Table 2.

Central composite design with the observed responses and predicted values for TPC, TFC and TSC

Run	Coded variable levels				Observer (Y1)a						Predicted (Y0)
	X1	X2	X3	X4	TPC (mg GAE/g)		TFC (mg RE/g)		TSC (mg SE/g)		TPC (mg GAE/g)		TFC (mg RE/g)		TSC (mg SE/g)
					M	E	M	E	M	E	M	E	M	E	M	E
1	− 1	1	− 1	1	33.64	33.60	5.30	4.80	0.31	0.49	31.70	35.65	5.52	5.01	0.31	0.47
2	0	0	0	− 2	42.34	40.60	6.40	6.70	0.09	0.26	44.02	42.74	6.53	6.96	0.20	0.28
3	− 1	− 1	1	− 1	27.84	30.60	5.20	4.90	0.14	0.31	29.55	31.38	5.38	5.36	0.11	0.29
4	0	0	0	2	45.24	46.60	6.50	5.20	0.38	0.46	45.66	46.07	6.32	5.25	0.32	0.44
5	1	− 1	− 1	1	34.22	31.20	6.50	6.60	0.19	0.35	36.36	30.43	6.05	6.55	0.15	0.35
6	1	1	1	1	40.02	40.40	6.90	7.30	0.29	0.36	42.00	44.65	7.03	7.78	0.32	0.41
7	0	0	0	0	62.64	64.80	10.70	11.90	0.68	0.67	60.15	66.31	10.36	11.41	0.64	0.64
8	0	0	0	0	62.06	63.40	10.60	11.70	0.67	0.63	60.15	66.31	10.36	11.41	0.64	0.64
9	1	1	− 1	− 1	33.64	31.80	6.20	8.90	0.18	0.21	32.14	32.15	5.85	8.94	0.16	0.24
10	0	− 2	0	0	30.74	34.40	6.80	7.30	0.13	0.44	35.98	40.79	7.24	7.77	0.22	0.45
11	− 1	1	− 1	− 1	28.42	26.40	4.90	6.70	0.19	0.24	29.55	28.03	5.24	6.46	0.16	0.26
12	− 1	− 1	1	1	25.52	31.20	4.40	6.20	0.14	0.32	25.90	30.89	4.56	6.11	0.13	0.30
13	0	0	0	0	55.68	68.60	9.60	11.10	0.56	0.7	60.15	66.31	10.36	11.41	0.64	0.64
14	0	0	0	0	58.58	67.80	10.10	10.90	0.61	0.68	60.15	66.31	10.36	11.41	0.64	0.64
15	1	1	− 1	1	37.2	38.40	6.40	7.20	0.24	0.39	35.23	35.97	6.45	6.47	0.26	0.40
16	− 1	1	1	− 1	30.16	31.20	5.5.	6.70	0.12	0.29	31.56	32.02	5.77	6.71	0.13	0.30
17	0	0	− 2	0	38.28	37.60	7.60	6.80	0.26	0.43	40.15	39.27	7.73	7.56	0.30	0.39
18	− 1	− 1	− 1	1	36.54	39.60	5.10	6.10	0.23	0.35	36.36	39.61	5.33	5.86	0.27	0.41
19	1	− 1	1	− 1	37.70	37.80	6.50	7.70	0.25	0.38	34.99	35.79	6.10	7.45	0.22	0.41
20	0	2	0	0	35.38	39.20	7.10	7.60	0.21	0.45	33.85	36.37	6.74	7.58	0.19	0.44
21	0	0	0	0	62.06	67.60	10.70	11.90	0.67	0.59	60.15	66.31	10.36	11.41	0.64	0.64
22	− 1	− 1	− 1	− 1	35.96	39.20	6.20	6.30	0.22	0.29	32.86	34.99	5.88	5.78	0.16	0.25
23	1	− 1	1	1	33.06	34.80	5.70	7.20	0.17	0.39	30.95	31.51	5.60	7.17	0.19	0.36
24	− 2	0	0	0	15.08	17.60	2.60	4.30	0.06	0.13	13.76	16.44	2.00	4.33	0.07	0.15
25	1	− 1	− 1	− 1	30.16	31.20	6.20	7.80	0.12	0.24	30.08	29.61	6.27	7.49	0.08	0.25
26	0	0	2	0	41.18	44.40	8.00	8.90	0.31	0.41	41.41	44.34	7.82	8.45	0.31	0.45
27	1	1	1	− 1	44.66	47.60	6.70	9.60	0.37	0.47	43.86	45.93	6.70	9.57	0.32	0.40
28	0	0	0	0	61.48	67.60	10.60	11.10	0.66	0.59	60.15	66.31	10.36	11.41	0.64	0.64
29	2	0	0	0	17.98	18.40	3.10	7.60	0.09	0.23	21.40	21.17	3.65	7.88	0.13	0.21
30	− 1	1	1	1	32.48	34.60	5.60	5.90	0.16	0.39	31.58	34.53	5.77	5.94	0.19	0.37

^aMean of triplicate samples, M methanol, E ethanol