Table 1.

Central composite design (CCD) for independent variables and corresponding response values (experimental).

Run	Independent Variables			Responses
	(X1)	(X2)	(X3)	TPC (Y1)	TFC (Y2)	DPPH (Y3)	CUPRAC (Y4)
1	75	4	70	4.30 ± 0.68	3.16 ± 0.73	10.81 ± 0.72	1.38 ± 0.05
2	25	2	50	3.81 ± 0.83	2.55 ± 0.52	10.25 ± 0.39	1.47 ± 0.02
3	75	2	50	3.90 ± 0.34	2.55 ± 0.25	9.75 ± 0.37	1.16 ± 0.16
4	100	3	60	4.30 ± 0.26	3.44 ± 0.65	10.11 ± 0.24	1.12 ± 0.10
5	75	2	70	3.50 ± 0.41	2.56 ± 0.32	9.95 ± 1.00	1.17 ± 0.07
6	50	3	60	4.53 ± 0.82	3.10 ± 0.21	10.45 ± 0.10	1.40 ± 0.08
7	0	3	60	3.01 ± 1.02	2.52 ± 0.25	9.57 ± 0.56	0.91 ± 0.06
8	75	4	50	4.31 ± 0.49	2.95 ± 0.45	9.88 ± 0.26	0.88 ± 0.04
9	50	3	60	4.30 ± 0.42	3.15 ± 0.54	10.40 ± 0.95	1.46 ± 0.08
10	50	3	60	4.51 ± 0.23	3.09 ± 0.98	10.42 ± 0.35	1.43 ± 0.04
11	50	3	80	3.78 ± 0.62	2.26 ± 0.10	9.50 ± 0.26	1.11 ± 0.02
12	50	3	60	4.46 ± 0.06	3.01 ± 1.02	10.48 ± 0.33	1.45 ± 0.06
13	50	3	60	4.48 ± 0.04	3.12 ± 0.56	10.41 ± 0.53	1.43 ± 0.16
14	25	4	70	3.15 ± 0.08	2.16 ± 0.46	9.60 ± 0.35	1.00 ± 0.13
15	50	3	60	4.51 ± 0.06	2.95 ± 0.29	10.20 ± 0.15	1.45 ± 0.19
16	50	3	40	3.85 ± 0.24	2.48 ± 0.37	9.60 ± 0.60	0.92 ± 0.15
17	25	2	70	3.25 ± 0.68	2.15 ± 0.19	9.36 ± 0.72	1.12 ± 0.07
18	50	1	60	2.87 ± 0.68	2.03 ± 0.49	9.80 ± 0.39	1.32 ± 0.10
19	50	5	60	2.90 ±0.64	2.50 ± 1.05	9.90 ± 0.72	0.86 ± 0.02
20	25	4	50	2.96 ± 0.80	2.38 ± 1.06	9.53 ± 0.39	0.75 ± 0.08

X₁: ethanol concentration (%); X₂: time (h); X₃: temperature (°C). TPC: total phenolic content (mg gallic acid equivalent/g dry weight extract); TFC: total flavonoid content (mg catechin equivalent/g dry weight extract); DPPH: DPPH radical scavenging activity (% inhibition); CUPRAC: cupric-reducing antioxidant capacity (µM ascorbic acid equivalent).