Comparative Gas Chromatographic–Mass Spectrometric Evaluation of Hop (Humulus lupulus L.) Essential Oils and Extracts Obtained Using Different Sample Preparation Methods

Abstract

The main aim of investigations was to identify chemotypes and determine differences between some domestic hop varieties and wild hops, which were collected from some regions of Lithuania and cultivated at the same edafoclimatic conditions in hops collection of Kaunas Botanical Garden of Vytautas Magnus University. One of objectives was to compare essential oils of hops (2 years harvest) by the evaluation of volatiles content. Among the main components of hop essential oils monoterpenes (β-myrcene) and sesquiterpenes (α-humulene and β-caryophyllene) were determined using gas chromatography coupled with mass spectrometry (GC-MS). Retention parameters (t R , calculated retention index, and Kovats retention index) and m /z value of molecular ion for selected compounds from hop essential oils were determined. Samples were prepared by applying solid phase microextraction (SPME), supercritical fluid extraction (SFE) and accelerated solvent extraction (ASE). The steam distillation was used to obtain hop essential oils. The chemometric comparison of domestic and wild hops based on GC-MS analysis data was carried out. The obtained statistical results allow us to classify the investigated wild forms and domestic varieties of hops according to the similarities of their chemotypes. The concentration of β-myrcene, α-humulene in hop essential oils obtained from cones 2 years harvests is much higher than other volatile organic compounds (15.2-23.7 % in total contribution). In analysed essential oils β-farnesene is a constituent in higher quantity of hop essential oils obtained from cones from second time harvest than from cones from first harvest. This can be explained by the year-toyear vegetation conditions difference.

Supercritical carbon dioxide hops extracts with antimicrobial properties

“…In connection with the brewing of beer, hulupons possess the desired bitter taste, but to a much lesser extent than the iso-α-acids. The MS spectra with the characteristic fragmentation ions permits the identification of the derivatives of humulone and lupulone in the investigated samples [23][24][25].…”

Essential Oils from Humulus Lupulus scCO2 Extract by Hydrodistillation and Microwave-Assisted Hydrodistillation

“…Ligor et al [ 23 ] obtained the essential oils from hops with a use of different techniques, such as supercritical fluid extraction, steam distillation, accelerated solvent extraction (ASE), and solid phase microextraction (SPME). The values for β-myrcene and α-humulene in obtained essential oils ranged from 15.7% to 21.1% and from 11.1% to 33.4%, respectively.…”

Antioxidant Effect of Nanoemulsions Based on Citrus Peel Essential Oils: Prevention of Lipid Oxidation in Trout

“…Identification protocol was carried out according to Ligor et al. [ 87 ] with some modification, using capillary GC (Perkin Elmer Clarus 500, Waltham, MA, USA) directly equipped with the mass spectrometer (Perkin Elmer Clarus). The column was used as SGE non‐polar capillary column (60 m × 0.25 mm, ID; BPX5 0.25 μm).…”