| In this paper,artificial selenium-enriched sweet potato was used as raw material to explore the factors affecting the yield of selenium-enriched sweet potato polysaccharide,the compared and analyzed of the extraction of ultrasonic selenium polysaccharide（USe P）,water-extracted selenium polysaccharide（Wse P）,water-extracted polysaccharide（WP）and ultrasonic polysaccharide（UP）in structural differences and in vitro antioxidant activity by two different processes.Based on the traditional hot water extraction method combined with ultrasonic extraction,the yield was optimized by response surface method,and the final yield of selenium-rich sweet potato polysaccharide was 3.02%.Ultrasonic selenium polysaccharide（USe P）water-extracted selenium polysaccharide（WSe P）,water-extracted polysaccharide（WP）,ultrasonic polysaccharide（UP）obtained by ultrasonic-assisted extraction and hot water extraction,the four kinds of polysaccharides were purified by DEAE-52 cellulose column chromatography,then,the four polysaccharides were purified by Sephadex G-100 gel column chromatography to obtain four purified polysaccharides.The physical and chemical properties and structural characterization of the four polysaccharides showed the same types of monosaccharides,but different proportions of monosaccharides.The combination mode of selenium and polysaccharide in selenium-enriched polysaccharide was selenate structure.SEM analysis showed that the surface of selenium-enriched polysaccharide was rough,but the surface of not selenium-enriched polysaccharide was smooth,The lamellar structure area of ultrasonic polysaccharide was smaller than that of water extracted polysaccharide,~1H NMR和13C NMR indicated that the four kinds of polysaccharide wereαandβpyran ring type polysaccharides.In vitro antioxidant activity analysis showed ultrasonic selenium polysaccharide had the strongest free radical scavenging ability and potential value. |
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