Table 2.

Central composite design for the decoction: temperature and time, with observed responses (total phenolic content, DPPH scavenging activity, and crude Pelargonium graveolens polysaccharide yield).

TEST	Factors				Responses
	X1		X2		Y1	Y2	Y3
	Temperature (°C)	Coded level	Time (min)	Coded level	Total phenolic content (mg GAE/gDM)	DPPH scavenging activity (%)	CPGP yield (%)
1	81	-1	10	-1	28.24	72.9	3.48
2	95	1	10	-1	36.04	81.93	8.97
3	81	-1	18	1	30.37	65.13	4.11
4	95	1	18	1	36.36	85.92	7.78
5	88	0	14	0	30.79	68.7	7.25
6	88	0	14	0	33.8	77.2	4.99
7	78	-1.41	14	0	27.05	60.5	4.06
8	98	1.41	14	0	36.54	88.44	8.21
9	88	0	8	-1.41	32.27	79.41	5.64
10	88	0	20	1.41	32.4	76.47	7.33
11	88	0	12	-0.5	31.64	73.11	4.68
12	88	0	16	0.5	31.63	83.19	5.48
13	84	-0.5	14	0	26.86	67.65	3.69
14	92	0.5	14	0	34.42	81.3	5.95
15	79	-1.3	12	-0.5	28.47	65.69	3.43
16	97	1.3	16	0.5	35.54	83.82	6.93