Applications of supercritical fluid extraction (SFE) of palm oil and oil from natural sources

Supercritical fluid extraction (SFE), which has received much interest in its use and further development for industrial applications, is a method that offers some advantages over conventional methods, especially for the palm oil industry. SC-CO? refers to supercritical fluid extraction (SFE) that uses carbon dioxide (CO?) as a solvent which is a nontoxic, inexpensive, nonflammable, and nonpolluting supercritical fluid solvent for the extraction of natural products. Almost 100% oil can be extracted and it is regarded as safe, with organic solvent-free extracts having superior organoleptic profiles. The palm oil industry is one of the major industries in Malaysia that provides a major contribution to the national income. Malaysia is the second largest palm oil and palm kernel oil producer in the World. This paper reviews advances in applications of supercritical carbon dioxide (SC-CO?) extraction of oils from natural sources, in particular palm oil, minor constituents in palm oil, producing fractionated, refined, bleached, and deodorized palm oil, palm kernel oil and purified fatty acid fractions commendable for downstream uses as in toiletries and confectionaries.     

Evaluation of tocopherol recovery through simulation of molecular distillation process

DISMOL simulator was used to determine the best possible operating conditions to guide, in future studies, experimental works. This simulator needs several physical-chemical properties and often it is very difficult to determine them because of the complexity of the involved components. Their determinations must be made through correlations and/or predictions, in order to characterize the system and calculate it. The first try is to have simulation results of a system that later can be validated with experimental data. To implement, in the simulator, the necessary parameters of complex systems is a difficult task. In this work, we aimed to determe these properties in order to evaluate the tocopherol (vitamin E) recovery using a DISMOL simulator. The raw material used was the crude deodorizer distillate of soya oil. With this procedure, it is possible to determine the best operating conditions for experimental works and to evaluated the process in the separation of new systems, analyzing the profiles obtained from these simulations for the falling film molecular distillator.     

Comparative analysis of the oil and supercritical CO2 extract of Ridolfia segetum (L.) Moris

Supercritical carbon dioxide extraction allowed to obtain the volatile oil of different aerial parts of Ridolfia segetum (L.) Moris. Extraction conditions were as follows: pressure, 90 bar; temperature, 50°C and carbon dioxide flow, Φ?=?1.0?kg?h^?1. Waxes were entrapped in the first separator set at 90?bar and ?10°C. The oil was recovered in the second separator working at 15?bar and 10°C. The main components of the flower oil were α-phellandrene (19.4%), terpinolene (20.5%), piperitenone oxide (11.6%), β-phellandrene (8.2%), (Z)-β-ocimene (7.8%), myristicin (7.5%) and p-cymene (4.4%). The comparison with the hydrodistilled (HD) oil reveal that the significative difference was the content of sesquiterpenes which are higher in the supercritical fluid extraction (SFE) products. Collection of samples at different extraction times during supercritical extraction, allowed to monitor the change of the oil composition. Lighter compounds, as hydrocarbon monoterpenes, were extracted in shorter times than the heavier hydrocarbon and oxygenated sesquiterpenes. The oil from the steams was characterized by a high content of α-phellandrene (12.9%), terpinolene (11.6%), myristicin (11.0%), p-cymene (9.9%), β-phellandrene (8.2%) and (Z)-β-ocimene (6.0%) while the main components of the fruits were found to be myristicin (70.8%), piperitenone oxide (19.9%) and dill apiole (4.2%).     

Transesterification of palm oil using supercritical methanol with co-solvent HCFC-141b

The transesterification of palm oil in supercritical methanol has been investigated without using any catalyst. HCFC-141b was used as co-solvent to reduce the molar ratio of methanol to palm oil under the milder conditions. The reaction was carried out in a flow-type tubular reactor. The residence time was fixed at 40 min. When the molar ratio of methanol to palm oil was set to 20:1 at 325 °C and 35 MPa, the optimum molar ratio of methanol to co-solvent was found to be 20:1. Addition of HCFC-141b increased FAME production even at the lower molar ratio of methanol to palm oil. In addition, a similar FAME content was obtained under the milder conditions (5 MPa lower pressure) compared with conditions without co-solvent at higher pressure. The role of HCFC-141b in the transesterification reaction under supercritical conditions was investigated.     

Mathematical modelling for extraction of oil from Dracocephalum kotschyi seeds in supercritical carbon dioxide

Extraction of oil from Dracocephalum kotschyi Boiss seeds using supercritical carbon dioxide was designed using central composite design to evaluate the effect of various operating parameters including pressure, temperature, particle size and extraction time on the oil yield. Maximum extraction yield predicted from response surface method was 71.53% under the process conditions with pressure of 220 bar, temperature of 35 °C, particle diameter of 0.61 mm and extraction time of 130 min. Furthermore, broken and intact cells model was utilised to consider mass transfer kinetics of extracted natural materials. The results revealed that the model had a good agreement with the experimental data. The oil samples obtained via supercritical and solvent extraction methods were analysed by gas chromatography. The most abundant acid was linolenic acid. The results analysis showed that there was no significant difference between the fatty acid contents of the oils obtained by the supercritical and solvent extraction techniques.     

Characterization of Volatile Flavor Compounds in Supercritical Fluid Separated and Identified in Gurum (Citrulluslanatus Var. colocynthoide) Seed Oil Using HSME and GC–MS

In this study, the volatile compound profiles of gurum seed oil were determined using two methods: supercritical CO₂ extraction (SFE) and the screw press process (SPP). For volatile compounds extraction and identification, headspace solid-phase micro-extraction (HS-SPME) and GC–MS were used, respectively. A total number of 56 volatile compounds were revealed and identified in oil extracted by SFE, while only 40 compounds were detected in extracted oil by SPP. Acids, aldehydes, esters, ketones, furans, and other components were present in the highest ratio in oil extracted by SFE. In contrast, alcohols and alkenes were found in the highest proportion in oil extracted by SPP. In this study, it was observed that SFE showed an increase in the amounts of volatile compounds and favorably impacted the aroma of gurum seed oil. The results reveal that different extraction methods significantly impact the volatile components of gurum seed oil, and this study can help evaluate the quality of the oil extracted from gurum seeds.     

Separation of γ-linolenic and other polyunsaturated fatty acids from Boraginaceae via supercritical CO2

Essential fatty acids were extracted from Echium amoenum (Boraginaceae) seed oil via supercritical carbon dioxide and the results were compared with conventional Soxhlet method as the base case of 100% recovery. The response surface methodology was used to optimize the effective extraction parameters. The chemical composition of recovered oil was analyzed by polar and non-polar gas chromatograph-flame ionization detector columns. The experimental results indicated that echium seed contained 25 wt% oil and the maximum extraction oil recovery of 92% was obtained via supercritical CO(2) at optimal operating conditions (43°C, 280 bar, 1.5 mL/min, 25 min static time and 130 min dynamic time). At similar operating conditions, applying 2.5 and 5 mol% ethanol as a modifier enhanced the recovery to 96 and 112%, respectively. The results showed that supercritical fluid extraction is a viable technique for separation of constituents such as γ-linolenic acid (7-8%), palmitic acid (6-7%), stearic acid (3-4%), oleic acid (12-13%), linoleic acid (19-20%), α-linolenic acid (40-41%) and stearidonic acid (8-9%) from Boraginaceae.     

紫草油有效成分的高效液相色谱测定法及其在超临界流体萃取制备紫草油中的应用

紫草提取制备成的紫草油能够预防及治疗婴儿尿布疹、皮肤溃烂、湿疹等多种皮肤疾患,临床应用非常广泛,超临界流体萃取是紫草有效成分提取的优选方法.该文建立了紫草油有效成分的高效液相色谱(HPLC)测定方法,并以紫草油所含的有效成分含量为评价指标,采用三因素三水平正交试验法对紫草超临界流体萃取制备过程中的几个重要因素(萃取压力...     

Grape seed oil extraction: Interest of supercritical fluid extraction and gas-assisted mechanical extraction for enhancing polyphenol co-extraction in oil

The aim of this study is to compare three oil extraction methods and to evaluate their efficiency for producing an oil rich in polyphenols. The three extraction methods are screw pressing, extraction by supercritical CO₂ percolation and the combination of these two processes (Gas-Assisted Mechanical Expression: GAME). Screw pressing is the most efficient process for producing grape seed oil with a high yield, but supercritical CO₂ process permits an increase of polyphenol co-extraction with oil. The GAME process allows extraction of more polyphenols than screw pressing and constitutes an interesting process considering oil yield.     

Characterization of Bioactive Compounds from Patchouli Extracted via Supercritical Carbon Dioxide (SC-CO2) Extraction

Patchouli extracts and oils extracted from Pogostemon cablin are essential raw material for the perfume and cosmetics industries, in addition to being used as a natural additive for food flavoring. Steam distillation is a standard method used for plant extraction. However, this method causes thermal degradation of some essential components of the oil. In this study, patchouli was extracted with supercritical carbon dioxide (SC-CO₂) under different conditions of pressure (10–30 MPa) and temperature (40–80 °C). The chemical components of the crude extracted oil and the functional group were characterized using gas chromatography-mass spectrometry (GC-MS) and Fourier Transform Infrared Spectroscopy (FT-IR). The extraction with supercritical carbon dioxide was shown to provide a higher yield (12.41%) at a pressure of 20 MPa and a temperature of 80 °C. Patchouli alcohol, Azulene, δ-Guaiene, and Seychellene are the main bioactive compounds that GC-MS results have identified. FTIR spectra showed alcohol, aldehyde, and aromatic ring bond stretching peaks. Extraction of patchouli with supercritical carbon dioxide provided a higher yield and a better quality of the crude patchouli oil.     

Application of PLE for the determination of essential oil components from Thymus vulgaris L

Essential plants, due to their long presence in human history, their status in culinary arts, their use in medicine and perfume manufacture, belong to frequently examined stock materials in scientific and industrial laboratories. Because of a large number of freshly cut, dried or frozen plant samples requiring the determination of essential oil amount and composition, a fast, safe, simple, efficient and highly automatic sample preparation method is needed.Five sample preparation methods (steam distillation, extraction in the Soxhlet apparatus, supercritical fluid extraction, solid phase microextraction and pressurized liquid extraction) used for the isolation of aroma-active components from Thymus vulgaris L. are compared in the paper. The methods are mainly discussed with regard to the recovery of components which typically exist in essential oil isolated by steam distillation.According to the obtained data, PLE is the most efficient sample preparation method in determining the essential oil from the thyme herb. Although co-extraction of non-volatile ingredients is the main drawback of this method, it is characterized by the highest yield of essential oil components and the shortest extraction time required. Moreover, the relative peak amounts of essential components revealed by PLE are comparable with those obtained by steam distillation, which is recognized as standard sample preparation method for the analysis of essential oils in aromatic plants.     

Comparative analysis of the oil and supercritical CO2 extract of Ridolfia segetum (L.) Moris

Supercritical carbon dioxide extraction allowed to obtain the volatile oil of different aerial parts of Ridolfia segetum (L.) Moris. Extraction conditions were as follows: pressure, 90 bar; temperature, 50 degrees C and carbon dioxide flow, Phi = 1.0 kg h(-1). Waxes were entrapped in the first separator set at 90 bar and -10 degrees C. The oil was recovered in the second separator working at 15 bar and 10 degrees C. The main components of the flower oil were alpha-phellandrene (19.4%), terpinolene (20.5%), piperitenone oxide (11.6%), beta-phellandrene (8.2%), (Z)-beta-ocimene (7.8%), myristicin (7.5%) and p-cymene (4.4%). The comparison with the hydrodistilled (HD) oil reveal that the significative difference was the content of sesquiterpenes which are higher in the supercritical fluid extraction (SFE) products. Collection of samples at different extraction times during supercritical extraction, allowed to monitor the change of the oil composition. Lighter compounds, as hydrocarbon monoterpenes, were extracted in shorter times than the heavier hydrocarbon and oxygenated sesquiterpenes. The oil from the steams was characterized by a high content of alpha-phellandrene (12.9%), terpinolene (11.6%), myristicin (11.0%), p-cymene (9.9%), beta-phellandrene (8.2%) and (Z)-beta-ocimene (6.0%) while the main components of the fruits were found to be myristicin (70.8%), piperitenone oxide (19.9%) and dill apiole (4.2%).     

Valuable Natural Antioxidant Products Recovered from Tomatoes by Green Extraction

Lycopene, β-carotene and ω-fatty acids are major compounds in tomatoes with known antioxidant activity, capable of preventing health disorders. The identification of potential natural sources of antioxidants, extraction efficiencies and antioxidant activity assessments are essential to promote such products to be used in the food, pharmaceutical or cosmetic industries. This work presents four added-value products recovered from tomatoes: pigmented solid oleoresin, pigmented oil and two raw extracts from supercritical and Soxhlet extraction. Different parameters including the matrices of tomatoes, extraction methods, green solvents and operating parameters were varied to obtain extracts with different qualities. Extract analysis was performed using UV–VIS, FT–IR, GC–MS, Folin–Ciocalteu and DPPH methods. The highest-quality extract was the solid oleoresin obtained from pomace using supercritical CO₂ extraction at 450 bar, 70 °C and 11 kg/h: 1016.94 ± 23.95 mg lycopene/100 g extract, 154.87 ± 16.12 mg β-carotene/100 g extract, 35.25 ± 0.14 mg GAE/g extract and 67.02 ± 5.11% inhibition DPPH. The economic feasibility of the three extraction processes (1:10:100 kg dried pomace/batch as scalability criterion) was evaluated. The most profitable was the supercritical extraction process at the highest capacity, which produces pigmented solid oleoresin and oil with high content of lycopene valorized with a high market price, using natural food waste (pomace).     

Extraction of Lepidium apetalum seed oil using supercritical carbon dioxide and anti-oxidant activity of the extracted oil

The supercritical fluid extraction (SFE) of Lepidium apetalum seed oil and its anti-oxidant activity were studied. The SFE process was optimized using response surface methodology (RSM) with a central composite design (CCD). Independent variables, namely operating pressure, temperature, time and flow rate were evaluated. The maximum extraction of Lepidium apetalum seed oil by SFE-CO? (about 36.3%) was obtained when SFE-CO? extraction was carried out under the optimal conditions of 30.0 MPa of pressure, 70 °C of temperature, 120 min of extraction time and 25.95 L/h of flow rate. GC-MS analysis showed the presence of four fatty acids in Lepidium apetalum seed oil, with a high content (91.0%) of unsaturated fatty acid. The anti-oxidant activity of the oil was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay and 2,2'-azino- bis(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) test. Lepidium apetalum seed oil possessed a notable concentration-dependent antioxidant activity, with IC?? values of 1.00 and 3.75 mg/mL, respectively.     

Simulation of Organic Liquid Product Deoxygenation through Multistage Countercurrent Absorber/Stripping Using CO2 as Solvent with Aspen-HYSYS: Process Modeling and Simulation

In this work, the deoxygenation of organic liquid products (OLP) obtained through the thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na₂CO₃ as a catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO₂) as a solvent, with an Aspen-HYSYS process simulator, was systematically investigated. In a previous study, the thermodynamic data basis and EOS modeling necessary to simulate the deoxygenation of OLP was presented. This work addresses a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 pressure pump, and 02 make-ups of CO₂, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and that the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95 and 92.78% (wt.) on a solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenated compounds with concentrations of up to 32.66% (wt.) on a solvent-free basis, showing that the organic liquid products (OLP) were deacidified and SC-CO₂ was able to deacidify the OLP and obtain fractions with lower olefin contents. The best deacidifying condition was obtained at 333 K, 140 bar, and (S/F) = 17.     

Valorization of Fermented Shrimp Waste with Supercritical CO2 Conditions: Extraction of Astaxanthin and Effect of Simulated Gastrointestinal Digestion on Its Antioxidant Capacity

Lactic acid fermentation increases the bioactive properties of shrimp waste. Astaxanthin is the principal carotenoid present in shrimp waste, which can be found esterified in the liquid fraction (liquor) after its lactic acid fermentation. Supercritical CO₂ technology has been proposed as a green alternative to obtain astaxanthin from fermented shrimp waste. This study aimed to optimize astaxanthin extraction by supercritical CO₂ technology from fermented liquor of shrimp waste and study bioaccessibility using simulated gastrointestinal digestion (GD) of the optimized extract. A Box–Behnken design with three variables (pressure, temperature, and flow rate) was used to optimize the supercritical CO₂ extraction. The optimized CO₂ extract was obtained at 300 bar, 60 °C, and 6 mL/min, and the estimated characteristics showed a predictive extraction yield of 11.17%, antioxidant capacity of 1.965 mmol of Trolox equivalent (TE)/g, and astaxanthin concentration of 0.6353 µg/g. The experiment with optimal conditions performed to validate the predicted values showed an extraction yield of 12.62%, an antioxidant capacity of 1.784 mmol TE/g, and an astaxanthin concentration of 0.52 µg/g. The astaxanthin concentration decreased, and the antioxidant capacity of the optimized extract increased during gastrointestinal digestion. In conclusion, our optimized supercritical CO₂ process is suitable for obtaining astaxanthin from shrimp by-products after lactic acid fermentation.     

Influence of extractions on physicochemical characterization and bioactivity of Piper nigrum oils: Study on the non-isothermal decomposition kinetic

Black pepper oils have been investigated frequently in the recent years. However, there is a significant variation in physicochemical properties and bioactivity of oils depended on extraction techniques. In this study, the systemic investigation of four various extraction methods was performed to evaluate the physicochemical characterizations, antioxidant and antibacterial activity. The investigation of ¹H NMR, FTIR and UV–Vis spectra confirmed presence of non-volatile components in oils extracted through supercritical CO₂ and hexane-soaking extractions which induced their typical thermal properties. The isothermal behaviour of extracted oils related to evaporation was within range of 3.2–7.3% (w/w) at 27 °C. The SEM images of the black pepper confirmed different operation manners of mechanism between extractions using the solvents and heating process. The lowest MIC for both essential oils from conventional hidrodistillation and microwave-assisted hidrodistillation against two bacteria including E. coli and B. subtilis were found to be 137 µg mL⁻¹. The non-isothermal decomposition kinetics were investigated on the essential oil of microwave-assisted hydrodistillation extraction. The activation energies and pre-exponent factors of non-isothermal decomposition were found to be in range of 36.5–73.7 KJ mol⁻¹ and 4.98 × 10³–1.97 × 10⁸ s⁻¹, respectively, dependent on conversional fractions of the oil. The results revealed that chemical components, physicochemical properties and bioactivity of black pepper essential oils depended on the extraction techniques.     

Extraction of Camphor Tree Essential Oil by Steam Distillation and Supercritical CO2 Extraction

The essential oil extracted from Cinnamomum camphora leaves is a mixture of volatile compounds, mainly terpenes, and is widely used in medicine, perfume and chemical industries. In this study, the extraction processes of essential oil from Cinnamomum camphora leaves by steam distillation and supercritical CO₂ extraction were summarized and compared, and the camphor tree essential oil was detected by GC/MS. The extraction rate of essential oil extracted by steam distillation is less than 0.5%, while that of supercritical CO₂ extraction is 4.63% at 25 MPa, 45 °C and 2.5 h. GC/MS identified 21 and 42 compounds, respectively. The content of alcohols in the essential oil is more than 35%, and that of terpenoids is more than 80%. The steam extraction method can extract volatile substances with a low boiling point and more esters and epoxides; The supercritical method is suitable for extracting weak polar substances with a high alcohol content. Supercritical CO₂ extraction can selectively extract essential oil components and effectively prevent oxidation and the escape of heat sensitive substances.     

Essential oil composition of Valeriana officinalis L. roots cultivated in Iran. Comparative analysis between supercritical CO2 extraction and hydrodistillation

The composition of essential oil extracted from Valeriana officinalis L. roots growing wild in Iran was studied by hydrodistillation and supercritical CO2 extraction. Forty-seven components representing 89.3% and 35 constituents varying from 86.1% to 95.1% of the oil obtained by hydrodistillation and supercritical CO2 were identified, respectively. The major components in the extracted oil from supercritical CO2 were isovaleric acid (18.7-41.8%), valerenic acid (8.2-11.8%), acetoxyvaleranone (5.6-9.6%), (Z)-valernyl acetate (4.5-6.5%), bornyl acetate (2.3-7.7%) and valerenol (3.7-5.2%), whereas by hydrodistillation were bornyl acetate (11.6%), valerenic acid (8.0%), (Z)-valernyl acetate (7.9%) and acetoxyvaleranone (7.6%). The analysis of the extracts was performed by capillary GC and GC/MS.     

Comparison of supercritical fluid and ultrasound-assisted extraction of carotenoids and chlorophyll a from Dunaliella salina

In the work described here the extraction processes of carotenoids and chlorophylls were analysed using two extraction techniques, namely ultrasound-assisted extraction and supercritical fluid extraction, and the results are compared. The solvents used for the ultrasound-assisted extraction were N,N′-dimethylformamide and methanol and for the supercritical fluid extraction, carbon dioxide. The raw material studied was Dunaliella salina, a microalgae characterized by the high levels of carotenoids present in its cellular structure. The results indicate that the supercritical fluid extraction process is comparable to the ultrasound-assisted extraction when methanol is used as solvent. In addition, the supercritical extraction process is more selective for the recovery of carotenoids than the conventional technique since it leads to higher values for the ratio carotenoids/chlorophylls. Finally, the effects of pressure and temperature on the extraction yields of the supercritical fluid extraction process were studied.