Neutralization of Soybean Oil Deodorizer Distillate for Vitamin Supplement Production

Table 3

Second experimental design matrix with real and coded variables’ values and studied responses.

Assay	Factors			Responses
	Na2CO3 concentration; (N)	Temperature; (°C)	Time; (min)	Reduction of FFA; content (%)	𝛼-TE content; (%)	Neutral SODD yield; (%)
1	3 (−1)	30 (−1)	2 (−1)	49.3^a	2.489^a	5.2^a
2	4 (1)	30 (−1)	2 (−1)	50.5^bcd	2.738^a	13.4^cde
3	3 (−1)	44 (1)	2 (−1)	49.3^a	2.151^a	7.7^ab
4	4 (1)	44 (1)	2 (−1)	50.2^bc	2.365^a	13.0^cde
5	3 (−1)	30 (−1)	3 (1)	49.5^a	2.214^a	5.5^a
6	4 (1)	30 (−1)	3 (1)	50.1^b	2.515^a	14.9^e
7	3 (−1)	44 (1)	3 (1)	49.7^ab	2.304^a	10.6^bcde
8	4 (1)	44 (1)	3 (1)	50.8^d	2.737^a	14.3^de
9	2.66 (−1.68)	37 (0)	2.5 (0)	49.6^a	2.285^a	7.0^a
10	4.34 (1.68)	37 (0)	2.5 (0)	50.8^d	2.681^a	24.5^f
11	3.5 (0)	25 (−1.68)	2.5 (0)	49.6^a	2.576^a	11.6^bcde
12	3.5 (0)	49 (1.68)	2.5 (0)	49.6^a	2.342^a	10.4^bcd
13	3.5 (0)	37 (0)	1.67 (−1.68)	49.6^a	2.304^a	9.2^abc
14	3.5 (0)	37 (0)	3.33 (1.68)	50.2^bc	2.367^a	13.3^cde
CP	3.5 (0)	37 (0)	2.5 (0)	50.2^bc	2.304^a	12.9^cde

Distinct letters in the same column indicate significant difference (𝑃<0.05) between values according to Tukey’s test. CP: central point (mean value of the quadruplicate).