FOOD SCIENCE ›› 2007, Vol. 28 ›› Issue (4): 145-148.

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Study on Extraction Conditions of Flavonoids from Gynura and Its Antioxidant Effects

 LU  Xiao-Xiang, TANG  Jin-Zhong   

  1. College of Bioteclmology and Food Science,Tianjin University of Commerce,Tianjin 300134,China
  • Online:2007-04-15 Published:2011-12-31

Abstract: The extraction of flavonoids in Gynura was studied and the antioxidant effects of the extract were evaluated as well.The results showed that the highest extraction rate of flavonoids can be obtained with 70% aqueous ethanlo soaked a ratio of solid to liquid 1:25 with microwave output power 600W and microwave irradiation time 120s.The optimum conditions of operation were decided as follows:the raw material is soaked for 30min at 50℃in water-bath,then with the assistance of microwave,the raw material is extracted once again.The extraction ratio for flavonoids is 59.7%.The restraint ratio of the extract towards DPPH(1,1-diphenyl-2- picryl hydrazyl)is 91.2% at 0.66mg/ml,and the restraint ratio of the extract to antioxidant lipids is 14.4% at 1.32mg/ml.

Key words: Gynura, flavonoids, extraction, antioxidative effect