Table 5.

The BBD design and the responses of the dependent variables

Test number	pH		L-Phe concentration (g/L)		Loaded liquid (mL/250 mL)		2-PE concentration (g/L)
	A	Code A	B	Code B	C	Code C	Y
1	2.0	0	7.5	− 1	32.5	+ 1	3.88
2	2.0	0	10.0	0	27.5	0	4.93
3	1.5	− 1	7.5	− 1	27.5	0	3.90
4	2.5	+ 1	10.0	0	32.5	+ 1	4.51
5	1.5	− 1	10.0	0	32.5	+ 1	4.08
6	1.5	− 1	10.0	0	22.5	− 1	4.39
7	2.5	+ 1	7.5	− 1	27.5	0	4.51
8	2.5	+ 1	12.5	+ 1	27.5	0	4.73
9	2.0	0	10.0	0	27.5	0	4.97
10	2.0	0	12.5	+ 1	22.5	− 1	4.75
11	2.5	+ 1	10.0	0	22.5	− 1	5.08
12	1.5	− 1	12.5	+ 1	27.5	0	4.33
13	2.0	0	12.5	+ 1	32.5	+ 1	4.65
14	2.0	0	10.0	0	27.5	0	5.02
15	2.0	0	7.5	− 1	22.5	− 1	4.17
16	2.0	0	10.0	0	27.5	0	4.89
17	2.0	0	10.0	0	27.5	0	5.01