Table 1: Treatments defined by fractional factorial experimental design with range of coded and real values to aqueous extraction of hibiscus calyces.

Treatment	X1 Enzyme (µL/1000 g)	X2 Temperature (ºC)	X3 Stirring Speed (rpm)	X4 Time of Extraction (h)
T1	-1 (0)	-1 (35)	-1 (200)	-1 (3)
T2	+1 (50)	-1 (35)	-1 (200)	+1 (5)
T3	-1 (0)	+1 (55)	-1 (200)	+1 (5)
T4	+1 (50)	+1 (55)	-1 (200)	-1 (3)
T5	-1 (0)	-1 (35)	+1 (400)	+1 (5)
T6	+1 (50)	-1 (35)	+1 (400)	-1 (3)
T7	-1 (0)	+1 (55)	+1 (400)	-1 (3)
T8	+1 (50)	+1 (55)	+1 (400)	+1 (5)