Table 5
Experimental values of response variables at the given extraction conditions within the response surfaces

Extraction conditions1)		Brown color intensity (OD at 420 nm)	Total phenolic compounds (μg/100 g)	ABTS radical scavenging activity (%)	Fe2+ chelating activity (%)
Ethanol conc. (%)	Extraction time (hr)
0	1	0.2754	1,293	4.77	43.82
15%	5	0.5492	2,397	15.62	54.78

Optimum extraction condition (5 hr at 150% ethanol) by the response surface methodology and basic condition (1 hr at water).