Green and efficient PEG-based ultrasound-assisted extraction of polysaccharides from superfine ground lotus plumule to investigate their antioxidant activities

In this study, the antioxidant activities of lotus plumule polysaccharides (LPP) were investigated to illustrate their health care function. Lotus plumule was superfine ground and carried out the polyethylene glycol (PEG)-based ultrasound-assisted extraction (UAE) of LPP. Response surface methodology (RSM) with Box-Behnken design (BBD) was used to optimize the extraction. The optimal extraction conditions were as follows: liquid-solid ratio 28.32 mL/g, extraction temperature 92.86 °C and extraction time 32.87 min, which gave the maximum yield of polysaccharides (13.92 ± 0.37%). The antioxidant activities in vitro of LPP were estimated by measuring the scavenging activities on DPPH radical, superoxide free radical, hydroxyl free radical and reducing power. The good antioxidant activities of LPP indicated that it could be one kind of natural antioxidants.