Supercritical extraction and antioxidant activity of major ingredients in Puerariae lobatae root, Pinus massoniana needle, Citrus reticulata peel and their mixture

Abstract

The edible herbs Puerariae lobatae root, Pinus massoniana needle, Citrus reticulata peel and their mixture “SGLUAP” were extracted by supercritical CO2 fluid replacing usual ethanol solution. Optimal conditions of the extraction were determined by conducting series of experiments with Box-Benhnken Design of three-variables and three-levels, data fitting and modeling, and analyzing the visual 3D response surface plots. Scavenging free radical rate (DPPH%) and inhibiting xanthine oxidase rate (XO%) of 14 major ingredients in herbs and total phenolic compounds in SGLUAP were assessed. Among them, gallic acid gave DPPH (%) of 94.5 % to be higher than the reference Vitamin C, and daidzein possessed XO (%) of 97.8 % to be much higher than the reference allopurinol. This work has demonstrated a reliable and efficient methodology for extraction optimization, antioxidant activity evaluation and quality assessment of natural products from herbs or plants.