Effects of Die Temperature and Repeated Extrusion on Chemical Components and Antioxidant Properties of Extruded White Ginseng

This study investigated the effects of die temperature and repeated extrusion on the chemical components and antioxidant properties of extruded white ginseng (EWG). Die temperature was adjusted to 100, 120, and followed by repeated extrusion under the same conditions with corresponding samples. Secondary extruded white ginseng (SEWG) at a die temperature of 120°C had the highest acidic polysaccharide content of all extrudates. Increasing die temperature and repeated extrusion both increased crude saponin content of the extrudate. Ginsenoside Rh1 was detected in the EWG (140°C) and SEWGs, whereas ginsenosides Rg3s and Rg3r were only detected in SEWG (140°C). The highest total phenolic content, DPPH radical scavenging activity, and reducing power obtained from SEWG (140°C) were 8.55±0.03 mg/g, 72.05±0.63%, and 0.80±0.004, respectively. In conclusion, repeated extrusion increases antioxidant activity and crude saponin contents for the development of improved ginseng products.