• Korean journal of food and cookery science
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• v.24 no.6
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• pp.905-911
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• 2008

Dried and roasted Gugija (Lycii fructus) were extracted with water, 50% ethanol and 100% ethanol, after which the physico-chemical properties of the extracts were evaluated. The extraction yield was higher when using water for the extraction solvent than when the other solvents were used, while the water extract of roasted Gugija had the highest yield. Furthermore the pH of the extracts increased as the ethanol concentration increased, and the pH of dried Gugija was higher than that of roasted Gugija when extracted using the same extraction solvent. The sugar concentrations of the extracts from dried and roasted Gugija were $15.0{\sim}20.1\;%Brix$ and $18.0{\sim}21.2\;%Brix$, respectively. The total polyphenol contents of the extracts from the dried and roasted Gugija were $6.9{\sim}19.0\;mg/g$ and $12.4{\sim}15.8\;mg/g$, respectively. Dried Gugija extract with water had a higher the total polyphenol contents than the other extract. The total polyphenol contents of roasted Gugija extracts were higher than those of dried Gugija, when using 50% or 100% ethanol for extraction solvent. The electron donating ability and total antioxidant activity of dried Gugija were $67.6{\sim}87.7%$ and $58.6{\sim}85.0%$, respectively, whereas those of roasted Gugija were $84.7{\sim}89.8%$ and $80.6{\sim}83.7%$, respectively. Dried and roasted Gugija extracts were higher electron donating ability and total antioxidant activity, when using water, and 50% or 100% ethanol, respectively. The predominant amino acid in all extracts was threonine. The essential amino acids constituted approximately $44.9{\sim}63.6%$ and $45.4{\sim}59.0%$ of the total amino acids of extracts from the dried and roasted Gugija, respectively. Finally, the total polyphenol contents and antioxidant activities showed that optimal extraction solvent would be water, and 50% or 100% ethanol for dried and roasted Gugija, respectively.