Supercritical Fluid Extraction Technique Research Articles

Green and sustainable recovery of polyphenols, flavonoids, alkaloids, and pigments from green tea leaves: Comparative analysis of Soxhlet, accelerated solvent, and supercritical fluid extraction techniques

The growing interest in green tea extracts for their applications in pharmaceutical, food, and cosmetic industries underscores the need for environmentally sustainable extraction methods. This study presents optimized strategies for the green recovery of bioactive compounds from Gun powder green tea leaves using Soxhlet extraction, accelerated solvent extraction, and supercritical fluid extraction techniques. By varying extraction solvents (supercritical CO2, ethanol, water, and their combinations) and temperatures (from 35 to 140 °C), high yields of polyphenols, flavonoids, alkaloids, and pigments were achieved. Key bioactive compounds extracted in significant quantities included caffeine (23.8 mass%), chlorophyll A (8.1 mg/g), chlorophyll B (0.7 mg/g), carotenoids (0.4 mg/g), epicatechin (7.7 mass%), catechin gallate (4.6 mass%), and epigallocatechin-3-gallate (30.2 mass%). The extract obtained in optimized processes demonstrated potent antioxidant activity (IC50 up to 88 μg/mL), strong antimicrobial activity (including methicillin-resistant Staphylococcus aureus- MRSA) with MIC up to 0.06 mg/mL, and selective anticancer activity against colon cancer cells. The presented findings provide a theoretical basis and technical guidance for enhancing the sustainable concentration of natural bioactive compounds, promoting their use in various industrial applications.

Green purification of Acmella oleracea extract by wiped-film short path molecular distillation boosts the insecticidal activity on mosquito larvae

The development of insecticide resistance by mosquito vectors highlighted an urgent need for effective and sustainable botanical insecticides. Acmella oleracea R.K. Jansen (Asteraceae)-derived extracts and the major constituents N-alkylamides have already demonstrated their potential as insecticidal and acaricidal agents. Nowadays, the development of scalable green extraction and purification processes in the manufacture of biopesticides is a topic of great interest. In this context, supercritical fluid extraction and wiped-film short path molecular (WSM) distillation techniques were combined for the first time to obtain an eco-friendly N-alkylamides-enriched fraction (AEF) from A. oleracea. This was characterized by a notably higher content of spilanthol and N-alkylamides than the supercritical fluid extract (SFE), as determined by HPLC-DAD-MS analysis. The AEF also contained free fatty acids (e.g., palmitic, linoleic, and linolenic acids) as revealed by GC-FID analysis. The mosquito larvicidal activity of SFE, AEF, and pure spilanthol was assessed against 3rd instar larvae of Aedes albopictus Skuse, Anopheles stephensi Liston, and An. gambiae Giles. Results showed that AEF exhibited an insecticidal efficacy comparable with that of spilanthol, and higher than that of SFE. These products were tested against human keratinocytes (HaCaT) confirming their dermal safety. The present study paves the way for the utilization of WSM distillation in the agrochemical industry for the manufacture of botanical insecticides. Indeed, this technique allows to avoid the use of organic solvents related to conventional extraction and spilanthol isolation procedures and gives a product devoid of undesired pigments appealing to other industrial application as well.

Phytochemical characterization of selected agro-waste extracts as kinetic inhibitors in methane hydrates formation

In this study of gas hydrate inhibition, the bio-active components (phytochemicals) and the influence of functional moieties and chemical structures on selected bio-inhibitors' performance were investigated by advanced analytical techniques. The agro-waste materials of interest are: orange mesocarp (Citrus sinensis (L)) extract (OME), red onion skin (Allium cepa) extract (ROSE), kolanut tesla (Cola acuminata) extract (KTE), coconut coir dusk (Cocos nucifera) extract (CCDE) and peanut skin (Arachis hypogea) extract (PSE). A CO2-enhanced supercritical fluid extraction (SFE) technique was used to extract the bioactive components from their parent materials. After the extraction, advanced analytical techniques including FTIR, NMR and HP-TLC with densitometry were used to identify and isolate functional groups, structurally characterize and quantify the bioactive compounds in the extracts primarily focusing on phenolic acids, flavonoids and tannins. A Bruker 500MZ NMR spectrometer and a CAMAG-semi-automatic HP-TLC system were used for the structural characterization and quantification respectively. Based on the number of anti-oxidants and radicals scavenging characteristics of the individual extracts' polyphenolic and tannin components, the expected hydrates inhibition capacities of the bio-extracts are in the magnitude: CCDE > ROSE > PSE > OME > KTE. The extracts are readily biodegradable and non-toxic and therefore do not pose ecological threat unlike PVP with only 31.50% biodegradation rate and may result in serious ecological risks in offshore environments. Lastly, the numbers of hydroxyl (OH) and meth-oxyl (MeoH) groups are the principal factors that influence the bio-inhibitors performance with hydroxyl group number being more important than that of the meth-oxyl group.

Supercritical Extraction Techniques for Obtaining Biologically Active Substances from a Variety of Plant Byproducts.

Supercritical fluid extraction (SFE) techniques have garnered significant attention as green and sustainable methods for obtaining biologically active substances from a diverse array of plant byproducts. This paper comprehensively reviews the use of supercritical fluid extraction (SFE) in obtaining bioactive compounds from various plant residues, including pomace, seeds, skins, and other agricultural byproducts. The main purpose of supercritical fluid extraction (SFE) is the selective isolation and recovery of compounds, such as polyphenols, essential oils, vitamins, and antioxidants, that have significant health-promoting properties. Using supercritical carbon dioxide as the solvent, supercritical fluid extraction (SFE) not only eliminates the need for hazardous organic solvents, e.g., ethanol, and methanol, but also protects heat-sensitive bioactive compounds. Moreover, this green extraction technique contributes to waste valorisation by converting plant byproducts into value-added extracts with potential applications in the food, pharmaceutical, and cosmetic industries. This review highlights the advantages of SFE, including its efficiency, eco-friendliness, and production of residue-free extracts, while discussing potential challenges and future prospects for the utilisation of SFE in obtaining biologically active substances from plant byproducts.

Taguchi approach for assessing supercritical CO2 (sCO2) fluid extraction of polyhydroxyalkanoate (PHA) from Chlorella Vulgaris sp. microalgae

This research explicitly investigates the utilization of Chlorella Vulgaris sp. microalgae as a renewable source for lipid production, focusing on its application in bioplastic manufacturing. This study employed the supercritical fluid extraction technique employing supercritical CO2 (sCO2) as a green technology to selectively extract and produce PHA's precursor utilizing CO2 solvent as a cleaner solvent compared to conventional extraction method. The study assessed the effects of three extraction parameters, namely temperature (40–60 °C), pressure (15–35 MPa), and solvent flow rate (4–8 ml/min). The pressure, flowrate, and temperature were found to be the most significant parameters affecting the sCO2 extraction. Through Taguchi optimization, the optimal parameters were determined as 60 °C, 35 MPa, and 4 ml/min with the highest lipid yield of 46.74 wt%; above-average findings were reported. Furthermore, the pretreatment process involved significant effects such as crumpled and exhaustive structure, facilitating the efficient extraction of total lipids from the microalgae matrix. This study investigated the microstructure of microalgae biomatrix before and after extraction using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Fourier-transform infrared spectroscopy (FTIR) was utilized to assess the potential of the extracted material as a precursor for biodegradable plastic production, with a focus on reduced heavy metal content through inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis. The lipid extracted from Chlorella Vulgaris sp. microalgae was analysed using gas chromatography-mass spectrometry (GC-MS), identifying key constituents, including oleic acid (C18H34O2), n-Hexadecanoic acid (C16H32O2), and octadecanoic acid (C18H36O2), essential for polyhydroxyalkanoate (PHA) formation.

Study on extract yield of papaya leaf powder using a supercritical fluid extraction technique

Study on extract yield of papaya leaf powder using a supercritical fluid extraction technique

Technical and Economic Evaluation of Bioactive Compounds from Schinus terebinthifolius Using Supercritical Carbon Dioxide

This study evaluated the technical and economic feasibility of using supercritical CO2 extraction for the production of bioactive compounds from Schinus terebinthifolius. Supercritical fluid extraction techniques employing carbon dioxide were employed to extract valuable compounds from S. terebinthifolius. The extraction was performed under different operating conditions, showing an increase in yield with higher pressures and temperatures. The bioactive compounds in the extract demonstrated significant potential in terms of their antioxidant and antimicrobial properties, making them valuable for applications in food preservation. The economic evaluation revealed a positive net present value (NPV) and favorable return on investment (ROI) within a two-year timeframe. The break-even point was determined to be below 25% production capacity, supporting the economic feasibility of the process. Overall, the utilization of supercritical CO2 extraction for bioactive compounds from S. terebinthifolius offers a sustainable and environmentally friendly extraction method while ensuring the extract’s integrity and quality. Although the operational costs and extractor contributions require consideration, the findings support the economic viability and commercial potential of this technique. Further research and development can enhance the efficiency and cost-effectiveness, making it an attractive option for various commercial applications.

Supercritical CO2 Extraction, Quantification and Pharmacological Screening of Steroidal Saponins from Fruits of Momordica charantia L

Momordica charantia L. (MC), a Cucurbitaceae family member, is the most recognized plant for its hypoglycemic activity. Charantin, a steroidal saponin, is the most studied potent phytochemical in MC for diabetes. This research paper aims at the extraction, quantification and pharmacological screening of charantin, from fruits of MC. Extraction was performed by using traditional soxhlet extraction and modified supercritical fluid extraction (SFE) techniques, and compared the results of both techniques in terms of percent extract yield, quantity of charantin and in-vitro antidiabetic activity of both extracts. (Soxhlet extract and SC-CO2 extract). Further, quantitative estimation of charantin in both extracts was done by HPLC-UV method and it was validated as per the ICH guidelines. When compared to soxhlet extract, the SC-CO2 extract displayed high antihyperglycemic activity by blocking α-amylase and α-glucosidase enzymes. Study also indicates that SC-CO2 extract had higher antioxidant activity (0.25 mg/mL) than soxhlet extract (0.33 mg/mL), signifying the SFE technique’s efficiency over the traditional soxhlet extraction method. In-vitro antidiabetic study indicated that the biomolecule charantin extracted from fruits of MC possess potent antidiabetic and high antioxidant activities and, therefore, hold potential for manufacturing innovative natural remedies to treat diabetes and its complications with no side effects.

Evaluation of the Capsaicinoid Extraction Conditions from Mexican Capsicum chinense Var. Mayapan with Supercritical Fluid Extraction (SFE)

Capsaicin (Cp) is a secondary metabolite produced by the Capsicum plant family. This molecule exhibits various biological properties such as antioxidant capacities, anti-obesogenic effects, and antidiabetic properties, among others. However, conventional extraction methods for Cp present several disadvantages including toxicity, extraction time, and low purity. Therefore, the utilization of supercritical fluid extraction techniques represents a viable option for obtaining highly pure and low-toxicity oleoresins (capsaicin-rich extracts). This approach involves the use of CO2 in the supercritical state and finds applicability in the pharmaceutical, food, and cosmetic industries. The Capsicum chinense variety from the Yucatán Peninsula is a crop with significant economic impact in the region, due to having the highest concentrations of Cp in Mexico. This significant characteristic is attributed to its adaptation to the unique conditions (climate, soil, solar radiation, humidity) of the southeastern region of Mexico. The objective of this study was to evaluate the effect of temperature (45 °C, 60 °C), pressure (1450 psi, 2900 psi), and extraction time (60 min, 120 min) on the supercritical fluid extraction of Cp and dihydrocapsaicin (DhCp) from Capsicum chinense Jacq. The results obtained demonstrated that the extraction conditions of 45 °C, 1450 psi, and 60 min yielded the highest concentration of Cp (37.09 ± 0.84 mg/g extract) and DhCp (10.17 ± 0.18 mg/g extract), while the highest antioxidant capacity (91.48 ± 0.24% inhibition) was obtained with 60 °C, 2900 psi, and 60 min. The findings of this study indicate that the lower the pressure and extraction time, the higher the concentrations of Cp and DhCp compared to previous reports. This represents an opportunity for cost reduction in production lines and improved utilization of Capsicum chinense in the agrifood industry through additional optimization processes.

Selection of Optimal Conditions of Inulin Extraction from Jerusalem Artichoke (Helianthus Tuberosus L.) Tubers by using Ultrasonic Water Bath

Ultrasonic extraction is an inexpensive, simple and efficient alternative to conventional extraction techniques, as compared with other novel extraction techniques such as microwave-assisted extraction & supercritical fluid extraction techniques, the ultrasound apparatus is cheaper and its operation is easier. Ultrasound assisted extraction has risen rapidly in the latest decade, and for most applications it has proven to be effective compared to traditional extraction techniques. In this paper, a method of ultrasonic-assisted extraction was used to extract Inulin from tubers of Jerusalem artichoke, which have been reported to have several medicinal properties and uses. Inulin is a storage carbohydrate found in many plants especially in chicory root, Jerusalem artichoke and dahlia tuber. In this study, the effect of time, temperature, pH and solid to liquid ratio on Inulin extraction from Jerusalem artichoke tubers by using ultrasonic water bath. The highest yield of Inulin were investigated from Jerusalem artichoke tuber was (99.47%) at temperature of 70°C, pH=7, 60 min and ratio of solid to solvent was (10gm/100ml). Then, The UV detector by colorimetric method with vanillin–sulfuric acid was used for the quantification of Inulin.

Current Technologies and Uses for Fruit and Vegetable Wastes in a Sustainable System: A Review.

The fruit and vegetable industry produces millions of tons of residues, which can cause large economic losses. Fruit and vegetable wastes and by-products contain a large number of bioactive substances with functional ingredients that have antioxidant, antibacterial, and other properties. Current technologies can utilize fruit and vegetable waste and by-products as ingredients, food bioactive compounds, and biofuels. Traditional and commercial utilization in the food industry includes such technologies as microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), ultrasonic-assisted extraction (UAE), and high hydrostatic pressure technique (HHP). Biorefinery methods for converting fruit and vegetable wastes into biofuels, such as anaerobic digestion (AD), fermentation, incineration, pyrolysis and gasification, and hydrothermal carbonization, are described. This study provides strategies for the processing of fruit and vegetable wastes using eco-friendly technologies and lays a foundation for the utilization of fruit and vegetable loss/waste and by-products in a sustainable system.

Supercritical Carbon Dioxide Technology for Recovering Valuable Phytochemicals from Cannabis sativa L. and Valorization of Its Biomass for Food Applications.

Supercritical carbon dioxide (CO2) extraction techniques meet all-new consumer market demands for health-promoting phytochemical compound-rich extracts produced from green and sustainable technology. In this regard, this review is dedicated to discussing is the promise of integrating high-pressure CO2 technologies into the Cannabis sativa L. processing chain to valorize its valuable pharmaceutical properties and food biomass. To do this, the cannabis plant, cannabinoids, and endocannabinoid system were reviewed to understand their therapeutic and side effects. The supercritical fluid extraction (SFE) technique was presented as a smart alternative to producing cannabis bioproducts. The impact of SFE operating conditions on cannabis compound extraction was examined for aerial parts (inflorescences, stems, and leaves), seeds, and byproducts. Furthermore, the opportunities of using non-thermal supercritical CO2 processing on cannabis biomass were addressed for industrial hemp valorization, focusing on its biorefinery to simultaneously produce cannabidiol and new ingredients for food applications as plant-based products.

Supercritical fluid extraction of torch ginger: Encapsulation, metabolite profiling, and antioxidant activity

ObjectivesThe objective of this study was first to perform the supercritical fluid extraction (SFE) and encapsulationof torch ginger (Etlingera elatior) inflorescences into a functional powder. Second objective was to evaluate the powder’s characteristics, metabolite profiles, and antioxidant activity. MethodsTorch ginger inflorescences were extracted via SFE technique, and the obtained extract was encapsulated by a spray-drying process with maltodextrin as an encapsulating agent. Subsequently, the powder was evaluated for its physical characteristics, determination of metabolite profiles by using a Fourier Transform Infrared Spectrophotometer (FTIR) and Gas Chromatography-Mass Spectrometry (GC–MS), and antioxidant activity. ResultsSpray drying encapsulation process managed to yield around 59.8% of torch ginger extract powder (TGEP) by using 10% of extract, which the obtained yield was twice higher than in another study. TGEP showed inconsistent agglomeration behaviour in particle size examination with distinct sizes concentrating at 2.2 μm and 17.4 μm, respectively. Brunauer-Emmett-Teller (BET) analysis of TGEP unveiled a considerably high surface area (1.13 m2/g), pore volume (0.218 cm3/g), and pore size (384.6 nm). The metabolites profile of TGEP was studied and characterized using two spectroscopic analyses. Analysis by the FTIR showed the presence of O–H, C–H, C = C, C = O, CO-O-CO, C-N, and C-O functional groups in the sample. Subsequently, the result of the GC–MS characterization revealed about 59 metabolites that predominantly fatty acids (30.5%), terpenes and derivatives (20.3%), fatty acid esters (16.9%), and alcohols (8.47%) were present in TGEP. The powder also demonstrated a high antioxidant activity based on the evaluation of its total phenolic content (23.3 ± 0.662 mg GAE/g TGEP), EC50 as determined from 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity assay (1.31 ± 0.002 mg/mL), and ferric reducing antioxidant power (2919.5 ± 19.9 μM TE/g TGEP), which were better than previous studies. ConclusionTherefore, this study unveiled TGEP as a functional powder with a high content of bioactive compounds with excellent bioactivity.

An eco-friendly method of extracting alizarin from Rubia tinctorum roots under supercritical carbon dioxide and its application to wool dyeing

Because of its low critical temperature and pressure levels, supercritical carbon dioxide (scCO2) is the most widely used supercritical fluid in the supercritical fluid extraction (SFE) technique. Alizarin was extracted from madder roots (Rubia tinctorum) using scCO2 under different conditions of co-solvent ratio (0–50%), temperature (45–95 °C), pressure (150–250 bar), extraction time (15–120 min), and flow rate (5–9 mL/min). Based on alizarin recovery and minimization of environmental risk, the optimum conditions were determined. SFE was optimum at 90% CO2:10% methanol (Me), 65 °C, 250 bar, 45 min, and 9 mL/min. The alizarin recovery, and its content in R. tinctorum extract (RE) under the optimum conditions were 1.34 g/kg roots, and 6.42%, respectively. Using conventional dyeing methods, wool fabrics were dyed with RE at different concentrations (2–6%). Various types of mordants were also used in the dyeing process, including chemical and bio-mordants. Color and fastness properties of dyed wool fabrics were evaluated based on RE concentration and mordant type. A higher RE concentration and the use of mordants, specifically Punica granatum (P. granatum) peels, increased the color characteristics. RE and dyed fabrics exhibited good antibacterial activity against the tested bacterial strains, especially Pseudomonas aeruginosa and Escherichia coli.

Compressed fluids and Soxhlet extraction for the valorization of compounds from Colombian cashew (Anacardium occidentale) nut shells aimed at a cosmetic application

The management of cashew nut shells in Vichada, Colombia, is a matter of deep concern for local farmers since this non-edible biomass accumulates in the farms and generates pollution. This study explores the valorization of cashew nut shells through supercritical fluid, subcritical water, and Soxhlet extraction techniques to recover valuable compounds for the formulation of a cosmetic cream. The profile of metabolites of the extracts was studied, and the cytotoxicity was determined. Supercritical fluid extraction showed high selectivity to phenolic compounds (134 ± 4.6 mg/mL). Soxhlet and subcritical water extractions recovered sugars and organic acids. It was demonstrated that including cashew extracts in the cream formulation resulted in similar rheology behavior compared to a commercial cream. The use of non-conventional extraction techniques to obtain natural compounds provides a novel perspective on the valorization of this biomass which could increase the circularity of the cashew agroindustry in Colombia.

Innovative and Green Extraction Techniques for the Optimal Recovery of Phytochemicals from Saudi Date Fruit Flesh

Saudi Arabia is one of the major producers of date (Phoenix dactylifera) fruit. Date fruit flesh is considered a healthy food due to the presence of natural antioxidants. Green and innovative supercritical fluid (SFE, 52.5 °C temperature, 27.50 MPa pressure, 5 mL CO2/min flow rate) and subcritical (SubCO2, 250 extraction cycles, 29 °C temperature, 6.8 MPa, 12 h, ethanol solvent) extraction techniques were used to produce flesh extracts from four Saudi date fruits (Sukari (SKFE), Ambara (AMFE), Majdool (MJFE) and Sagai (SGFE)), and extracts prepared using 6 h Soxhlet extraction at 70 °C for 16 h using n-hexane as solvent, were taken as control. SFE produced the highest (p < 0.05) extract yields, whereas the SubCO2 method recovered significantly higher (p < 0.05) amounts of phytochemicals. Total phenolics (186.37–447.31 mg GAE/100 g), total flavonoids (82.12–215.28 mg QE/100 g), total anthocyanins (0.41–1.34 mg/100 g), and total carotenoid (1.24–2.85 mg BCE/100 g) were quantified in all the flesh extracts. The biological properties evaluation showed that flesh extracts had high antioxidant (17.79–45.08 µg AAE/mL), antiradical (191.36–34.66 µg/mL DPPH IC50), ferric-reducing (2.18–5.01 mmol TE/100 g) and ABTS-scavenging (444.75–883.96 µmol TE/100 g) activities. SubCO2 was the best technique and Majdool the best date variety, in terms of both phytochemicals and biological properties.

Optimization of Extraction of Natural Antimicrobial Pigments Using Supercritical Fluids: A Review

It has become increasingly popular to replace chemically synthesized compounds with natural counterparts mostly found in natural sources, such as natural pigments. The conventional extraction processes for these compounds are limited by the toxicity and flammability of the solvents. To obtain pure extracts, it is always a longer process that requires several steps. Supercritical fluid extraction (SFE) is a cutting-edge green technology that is continuously increasing and expanding its fields of application, with benefits such as no waste produced, shorter extraction time, automation, and lower solvent consumption. The SFE of natural pigments has high potential in food, textiles, cosmetics, and pharmaceuticals; there are a number of other applications that can benefit from the SFE technique of natural pigments. The pigments that are extracted via SFE have a high potential for application and sustainability because of their biological and antimicrobial properties as well as low environmental risk. This review provides an update on the SFE technique, specifically as it pertains to the optimization of health-promoting pigments. This review focuses on antimicrobial pigments and the high efficiency of SFE in extracting pure antimicrobial pigments. In addition, the optimal conditions, biological activities, and possible applications of each category are explained.

Optimization of Molecular Composition Distribution of Slurry Oil by Supercritical Fluid Extraction to Improve the Structure and Performance of Mesophase Pitch

The composition distribution of slurry oil has a significant impact on the structure and performance of the mesophase. In this study, supercritical fluid extraction oil (SFEO) and extraction components were extracted from two slurry oils (SLOs) using the supercritical fluid extraction (SFE) technique. The fundamental properties and composition distribution of two SLOs and associated SFEOs were thoroughly investigated. Electron microscopy and spectroscopic techniques were employed to study the morphology and structures of mesophase pitch produced by carbonizing SLOs and their extraction components under the same conditions. The findings revealed that, compared to SLO–LH, SLO–SH has a higher proportion of 4–5 aromatic rings and a narrower hydrocarbon distribution range. In SLO–LH, O1, N1, and N1O1 molecules with long side chains and poor flatness make up the majority of the heterocyclic aromatic hydrocarbons. The distribution of CH compounds can be narrowed by using supercritical fluid extraction to efficiently separate various heteroatom-containing compounds with a higher condensation degree. After supercritical extraction, the mesophase content, texture distribution, and graphitization degree of the mesophase were improved. Polycyclic aromatic hydrocarbons with high planarity help polymer macromolecules stick together and build up in an orderly way. Heterocyclic aromatic hydrocarbons with high condensation and low planarity, on the other hand, play an important role in the formation of mosaic structures.

Ultrasound and supercritical fluid extraction of phytochemicals from purple tamarillo: Optimization, comparison, kinetics, and thermodynamics studies

The parameters for extraction of phenolic compounds and anthocyanins in purple tamarillo using supercritical fluid (SCFE) and ultrasound-assisted extraction (UAE) techniques were optimized. Optimizations of extraction techniques were done using Box-Behnken design in response surface methodology. Based on the total phenolic content, the experimental range for the independent variables in SCFE was set at 30 to 60 min, 40–60 °C, and 150 to 180 bars of pressure (TPC). Similarly, for UAE, the selected independent variables were 10–30 min time, 40–60 °C temperature and 20–60% amplitude. The optimized conditions for SCFE were determined to be 49.42 min, 49.28 °C and 176.63 bar pressure, and at the optimized parameters, the TPC was 16.12 mg GAE/g and anthocyanins was 0.62 mg C3G/g in the extract. The optimized parameters for UAE were 19.14 min, 51.53 °C, and 50.53% amplitude, which yielded 21.06 mg GAE/g TPC and 0.71 mg C3G/g anthocyanins. Four phenolic acids (gallic acid, chlorogenic acid, caffeic acid, and p-coumaric acid) and three anthocyanins (delphinidin-3-O-rutinoside, cyanidin-3-O-rutinoside, and pelargonidin-3-O-rutinoside) were identified by HPLC in both the extracts. However, higher concentration of phenolic acids and anthocyanins were extracted by UAE as compared to SCFE. SEM morphology of sample matrix showed extensive disintegration after UAE process. The optimized extract can be used in the food industry as a natural colorant in place of synthetic pigments that are bad for customers' health and wellbeing. The extract also can act as a source of potential antioxidants and can be used in the development of new functional foods.

Dandelion seeds as a new and valuable source of bioactive extracts obtained using the supercritical fluid extraction technique

The present study was intended to explore dandelion seeds as a new source of biologically active constituents using an environmentally friendly extraction technique. The process-function relationships were determined by following the influence of temperature (40 and 60 °C) and pressure (from 100 to 450 bar) on the amount of separated extract, its density, composition, and bioactivity. It was shown that the supercritical CO2-assisted technique enables the separation of 0.6–25.0% extract having a density in a range of 827–941 kg/m3. Extracts contained a high amount of unsaturated fatty acids (89.9–90.6%) including linoleic acid (71%) and α-linolenic acid (up to 0.9%), as well as phenolic (5.5–12.1 mg GAE/g) and flavonoid compounds (208.6–564.5 μg QE/g). The antioxidant activity test showed that 20 mg/mL extract solutions inhibit 26.0–64.4% DPPH radical. In addition, extracts showed significant antimicrobial activity, especially against Gram-positive Bacillus subtilis and Micrococcus luteus. There was no cytotoxic effect on normal green monkey kidney cells and human skin fibroblasts nor on hypopharyngeal cancer, cervical adenocarcinoma, and colon cancer cells. The study indicated the possible safe application of bioactive dandelion seeds extract in the pharmaceutical, food, and cosmetic industry.