OBJECTIVE To optimize the ultrasonic-assisted extraction technology of the total flavonoids from blueberry and study the antioxidant activity of the extract. METHODS The extraction technology of the total flavonoids from blueberry was optimized by orthogonal experiment using lutin as standard compound with ethanol concentration, extraction time, amount of solvent and extraction times as factors and with extraction yield of total flavonoids as index. The antioxidant activity of the extract was tested by usin...