Abstract: Corn skin as the material in this study is a kind of by-product which comes from corn starch factory. High physiologicactivity and excellent quality corn dietary fiber can be produced using this material through supercritical CO2 fluid extraction andextrusion. The optimum technique was screened out through orthogonal test and analysis. When Supercritical fluid extractionpressure 30MPa, temperature35℃, time100min, CO2 flow 23L/h, the extrusion temperature is 145℃ and the water content ofmaterial is 60%, feed speed 20kg/h, rotational speed 220r/min, the content of soluble dietary fiber is 14.8%,expansive power is18.2ml/g, holding water power is 9.3g/g, bound water power is 6.3g/g. By analyzing the blood-fat level of rats, the result show thatthe total serum cholesterol of rats reduced 37.1% with feeding extruded corn dietary fiber, and low density lipoproteincholesterol reduced 49.7%, and total glyceride reduced 40.2%, and high density lipoprotein cholesterol reduced 0.7%. The resultsabove say that the dietary fiber is high quality corn dietary fiber.

Key words: supercritical CO2 fluid extraction, extrusion technology, corn dietary fiber