Enhancing the Quality of Ginseng–Astragalus Medicinal Food Using Twin-Screw Extrusion

Twin-screw extrusion is a promising method to transform medicinal herbs into functional food ingredients. However, limited research has focused on the application of this technique to ginseng-astragalus compounds. In this study, the response surface methodology (RSM) was used to optimize the extrusion process (screw speed, temperature, and moisture content). The optimal parameters (208 rpm, 128 °C, 29%) significantly increased ginsenoside, polysaccharide, phenolic content, and antioxidant capacities (DPPH•, OH•, O₂^-•). Furthermore, extrusion improved the aroma profile while reducing bitterness, as revealed by electronic nose and electronic tongue, and PCA. The treated product also exhibited enhanced antibacterial activity. These findings demonstrate that twin-screw extrusion is an effective tool for developing medicinal food products with improved quality and biofunctionality. The response surface methodology model showed high reliability (R² > 0.95) with prediction errors and relative standard deviations below 5%, confirming the robustness of the optimization.