A soy protein product which is completely soluble and is capable of providing transparent and heat stable solutions at low and neutral pH values is produced by extracting a soy protein source material with water at low pH, subjecting the resulting aqueous soy protein solution to ultrafiltration and optional diafiltration to provide a concentrated and optionally diafiltered soy protein solution, which may be dried to provide the soy protein product. The soy protein product may be used for protein fortification of, in particular, soft drinks and sports drinks, without precipitation of protein.
