标题：Effects of ultrasound-assisted extraction conditions on the recovery of phenolic compounds and in vitro antioxidant activity of jujube ( Ziziphus jujuba mill.) leaves
期刊名称：Annals of the University Dunarea de Jos of Galati. Fascicle VI : Food Technology
印刷版ISSN：1843-5157
电子版ISSN：2068-259X
出版年度：2018
卷号：42
期号：1
页码：1-13
出版社：Galati University Press
摘要：The optimum conditions for the Ultrasound-Assisted Extraction (UAE) of total
phenolics and antioxidant activity from jujube leaves were studied. The effect of
the solvent nature (acetone, methanol, ethanol and water), solvent concentration
(25-100%; v/v), ultrasound intensity (25-100%), solid/solvent ratio (1/50-1/300;
w/v) and extraction time (1-15 min) were also determined. The total phenolic
content was used to determine the phenolic compounds. Ferric-reducing power
and 2,2-diphenyl-1-picrylhydrazyl (DPPH) were used to evaluate the antioxidant
activity. All the ultrasound-assisted extraction parameters that were investigated
had from a statistically point of view significant effects (p<0.05) upon the
phenolic compound extraction and antioxidant activity. The best extraction
conditions were obtained by using methanol 60 %, a sonication intensity of 75
%with a solid/solvent ratio of 1/200(w/v), for 10 min. As such, the obtained
values were 6.0g gallic acid equivalents/100g for total phenolic content, 3.886 g
ascorbic acid equivalents/100g for free radical scavenging activity and 2.587 g
ascorbic acid equivalents/100g for ferric reducing power. The phenolic content
was positively correlated with the antioxidant activities.
