title: Extraction of α-humulene-enriched oil from clove using ultrasound-assisted supercritical carbon dioxide extraction and studies of its fictitious solubility.
abstract: Clove buds are used as a spice and food flavoring. In this study, clove oil and α-humulene was extracted from cloves using supercritical carbon dioxide extraction with and without ultrasound assistance (USC-CO2 and SC-CO2, respectively) at different temperatures (32-50°C) and pressures (9.0-25.0MPa). The results of these extractions were compared with those of heat reflux extraction and steam distillation methods conducted in parallel. The extracts obtained using these four techniques were analyzed using gas chromatography and gas chromatography/mass spectrometry (GC/MS). The results demonstrated that the USC-CO2 extraction procedure may extract clove oil and α-humulene from clove buds with better yields and shorter extraction times than conventional extraction techniques while utilizing less severe operating parameters. Furthermore, the experimental fictitious solubility data obtained using the dynamic method were well correlated with density-based models, including the Chrastil model, the Bartle model and the Kumar and Johnston model.
authors.affiliation: Department of Applied Geoinformatics, Chia Nan University of Pharmacy and Science, Tainan 71710, Taiwan.
authors.forename: Ming-Chi
authors.initials: MC
authors.lastname: Wei
authors.affiliation: Institute of Chinese Medical Sciences, State Key Laboratory of Quality Research in Chinese Medicine, University of Macau, Taipa, Macau, China.
authors.forename: Jianbo
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department and Graduate Institute of Pharmacology, Kaohsiung Medical University, Kaohsiung 80708, Taiwan. Electronic address: ycyang230@gmail.com.
authors.forename: Yu-Chiao
authors.initials: YC
authors.lastname: Yang
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D025924:Chromatography, Supercritical Fluid / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D000081222:Monocyclic Sesquiterpenes; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification*; D010938:Plant Oils / Q000737:chemistry / Q000302:isolation & purification*; D012717:Sesquiterpenes / Q000032:analysis / Q000302:isolation & purification; D012995:Solubility; D027842:Syzygium / Q000737:chemistry*; D014465:Ultrasonics / Q000379:methods*
chemical_list: D000081222:Monocyclic Sesquiterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D012717:Sesquiterpenes; D002245:Carbon Dioxide; C042686:humulene
keywords: Clove; Gas chromatography/mass spectrometry; Solubility; Ultrasound-assisted supercritical CO(2) extraction; α-Humulene