Abstract:

The total flavonoids extracted from kudzuvine roots from western Hunan province were separated by precipitation
with added calcium ion. Single-factor experiments were carried out to investigate the effects of the amount of added
precipitating agent, precipitation time and temperature on the yield of total flavnoids. In further studies, according to
the principle of Box-Behnken experimental design, the three variables (process conditions) at three selected levels were
optimized by response surface methodology. Results showed that an extraction yield of total flavonoids of 0.658 9% was
obtained when 50 mL of kudzuvine root extract was precipitated for 45 min by adding 70 mL of saturated clarified limewater
at 60 ℃, which was consistent with the model predicted value.

Key words: total flavonoids, kudzuvine root, ion precipitation, response surface methodology