Evaluation of the effects of temperature and pressure on the extraction of eugenol from clove (Syzygium aromaticum) leaves using supercritical CO2

In this study, the effect of operational conditions on the extraction of clove leaves using CO2 on eugenol yield and content was investigated. The conditions used in the supercritical extraction with CO2 included temperatures of 40, 50, and 60 degrees C and pressures of 150, 185 and 220 bar. The highest yield (1.08 wt%) and highest eugenol content were obtained at 40 degrees C and 220 bar. The main components identified in the clove extract were eugenol (29.73%), chavicol (13.31%), n-pentacosane (11.66%), hexacosanal (11.37%), and vitamin E (9.30%). The extracts were evaluated for their antioxidant capacities by the DPPH and FRAP methods, and quantification of the phenolic compounds was done by the Folin-Ciocalteu method. The best results among the conditions were obtained at the lowest pressure and temperature, 150 bar and 40 degrees C. The Sovova model satisfactorily described the extraction kinetics in all the studied conditions.