Table 1.

Box–Behnken Design (BBD) experimental design with the independent variables and observed responses.

Run Order a	Ethanol% (X1)	Extraction Time (X2) (min)	Solvent-to-Material Ratio (X3) (mL/g)	Yield%	TPC b (mg GAE/g DM)	TFC b (mg QE/g DM)	DPPH Assay b IC50 (µg/mL)
1	40	20	20	9.30	11.1 ± 0.56	1.98 ± 0.01	55.3 ± 0.32
2	80	20	20	15.20	21.2 ± 0.65	3.11 ± 0.01	85.4 ± 0.15
3	40	45	20	10.50	13.3 ± 0.32	1.88 ± 0.01	56.3 ± 0.27
4	80	45	20	17.50	22.2 ± 0.29	3.25 ± 0.01	92.4 ± 0.37
5	40	30	10	9.60	12.8 ± 0.18	1.20 ± 0.01	49.3 ± 0.29
6	80	30	10	16.20	22.3 ± 0.33	2.65 ± 0.01	88.2 ± 0.21
7	40	30	30	9.20	11.1 ± 0.14	0.65 ± 0.01	51.6 ± 0.36
8	80	45	30	18.00	23.2 ± 0.11	3.26 ± 0.01	87.2 ± 0.77
9	60	20	10	13.30	13.5 ± 0.65	0.96 ± 0.01	65.1 ± 0.54
10	60	45	10	13.20	14.2 ± 0.54	0.85 ± 0.01	61.1 ± 0.11
11	60	20	30	13.10	14.1 ± 0.64	0.75 ± 0.01	63.8 ± 0.91
12	60	45	30	12.90	13.2 ± 0.26	0.84 ± 0.01	59.2 ± 0.46
13	60	30	20	12.90	13.6 ± 0.45	0.59 ± 0.01	52.1 ± 0.61
14	60	30	20	12.60	13.2 ± 0.19	0.59 ± 0.01	52.6 ± 0.45
15	60	30	20	12.60	12.6 ± 0.57	0.61 ± 0.01	49.8 ± 0.32
16	60	30	20	12.50	13.2 ± 0.75	0.61 ± 0.01	52.6 ± 0.41
17	60	30	20	12.50	13.6 ± 0.94	0.59 ± 0.01	52.8 ± 0.67

^a Run order—randomized. ^b The values are given as mean ± standard deviation of triplicate determinations; total phenolic content (TPC) expressed as mg GAE/g DM; total flavonoid content (TFC) expressed as mg QE/g DM; free radical scavenging activity expressed as µg/mL; DM: dry matter.