Abstract:

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.

Key words: water chestnut hull, total flavonoids, ultrasonic-assisted extraction