Optimization of hop essential oil extraction by means of supercritical CO2

Abstract

Supercritical fluid extraction (SFE) can reduce sample preparation time and the recovery can be equal or better than that of the classical extraction techniques for solid and semi-solid samples. Extraction efficiency and speed can benefit from specific properties of a supercritical fluid. Essential oils were extracted from “Marynka” variety hop using supercritical carbon dioxide extraction. The highest essential oil recovery was obtained at the optimized conditions of extraction, i. e., trap temperature 5 °C, extraction pressure 85 bar and extraction time 10 min. Gas chromatography with mass spectrometry was used for determination of quantitative and qualitative composition of the extracted essential oils. The following main compounds were identified in the essential oils from “Marynka” hop calculating retention indices and using mass spectra library: α-pinene, β-myrcene, limonene, humulene, copaene, cubebene, β-caryophyllene and α-caryophyllene. Keywords: supercritical fluid extraction, essential oils, hops, gas chromatography –mass spectrometry