三百棒多糖的流变学特性及抗氧化活性研究

Rheological Properties and Antioxidant Activities of Polysaccharide from Toddalia Asiatica Lam

目的研究三百棒多糖的流变学特性和抗氧化活性。方法用水提醇沉法提取三百棒多糖,将所得样品进行纯化处理,采用流变仪测定质量浓度、pH值、温度、金属离子等因素对三百棒多糖溶液黏度的影响;以Vc为对照品,通过Fenton法和DPPH的清除率考察体外抗氧化活性。结果三百棒多糖的流动行为受其质量浓度、pH值、温度以及离子浓度、离子种类的影响,具体表现为:三百棒多糖溶液的黏度随着三百棒多糖质量浓度的升高而增加;pH 4.0和pH 9.0时三百棒多糖溶液黏度明显低于pH7.0。Na+可使三百棒多糖的表观黏度显著增大,但是Na+浓度从0.5%升高到1.0%时,三百棒多糖的黏度反而有所下降;Ca^(2+)可使三百棒多糖溶液的黏度下降,Ca2+浓度增大,黏度变小。温度在20～60℃范围内三百棒多糖溶液的黏度快速下降,其耐温性不是很好。三百棒多糖浓度达到10.0 mg·mL^(-1)时对2种自由基的清除率接近2.0mg·mL^(-1)Vc。结论三百棒多糖水溶液表现为典型的非牛顿假塑性流体特性,抗氧化活性试验表明三百棒多糖具有很好的抗氧化活性。

OBJECTIVE To investigate the antioxidant effects and rheological properties of polysaccharide from Toddalia asiatica Lam(TALP). METHODS Extracted TALP by the water-extracting and achohol-precipitating method, collected and purified the sample. The influences of concentration, pH, temperature, metal ions and other factor on viscosity of TALP were measured by rheometer. Compared with Vc, the in vitro antioxipant activities were studied by the Fenton method and DPPH radical scavenging. RESULTS TALP flow behavior was affected by its concentration, pH, temperature, cation type and concentration. Specifically, the viscosity of TALP solution increased with the mass concentration of TALP. The viscosity of TALP solution at pH 4.0 or pH 9.0 was obviously lower than that at pH 7.0. The add of Na+ significantly increased the viscosity of TALP solution, however, the viscosity of TALP solution got lower when the concentration of Na+ increased from 0.5% to 1.0%. The viscosity of TALP solution was decreased when Ca2+ was added, and the viscosity was lower when the concentration of Ca2+ was higher. The viscosity of TALP solution quickly dropped at the temperature among 20-60 ℃, because of its bad temperature resistance. The scavenging rate on 2 free radicals of TALP solution(10.0 mg·mL-1) was nearly with 2.0 mg·mL-1 Vc. CONCLUSION The aqueous TALP solution is a typical of non-Newtonian pseudoplastic fluid. Antioxidant activity assay indicates that TALP has favorable antioxidant activity.