The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan

The Application of Supercritical Fluid Extraction in Phenolic Compounds Isolation from Natural Plant Materials

The separation of phenolic compounds by supercritical fluid extraction has been widely studied throughout the last two decades. This is evidenced by a number of publications and articles. Supercritical fluid extraction (SFE) has become thus the effective method of separating the mentioned group of compounds. On the other hand, SFE is a beneficial approach in plant waste materials utilization and reduction of environmental burdens caused by the wastes. The aim of the study is to gather and systematize available information on the phenolic compounds separation that have been reported so far as well as to evaluate whether there is one optimal supercritical fluid extraction method for the phenolic compounds

Influence of supercritical carbon dioxide extraction process temperature and co-solvent addition on the quality of green tea leaves extracts

Interest in the separation of green tea extracts continues to grow due to its significant bioactivity, wide applicability as well as a large number of green tea spices, variety of extraction techniques, and lack of systematic data. The present early stage work was intended to estimate the effect of temperature and co-solvent addition on an amount of separated constituents from green tea (gunpowder tea variety, China) during the supercritical carbon dioxide (sc-CO2) extraction process. For this purpose, the temperature of the supercritical extraction process was increased up to 90 °C at a constant pressure of 30 MPa. After the selection of appropriate conditions, co-solvents (ethanol, ethanol/water, and water) were added to sc-CO2. Obtained extracts were analyzed regarding total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity, total chlorophyll, and total carotenoid content. The results of the supercritical extraction process were compared with the conventional extraction process (extraction using Soxhlet apparatus). The results showed that a linear decrease in the density of neat sc-CO2 led to a linear increase in extraction yields up to 5.5%. The addition of co-solvents had a variable effect on the amount of separated extracts. While it increased extraction yields at a lower temperature, it decreased extraction yields at a higher temperature. An increase in temperature for the extraction process with neat sc- CO2 also decreased TPC, TFC, chlorophylls, and carotenoids content. The addition of co-solvents to sc-CO2 increased amounts of tested compounds in obtained extracts. It was interesting to notice a decrease in the amount of tested compounds with an increase in water content during extractions. The highest values of TPC and TFC detected were 136.5 mg GAE/g and 40.7 mg QE/g, respectively. Extract solutions with a concentration of 20 mg/mL inhibited up to 65% of DPPH radical. Chlorophyll A, chlorophyll B, and carotenoids were detected in amounts up to 8.1 g/kg, 0.7 g/kg, and 0.5 g/kg of dry extract, respectively. Extracts obtained by conventional extraction contained higher amounts of TPC and TFC. On the other hand, those extracts contained lower amounts of total chlorophylls and carotenoids. Although supercritical extraction processes from green tea leaves have been performed for decades and its industrial application is present, there are still many unknowns. To the best of our knowledge, this is the first report in available literature on chlorophyll and carotenoid contents in supercritical extracts from green tea. Also tested process parameters enabled the achievement of higher yields (for neat sc-CO2) as well as higher TPC compared with previously reported ones for green tea supercritical extracts. Chemical analysis of obtained extracts is pending

Supercritical Carbon Dioxide (scCO2) Extraction of Phenolic Compounds from Lavender (Lavandula angustifolia) Flowers: A Box-Behnken Experimental Optimization

Due to their numerous health benefits associated with various diseases and anti-oxidation properties, the phenolic compounds collectively referred to as phytochemicals have attracted a lot of interest, however, a single extraction method for polyphenols has not been developed yet. Supercritical fluid extraction, a green extraction method, provides the final product without organic solvent residues. In this work the extraction of lavender was performed using supercritical carbon dioxide. A statistical experimental design based on the Box-Behnken (B-B) method was planned, and the extraction yields and total phenolic contents were measured for three different variables: pressure, temperature and extraction time. The ranges were 200–300 bar, 40–60 °C and 15–45 min. The extracts yields from scCO2 extraction were in the range of 4.3–9.2 wt.%. The highest yield (9.2 wt.%) was achieved at a temperature of 60 °C under the pressure of 250 bar after 45 min. It also corresponded to the highest total phenolic content (10.17 mg GAE/g extract). Based on the study, the statistically generated optimal extraction conditions to obtain the highest total phenolic compounds concentration from flowers of Lavandula angustifolia were a temperature of 54.5 °C, pressure of 297.9 bar, and the time of 45 min. Based on the scavenging activity percentage (AA%) of scCO2 extracts, it is concluded that the increase of extraction pressure had a positive influence on the increase of AA% values

Antifungal Properties of Fucus vesiculosus L. Supercritical Fluid Extract Against Fusarium culmorum and Fusarium oxysporum

In this study, potential antifungal properties of a brown alga Fucus vesiculosus were evaluated. The algal extract was obtained with the use of supercritical fluid extraction (scCO2) at a temperature of 50 °C under a pressure of 300 bar. The aqueous solution of the extract at the concentration of 0.05%, 0.2%, 0.5% and 1.0% was studied against pathogenic fungi on a liquid RB medium. This study is the first report on antifungal properties of the brown algae F. vesiculosus scCO2 extract against Fusarium culmorum and Fusarium oxysporum phytopathogens. The concentrations of the studied extract (0.5% and 1.0%) were demonstrated to have an ability to inhibit 100% growth of macroconidia within 144 h, as well as an ability to cause their total degradation. As a result of the study, the antifungal effect of fucosterol against F. culmorum was also indicated. The total macroconidia growth was inhibited by 1.0% fucosterol. Moreover, at lower concentrations (0.05–0.2%) of fucosterol, macroconidia were characterized by shorter length and structural degradation was observed. The mycelial growth of Fusarium oxysporum (Fo38) by 1% scCO2 F. vesiculosus extract was analyzed at the level of 48% after 168 h of incubation, whereas 100% extract was found to be effective in F. culmorum (CBS122) and F. oxysporum (Fo38) growth inhibition by 72% and 75%, respectively after 168 h of incubation

SUPERCRITICAL CO2 EXTRACTION FROM DANDELION: THE EFFECT OF PRESSURE ON EXTRACTS YIELD AND COMPOSITION

Dandelion (Taraxacum officinale) is becoming an industry valuable crop due to the increase in its utilization in the food and phytopharmaceutical industry. Nonetheless, its application is still limited especially considering its extracts. Therefore, this study was aimed at exploring dandelion seeds as a source of bioactive compounds. For this purpose, an environmentally friendly supercritical CO2 extraction technique was employed and extracts were separated at pressures of 10-45 MPa and a temperature of 313 K. Obtained extracts were characterized using a gas chromatograph equipped with mass spectroscopy (GC-MS), a gas chromatograph equipped with flame ionization detector (CGFID), as well as by Folin–Ciocalteu and DPPH assays using a UV/VIS spectrophotometer. It was shown that the selection of process pressure determined both extract yield and extract composition. An increase in pressure increased extraction yield from 7.4 to 25.2% and the content of dominant linoleic and oleic fatty acids (from 536.3 to 658.3 mg/g and 125.8 to 161.7 mg/g, respectively). Total phenolic and flavonoid content in obtained extracts ranged from 5.5 to 9.0 mg GAE/g and from 208.6 to 497.5 mg QE/g, respectively. The strongest DPPH radical scavenging activity with inhibition of 64.4% was recorded for extract obtained at 10 MPa for extract solution concentration of 20 mg/mL. Obtained results confirmed that extracts obtained from dandelion seeds are a valuable source of bioactive compounds

Supercritical fluid extraction from dandelion seeds

Investigations of the process of supercritical fluid extraction (SFE) from dandelion were so far mainly focused on extractions from herb, leaves and root [1-3]. In the work presented here, the extraction process from seeds was investigated on a laboratory and semi-industrial scale equipment. The milled plant material with an average particle size of 0.41 ± 0.02 mm was used in all experiments. All SFEs were conducted with carbon-dioxide in supercritical state (SCCO2) as a solvent on pressure of 450 bar and temperature of 60°C, as these parameters were previously shown to be optimal for obtaining high-value extracts from dandelion seeds [4]. Experiments were conducted on laboratory (dia.=7.7 cm, vol=0.56 l, CO2 flow=11 kg/h) and semiindustrial (dia.=23.5 cm, vol.=397 l, CO2 flow=240 kg/h) scale equipment. On both scales several experiments were conducted with initial mass of the plant material (Ms) being the only variable parameter: laboratory scale Ms=26–104 g; semi-industrial scale Ms=2.2–8.8 kg. Fractions of extract were collected during the extractions in order to obtain data on the kinetics of the SFE processes. The results of the performed experiments are depicted in Figure 1. It can be seen that for both scales the rate of SFE, as well as the final yield, increases with increase of the mass of plant material, indicating that with the selected conditions, namely flowrate of CO2, the residence time was not long enough to allow saturation of the CO2 in the first part of the process, nor to enable extraction of all available extract. Similar trends on both scales can be perceived as a good basis for further investigations aiming at scale-up of the process of SFE from dandelion seeds. Experiments with larger packed bed height, which would enable higher residence times, should be conducted in order to achieve saturation at least in the first part of the SFE process. Mathematical models of the SFE process, supported by models for estimation of the kinetic parameters, should be applied to gain full insight into the phenomenology of the SFE process

The Influence of Subcritical Water Extraction Parameters on the Chemical Composition and Antioxidant Activity of Walnut (<i>Juglans regia</i> L.) Bark Extracts

This study investigated the impact of subcritical water extraction parameters on the polyphenols and flavonoids content in extracts made of the bark of walnut (Juglans regia L.), as well as antioxidant activity measured using the DPPH and FRAP methods. The total polyphenols (TPC) and flavonoid (TFC) were determined using the spectrophotometric (UV-Vis) method. The response surface methodology (RSM) was employed to optimize the yield of bioactive compounds. On the basis of developed model, the highest polyphenols (192.2 mg (GAE)/100 g (dry mass)) (GAE—gallic acid equivalent), flavonoids (88.3 mg(QE)/100 g (dry mass)) (QE—quercetin equivalent) contents and antioxidant activity (21.3 × 10−6 MTE/1 g (dry mass)) (TE-Trolox equivalent) were obtained under the following extraction conditions: temperature 131.6 °C, raw material fraction size 0.9 mm and process time 10 min. The greatest impact on the extraction yield was observed in the case of the temperature, whereas the raw material fraction size and the process time had a secondary impact. Obtained results indicate that a smaller particle size and a shorter time may improve the process; however, a reduction in particle size can be challenging for a pressure cell filtration system and consequently increase the cost of the raw material pretreatment process. With the reduction in the process time, a lower cost of extract production can be achieved. This study confirmed the importance of a proper selection of extraction parameters to obtain the demanded extract composition

The separation of biologically active extracts from chamomile seeds

The main aim of this study was to evaluate chamomile seeds as a new source of valuable bioactive compounds. For this purpose, a green extraction technique was employed with supercritical carbon dioxide (sc-CO2) as a solvent and ethanol as a co-solvent. The extracts from chamomile seeds with an average particle size of 0.20 mm were extracted at pressures of 30 and 45 MPa and temperatures of 40 and 60 °C. The composition of extracts was investigated by a gas chromatography-mass spectrometry analytical method as well as Folin−Ciocalteu assay (for total phenolic content) and total flavonoid content test. The antioxidant activity of obtained chamomile extracts was evaluated using DPPH radical. The antimicrobial effect of extracts was tested on yeasts, Gram-positive, and Gram-negative bacteria while the cytotoxic effect was evaluated on normal and cancer cells. The extraction process parameters were evaluated and results showed a significant effect of operating pressure, temperature, and the addition of co-solvent on the amount of separated chamomile extract and its composition. The extraction yield ranged from 2.1 to 5.4% and extracts contained high amounts of unsaturated fatty acids. The addition of ethanol as a co-solvent (40 w/w%) had a slight influence on total phenolic and flavonoid contents increasing their values from 29.1 to 31.5 mg GAE/g and from 2.1 to 4.2 mg QE/g, respectively. The obtained supercritical chamomile extracts showed antioxidant activity achieving values of IC50 around 10 mg/mL. The antimicrobial activity of extracts was most pronounced against Bacillus subtilis. Extracts did not show cytotoxic activity against normal cells. Overall, results indicated a significant potential of extracts from chamomile seeds, produced in an environmentally friendly manner, to be used as a functional food or phytopharmaceuticals

Essential Oils from <i>Humulus Lupulus</i> scCO₂ Extract by Hydrodistillation and Microwave-Assisted Hydrodistillation

Two different extraction methods were used for a comparative study of essential oils obtained from the Humulus lupulus scCO2 (sc-supercritical) extract: microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD). As a result, the best conditions for the maximum essential oil production were determined for the MAHD method at 335 W microwave power for 30 min at water to raw material ratio of 8:3. The obtained essential oils were enriched in &#946;-myrcene in the amount of 74.13%&#8315;89.32% (wt%). Moreover, the first application for determination of the above-mentioned volatile compounds by supercritical fluid chromatography (SFC) with photo-diode array detection (PDA) is presented, which in comparison with gas chromatography coupled with mass spectrometry (GC-MS/MS) resulted in similar values for &#946;-myrcene and &#945;-humulene in obtained samples within less than 1 min