| dc.description.abstract | Grape peel is rich in antioxidants which have been associated with useful effects on health.
It is presents as a good source of functional compounds, such as phenolic compounds. The
purposes of this study are to determine the total phenolic content and antioxidant activity of
ethanolic extracts of Ninh Thuan grape peel by using Ultrasound-assisted extraction
technology, and also to find out the optimum conditions of Ultrasound-assisted extraction.
The experiments were carried out according to three variables (extraction temperature,
extraction time and ethanol concentration) with nine level of ethanol concentrations (10%,
20%, 30%, 40%, 50%, 60%, 70%, 80% and 90%), four level of times (15 min, 25 min, 35
min and 45 min), 4 level of temperatures (40oC, 45oC, 50oC, 55oC). Folin-Ciocalteau method
was used to analyze total phenolic content and DPPH radical scavenging activity assay was
used to determine antioxidant activity. The optimal conditions include 50% ethanol, 45oC, 25
minfor the maximum total phenolic content and highest antioxidant activity. Overall, the
results suggested that the Ultrasound-assisted extraction technology could enhance the
efficiency of antioxidant extraction from Grape peel and extraction conditions (time,
temperature, solvent concentration) could effect to productivity.
Keywords: Grape peel, ultrasound assisted extraction, total phenolic, antioxidant activity,
DPPH assay | en_US |
