Supercritical carbon dioxide hops extracts with antimicrobial properties (original) (raw)
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Molecules
Given the health-beneficial properties of compounds from hop, there is still a growing trend towards developing successful extraction methods with the highest yield and also receiving the products with high added value. The aim of this study was to develop efficient extraction method for isolation of bioactive compounds from the Polish “Marynka” hop variety. The modified two-step supercritical fluid extraction allowed to obtain two hop samples, namely crude extract (E1), composed of α-acids, β-acids, and terpene derivatives, as well as pure xanthohumol with higher yield than that of other available methods. The post-extraction residues (R1) were re-extracted in order to obtain extract E2 enriched in xanthohumol. Then, both samples were subjected to investigation of their antibacterial (anti-acne, anti-caries), cytotoxic, and anti-proliferative activities in vitro. It was demonstrated that extract (E1) possessed more beneficial biological properties than xanthohumol. It exhibited not...
Antioxidants, 2021
The article presents the optimization of supercritical CO2 extraction (SFE-CO2) parameters using response surface methodology (RSM) with central composite design (CCD) in order to produce single variety hop (cv. Ella) extracts with high yield and strong in vitro antioxidant properties. Optimized SFE-CO2 (37 MPa, 43 °C, 80 min) yielded 26.3 g/100 g pellets of lipophilic fraction. This extract was rich in biologically active α- and β-bitter acids (522.8 and 345.0 mg/g extract, respectively), and exerted 1481 mg TE/g extract in vitro oxygen radical absorbance capacity (ORAC). Up to ~3-fold higher extraction yield, antioxidant recovery (389.8 mg TE/g pellets) and exhaustive bitter acid extraction (228.4 mg/g pellets) were achieved under the significantly shorter time compared to the commercially used one-stage SFE-CO2 at 10–15 MPa and 40 °C. Total carotenoid and chlorophyll content was negligible, amounting to <0.04% of the total extract mass. Fruity, herbal, spicy and woody odor of ...
Plants
This work investigates the efficiency of supercritical fluid extraction of hops with a variety of solvents including carbon dioxide (CO2), propane, sulfur hexafluoride (SF6), and dimethyl ether (DME) at various densities (low-density and high-density). Operating parameters were 50 bar, 100 bar and 150 bar and 20 °C, 40 °C, 60 °C and 80 °C for all solvents, respectively. The influence of process parameters on the total yield of extraction and content of bitter acids in the extracts has been investigated. The mathematical model based on Fick’s second law well described the experimental extraction results. Furthermore, HPLC analysis has been used to determine α- and β-acids in extracts. The yield of bitter compounds in hop extracts was largely influenced by the type of solvent, the temperature and pressure applied during extraction. The results show that CO2 and propane were roughly equivalent to DME in solvating power, while SF6 was a poor solvent at the same conditions. The highest y...
Green Chemistry Letters and Reviews
This paper attempts to demonstrate empirically the possibility of using a hydrophobic extract of hop cone obtained under the conditions of supercritical carbon dioxide to produce all-purpose cleaner with antimicrobial activity and low irritant potential. A series of prototypes of products varied by the extract concentration was developed. The formulations were assessed for physicochemical properties: particle size, turbidity, and color. The results indicate that the hydrophobic extracts of hop cone can be a valuable component of chemical products intended for washing, having a broad spectrum of action and contributing to improvement of the product's safety.
Acta veterinaria, 2009
The multiresistance of bacteria to antibiotics, as well as the lack of new antibiotics on the market encouraged the reasearch of antibacterial activity of non-antibiotic substances including plant extracts. During the previous decades, it has been proven that extracts of certain plants have a strong antibacterial activity, but their clinical use was limited due to the presence of organic solvents. However, plant extracts obtained by the process of supercritical fluid extraction contain no traces of solvents, and the latest researches have established that they do have antibacterial effects on some gram-positive bacteria. This comparative study included extracts of Common Mullein, Angelica and Echinacea obtained by means of supercritical fluid extraction, Soxlet extraction and ultrasound-assisted extraction. The study of their antibacterial activity was performed on some strains of Staphylococcus, Enterobacter cloacae and E. coli isolated from clinical material of human and animal origin.
Bulletin of entomological research, 2015
Xanthohumol, a prenylated flavonoid from hops, and a supercritical carbon dioxide extract of spent hops were studied for their antifeedant activity against stored product insect pests: Sitophilus granarius L., Tribolium confusum Duv. and Trogoderma granarium Everts. Xanthohumol exhibited medium deterrent activity against the adults of S. granarius L. and larvae of T. confusum Duv. The spent hops extract was more active than xanthohumol towards the adults of T. confusum Duv. The potential application of the crude spent hops extract as a feeding deterrent against the stored product pests is proposed.
Cerevisia, 2013
A new methodology for the selective isolation of varietal total hop essential oil from hop pellets and further chromatographic fractionation of total hop oil into terpeneless polar hop essence, is presented. The methodology is essentially based on supercritical fluid extraction (SFE) of total hop essential oil using carbon dioxide of appropriate density, followed by solid phase extraction (SPE) using octadecylsilica and ethanol/water mixtures for preparation of polar hop essence. Different SFE temperature-pressure combinations were tested for extraction of total hop essential oil from pellets. A carbon dioxide density of 0.50 g/mL (50 • C, 110 atm), proved to be the best compromise in view of selective and quantitative extraction of total hop essential oils. Further fractionation of total hop essential oil by SPE in order to remove hydrocarbons, resulted in varietal polar hop essence, highly enriched in water-soluble, oxygenated hop oil constituents. All of the applied procedures of the proposed SFE/SPE methodology are in full accordance with the principles of clean-label technology. As a result, the novel hop aroma products are fully compatible with the beer matrix. When added to beer, the novel hop oil preparations impart a typical, varietal dependant pleasant hoppy character and increase beer bitterness and mouthfeel.
Journal of the Serbian Chemical Society, 2010
The present study deals with the supercritical carbon dioxide (SC--CO 2 ) extraction and hydrodistillation (HD) of dried bay leaves (Laurus nobilis L.). The chemical composition and antibacterial activity of the SC-CO 2 extract and essential oil (EO) from dried leaves of bay were compared to each other and literature data. Qualitative and quantitative analyses of the SC-CO 2 extract and EO were performed using GC-FID and GC-MS analytical methods. A significant difference in the chemical composition of the SC-CO 2 extract and EO was observed. The EO comprised high contents of monoterpenes and their oxygenated derivates (98.4 %), principally 1,8-cineole (33.4 %), linalool (16.0 %) and α-terpinyl acetate (13.8 %), sabinene (6.91 %) and methyl eugenol (5.32 %). The SC-CO 2 extract comprised twice less monoterpenes and their oxygenated derivates (43.89 %), together with sesquiterpenes (12.43 %), diterpenes (1.33 %) and esters (31.13 %). The major components were methyl linoleate (16.18 %), α-terpinyl acetate (12.88 %), linalool (9.00 %), methyl eugenol (8.67 %), methyl arachidonate (6.28 %) and eugenol (6.14 %). An investigation of the antibacterial activity of bay SC-CO 2 extract and EO was completed on different Staphylococcus strains using the broth macrodilution method. Staphylococcus intermedius strains were the most susceptible to both the SC-CO 2 extract and EO (MIC = 640 µg/ml).
Horticulturae
This study evaluates the content of essential oils (EOs) and prenylated flavonoid Xanthohumol (XN) in extracts of Slovenian hops, cultivar Aurora, obtained by using fluids of different polarity. It is a continuation of our previous work, investigating the extraction of bitter acids from hops. Extraction was conducted semi-continuously, using sub- and supercritical fluids of different polarity, i.e., carbon dioxide (CO2) and propane as non-polar and dimethyl ether (DME) as the polar solvent. The experiments explored a temperature range between 20 °C and 80 °C and pressures ranging from 50 bar to 150 bar. The content of XN in extracts was analysed using high-performance liquid chromatography and experiments demonstrated the largest concentration of XN was obtained using DME. In order to analyse the EO components in extracts, connected with a distinct odour, the steam distillation of extracts was performed and GC analysis was employed. Hop oil derived from CO2 extracts at specific cond...