Neutralization of Soybean Oil Deodorizer Distillate for Vitamin Supplement Production

Table 2

First 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	2 (−1)	25 (−1)	2 (−1)	32.6^a	1.724^a	33.0^c
2	4 (1)	25 (−1)	2 (−1)	34.3^c	1.797^a	42.5^d
3	2 (−1)	50 (1)	2 (−1)	40.1^de	2.346^bc	7.5^a
4	4 (1)	50 (1)	2 (−1)	41.6^f	2.750^d	14.7^b
5	2 (−1)	25 (−1)	6 (1)	32.5^a	1.685^a	36.9^cd
6	4 (1)	25 (−1)	6 (1)	33.4^b	1.691^a	42.2^d
7	2 (−1)	50 (1)	6 (1)	39.8^de	2.416^c	12.9^ab
8	4 (1)	50 (1)	6 (1)	42.6^g	2.585^cd	12.8^ab
CP	3 (0)	37.5 (0)	4 (0)	40.6^e	2.710^d	16.9^b

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).