Abstract: In this research, corn yellow powder is by-product of starch factory,using corn yellow powder as material to extract zein after supercritical CO2 fluid extraction, then manufacture oligopeptides using this zein through enzymolysis. The optimum technique condition of supercritical CO2 fluid extraction was determined through orthogonal test. When supercritical CO2 fluid extraction, the pressure is 25 MPa, temperature is 45℃, time is 100 min, CO2 flow is 30 L/h. percentage extraction is 8.06%, after extracting the content of protein is 90.46%, fat is 0.1%. Compare with non- supercritical CO2 fluid extraction and treatment by organic solvent, zein percentage extraction of corn yellow powder is more than 50.33% and 35.69%. Manufacturing oligopeptides using higher purity zein through enzymolysis, hydrolytic degree of zein more than 47.16% and 36.75% compare withl non- supercritical CO2 fluid extraction and treatment by organic solvent .

Key words: supercritical CO2 extraction, zein, extraction rate, hydrolytic degree