Supercritical Carbon Dioxide Method Research Articles

Determination of Carotenoid Bioavailability from Palm Oil Microencapsulation

Indonesia is the largest palm oil supplier in the world with a total production value of 20.97 million tons. Palm oil has a high content of carotenoids that act as antioxidants in the body. However, carotenoids and their derivatives have a conjugated structure that is unstable to oxidation and easily damaged. One of the optimal efforts to maintain the stability of carotenoids is by microencapsulation. This study aims to determine the efficiency of the palm oil microencapsulation method in maintaining the carotenoid components in it. The method used in this research is Systematic Literature Review based on Google Scholar, ScienceDirect, and Springer databases with predetermined inclusion criteria. The results showed that all palm oil microencapsulation methods produced good efficiency values and stable physicochemical characteristics of carotenoids even including other micronutrients such as vitamin E, moisture content, fatty acids, etc. which were also classified as stable. Overall, the supercritical carbon dioxide (SEDS) method produced the best quality while the spray drying method is a good choice for commercial microencapsulation. The conclusion of this study is that microencapsulation is able to protect the bioavailability of carotenoids in palm oil in a stable condition with values that are still within the standard range so as to produce better palm oil products as food ingredients for further use in a food product

Experimental - Theoretical approach for determination of Metformin solubility in supercritical carbon dioxide: Thermodynamic modeling

Metformin, as an anti-hyperglycemic, is the main medicine for treating diabetes of type II. However, its daily dose is high due to its incomplete absorption and short half-life, which leads to digestive problems and patient complaints. Controlled release and increased bioavailability of this drug can be achieved using novel drug delivery systems produced with an appropriate supercritical carbon dioxide (scCO2) method. However, the solubility of Metformin in scCO2 is an essential parameter for this purpose which needs to be evaluated prior to the processing. In the current research, solubility of Metformin in scCO2 was determined at temperatures of 308, 318, 328, and 338 K, and pressures of 140, 170, 200, 230, 260, and 290 bar. It was obtained between 0.39 × 10−6 up to 1.23 × 10−6 (mole fraction). Also, the resulting values were correlated through an equation of state (Peng-Robinson (PR-EoS)) and eight well-known empirical correlations (Chrastil, Sung and Shim, Adachi and Lu, Si-Moussa, Bartle, Jafari Nejad, Keshmiri, and Jouyban). The average AARD% value of 8.24 for the PR-EoS model confirmed its satisfactory precision to predict the Metformin solubility in scCO2. Among the mentioned empirical models, the models defined by Jafari Nejad (AARD% of 4.36 and AICc of −997.07) and Keshmiri (AARD% of 4.73 and AICc of −1048.81) show the highest correlation accuracy. Moreover, the total mixing heat, the vaporization enthalpy, and the solvation enthalpies of the Metformin-scCO2 mixture were computed.

Optimization of fucoxanthin extraction obtained from natural by-products from Undaria pinnatifida stem using supercritical CO2 extraction method.

In the recent years, edible brown seaweed, Undaria pinnatifida, has presented beneficial effects, which may be correlated with this species containing major bioactive compounds, such as carotenoids, fatty acids, and phytosterols. Marine carotenoid fucoxanthin is abundantly present in edible Undaria pinnatifida and features strong bioactive activities. The stem of Undaria pinnatifida is very hard to gnaw off and cannot be swallowed; therefore, it is usually discarded as waste, making it an environmental issue. Hence, making full use of the waste stem of Undaria pinnatifida is an urgent motivation. The present study aims to explore the optimal preparation technology of fucoxanthin from Undaria pinnatifida stems using supercritical carbon dioxide methods and provides approaches for the extraction and preparation of bioactive compounds from a waste seaweed part. With the comprehensive optimization conditions applied in this study, the experimental yield of fucoxanthin agreed closely with the predicted value by > 99.3%. The potential of α-amylase and glucoamylase to inhibit bioactive compounds was evaluated. The results demonstrated that the inhibition activity (IC50 value) of α-amylase (0.1857 ± 0.0198 μg/ml) and glucoamylase (0.1577 ± 0.0186 μg/ml) varied with extraction conditions due to the different contents of bioactive components in the extract, especially fucoxanthin (22.09 ± 0.69 mg/g extract). Therefore, this study confirmed supercritical fluid extraction technology to be a useful sample preparation method, which can effectively be used to prepare fucoxanthin from waste marine resources. This method can potentially be applied in functional food and related industries.

Phytochemical Compositions and Antioxidant Activities of Essential Oils Extracted from the Flowers of Paeonia delavayi Using Supercritical Carbon Dioxide Fluid.

Essential oils were extracted from dark-purple, red and yellow petals of Paeonia delavayi using Supercritical Carbon Dioxide method. The compositions of essential oils were analyzed using gas chromatography-mass spectrometry (GC-MS). Antioxidant activity assays were carried out using DPPH, ABTS- and FRAP methods. Total polyphenols and total flavonoids were measured to evaluate the in vitro antioxidant activity in addition to the volatile compounds contained in the essential oils extracted from the flower petals of P. delavayi with the three flower colors. A total of 194 compounds were detected from essential oils of P. delavayi flowers, including 83 in dark-purple petals, 90 in red petals and 80 in yellow petals. These compounds mainly include alcohols, aldehydes, ketones, alkenes, alkanes, esters and polyphenols. The results showed that the volatile compounds accumulated differentially among the essential oils from the different colors of flower petals. Principal component analysis (PCA) indicated that essential oils derived from dark-purple and red petals were more closely clustered while the yellow petal essential oil was very different with both the purple-red and red. Antioxidant assays suggested that the radical scavenging activity and the iron reduction antioxidant activity in the essential oils were highly correlated with the flower petal colors. These results suggest P. delavayi flower petals are potentially good resources for high quality essential oils and natural antioxidants.

Sustained release ketamine-loaded porous silicon-PLGA microparticles prepared by an optimized supercritical CO2 process.

Ketamine in sub-anaesthetic doses has analgesic properties and an opioid-sparing effect. Intrathecal (i.t.) delivery of analgesics bypasses systemic metabolism and delivers the analgesic agent adjacent to the target receptors in the spinal cord and so small doses are required to achieve effective pain relief. In order to relieve intractable cancer-related pain, sustained-release ketamine formulations are required in combination with a strong opioid because frequent i.t. injection is not practical. In this study, ketamine or ketamine-loaded porous silicon (pSi) were encapsulated into poly(lactic-co-glycolic acid) (PLGA) microparticles by a novel supercritical carbon dioxide (scCO2) method, thereby avoiding the use of organic solvent. Multiple parameters including theoretical drug loading (DL), presence of pSi, size of scCO2 vessel, PLGA type, and use of co-solvent were investigated with a view to obtaining high DL and a sustained-release for an extended period. The most important finding was that the use of a large scCO2 vessel (60mL) resulted in a much higher encapsulation efficiency (EE) compared with a small vessel (12mL). In addition, pre-loading ketamine into pSi slightly improved the level of drug incorporation (i.e. EE and DL). Although the in vitro release was mainly affected by the drug payload, the use of the large scCO2 vessel reduced the burst release and extended the release period for PLGA microparticles with 10% or 20% ketamine loading. Together, our findings provide valuable information for optimization of drug delivery systems prepared with the aid of scCO2.

Experimental Optimization and Modeling of Supercritical Fluid Extraction of Oil from Pinus gerardiana

AbstractThe influence of different temperatures, pressures, and flow rates on the supercritical fluid extraction (SFE) of oil from Pinus gerardiana was investigated. Extraction was designed using the Box‐Behnken design and artificial neural network. Furthermore, a mathematical model of broken and intact cells was applied to consider mass transfer kinetics of extracted natural materials. The experimental oil extraction was performed by Soxhlet and supercritical carbon dioxide methods and the yield and composition of the obtained oils was compared. Although the yield of the SFE process was lower than that of the Soxhlet extraction, the SFE presented the advantage of shorter extraction time and lower temperatures. Also, the chemical compositions of the obtained oils from Soxhlet and SFE processes were the same.

Comparison of the Properties of the Extracts Prepared by a Supercritical Carbon Dioxide Method under Four Different Conditions

Comparison of the Properties of the Extracts Prepared by a Supercritical Carbon Dioxide Method under Four Different Conditions

A supercritical fluid technology for liposome production and comparison with the film hydration method

Liposomes were produced by an innovative method using supercritical carbon dioxide as a dispersing agent. A quality by design strategy was used to find optimal production conditions with specific parameters (lipid concentration, dispersion volume, agitation rate, temperature and pressure) allowing the production of liposomes with predicted physicochemical characteristics (particles size and PdI). Two conditions were determined with specific production parameters. It was shown that these two conditions allowed the production of liposomes of different compositions and that most of the liposome formulations had size and dispersity in accordance with the prediction values. The condition involving the higher lipid concentration showed a higher variability in terms of size and dispersity. However, this variability remained acceptable. This innovative supercritical method allowed the production of liposomes with physicochemical characteristics similar to those obtained by the conventional thin film hydration method. This new supercritical carbon dioxide method easily scalable in GMP conditions is a one-step production method contrarily to conventional methods which generally need an additional step as extrusion to homogenize the size of liposomes.

Effect of flow rate, particle size and modifier ratio on the supercritical fluid extraction of anthocyanins from Hibiscus sabdariffa (L).

This work aims to evaluate the effects of different particle size, flow rate and modifier ratio on the extraction yield and anthocyanins content of Hibiscus sabdariffa L (Roselle) by using supercritical carbon dioxide (SC-CO2) method. SC-CO2 extraction was carried out at constant pressure and temperature, 10MPa and 70°C respectively with 75% (v/v) ethanol as a modifier. The result shows that 120 minutes was the efficient extraction time at a determination of flow rate. The trend and results for the extraction yield and anthocyanins were varied in all parameters studied. The finding shows that a low flow rate (4 ml/min), smaller particle size (200-355 µm) and high percentage ratio of modifier (10%) could obtain more anthocyanins content. Thus, the manipulation of several parameters in the SC-CO2 extraction process could enhance the selectivity of anthocyanins extraction from the total extract.

Optimization of coenzyme Q10 encapsulation in liposomes using supercritical carbon dioxide

Coenzyme Q10 (CoQ10)-loaded liposomes were prepared with soy lecithin utilizing a single step supercritical carbon dioxide (SCCO2) method, which did not require the use of organic solvents, buffers or surfactants. The effects of pressure, temperature, pressurization rate and CoQ10-to-lecithin ratio on bioactive loading (BL), particle size (Ps) and polydispersity index (PdI) were investigated and modeled by response surface methodology (RSM). Pressure and concentration of CoQ10 had a great influence on the three responses. High pressures led to lower BLs, but also particles with smaller Ps and PdI. High concentrations of CoQ10 allowed obtaining higher BLs and lower PdI, but also higher Ps. High pressurization rates were needed to obtain high BLs, but, in contrast, it also led to higher PdIs. Temperature had a positive influence only on the PdI. The optimum conditions predicted by the model to simultaneously maximize the BL and minimize the Ps and PdI were 30 MPa, 40 °C, 6 MPa∙min−1 and 17 mol% CoQ10 (BL of 4.2 %, Ps of 177 nm and PdI of 0.313). Furthermore, encapsulation efficiencies between 87.6–99.7 % were achieved and semi-spherical stable particles (zeta potential ≈ −70 mV) were formed. Differential scanning calorimetry indicated a potential loss of crystallinity upon the encapsulation of CoQ10 into the liposomes. The findings reveal the great potential of this SCCO2 method for the encapsulation of CoQ10 in liposomes.

Development of Flame-Resistant Cotton Fabrics with Casein Using Pad-dry-cure and Supercritical Fluids Methods

Traditional pad-dry-cure (PDC) and supercritical carbon dioxide (scCO2) methods were used to study the effectiveness of cotton fabrics treated with casein from bovine milk and eco-friendly inorganic materials, urea and diammonium phosphate. Trials were completed successfully. Thermogravimetric analysis (TGA), microscale combustion calorimeter (MCC), 45° angle and vertical flammability (clothing textiles test) and limiting oxygen index (LOI) tests were carried out for the treated cotton fabrics. When the treated fabrics were tested using the 45° angle flame, the ignited fabrics self-extinguished and left behind a streak of char. Treated higher add-on fabrics were neither consumed by flame, nor produced glowing embers upon self-extinguishing. All untreated cotton fabrics showed limiting oxygen index (LOI) values of about 18% oxygen in nitrogen. For formulations with casein, urea and diammonium phosphate, LOI values of treated fabrics were 29-40% oxygen in nitrogen when add-on values for the formulation were 9.5-18.7wt%. Furthermore, scanning electron microscope (SEM) was employed to characterize the chemical structure on the treated fabrics, as well as, the surface morphology of char areas of treated and untreated fabrics. The results indicate that fabrics treated with casein are flame resistant. The treated fabrics exhibited improved thermal stability, as evidenced by increased ignition times and lower heat release rates. The results of this study show that casein coated flame-resistant fabrics can be readily applied to textile fabrics using a continuous process that is ideal for commercial and industrial applications.

Drug loading with supercritical carbon dioxide deposition on different silica derivatives: Carvedilol study

Supercritical carbon dioxide is a promising method used to load water insouble drugs over different drug carriers. In this study, it is offered as an alternative method to load Carvedilol as a drug over different kinds of silica materials via supercritical carbon dioxide method. Two kinds of silica materials either spherical silica or MCM-41 were synthesized for this purpose. The characterization of the silica materials were carried out by using SEM, BET, XRD and FT-IR. Spherical silica materials were obtained by changing the synthesis temperatures as 70, 80 and 90 °C. The diameters of the synthesized silica structures were increased with an increase in the temperature. Among the other spherical silica materials, the best homogeneity was obtained for 70 °C synthesis temperature so it is chosen as drug carrier for spherical silica. BET surface areas of spherical silica and MCM-41 were 345.9 m2/g and 1057.0 m2/g, respectively. Carvedilol, poorly water souble drug, was loaded over spherical silica and MCM-41 and subsequently characterized by XRD, BET, SEM and FT-IR. Carvedilol was loaded over these silica materials. Drug loading over these materials were achieved as 42% and 26% for spherical silica and MCM-41, respectively.

Optimization of SC-CO2 Time Conditions and Permethrin Concentration in Laminated Bamboo Production Using Surface Response Methodology

Supercritical carbon dioxide method has starting to be used as environmental friendly method in preserving wood. It is expected to maintain physical and mechanical properties of bamboo. The purpose of this study was to determine the effect of the duration times of supercritical conditions and permethrin preservative concentrations on optimization of shear strength of laminated bamboo impregnated by using supercritical carbon dioxide in the initial process (blades) and final process (laminated bamboo). The RSM-CCD experimental design was used to determine the effect of duration times of supercritical carbon dioxide for 20, 25, 30, 35, 40 minutes and the effect of permethrin concentrations 0.1, 0.3, and 0.5% against the shear strength of laminated bamboos. Response surface analysis, using 10 version of design expert software, has been done to get the optimum condition which would produce maximum of shear strength. The results showed that permethrin concentrations have stronger influenced (based on RSM analysis) on the shear strength and durability of laminated bamboo than the times of supercritical carbon dioxide conditions. Optimization of the two combinations of increasing shear strength and endurance were supercritical conditions = 22.71 minutes, and preservative permethrin concentration = 0.24%. Shear strength of shear strength and decrease in combination weight is 85 kg / cm2 and 0.38%.

Novel Approach to Dye Polyethylene Terephthalate (PET) Fabric in Supercritical Carbon Dioxide with Natural Curcuminoid Dyes

The use of natural dyes has increased in the last few decades due to the eco-friendly approach of dyeing. There are still some limitations that are associated with natural dyes, such as dyeing efficiency, reproducibility of shades, process complexity, availability etc. The main problem associated with the dyeing property of natural dyes is “low exhaustion”. In this study, natural dyestuff from Curcuma longa L. was extracted and polyethylene terephthalate fabric was dyed with it in the same bath by employing the supercritical carbon dioxide method. The method was developed to improve the dye-ability of natural dyes and reduce the process time and effluent. Curcuminoid dye exhaustion on PET fabric showed almost 80% by using supercritical carbon dioxide dyeing methods, and the highest colour strength (K/S = 12) was obtained. Coloured polyethylene terephthalate fabric treated with supercritical carbon dioxide showed deeper shades (L* = 72.92) and better fastness properties as compared with high temperature exhaust dyeing methods.

Preliminary study on lipid extraction from Nannochloropsis salina using supercritical carbon dioxide method

The issues involved with conventional lipid extraction methods, such as the usage of toxic solvents and accumulation of chemical waste, has motivated researchers to find an alternative approach to the extraction technology. One of the alternatives is via the Supercritical Carbon Dioxide (SC-CO2) method. This extraction method is considered as green as it provides a clean, selective and efficient process. Although the SC-CO2 method has been successfully used to extract lipids from microalgae, there are still some issues related to sample preparation and process parameters that need to be resolved. Therefore, this study investigates the effect of adding a modifier (ethanol) and using different types of holders (cotton and steam bun cloth) has on the yield of lipid from Nannochloropsis salina. The usage of a holder is required during the process due to the fine particles of the microalgae which have the potential to clog the instrument used. The SC-CO2 extraction without the modifier was conducted for 4 hours at 60°C, 30 MPa and CO2 flow rate of 4 ml/min, while the extraction with the modifier was conducted using 3.8 ml/min CO2 and 0.2 ml/min ethanol. It was found that the highest lipid yield of 0.16 g lipid / g dried microalgae was achieved using cotton cloth as a holder with the addition of the modifier. Lower amount of lipids were obtained when using the Soxhlet method (0.08 g lipid / g dried microalgae) and SC-CO2 without modification (0.02 g lipid / g dried microalgae). These preliminary findings show that the SC-CO2 process requires modifications to enhance the lipids yield from microalgae.

Biological activity of Boswellia serrata Roxb. oleo gum resin essential oil: effects of extraction by supercritical carbon dioxide and traditional methods

ABSTRACTThe findings of this study suggests that chemical composition, essential oil yield, antioxidant and antimicrobial activity of Boswellia serrata oleo gum resin essential oils extracted by hydro distillation, steam distillation and supercritical fluid carbon dioxide methods vary greatly from each other. The optimum essential oil yield was obtained using hydro distillation method (8.18 ± 0.15 %). The essential oils isolated through different extraction methods contained remarkable amounts of total phenolics and total flavonoids. Essential oil isolated through supercritical fluid carbon dioxide extraction exhibited better antioxidant activity with highest free radical scavenging potential (96.16 ± 1.57 %), inhibition of linoleic acid oxidation (94.18 ± 1.47 %) and hydrogen peroxide free radical scavenging potential (68.25 ± 1.02 %). Moreover, the antimicrobial activity of essential oils was performed through well diffusion, resazurin microtiter plate and micro dilution broth assay assays. The essential oil isolated through steam distillation method revealed highest antimicrobial activity with maximum inhibition zone (24.21 ± 0.34 to12.08 ± 0.30 mm) and least MIC values (35.18 ± 0.77 to 281.46 ± 7.03 µg/mL). The comparison of chemical composition of essential oils isolated at different extraction methods have shown that the concentration of α-thujene, camphene, β-pinene, myrcene, limonene, m-cymene and cis-verbenol was higher in steam distilled essential oil as compared to hydro and supercritical fluid carbon dioxide extracted essential oils. These compounds may be responsible for the higher antimicrobial activity of Boswellia serrata oleo gum resin steam distilled essential oil.

Cytotoxic Deoxypodophyllotoxin Can Be Extracted in High Purity from Anthriscus sylvestris Roots by Supercritical Carbon Dioxide.

Deoxypodophyllotoxin is present in the roots of Anthriscus sylvestris. This compound is cytotoxic on its own, but it can also be converted into podophyllotoxin, which is in high demand as a precursor for the important anticancer drugs etoposide and teniposide. In this study, deoxypodophyllotoxin is extracted from A.sylvestris roots by supercritical carbon dioxide extraction. The process is simple and scalable. The supercritical carbon dioxide method extracts 75 - 80% of the total deoxypodophyllotoxin content, which is comparable to a single extraction by traditional Soxhlet. However, less polar components are extracted. The activity of the supercritical carbon dioxide extract containing deoxypodophyllotoxin was assessed by demonstrating that the extract arrests A549 and HeLa cells in the G2/M phase of the cell cycle. We conclude that biologically active deoxypodophyllotoxin can be extracted from A.sylvestris by supercritical carbon dioxide extraction. The method is solvent free and more sustainable compared to traditional methods.

Encapsulation of anthocyanin in liposomes using supercritical carbon dioxide: Effects of anthocyanin and sterol concentrations

Anthocyanin-loaded liposomes were prepared via an improved supercritical carbon dioxide (SC-CO2) method. The effects of anthocyanin and cholesterol concentrations were studied in terms of the particle size distribution, encapsulation efficiency (EE), bioactive loading, morphology, zeta potential, anthocyanin-phospholipid interaction and in vitro release profiles. Anthocyanin-loaded liposomes had a particle size of 159±0.2nm, polydispersity index of 0.244±0.02, EE of 50.6% and zeta potential of −40.2mV. Elevated anthocyanin concentration increased the particle size with reduced uniformity due to enhanced electrostatic interactions and hydrogen bonding between anthocyanin and phospholipids. Liposomes exhibited unilamellar, spherical and near-spherical shapes with increased asymmetry and heterogeneity in the bilayer packing upon increased anthocyanin and cholesterol addition. The anthocyanin release from liposomes was slow (≤35.9%) in the simulated gastric fluid but rapid in the simulated intestinal fluid, induced by the degradation of the vesicles by pancreatin. Anthocyanin-loaded liposomes show great potential for functional food and nutraceutical applications.

Experimental optimization and mathematical modeling of the supercritical fluid extraction of essential oil from Eryngium billardieri: Application of simulated annealing (SA) algorithm

This article presents experimental results and mathematical modeling predictions of the extraction of essential oil from Eryngium billardieri, for the first time, using supercritical carbon dioxide (SCCO2) method. Design of experiments and experimental optimization were carried out with a response surface methodology (RSM) to investigate the effects of different operating parameters including pressure (100–300bar), temperature (308–328K), particle size (0.45–1.05mm) and extraction time (30–150min). The maximum extraction yield was found to be 0.8522% w/w at the optimum conditions 300bar, 308K, 0.75mm and 130min. Moreover, in order to describe the kinetic behavior of extraction process, a mathematical model based on the Brunauer-Emmett-Teller (BET) theory of adsorption with three adjustable parameters was developed for correlating experimental data. Model parameters have been optimized by applying simulated annealing (SA) algorithm. The obtained results from model predictions were consistent with experimental data in the different extraction conditions.

Optimization of Supercritical CO2 Extraction of Essential Oil from Artemisia annua L. by Means of Response Surface Methodology

In this paper, the extraction of essential oils from Artemisia annua L. with supercritical carbon dioxide method has been studied by means of the parameter optimization using response surface methodology. The extracted oil was then purified with molecular distillation. The results showed that the response surface methodology was an effective tool to predict optimal values of extraction parameters, with which the crude oil yield of 11.17% could be achieved at 25 MPa pressure, 50°C, 25 g/minute carbon dioxide flow rate and 2 hours extraction time. The purification below 120°C could produce high-quality essential oil with the yield of 56.1%. The essential oil was mainly composed of six bioactive terpenes, namely limonene, (1s)-α-pinene, β-pinene, β-farnesene, α-caryophyllene, γ-elemene. It was suggested that A. annua L. was a potential source of antimicrobial/ antioxidant compounds and the combination of supercritical carbon dioxide and molecular distillation was a good process for the isolation of essential oil.