Optimization of Ultrasound-Assisted Extraction of Total Flavonoids from Dendranthema indicum var. aromaticum by Response Surface Methodology

Table 7

Comparison of total flavonoids (TF) extraction rate with or without ultrasound treatment.

	Ultrasound treatment	Solid/liquid ratio (g/mL)	Temperature (°C)	Time	TF extraction rate (g QE^a/100 g DW)^b
General conditions	With	1 : 20	40	30 min	0.351 ± 0.025
	Without	1 : 20	40	30 min	0.033 ± 0.005
	Without	1 : 20	40	24 h	0.301 ± 0.011
Optimized conditions	With	1 : 23	60	40 min	0.424 ± 0.029
	Without	1 : 23	60	40 min	0.037 ± 0.006
	Without	1 : 23	60	24 h	0.229 ± 0.010

^aQuercetin equivalent. ^bMean ± SD (n = 3).