Abstract:

To study the extraction processes of rich selenium inulin polysaccharide extraction and its vitro antioxidant activities, this study used sodium selenite as the selenium source, add sodium selenite to potting soil for selenium-enriched culture of Jerusalem artichoke. Based on the single factor experiment, the response surface methodology was applied to optimize the factors affecting the extraction of selenium-enriched Jerusalem artichoke polysaccharide (ultrasonic time, ultrasonic power, liquid-to-solid ratio). Then, the scavenging ability of Se-enriched and non-Se-enriched Jerusalem artichoke polysaccharide were explored to the hydroxyl radical,1,1-diphenyl-2-trinitrophenylhydrazine(DPPH) and superoxide anion. The results showed that the Jerusalem artichoke could positively absorb selenium and convert it to organic selenium. The optimal extraction condition was: ultrasonic time of 60 min, ultrasonic power of 450 W and liquid-to-solid ratio of 25:1 (mL/g), which could attain the highest extraction rate of Se-inulin (13.52%). Selenium-enriched Jerusalem artichoke polysaccharide (Se-inulin) and ordinary inulin (inulin) showed a good dose-effect relationship on hydroxyl radical, DPPH radical and superoxide radical scavenging activity, and the maximum clearance rate could reach 80.34%, 89.19% and 88.54%, respectively. The antioxidant activity of Se-inulin was better than that of inulin. In conclusion, this study could provide a theoretical basis for the future development of Se-enriched Jerusalem artichoke products.

Key words: Se, inulin, ultrasonic extraction, response surface methodology, antioxidant activity