Protein isolates are refined form of protein containing the greater amount of protein with greater digestibility. Nowadays it__ampersandsignrsquo;s the major source of cheap proteins especially for athletes, bodybuilders, vegetarians, and has gained wide application in various beverages and dairy industries, and infant foods due to its different functional properties. It is widely produced from deoiled cake of legumes such as peanuts, cowpeas, soybeans, etc and animal sources like fish and milk by a combination of isoelectric and alkaline precipitation using H2SO4 and NaOH, followed by centrifugation to obtain the pure isolates which can further be dried to powdered form of about 90% protein. The problem of antinutritional factors in legumes can be successfully reduced by these processing methods.