Table 1
Experimental data on brown color intensity, total phenolic compounds, ABTS radical scavenging activity and Fe²⁺ chelating activity of the dr ied Gugija (Lycium chinensis Mill) under different conditions based on central composite design for response sur face analysis

Exp. No.¹⁾	Extraction conditions		Brown color intensity (OD at 420 nm)	Total phenolic compounds (μg/100 g)	ABTS radical scavenging activity (%)	Fe²⁺ chelating activity (%)
Exp. No.¹⁾	Ethanol conc. (%)	Extraction time(hr)	Brown color intensity (OD at 420 nm)	Total phenolic compounds (μg/100 g)	ABTS radical scavenging activity (%)	Fe²⁺ chelating activity (%)
1	60 ( 1)	4 ( 1)	0.803²⁾	1,634	6.88	29.87
2	60 ( 1)	2 (-1)	0.747	1,688	7.35	29.08
3	20 (-1)	4 ( 1)	0.586	2,126	12.85	48.29
4	20 (-1)	2 (-1)	0.455	1,711	7.93	44.44
5	40 ( 0)	3 ( 0)	0.655	2,072	8.23	44.27
6	40 ( 0)	3 ( 0)	0.659	2,033	8.17	43.70
7	80 ( 2)	3 ( 0)	0.704	1,427	6.88	27.40
8	0 (-2)	3 ( 0)	0.425	1,296	8.31	59.36
9	40 ( 0)	5 ( 2)	0.641	2,264	11.04	42.01
10	40 ( 0)	1 (-2)	0.606	2,318	7.83	41.36

The number of experimental conditions by central composite design.
Data were expressed as mean of triplicate determinations.