Essential Oil Extracted from Cymbopogon citronella Leaves by Supercritical Carbon Dioxide: Antioxidant and Antimicrobial Activities

Table 1

Experimental range and levels of independent variables.

Variables	Symbol	Code levels
		−1	0	1
Extraction time (min)	X1	110	120	130
Extraction pressure (MPa)	X2	22	25	28
Extraction temperature (°C)	X3	32	35	38
CO2 flow (L/h)	X4	16	18	20