavior.