Table 1.

Factors and levels of variation in central composite design (CCD)

Study type	Response Surface
Design type	Central composite		Runs 20
Design mode	Quadratic		Blocks—No blocks
Factor	Name	Units	Type	Minimum	Maximum
A	Incubation period	Days	Numeric	1.98	7.02
B	pH		Numeric	4.32	7.68
C	Temperature	°C	Numeric	19.89	45.11

Response	Name	Units	Obs	Analysis
R1	Xylanase	IU/gds	20	Polynomial