Abstract:To explore the application potential of polysaccharides from the peels of Chinese water chestnut (Eleocharis dulcis) in the food field, X-ray diffraction spectroscopy, thermogravimetric analysis, Zeta potential analysis, ubbelohde viscosity measurement method, infrared spectroscopy were used to investigate the physical and chemical properties of purified polysaccharides, WVP-1and WVP-2, including crystallizability, stability and viscosity; the cell antioxidant assay and AAPH-induced erythrocyte hemolysis assay were used to evaluate the antioxidant activity of WVP-1 and WVP-2. The results showed that WVP-1 and WVP-2 had few crystalline regions and existed mainly in amorphous form; the glass transition temperatures of WVP-1 and WVP-2 were 61.30 and 69.50 ℃; their thermal decomposition temperatures were 290.50 and 308.50 ℃; the zeta potential values were 9.60 and -18.50 mV; the intrinsic viscosities were 5.33×10-3 and 3.80×10-2 mL/mg; the degree of esterification of the pectin polysaccharide, WVP-2 was 15.00%. In addition, in the concentration range of 62.5~1000 μg/mL, WVP-1 and WVP-2 could effectively inhibit the increase in the level of ROS induced by AAPH in HepG2 cells, and also protected effectively erythrocytes against AAPH attack and oxidative hemolysis. In summary, WVP-2 has better stability, viscosity and antioxidant activity than WVP-1, and WVP-2 is a pectin with low esterification degree, which can be used in the food field as a food additive and functional active ingredient.
