Subcritical Propane Extraction Research Articles

Comparative analysis on the properties of egg yolk lipids extracted by different extraction methods.

Egg yolk lipids are important components in egg yolk. Compared with proteins, minerals, vitamins and pigments in egg yolk, there is a lack of systematic research on extraction methods and characteristics of yolk lipid. Therefore, in this study, the extraction of egg yolk lipids by supercritical CO2 fluid extraction (SFE), subcritical propane extraction (SPE) and ethanol solvent extraction (SE) was studied, and the differences in composition and physicochemical properties of the three yolk lipids were analyzed. The egg yolk lipids extracted by SFE had the advantages of high unsaturated fatty acid content, low saponification value, acid value, peroxide value, and high content of neutral lipids such as triglyceride and cholesterol, but the polar phospholipids were completely retained in the yolk powder. The efficiency of lipid extraction of SPE was the highest among all the three methods, but the extraction capacity to the polar phospholipid was in the middle of the three methods. The efficiency of lipid extraction of SE was low, but the extraction capacity to the polar phospholipid was the highest. Suitable extraction methods could be selected based on the specific application requirements of egg yolk lipids and low-fat egg yolk powders.

Characterisation of flavourous sesame oil obtained from microwaved sesame seed by subcritical propane extraction

This study developed a novel and green method to produce fragrant sesame oil using microwaves and subcritical extraction (SBE). Sesame seeds were microwaved at 540 W for 0–9 min before subcritical propane extraction at 40 °C and 0.5 MPa. SBE caused less deformation to the cellular microstructure of sesame cotyledons while dramatically improving oil yield (96.7–97.1 %) compared to screw processing (SP) (53.1–58.6 %). SBE improved extraction rates for γ-tocopherol (381.1–454.9 μg/g) and sesame lignans (917.9–970.4 mg/100 g) in sesame oil compared to SP (360.1–443.8 μg/g and 872.8–916.8 mg/100 g, respectively). Microwaves generated aroma-active heterocyclics and phenolics faster than hot-air roasting in sesame oil with a better sensory profile. SBE had a higher extraction rate for aroma-active terpenes, alcohols, and esters while reducing the concentrations of carcinogenic PAHs and HCAs in sesame oil. The novel combination process of microwaves and subcritical extraction is promising in producing fragrant sesame oil with superior qualities.

Extraction of oil, carotenes and tocochromanols from oil palm (Elaeis guineensis) fruit with subcritical propane

This work aims to screen the extraction of oil and bioactive compounds including carotenes and tocochromanols from oil palm fruit with subcritical propane and without using a cosolvent. The overall extraction curves of palm oil with subcritical propane were studied and compared to those extracted with supercritical carbon dioxide. Carotenes and tocochromanols were evaluated not only in the extracted oil, but also in the oil of residual fiber in order to calculate the efficiency to recover these valuable compounds. The experimental results showed that oil yield of up to 70 % could be obtained within 120 minutes with subcritical propane at 50 bar and a flow rate of 35 kg·h−1·kg−1. It was also shown that compressed propane is an excellent solvent for the extraction of oil enriched in carotenes and tocochromanols. Subcritical propane extraction can be used as an alternative process for the simultaneous recovery of these valuable minor components from palm fruit.

Super/subcritical fluid extraction combined with ultrasound-assisted ethanol extraction in propolis development

Propolis has attracted commercial interest as a good source of flavonoids and terpenes. This study applied a two-step sequential extraction process, consisting of a super/subcritical extraction step and an ultrasound-assisted ethanol extraction (UAEE) step to raw propolis. The yields of propolis extracts and the extraction rates of flavonoids and terpenes have been used to evaluate the different extraction methods. The results have indicated that the yields of propolis extracts, total flavonoids, and eight characteristic flavonoids from subcritical fluid extraction (SFE) were much higher than the yields from supercritical CO2 extraction (SC-CO2), especially when the subcritical mixed-fluids extraction (SMFE) and subcritical subsection extraction (SSE) techniques were used. However, the extraction rate of terpenes from subcritical propane extraction (SPE) was obviously higher than the rates obtained with the other techniques. Furthermore, compared with the ethanol extracts of the super/subcritical raffinates, there is still a considerable amount of flavonoids in SPE raffinates (at 114.48 mg/g raffinate). SMFE and SSE can achieve efficient extraction of flavonoids, but synchronous extraction of terpenes and flavonoids can be achieved via two-step sequential extraction with SPE and UAEE. These findings provide a solid theoretical foundation for the effective extraction of propolis.

Ultrasound-assisted desolventizing of fragrant oil from red pepper seed by subcritical propane extraction.

In the present study, ultrasound was used to remove the residual solvent from the fragrant oil of red pepper seed obtained by subcritical propane extraction. The physical and chemical characteristics, particularly the volatile flavor compounds present of the oil before and after ultrasound-assisted desolventizing were comprehensively analyzed to determine the effect of the desolventizing process on product quality. The results showed that the maximum loss of residual solvent was achieved at a temperature of 90°C maintained for 70min with ultrasound applied during the entire process. After this treatment only a small amount of solvent (2.3% based on the total residual solvent originally present) remained in the oil. Although it was hypothesized that ultrasound treatment could result in the loss of volatile components, the analytical results showed no obvious reduction in the components associated with the typical aroma of the oil. After ultrasonic treatment, the oil also had good oxidation stability and quality. Additionally, after ultrasonic desolventizing, the oil samples were more suitable for cooking because they could more effectively minimize oxidation. Thus, these results demonstrate that this new ultrasonic technique is an effective and efficient method for removing the solvent remaining in fragrant oil after subcritical propane extraction.

Subcritical propane extraction of high-quality inajá (Maximiliana maripa) pulp oil

The Maximiliana maripa is an important palm tree from Brazilian vegetation whose fruits present oily pulp and kernel. This study aimed at obtaining inajá pulp oil (IPO) by subcritical propane extraction and compare with the conventional Soxhlet extraction. The subcritical propane extractions were performed at different conditions to investigate the effects of temperature and pressure on the yield, chemical composition, and bioactive compounds of the oil. The subcritical propane provided fast extractions and high yields, reaching up to 28.66 wt% at 313 K and 6 MPa. The IPO presented high quality with a rich composition of oleic and palmitic acids, phenolic compounds, β-Carotene, antioxidant activity, and excellent thermal stability, showing great potential for use in the food, pharmaceutical, and cosmetic industries.

Characterization of fragrant oil extracted from pepper seed during subcritical propane extraction

The aim of this investigation was to characterize oils extracted from pepper seed (Capsicum annuum L.) by subcritical propane at various stages of the extraction. During the extraction, the pepper seed oil (PSO) was sampled at five different times. The various oil fractions were named: PSO-1 (0–3 min), PSO-2 (4–6 min), PSO-3 (7–9 min), PSO-4 (10–12 min), and PSO-5 (13–15 min). Results showed that 97.2% of total oil content was extracted before PSO-4. There were no significant difference in fatty acid composition between the oil samples; however, results show that extraction time did significantly affect other chemical constituents (i.e., tocopherols, sterols, and volatile flavor compounds), and thermal stability. This investigation provides important information for the application of pepper seed and for further development of subcritical fluid extraction.

Subcritical extraction of oil from black and white chia seeds with n-propane and comparison with conventional techniques

Subcritical fluid extraction from Chia seeds (Salvia hispanica L.) using n-propane as a solvent and classical extractions as Soxhlet and ultrasonic extraction in n-hexane were performed to obtain oil rich extract. Influence of elevated operating pressure (up to 300 bar) and temperature (40 °C and 60 °C) on the extraction yield and extract composition is presented. Higher solvent density contributed to higher extraction yield, which increased from 14.38% to 20.8%. Extraction kinetic curves were modelled using Brunner’s equation and the model has been proved to fit well to the results. Compositions of extracts obtained by different methods were analysed and compared by gas chromatography (GC). Presence of palmitic, stearic, oleic, linoleic and linolenic free fatty acid has been confirmed. The highest proportion of linolenic (almost 60%) and linoleic acid is attained in oils obtained by subcritical propane extraction.

Extraction and modeling of flaxseed (Linnum usitatissimum) oil using subcritical propane

This study aimed at investigating flaxseed (Linnum usitatissimum) oil extraction using subcritical propane. Extractions were performed in a laboratory scale unit at temperature (20–60 °C) and pressure (80–120 bar) experimental conditions. Subcritical extraction process kinetic aspects evaluation was performed using four mathematical models found in the literature. The subcritical propane process successfully extracted Omega 3-6-9 fatty acids presenting good yielding in the experimental conditions studied. Physical characterization for commercial and subcritical propane extraction oils presented 1.477 and 1.473 refractive indexes at 40 °C, respectively. The oil extracted using subcritical propane presented free fatty acid contents lower than commercial oil (0.95% wt vs 1.37% wt). The adjusted parameters models presented good fitting with the experimental data under the investigated conditions.

Linseed (Linum usitatissimum) Oil Extraction Using Different Solvents.

SummaryThis work aims at characterizing linseed oil obtained using different extraction methods (hexane, subcritical propane and pressurized ethanol), and comparing the results with commercial linseed oil extracted by cold mechanical press method. An experimental design helped to evaluate temperature and pressure effects on the oil extraction using propane and ethanol. Gas chromatography assisted in evaluating the essential fatty acids. There were no significant differences among the ω-3, 6 and 9 fatty acids from linseed oil obtained using the different extraction methods. Only the acidity of linseed oil extracted by subcritical propane (0.956%) showed significant differences among the physicochemical parameters. Extraction using organic solvent (Soxhlet) gave a 36.12% yield. Extraction using subcritical propane at 107 Pa and 40 °C for 1.5 h gave a better yield (28.39%) than pressurized ethanol (8.05%) under similar conditions. Linseed oil extraction using subcritical propane was economically viable, resulting in a 124.58 US$/L product cost. The results present subcritical propane extraction as a promising alternative for obtaining linseed oil at mild temperature and pressure conditions, without losing quality and quantity of fatty acids such as ω-3, 6 and 9.

Extraction and characterization of radish seed oils using different methods

Purpose: To evaluate the impact of three different extraction methods on oil yield, physicochemical properties and bioactive ingredients of radish seeds. Methods: Radish seed oil was prepared by traditional solvent extraction (SE), supercritical carbon dioxide extraction (SCE) and sub-critical propane extraction (SPE). The yield, physicochemical properties, fatty acid composition and oxidative stability of the oil extracts were compared. The contents of tocopherol and sulforaphene in the oils were also determined. Results: The oil yield obtained by SPE, SE, SCE were 33.69, 27.17 and 24.10 %, respectively. There were no significant differences in physicochemical properties and fatty acid composition of oils extracted by the three methods. However, SCE oil had the best oxidative stability, and highest contents of vitamin E and sulforaphene, followed by oils from SPE and SE Conclusion: SCE is highly selective for tocopherol and sulforaphene, which could explain its high oil oxidative stability. These results suggest that of the three extraction methods, SCE is best suited for preparing medicinal radish seed oil. Keywords: Radish seed oil, Different extraction methods, Fatty acid composition, Tocopherol, Sulforaphene

Extraction and characterization of <i>Raphanus Sativus</i> seed oil obtained by different methods

Purpose: To evaluate the impact of three different extraction methods on yield, physicochemical properties and bioactive ingredients of Raphanus sativus seed oil.Methods: Raphanus sativus seed oil was prepared by traditional solvent extraction (SE), super-critical carbon dioxide extraction (SCE) and sub-critical propane extraction (SPE). The yield, physicochemical properties, fatty acid composition and oxidative stability of the oil extracts were compared. The contents of tocopherol and sulforaphene in the oils were also determined.Results: The oil yield obtained by SPE, SE and SCE were 33.69, 27.17 and 24.10 %, respectively. There were no significant differences in physicochemical properties and fatty acid compositions of oils extracted by the three methods. However, SCE oil had the best oxidative stability, and highest contents of vitamin E and sulforaphene, followed by oils from SPE and SE.Conclusion: SCE is highly selective for tocopherol and sulforaphene, which could explain its high oil oxidative stability. These results suggest that of the three extraction methods, SCE is best suited for preparing medicinal radish seed oil.Keywords: Raphanus sativus seed oil, Different extraction methods, Fatty acid composition, Tocopherol, Sulforaphene

High efficiency metal removal from hexane-extracted algae oil using super and subcritical propane

As a renewable energy source, oil-producing algae have received much attention in recent years. Raw oil, which is normally extracted from algae using solvents such as hexane or ethyl acetate, includes trace metal compounds that rapidly deactivate the hydrogenation catalyst. In this study, metal removal from hexane-extracted algae oil with supercritical and subcritical propane extraction was examined at temperatures from 40°C to 130°C and at 6MPa pressure. The results showed that the metal concentration became decreasing with temperature increasing and metals were not detectable at 114°C. Using these results, an energy saving process was proposed. Simulation results showed that the metal removal required a mere 3–4% energy consumption compared to a lower heating value of raw oil.

Preparation and characterization of foxtail millet bran oil using subcritical propane and supercritical carbon dioxide extraction.

The foxtail millet (Setaria italica Beauv) bran oil was extracted with traditional solvent extraction (SE), supercritical carbon dioxide extraction (SCE) and subcritical propane extraction (SPE) and analyzed the yield, physicochemical property, fatty acid profile, tocopherol composition, oil oxidative stability in this study. The yields of foxtail millet bran oil by SE, SCE and SPE were 17.14%, 19.65%, 21.79% of raw material weight (corresponded to 75.54%, 86.60%, 96.03% of the total amount of the oil measured by using Soxhlet extraction), respectively. The effect of the extraction methods on the physicochemical properties (peroxide value, saponification value and color) was significant while the difference in fatty acid profile was negligible based on GC analysis. The major components of vitamin E in the obtained oils were identified as α- and β-tocopherols by HPLC, and SPE was superior to SE and SCE in the extraction of tocopherols. In Rancimat test, the oil obtained by SPE showed the highest oil oxidative stability, which could attribute to its high tocopherol content and low peroxide value. In view of oil quality, SPE employed smaller times and lower pressures compared to SE and SCE. SPE was a suitable and selective method for the extraction of the foxtail millet bran oil.

Changes in the chlorophyll and carotenoid content and composition of ground thyme leaves as a function of supercritical carbon dioxide and subcritical propane extraction

This work was conducted to study the changes in the content and composition of chlorophylls and carotenoids in ground thyme leaves as a function of supercritical carbon dioxide and sub-critical propane extraction. the results indicated that the maximum oleoresin yield could be obtained with supercritical carbon dioxide at 400 bar and 35 or 55 °C and sub-critical propane at 50 bar. Pigment solvating capacity of supercritical carbon dioxide increased with the increase of extraction pressure. Substantial variation was noticed in pigment composition between raw material, oleoresin and residues (powders after extraction). Chlorophyll b, chlorophyll a and the Mg-free derivatives were the dominant pigments in the raw material with other derivatives being minor constituents. After extraction with supercritical carbon dioxide at 35 °C and pressures higher than 200 bar, epimerisation and oxidation of chlorophylls lead to marked accumulation of artefacts in the residues. The content of oxidized chlorophylls was incr...

Extraction of cardamom oil by supercritical carbon dioxide and sub-critical propane

Supercritical CO 2 and sub-critical propane extraction conditions on quality attributes of cardamom oil were studied. The yield and solvent extractability were examined as a function of extraction conditions such as temperature, pressure and solvent/solid ratio. Of the quality components of the recovered oil, pigments (chlorophylls and carotenoids), volatile constituents, fatty acids and tocopherols, were determined by high-performance liquid chromatography (HPLC) and gas chromatography–mass spectroscopy (GC–MS). Cardamom was found easy-to-extract by fluid CO 2 even at sub-critical conditions with very cost-effective ratio of solvent/solid. However, the maximum level of natural pigments and antioxidants achieved was found in extracts recovered by supercritical fluid CO 2 and sub-critical propane. Addition of ethanol to CO 2 up to 25% did not improve the extractability of fatty acids, but had negative effect on aroma profile and positively affected the natural pigment of the extract. Propane was found to be more capable than CO 2 to recover seed oil at sub-critical conditions with lower ratio of solvent/solid and better quality attributes. Supercritical fluid extraction conditions affected to some extent fatty acid composition and content of volatiles in the recovered extracts.

Improved methods for decolorizing corn zein

The yellow color of corn and corn processing co-products is due to xanthophylls and β-carotene. Colorless zein commands a premium price and the resulting extracted carotenoids possess nutraceutical value. Our objectives were to devise methods for decolorizing zein and develop methodology to quantify color removal. Decolorizing methods include: subcritical propane and supercritical fluid extraction with carbon dioxide of zein with ethanol entrainers; ultrafiltration/diafiltration on a tangential flow system; partitioning with toluene; column chromatography on Sephadex LH-60; batch treatment with activated carbon. Residual color was assessed by dissolving zein control or decolorized product in glacial acetic acid, filtration, and reading absorbances of dilutions at 448 nm. Analysis of covariance from comparative logarithmic regressions of control zein and decolorized product dilutions was evaluated to determine the extent of residual color. Because, a covariate by treatment interaction was detected in treatments for supercritical fluid extractions an Analysis of Variance model comparing treatment method means at each dilution factor level was used. Results showed that subcritical propane extraction of zein with ethanol entrainer gave the least color removal. A commercial white zein possessed a similar degree of residual color as did ethanolic zein solutions partitioned with toluene. Almost complete removal was achieved by extractions of zein from corn gluten meal followed by batch treatment of those extracts with activated carbon. However, recovered yield was lowest with this procedure. Supercritical fluid extraction with carbon dioxide of zein with 15% ethanol entrainer for 15 min at 68,950 kPa and 70 °C decolorized zein slightly less than did either the column chromatographic method with Sephadex LH-60 or a diafiltration of zein ethanolic solutions ultrafiltered through the 5000 Da molecular weight cut-off membrane. These three methods gave excellent recoveries of decolorized zein product. The supercritical fluid method has the advantages of no need to spray-dry the final product and does not require the copious volumes of ethanol needed for color removal by the other methods. This method would utilize the carbon dioxide and ethanol byproducts generated by the fermentation process used for producing ethanol.

Supercritical CO(2) and subcritical propane extraction of pungent paprika and quantification of carotenoids, tocopherols, and capsaicinoids.

Ground paprika (Capsicum annuum L.) was extracted with supercritical carbon dioxide (SC-CO(2)) and subcritical propane at different conditions of pressure and temperature to estimate the yield and variation in carotenoid, tocopherol, and capsaicinoid contents and composition. The yield of paprika extract was found to be affected by the extraction conditions with SC-CO(2) but fairly constant at different conditions with subcritical propane. The maximum yields of oleoresin were 7.9 and 8.1% of ground paprika by SC-CO(2) and subcritical propane, respectively. The quantitative distribution of carotenoids, tocopherols, and capsaicinoids between paprika extract and powder was influenced by extraction conditions. SC-CO(2) was inefficient in the extraction of diesters of xanthophylls even at 400 bar and 55 degrees C, whereas tocopherols and capsaicinoids were easy to extract at these conditions. Under mild conditions subcritical propane was superior to SC-CO(2) in the extraction of carotenoids and tocopherols but less efficient in the extraction of capsaicinoids.

Supercritical CO2 and Subcritical Propane Extraction of Spice Red Pepper Oil with Special Regard to Carotenoid and Tocopherol Content

A study is conducted to optimize the supercritical fluid extraction of spice paprika oil (oleoresin) using supercritical (SF) CO 2 and subcritical propane as the solvents. The main focus is on carotenoid and tocopherol composition as the quality attributes of technological and nutritional interest. The maximum oil yield is 7.2 and 8.8 g per 100 g paprika with SF-CO 2 and subcritical propane, respectively. For the implementation of complete extraction at the given conditions, the ratio of solvent to solid is found to be 6.0 and 1.0 using SF-CO 2 and propane, respectively. The carotenoids, particularly fatty acid esters of red xanthophylls, are hardly solubilized by SF-CO 2 , whereas with subcritical propane, 80-94% of such components could be mildly extracted. Tocopherols were easy to extract using either fluid, with propane being the most efficient solvent. The result of the impact of extraction conditions on the major carotenoids (such as capsanthin monoester, β-carotene, capsorubin diesters, and capsanthin diesters, as well as α-, β- and γ-tocopherol) are tabulated with special focus on the degree of loss during extraction by the two solvents.