Thise study aimed to determine the optimum antioxidant extraction conditions of dried Gugija (Lycium chinensis Mill). To determine the operational parameters, including ethanol concentration (X1, 0~80%) and extraction time (X2, 1~5 hr), a response surface methodology was applied to monitor brown color intensity, total phenolic compounds, ABTS radical scavenging activity, and Fe2+ chelating activity. Coefficients of determinations (R2) of the models were 0.8486~0.9214 (p<0.05~0.1) in dependent parameters. Brown color intensity of Gugija extracts reached a maximum of 0.75 (OD in 420 nm) under extraction conditions of 2.88 hr in 78.10% ethanol. Total phenolic compounds reached a maximum of 2,355 μg under extraction conditions of 4.94 hr in 30.17% ethanol. ABTS radical scavenging activity was 13.83% at 4.61 hr and 16.21% ethanol. Fe2+ chelating activity showed a maximum of 58.54% under extraction conditions of 3.39 hr in 0.76% ethanol. Optimum extraction conditions (5 hr extraction in 15% ethanol) were obtained by superimposing the contour maps with regards to total phenolic compounds, ABTS radical scavenging activity, and Fe2+ chelating activity of dried Gugija. Maximum values of total phenolic compounds, ABTS radical scavenging activity, and Fe2+ chelating activity under optimum extraction condition were 2,397 μg, 15.62% and 54.78%, respectively.

• 이기동(중부대학교 식품생명과학과) | Gee-Dong Lee Corresponding author