Table 1

Factors	Corresponding variable	Coded level of variable
Factors	Corresponding variable	- 1	0	1
A	Temperature (°C)	30	40	50
B	pH	3	5	7
C	Tween 80 (% v/v)	0	0.75	1.5
D	Agitation (rpm)	100	300	500

Table 1: Experimental range and levels of independent variables studied using a two level fractionated factorial design (2^4-1) in terms of actual and coded factors.