Table 1. Experimental design in coded and actual factors and responses

Run	Design point	X1	X2	X3	X4	F1	F2	F3	F4	Y1	Y2
1	1	–1	–1	–1	–1	8	34.5	12	0.065	64.5	5.94
2	2	1	–1	–1	–1	12	34.5	12	0.065	78.1	5.93
3	3	–1	1	–1	–1	8	39.5	12	0.065	73.5	5.4
4	4	1	1	–1	–1	12	39.5	12	0.065	83.4	5.46
5	5	–1	–1	1	–1	8	34.5	20	0.065	80.1	4.85
6	6	1	–1	1	–1	12	34.5	20	0.065	86.5	5.07
7	7	–1	1	1	–1	8	39.5	20	0.065	75.2	4.73
8	8	1	1	1	–1	12	39.5	20	0.065	87.7	4.86
9	9	–1	–1	–1	1	8	34.5	12	0.155	72.1	5.67
10	10	1	–1	–1	1	12	34.5	12	0.155	77.3	5.81
11	11	–1	1	–1	1	8	39.5	12	0.155	68.5	5.25
12	12	1	1	–1	1	12	39.5	12	0.155	81.5	5.41
13	13	–1	–1	1	1	8	34.5	20	0.155	79.6	4.48
14	14	1	–1	1	1	12	34.5	20	0.155	89.4	4.63
15	15	–1	1	1	1	8	39.5	20	0.155	79.1	4.71
16	16	1	1	1	1	12	39.5	20	0.155	85.6	4.86
17	17	–2	0	0	0	6	37	16	0.11	78.4	4.84
18	18	2	0	0	0	14	37	16	0.11	82.9	5.08
19	19	0	–2	0	0	10	32	16	0.11	86.1	4.43
20	20	0	2	0	0	10	42	16	0.11	73.6	5.04
21	21	0	0	–2	0	10	37	8	0.11	39.7	6.39
22	22	0	0	2	0	10	37	24	0.11	89.5	4.4
23	23	0	0	0	–2	10	37	16	0.02	85.2	5.05
24	24	0	0	0	2	10	37	16	0.2	87.4	4.97
25	25	0	0	0	0	10	37	16	0.11	84.1	5.15
26	25	0	0	0	0	10	37	16	0.11	85.6	5.14
27	25	0	0	0	0	10	37	16	0.11	87.3	5.15

Actual factors: F₁, skim milk concentration (%), 1.0% glucose was added to each skim milk conc.; F₂, incubation temperature (°C); F₃, incubation time (hours); F₄, starter added amount (%).
Responses: Y₁, angiotensin converting enzyme (ACE) inhibitory activity (%); Y₂, pH.