Optimization of the Aqueous Extraction of Phenolic Compounds from Olive Leaves

Antioxidants

Chloe D. Goldsmith²  Quan V. Vuong²  Costas E. Stathopoulos¹  Paul D. Roach²  Christopher J. Scarlett²  Maria G. Miguel³ 

[1] Faculty of Bioscience Engineering, Ghent University Global Campus, Incheon 406-840, South Korea; E-Mail:;School of Environmental & Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia; E-Mails:School of Environmental & Life Sciences, University of Newcastle, Ourimbah, NSW 2258, Australia;

关键词: olive leaves;    phenolic compounds;    green extraction solvents;    waste valorisation;    Olea europaea;    response surface methodology (RSM);   

DOI  :  10.3390/antiox3040700

来源: mdpi

【 摘 要 】

Olive leaves are an agricultural waste of the olive-oil industry representing up to 10% of the dry weight arriving at olive mills. Disposal of this waste adds additional expense to farmers. Olive leaves have been shown to have a high concentration of phenolic compounds. In an attempt to utilize this waste product for phenolic compounds, we optimized their extraction using water—a “green” extraction solvent that has not yet been investigated for this purpose. Experiments were carried out according to a Box Behnken design, and the best possible combination of temperature, extraction time and sample-to-solvent ratio for the extraction of phenolic compounds with a high antioxidant activity was obtained using RSM; the optimal conditions for the highest yield of phenolic compounds was 90 °C for 70 min at a sample-to-solvent ratio of 1:100 g/mL; however, at 1:60 g/mL, we retained 80% of the total phenolic compounds and maximized antioxidant capacity. Therefore the sample-to-solvent ratio of 1:60 was chosen as optimal and used for further validation. The validation test fell inside the confidence range indicated by the RSM output; hence, the statistical model was trusted. The proposed method is inexpensive, easily up-scaled to industry and shows potential as an additional source of income for olive growers.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.