Extraction of polysaccharides from Codonopsis pilosula by fermentation with response surface methodology

Codonopsis pilosula is a kind of traditional Chinese medicine used to treat weak spleens, stomach problems, anemia, and fatigue. Polysaccharide is one of main components of Codonopsis pilosula. In this study, response surface methodology (RSM) was used to optimize the extraction parameters of Codonopsis pilosula polysaccharides (CPP) by fermentation. The exaction temperature (°C), yeast liquid volume (2 mg/ml, ml), and time (h) were employed effects. Results indicated that the best extraction conditions were the following: extraction temperature 24.75°C, yeast liquid volume 2.96 ml (5.92 mg), and a fermentation time of 21.03 hr. After purification with DE52 and Sephadex G-100, the molecular structure was determined by ultraviolet-visible (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) (¹H and ¹³C). The monosaccharide composition of CPP1 was determined to be mannose (1.76%), glucose (97.38%), and arabinose (0.76%). CPP1 exhibited high antioxidant activities in scavenging ABTS radicals, ferreous ions, and superoxide ion radicals. Thus, CPP1 could be used as an antioxidant or functional food.