研究芡实多糖的体外抗氧化及抑菌特性。采用微波辅助酶法获得芡实多糖,研究芡实多糖的总还原能力,对O2-·、·OH、DPPH·三种自由基的清除效果及其对油脂氧化与微生物生长的抑制作用,并以Vc为对照进行比较。结果表明∶芡实多糖总还原能力较强,对O2-·、·OH和DPPH·均有一定的清除效果,其IC50分别为4.8、6.7和6.1 mg/m L,但均低于Vc的清除效果。芡实多糖对猪油和芝麻油有一定的抗氧化效果,在油脂氧化初期,其抗氧化效果与Vc相当。芡实多糖对金黄色葡萄球菌、酿酒酵母、枯草杆菌和大肠杆菌有抑制作用;当多糖质量浓度为10 mg/m L时,最大抑菌圈直径分别为16.00、13.63、12.50和11.25 mm,对大肠杆菌和枯草杆菌的最低抑菌浓度为4 mg/m L,对金黄色葡萄球菌和酿酒酵母的最低抑菌浓度为2 mg/m L。

The antioxidant and antimicrobial activities of Euryale ferox polysaccharides were assessed in this paper. The polysaccharides were extracted with microwave assisted enzyme method. Using the same concentration of Vc as the control,the antioxidant activities of polysaccharides were investigated by total reducing power and scavenging superoxide anion,hydroxyl radical and DPPH free radical. The inhibitions were also measured through testing lipid oxidation and the growth of microorganism. The results showed that the polysaccharide from Euryale ferox had strong reducing ability to free radical. The polysaccharides had certain scavenging ability on superoxide anion,hydroxyl radical and DPPH free radical with IC50 of 4. 8,6. 7 and 6. 1 mg / m L,but less than Vc's ability to remove them. The Euryale ferox polysaccharides had certain ability of restraint on lard and sesame oil oxidation that was similar to Vc especially in initial lipid oxidation. The polysaccharides had the inhibiting effect on S. aureus,S. cerevisiae,B. subtilis and E. coli. The maximum of antibacterial circle were 16. 00 mm,13. 63,12. 50 and 11. 25 mm respectively when the polysaccharide concentration was 10 mg / m L. The MIC of E. coli and B. subtilis was 4 mg / m L while MIC of S.aureus and S. cerevisiae was 2 mg / m L.