Solid-State Fermentation of Aspergillus niger to Optimize Extraction Process of Isoliquiritigenin from Glycyrrhiza uralensis

Table 3

Test of significance for the regression coefficient.

Source	Sum of squares	Df	Mean square	F value	value
Model	1.11	9	0.12	33.51	<0.0001
A-pH	2.112 × 10^−3	1	2.112 × 10^−3	0.57	0.4739
B-solid-liquid ratio	0.023	1	0.023	6.26	0.0408
C-inoculation amount of A. niger	0.33	1	0.33	88.91	<0.0001
AB	0.036	1	0.036	9.78	0.0167
AC	2.500 × 10^−5	1	2.500 × 10^−5	6.776 × 10^−3	0.9367
BC	0.016	1	0.016	4.23	0.0786
A^2	0.010	1	0.010	2.78	0.1391
B^2	0.18	1	0.18	50.04	0.0002
C^2	0.46	1	0.46	125.71	<0.0001
Residual	0.026	7	3.690 × 10^−3
Lack of fit	0.011	3	3.708 × 10^−3	1.01	0.4759
Pure error	0.015	4	3.676 × 10^−3
Cor total	1.14	16