Table 4.
Regression coefficients and of the predicted second order polynomial models for total phenolic content, DPPH free radical scavenging activity and antimicrobial activity

Model parameter	Total phenolic content		DPPH radical scavenging activity		Antimicrobial activity (mm)
	Regression coefficient	P-value	Regression coefficient	P-value	Regression coefficient	P-value
	Intercept	-142.407500	0.0493	-427.675000	0.0375	-128.625000	0.0069
Linear
X1	2.854650	0.0442	5.704250	0.0124	3.070000	0.0014
X2	3.587350	0.0305	7.862000	0.0032	0.817500	0.1879
X3	0.197367	0.0805	-0.311417	0.0711	-0.244167	0.1084
Quadratic
X12	-0.020490	0.0335	-0.031550	0.0127	-0.019500	0.0007
X22	-0.031990	0.0150	-0.054300	0.0022	-0.004167	0.2299
X32	-0.007471	0.0012	-0.001117	0.0593	-0.000778	0.0800
Interaction
X1X2	0.006000	0.0776	-0.009250	0.0590	-0.002500	0.4994
X1X3	0.001250	0.0859	-0.002333	0.0771	0.004167	0.0092
X2X3	0.008417	0.0254	0.008750	0.0157	-	1.0000