双水相法萃取白及多糖及其对亚硝酸盐的清除作用

以白及块茎为试材,采用超声辅助聚乙二醇6000/磷酸氢二钾(PEG 6000/K2HPO4)双水相法提取白及多糖,通过单因素和响应面(BBD中心组合)试验相结合分析料液比、提取时间、多糖粗提液体积、PEG 6000用量、K2HPO4用量对多糖提取率的影响,以期为高效提取白及多糖提供参考依据。结果表明:多糖粗提液体积和PEG 6000用量、PEG 6000用量和K2HPO4用量交互作用显著,而多糖粗提液体积和K2HPO4用量的交互作用较弱,对白及多糖提取率的影响因素大小为PEG 6000用量>多糖粗提液体积>K2HPO4用量;最佳工艺条件为多糖粗提液体积5.0 mL,K2HPO4用量1.0 g,PEG 6000用量2.0 g;在最优工艺条件下经过3次平行试验,多糖提取率为72.81%,与预测值的偏差为0.94%,说明工艺条件稳定可行,结果重现性较好。白及多糖对亚硝酸盐有一定的清除作用,并且清除率随多糖浓度提高而增大。由此说明,优选出的白及多糖提取工艺具有良好的预测性。

Extraction Polysaccharides From Bletilla striata by Aqueous Two Phase System and Its Clearance to Nitrite

Taking Bletilla striata as experimental material,the Ultrasonic-assisted PEG 6000/K2HPO4 were aqueous two phase system composed of polyethylene glycol 6000/dipotassium hydrogen phosphate,was applied to extract polysaccharides from Bletilla striata.The effects of solid-liquid ratio,extracted time,polysaccharide extract volume,PEG 6000 dosage and K2HPO4 dosage on polysaccharide extraction rate were analyzed by single factor and response surface methodology(BBD central composite).The results indicated that the polysaccharides extract volume and PEG 6000 dosage,the PEG 6000 and K2HPO4 dosage had significant interaction,while the polysaccharide extract volume and the amount of K2HPO4 had a lower interaction.The factor affected the extraction rate of polysaccharide were as follows,PEG 6000 dosage>polysaccharide extract volume>K2HPO4 dosage;the optimal process condition were 5.0 mL polysaccharide extract volume,K2HPO4 dosage was 1.0 g,and PEG 6000 dosage was 2.0 g.Three parallel tests were proceeded under optimal process conditions,the polysaccharide extraction rate was 72.81%,which was lower than the predicted value.The deviation was 0.94%,indicated that the process conditions were stable and feasible,and the results were reproducible.Bletilla striata polysaccharides had a specific effect on nitrite clearance,and the clearance rate increased along with the increase of polysaccharides concentration.This demonstrates the optimized extraction process of polysaccharides has great predictability,and this research can provide a suggestion for the efficient extraction of Bletilla striata polysaccharide.