. 2019 Apr 26;24(9):1642. doi: 10.3390/molecules24091642

Table 2.

Values obtained for the experimental and predicted response variables of RCSO concentrate by central composite rotatable design 2⁴ + star based on the response surface methodology ¹.

Run	Process Variables ^*				Response Variables ^**
	Process Variables ^*				Experimental Values			Predicted Values
	A	B	C	D	R₁	R₂	R₃	R₁’	R₂’	R₃’
1	1.5	−15	14.3	200	40.44	10.47	11.04	33.77	13.77	14.00
2	4.5	−15	14.3	200	12.64	28.41	44.38	12.23	28.09	45.89
3	1.5	15	14.3	200	48.71	9.22	9.52	40.35	9.52	10.23
4	4.5	15	14.3	200	17.45	25.09	32.69	18.82	23.85	26.94
5	1.5	−15	36.8	200	36.25	10.46	11.13	29.02	13.22	15.24
6	4.5	−15	36.8	200	10.44	24.42	55.91	21.55	27.55	47.14
7	1.5	15	36.8	200	4.22	7.96	8.18	20.22	8.98	11.47
8	4.5	15	36.8	200	18.12	24.87	30.47	12.76	23.30	28.18
9	1.5	−15	14.3	600	41.74	10.23	10.89	44.89	14.52	14.71
10	4.5	−15	14.3	600	12.77	30.20	46.43	12.14	28.84	46.61
11	1.5	15	14.3	600	78.45	9.02	9.41	68.43	10.27	10.94
12	4.5	15	14.3	600	16.11	25.16	34.34	21.40	24.60	27.65
13	1.5	−15	36.8	600	45.49	9.91	10.06	40.14	13.97	15.96
14	4.5	−15	36.8	600	9.86	27.56	48.55	7.17	28.30	47.85
15	1.5	15	36.8	600	58.94	7.84	7.91	48.30	9.73	12.18
16	4.5	15	36.8	600	12.64	23.05	28.93	15.33	24.05	28.89
17	0	0	25.5	400	57.38	6.33	6.39	67.84	-0.77	0.94
18	6	0	25.5	400	15.86	25.45	30.43	13.34	27.88	49.55
19	3	−30	25.5	400	12.21	29.26	44.37	19.61	24.94	36.61
20	3	30	25.5	400	33.82	13.52	14.65	34.36	16.45	13.88
21	3	0	3.05	400	12.71	20.41	22.67	25.65	21.24	24.00
22	3	0	48.0	400	16.31	23.01	28.93	14.83	20.15	26.49
23	3	0	25.5	0	19.11	22.62	25.72	13.39	19.95	24.53
24	3	0	25.5	800	16.47	26.07	33.39	27.09	21.44	25.95
25	3	0	25.5	400	20.77	22.43	25.82	20.24	20.69	25.24
26	3	0	25.5	400	20.74	21.40	25.20	20.24	20.69	25.24
27	3	0	25.5	400	17.20	24.00	29.15	20.24	20.69	25.24
28	3	0	25.5	400	22.74	18.23	20.23	20.24	20.69	25.24
Equations									R² Adjusted
Total FA yield = 57.60 − 19.47A + 0.26B − 0.87C + 0.08D + 2.26AA+ 0.01BB + 0.21AC − 0.02AD − 0.02BC + 0.001BD									0.72(1)
EPA = −0.90 + 9.53A − 0.14B − 0.79AA									0.84(2)
DHA = −1.19 + 8.10A + 0.17B − 0.19AB									0.81(3)
EPA+DHA = 3.52 + 12.88A − 0.52B									0.80(4)

¹ Central composite design: 2⁴ + star, which studies the effects of 4 factors in 28 runs based on the RSM. * Independent variables: A (urea/FA content ratio, w/w), B (crystallization temperature, °C), C (crystallization time, h), and D (stirring speed, rpm).** Response variables: R₁ (total FA yield, g FA in the non-urea complexing fraction/100 g initial saponified oil FA), R₂ (EPA content, g/100 g total FA), and R₃ (DHA content, g/100 g total FA). Predicted response variables: R₁’, R₂’, and R₃’.