Effect of Extraction Methods on the Composition of Essential Oils

Abstract

The aim of this work is to demonstrate our results on comparison of composition of essential oil fractions obtained by traditional steam distillation and supercritical fluid extraction. The plant materials for the various extraction methods were selected from the Asteraceae and Lamiaceae families. For the supercritical fluid extraction (SFE) carbon dioxide was used as supercritical solvent. The extracts were collected by stage wise precipitation in two separators. The waxy product and extract rich in essential oil were collected in the lst and in the 2nd separator respectively. The traditional water steam distillation (SD) was carried out in the special apparatus of the Hungarian Pharmacopoea (7 th ed.). GC analysis was carried out on capillary silica fused columns coated with DB-1701 and the specific chiral columns coated with Rt-β DEX m or Rt-β DEX sm. Comparing the composition of steam distilled oils with that of volatile SFE fractions the following general characteristics were established. The SFE fractions were richer in monoterpene-esters and poorer in alcohols than the traditional essential oils (clary sage, lavander). Regarding the distribution of the monoterpene and sesquiterpene compounds, the SFE fractions contained sesquiterpene hydrocarbons in higher percentage than the distilled oils (Salvia triloba). Furthermore, the proportion of sesquiterpenes increased in SFE fractions collected successively with time (Salvia officinalis) similar to the ratio of oxygenated monoterpenes to monoterpene hydrocarbons (Rosmarinus officinalis). In other cases it was verified that part of the mono-and sesquiterpenes were present originally in bound form (glycosides) in plants. Thus they appeared only in essential oil fractions after previous acidic treatment (Thymus, Origanum, Satureja species). During the supercritical extraction the azulenogene sesquiterpene lactones did not transform to azulenes (in chamomile, yarrow), but the non volatile SFE fraction of some Asteraceae plants contained sesquiterpene-γ-lactones of unchanged structure.

Propagation Method and Distillation Apparatus Type Affect Essential Oil from Different Parts ofMatricaria recutitaL. Plants

“…Differences between the steam distilled oil and SFE fraction of chamomile were also found by Lemberkovics and co-workers 41 . They postulated that during supercritical fluid extraction the azulenogene sesquiterpene-lactones (such as matricine) did not transform to azulenes and remained in the plant matrix.…”

Assessment techniques of antimicrobial properties of natural compounds of plant origin: current methods and future trends

“…Some methods are employed when a particular class of compounds is targeted. For example when one is interested in essential oils, then the method of choice would be steam distillation, volatile solvent extraction or supercritical fluid extraction (Lemberkovics et al, 2002). Maceration, maceration with sonication, Soxhlet extraction and SFE with hexane or CO 2 was compared for the extraction of low-polarity compounds from Mikania glomerata and SFE-hexane proved to be the most effective.…”

Evaluation of the Physicochemical Properties and Antimicrobial Activities of Bioactive Biodegradable Films

“…Therefore, only the essential oils of Myrtus communis and Ziziphus spina-christi were used. The method of extraction (Lemberkovics et al, 2003) and the origin of the samples (Tuberoso et al, 2006) have effect on the composition of essential oils in aromatic plants.…”