The optimal condition for ultrasonic extraction of flavone from seeds of Chinese dates was investigated by orthogonal test.The total flavone content of seeds of Chinese dates was determined by using spectrophotometry method with rutin as reference substance.In the single factor analysis,the effect of ultrasonic-wave power,extraction time,extraction temperature,solid-liquid ratio and ethanol(extraction solvent)volume fraction were measured.The orthogonal test was used to optimize the conditions of extraction...