. 2018 Jul 27;27(6):1607–1617. doi: 10.1007/s10068-018-0441-y

Table 3.

Central composite design with experimental values of target responses of from cinnamon extract by RE method

Exp. No.^a	Extraction condition			Target responses
Exp. No.^a	Ethanol conc. (%)	Extraction temp. (^oC)	Extraction time (min)	Total yield (%)	Cinnamic acid (mg/100 mL)	Cinnamaldehyde (mg/100 mL)
1	25 (− 1)^b	60 (− 1)	1.5 (− 1)	0.65 ± 0.01	5.30 ± 0.03	129.06 ± 0.07
2	25 (− 1)	60 (− 1)	3.5 (1)	0.68 ± 0.01	5.42 ± 0.05	134.64 ± 0.05
3	25 (− 1)	80 (1)	1.5 (− 1)	0.79 ± 0.01	5.43 ± 0.02	131.44 ± 0.11
4	25 (− 1)	80 (1)	3.5 (1)	0.75 ± 0.01	5.26 ± 0.03	117.53 ± 0.00
5	75 (1)	60 (− 1)	1.5 (− 1)	0.83 ± 0.00	5.86 ± 0.02	223.44 ± 0.11
6	75 (1)	60 (− 1)	3.5 (1)	0.84 ± 0.03	6.15 ± 0.01	228.05 ± 0.10
7	75 (1)	80 (1)	1.5 (− 1)	0.94 ± 0.04	6.24 ± 0.00	232.64 ± 0.13
8	75 (1)	80 (1)	3.5 (1)	0.98 ± 0.02	6.25 ± 0.02	232.46 ± 0.26
9	50 (0)	70 (0)	2.5 (0)	0.89 ± 0.02	6.23 ± 0.05	221.43 ± 0.09
10	50 (0)	70 (0)	2.5 (0)	0.89 ± 0.02	6.24 ± 0.06	220.11 ± 0.03
11	0 (− 2)	70 (0)	2.5 (0)	0.41 ± 0.01	4.93 ± 0.00	96.65 ± 0.03
12	100 (2)	70 (0)	2.5 (0)	0.73 ± 0.01	6.04 ± 0.01	225.67 ± 0.05
13	50 (0)	50 (− 2)	2.5 (0)	0.80 ± 0.05	5.89 ± 0.01	217.91 ± 0.17
14	50 (0)	90 (2)	2.5 (0)	0.93 ± 0.01	6.09 ± 0.02	219.36 ± 0.25
15	50 (0)	70 (0)	0.5 (− 2)	0.87 ± 0.03	6.16 ± 0.00	233.11 ± 0.05
16	50 (0)	70 (0)	4.5 (2)	0.90 ± 0.02	6.07 ± 0.04	214.16 ± 0.07
R²				0.9857	0.9112	0.8819
Morphology				Maximum	Maximum	Saddle point
F-ratio of ethanol concentration				76.72***	14.33*	10.51***
F-ratio of extraction temperature				11.73***	1.08	0.06
F-ratio of extraction time				0.46	0.43	0.07

^aThe number of experimental conditions by central composite design

^bCoded level of independent variables

*Significant at p < 0.1; **significant at p < 0.05; ***significant at p < 0.01