A stable okara concentrate is provided, being a protein-rich powder to be used in producing healthy foodstuffs, enriched in proteins, dietary fibers, and free of cholesterol, essentially consisting of natural materials not contacted with any toxic or harmful substances during their production. Useful premixes for use in food industry or household are also provided. The concentrate may be made from a by-product obtained in soybeans processing. Food products comprising the okara concentrate are also provided.