Effect of different material ratio on flavonoid contents: The treated jujube powder 2g was took to a flat-bottomed flask, 50% ethanol to the material ratio 1: 20, 1: 30, 1: 40, 1: 50 mixed, And heated to reflow in water bath at 70 °C for 30 min. After filtrated, the volume was 100 mL. The absorbance was measured and the flavonoid contents was calculated.