Table 1.

Actual and coded values for full factorial experimental design.

Factor	Ultra-Turrax Pretreatment			Ultrasound-Assisted Pretreatment
	−1	0	+1	−1	0	+1
Stirring rate (rpm) (X1)	10,000	20,000	30,000
Sample mass (g) (X2)	0.3	0.6	0.9
Solvent concentration (%v/v) (X3)	40	60	80
Time (sec) (X4)	30	60	90
Sample mass (g) (X1)				0.3	0.6	0.9
Solvent concentration (%v/v) (X2)				40	60	80
Time (sec) (X3)				10	20	30
Temperature (°C) (X4)				30	50	70