Table 1.

Factors and levels of orthogonal experimental design.

Levels	Factors
	A	B	C	D
	Extraction Time (min)	Ethanol Concentration (%)	Extraction Temperature (°C)	Extraction Frequency (kHz)
1	40	30	55	28
2	50	40	60	40
3	60	50	65	56
4	70	60	70	80