Abstract:

Ultrasonic or constant temperature shaking water bath was used for extraction of total flavonoids from tartary buckwheat in the present study. The optimal ultrasonic-assisted and constant temperature shaking water bath extraction procedures were investigated by single factor and orthogonal array methods. Meanwhile, HPLC determination based on the two optimized extraction techniques of total flavonoids in tartary buckwheat was carried out. Results showed that the optimal values of crucial parameters affecting extraction of total flavonoids, including ethanol concentration, liquid/solid ratio and extraction time were 80%, 40:1 and 30 min for ultrasonic-assisted extraction and 80%, 30:1 and 3 h for constant temperature shaking water bath extraction. Very close yields of total flavonoids were obtained in extraction from tartary buckwheat by both techniques. However, much less time consumption was needed for ultrasonic-assisted extraction. Moreover, analytical figures of merit including spike recovery, reproducibility and precision for HPLC determination of total flavonoids in tartary buckwheat, in which both techniques were used for sample preparation, were satisfying.

Key words: tartary buckwheat, total flavonoids, rutin