Supercritical CO2 Extraction And Optimization of Total Phenols From Strawberry tree (Arbutus unedo L.) Fruits: A Comparative Study

• Published in: Planta Medica
• Main Authors: Akay, Ş, Alpak, I, Yeşil Çeliktaş, Ö
• Format: Conference Proceeding
• Language: English
• Published: 05.08.2011
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-0031-1282646

Arbutus unedo L. is an evergreen shrub of Ericaceae family growing on rocky slopes or in pine forests at the Mediterranean countries. Fruits of A. unedo were reported to possess astringent, diuretic and antiseptic properties and to have high flavonoid content, majorly proanthocyanidins, anthocyanins as glycosides of cyanidin and delphinidin with cyanidin-3 galactoside. Moreover, elagic acid, vitamin C, vitamin E and caretenoids were also quantified. The aim of this study was to optimize total phenol composition and radical scavenging activities of A. unedo fruits by supercritical fluid extraction, using response surface methodology and to compare the total phenol contents with that of traditional water and ethanol extractions. The independent variables were temperature (30–80°C), pressure (50–300bar) and co-solvent ratio (0–20%). The antioxidant capacities were determined by Folin-Ciocalteu and DPPH radical scavenging methods, whereas β-carotene bleaching method was used to evaluate the oxidative stability of the extracts in the linoleate emulsion model. The results demonstrated that temperature and co-solvent were more effective on yields of the compounds, whereas the effect of pressure was not noticeable. Optimum extraction conditions were elicited as 60bar, 48°C and 19.7% yielding 25.72mg GAE total phenols/g extract and 99.9% radical scavenging capacity which were significantly higher than water (24.89mg/g; 83.8%) and ethanol extracts (15.12mg/g; 95.8%), whereas oxidation rate ratio (0.892) was close to that of water extract (0.661) demonstrating challenges as a green separation process for industrial applications.