College of Food Science and Pharmacy, Xinjiang Agricultural University, Urumqi 830052, PR China; Key Laboratory of Plants Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011, PR China. Electronic address: [Email]
In this paper, polysaccharides from the seeds of three species of genus Glycyrrhiza were extracted to investigate the physicochemical properties, structural characteristics and antioxidant activities. The polysaccharides were composed of xylose, mannose, galactose, and glucose with different molar ratio. Fourier transform infrared spectroscopy showed the presence of key functional groups of polysaccharides whereas scanning electron microscopy analysis revealed the characteristic morphology of different polysaccharides, and thermogravimetric analysis exhibited good thermal stability of all samples. The antioxidant activities of polysaccharides were evaluated in vitro. All the three polysaccharides demonstrated strong reducing power, as well as scavenging activity against DPPH, ABTS, and hydroxyl free radicals. Antioxidant assays indicated that all the polysaccharides have obvious antioxidant activities and possess a potential development and application value in food, cosmetics as well as pharmaceutical industries.