Ultrasound-assisted Extraction of Total Flavonoids from Water Chestnut Hull

Ultrasonic technique was employed to extract total flavonoids from water chestnut hull with ethanol. Effects of four crucial factors including ethanol concentration, liquid/material ratio (V/m), extraction duration and repeated extraction times on extraction yield of total flavonoids were investigated by one-factor-at-a-time method. Subsequently, all these factors were optimized using orthogonal array design. The optimal parameters for extracting total flavonoids were as follows: ethanol concentration 50% and liquid/material ratio 10:1 for an extraction duration of 0.5 h repeated twice, and the yield of total flavonoids was up to 0.81% under these optimized conditions. The ultrasonic-assisted extraction for total flavonoids in water chestnut hull is a time- and cost-saving and highly efficient method.