Optimization of polysaccharides extraction from Dendrobium officinale Kimura et Migo and investigation on its antioxidant activity

【Objective】This study aimed to optimize polysaccharides extraction fromDendrobium officinale Kimura et Migo and investigate its antioxidant activity.【Method】The response surface method(RSM)based mathematical model was established using polysaccharides extraction rate as response value, and using extraction time,extraction frequency,and ratio of water to feedstock as experimental factors to screen optimum extraction conditions for polysaccharide extraction from D.officinale Kimura et Migo. Antioxidant activity of polysaccharides was studied by DPPH and ABTS free radical elimination method. 【Result】The optimum conditions obtained by RSM were:number of extraction times was 3,duration of extraction was 2hand ratio of water to feedstock was 75mL/g.Under the optimal conditions,the predicted extraction rate was 36.57%,while the experimental extraction rate was 34.96%,with a difference of less than 5%.IC50 of DPPH and IC50 of ABTS were 1.20and 3.65mg/mL,respectively.【Conclusion】Optimization of the polysaccharide extraction from D.officinale Kimura et Migo by RSM was convenient and feasible,and obtained polysaccharides had good antioxidant activity.