Supercritical extraction of evening primrose oil: Experimental optimization via response surface methodology

Supercritical carbon dioxide (CO₂) effective extraction parameters (pressure, temperature, static extraction time, and dynamic extraction time) of oil recovery from evening primrose seeds were optimized via response surface methodology (RSM). The results of this study indicated that the linear terms of static and dynamic time and the quadratics of temperature and pressure, as well as the interactions of temperature and static time, pressure and temperature had a significant effect on the oil recovery. The optimum extraction conditions of 14.2 MPa, 47.3°C, 30 min (static extraction time) and 150 min (dynamic extraction time) were obtained. Applying the optimum conditions, a mean experimental recovery of 92.98% (triplicate experiment) was achieved, which is well compatible with the RSM‐predicted value (93.61%). The fatty acid composition of extracted evening primrose oil using supercritical CO₂ was compared with that obtained by Soxhlet method in which minor difference was observed. © 2011 American Institute of Chemical Engineers AIChE J, 2011     

Supercritical carbon dioxide extraction of oil from Mexican chia seed (Salvia hispanica L.): Characterization and process optimization

Supercritical carbon dioxide (SC-CO₂) was employed to extract oil rich in omega-3 fatty acids (FAs) from chia seeds, and the physicochemical properties of the oil were determined. A central composite rotatable design was used to analyze the impact of temperature (40 °C, 60 °C and 80 °C), pressure (250 bar, 350 bar and 450 bar) and time (60 min, 150 min and 240 min) on oil extraction yield, and a response surface methodology (RSM) was applied. The extraction time and pressure had the greatest effects on oil. The highest oil yield was 92.8% after 300 min of extraction time at 450 bar. The FA composition varied depending on operating conditions but had a high content of α-linolenic acid (44.4-63.4%) and linoleic acid (19.6-35.0%). The rheological evaluation of the oils indicated a Newtonian behavior. The viscosity of the oil decreased with the increase in temperature following an Arrhenius-type relationship.     

Modeling and optimization of process parameters for supercritical CO2 extraction of Argemone mexicana (L.) seed oil

This research article deals with the determination of optimal conditions of extraction parameters (e.g. temperature (60–100?°C), pressure (200–350?bar), particle size (0.5–1.0?mm), flow rate-CO₂ (5–15?g/min), and the % of co-solvent (0.0–10% of flow rate-CO₂) resulting to the optimal cumulative extraction yield during the supercritical fluid extraction of Argemone mexicana (L.) seed oil with and without a modifier (ethanol) using a supercritical carbon dioxide as solvent. A “five-factors-three-levels” Box-Behnken design under the response surface methodology was used to show independent and interactive effects of extraction parameters. A mathematical regression model was expressed properly by a quadratic second-order polynomial equation. The maximum oil yield (42.86%) from A. mexicana seeds was obtained with the optimal conditions (85?°C, 305?bar, 0.75?mm, 11?g/min, and 9% of flow rate-CO₂) of extraction parameters. The fatty acids analysis of the seed oil was done using gas chromatography and found its suitability as bio-fuel.     

Solvent-assisted extraction of oil from papaya (Carica papaya L.) seeds: evaluation of its physiochemical properties and fatty-acid composition

ABSTRACT

The present work reports the solvent-assisted extraction of oil from papaya (Carica papaya L.) seeds. Various operating parameters such as solid solvent ratio, temperature and time on oil yield, and its effects have been investigated using response surface methodology. The experimental oil yield (20.30 ± 0.03%) at optimal condition was well agreed with the predicted value. The compositions from GC-FID results showed saturated fatty acid (20.94%), monounsaturated fatty acid (73.12%), and polyunsaturated fatty acid (4.96%). It was also found that the solvent-assisted extraction is a simple and effective method for extraction of oil from papaya seeds.     

Steaming,boiling after pre-frying,and stir-frying influence the fatty acid profiles and oxidative stability of soybean oil blended with docosahexaenoic acid algal oil

The objective of this study was to improve the content of docosahexaenoic acid (DHA) and obtain the blended oils used for different cooking methods (steaming, boiling, and stir-frying) by blending 0%–15% DHA algal oil into soybean oil. It was shown that the addition of DHA algal oil increased saturated fatty acid (SFA) (1.57%) but decreased monounsaturated fatty acid (MUFA) (0.76%) and polyunsaturated fatty acid (PUFA) (0.68%). Various cooking methods significantly changed the fatty acid (FA) compositions. Steaming is a more effective way to prevent DHA loss and the production of trans-fatty acid than boiling and stir-frying. Besides, a positive result from free fatty acid (FFA) and peroxide value also demonstrated that steaming was a better way to protect oils. Overall, the soybean oil blended with 3% DHA algal oil with better oxidative stability and could be recommended for daily application by steaming.     

Response surface optimization of Smyrnium cordifolium Boiss (SCB) oil extraction via supercritical carbon dioxide

In this study, the essential oil of aerial parts of a species of a plant called Smyrnium cordifolium Boiss (SCB) was extracted by supercritical CO₂. The essence was analyzed by the method of GC/MS. Design of experiments was carried out with response surface methodology by Minitab 16 software to optimize four operating variables of supercritical carbon dioxide (SC-CO₂) extraction (pressure, temperature, CO₂ flow rate and extraction dynamic time). This is the first report announcing optimization of the operation of supercritical extraction of SCB in laboratorial conditions. Optimizing process was done to achieve maximum yield extraction. Independent variables were dynamic time (t_d), pressure (P), temperature (T) and flow rate of SC-CO₂ (Q) in the range of 30–150 min, 10–30 MPa, 40–60 °C and 0.5–1.7 ml/min, respectively. The experimental optimal recovery of essential oil (0.8431, w/w%) was obtained at 13.43 MPa, 40 °C, 150 min (dynamic) and 1.7 ml/min (CO₂ flow rate).     

Supercritical extraction of grape seed oil at industrial-scale: Plant and process design,modeling, economic feasibility

The aim of this paper is to present the results of a study on the possible use of exhausted grape marc for obtaining grape seed oil by means of the supercritical technology. An industrial-scale supercritical extraction plant (three extractors in series working in the counter-current mode) has been designed based on the availability of grape seeds of a region in the north of Italy, namely 3000 ton/year (3 × 10⁶ kg/year). The process has been analyzed in depth and modeled and the results indicate that the proposed industrial application could be economically interesting: the breakeven point, which makes the process economically sustainable, is a value of 5.9 €/kg for the supercritical extracted grape seed oil.     

PGS-COM: A hybrid method for constrained non-smooth black-box optimization problems: Brief review,novel algorithm and comparative evaluation

In the areas of chemical processes and energy systems, the relevance of black-box optimization problems is growing because they arise not only in the optimization of processes with modular/sequential simulation codes but also when decomposing complex optimization problems into bilevel programs. The objective function is typically discontinuous, non-differentiable, not defined in some points, noisy, and subject to linear and nonlinear relaxable and unrelaxable constraints. In this work, after briefly reviewing the main available direct-search methods applicable to this class of problems, we propose a new hybrid algorithm, referred to as PGS-COM, which combines the positive features of Constrained Particle Swarm, Generating Set Search, and Complex. The remarkable performance and reliability of PGS-COM are assessed and compared with those of eleven main alternative methods on twenty five test problems as well as two challenging process engineering applications related to the optimization of a heat recovery steam cycle and a styrene production process.     

Application of response surface methodology for the optimization of supercritical carbon dioxide extraction and ultrasound-assisted extraction of Capparis spinosa seed oil

Caper (Capparis spinosa) seed oil growing wild in Iran was extracted using supercritical CO₂ and ultrasound-assisted extraction methods. The experimental parameters of SFE and UAE were optimized using a rotatable central composite design. The highest yield for SFE was obtained at a pressure of 355 bar, temperature of 65 °C, modifier volume of 140 μL, static and dynamic extraction time of 10 and 35 min, respectively, and for UAE was gained at solvent volume of 23 mL, sonication time of 45 min and temperature of 40 °C. This resulted in a maximum oil recovery of 25.1% and 27.9% for SFE and UAE, respectively. The extracts with higher yield from both methods were subjected to transesterification and GC–MS analysis. SFE and UAE processes selectively extracted the fatty oils with high percentage of omega-6 and omega-9-fatty acids. The major components of the extracted oils from both methods were linoleic, oleic, its positional isomer cis-vaccenic and Palmitic acid.     

Fatty acid composition, extraction, fractionation, and stabilization of bullfrog (Rana catesbeiana) oil

The oil extracted from the fat-storage organ (fat body) of the bullfrog (Rana catesbeiana) was characterized for its fatty acid composition. The main fatty acids were palmitic (18.1%), stearic (4.1%), myristic (2.7%), oleic (31.7%), and linoleic (12.9%) acids. Long-chain polyunsaturated fatty acids were also present in significant amounts, i.e., eicosapentaenoic (1.5%) and docosahexaenoic (4.7%), and were probably derived from the fish meal content of the diet. A partially fractionated oil was extracted from the homogenized and frozen fat body with an oleic acid content of 43.2%. The natural alkaloid boldine, added at 0.5 mg/g oil level, improved the oxidative stability by a factor ranging from 1.7 to 2.4, as assessed by the Oil Stability Index method between 90 and 110°C. The stabilization effect of boldine was higher than that of naringenin, morin, and quercitin and for the synthetic antioxidant butylated hydroxytoluene at the same concentration level.     

Fabrication of gelatin/chitosan nanofibrous scaffold: process optimization and empirical modeling

Electrospinning is a very useful technique for producing polymeric nanofibers by applying electrostatic forces. This study reports on the modeling and optimization of the electrospinning process of gelatin/chitosan, using response surface methodology. The individual and the interaction effects of the gelatin/chitosan blend ratio (50/50, 60/40 and 70/30), applied voltage (20, 25 and 30 kV) and feeding rate (0.2, 0.4 and 0.6 mL h^?1) on the mean fiber diameter and standard deviation of the fiber diameter were investigated on optimization section, using scanning electron microscopy. To fabricate the nanofibrous gelatin/chitosan blend, trifluoroacetic acid/dichloromethane was selected as the solvent system. The model obtained for the mean fiber diameter has a quadratic relationship with applied voltage and feeding rate. The interaction between applied voltage and flow rate were found significant but the interactions of blend ratio and flow rate and also blend ratio and applied voltage were negligible. A quadratic relationship was obtained for applied voltage and flow rate with standard deviation of the fiber diameter and there was no interaction between the parameters in the model. The optimum condition for electrospinning of gelatin/chitosan was also introduced using the model obtained in this study. Scanning electron micrographs of human dermal fibroblast cells on the nanofibrous structures show good attachment and proliferation on the fabricated scaffold surface. Electrospun gelatin/chitosan nanofibrous mats have great potential for use as a scaffold for skin tissue engineering. © 2014 Society of Chemical Industry     

Vernolic and cyclopropenoid fatty acids in Plectranthus mollis,syn. Plectranthus incanus,link seed oil: A rich source of oil

Plectranthus mollis, syn. Plectranthus incanus Link seed oil contains the following acids: palmitic (7.2%), stearic (13.6%), oleic (21.7%), linoleic (46.5%), malvalic (2.3%), sterculic (3.2), and vernolic (6.1%).     

Comparison of solvent systems on extraction,quality characteristics,and volatile compounds of palm kernel oil

Hexane (HEX) and dichloromethane (DCM) have been used to extract oils from various sources due to their expansive solubility and low volatility that ease removal at low temperatures. However, environmental and health concerns make them undesirable solvents. The aim of this study was to evaluate the extraction efficiency and physicochemical characteristics of palm kernel oil (PKO) extracted with the addition of acetone in HEX-acetone (1:1, vol/vol) and DCM-acetone (1:1, vol/vol) mixtures as an alternative to DCM and HEX alone. PKO extracted with co-solvent systems had better quality characteristics compared with single solvent extracts. The oil recovered, free fatty acid content, peroxide value and other quality characteristics, and thermal properties were within the range for PKO, and similar oils as stipulated in standards. Monounsaturated fatty acid content in PKO was up to 70% of which lauric acid was the most abundant (48%–52%). A total of 50 volatile compounds were identified by GC–MS in all the extracts including amide (1), alcohol (1), aldehydes (2), ketones (3), acids (6), esters (6) and hydrocarbons (31) with higher numbers of volatiles in the HEX extracts compared to the DCM extracts. Dodecanoic acid, hexanal, and 2-undecanone were the most abundant acid, aldehyde, and ketone, respectively. Principal component analysis (PCA) differentiated the volatiles identified on the polar and non-polar columns with 88.2% and 8.8%, and 67.3% and 19.6% of the variation accounted for by PC1 and PC2, respectively, with several common volatile components forming a cluster from all the solvents used.     

Deep eutectic solvents aqueous two-phase system based ultrasonically assisted extraction of ursolic acid (UA) from Cynomorium songaricum Rupr.

Deep eutectic solvents (DESs) are new green solvents that have attracted the attention of the scientific community mainly due to their unique properties and special characteristics, which are different from those of traditional solvents. A method based on ultrasonically assisted deep eutectic solvent aqueous two-phase systems (UAE-DES-ATPS) was developed for extracting ursolic acid (UA) from Cynomorium songaricum Rupr. Four different types of choline chloride-based DESs were prepared. Choline chloride-glucose (ChCl-Glu) exhibited good selective extraction ability. An optimum DES-ATPS of 36% (w/w) ChCl-Glu and 25% (w/w) K₂HPO₄ was considered to be a satisfactory system for extracting UA. Response surface methodology (RSM) method was utilized to optimize the extraction of UA using UAE-DES-ATPS. The quadratic models were extremely significant (p?<?0.01) for all the parameters studied with high correlation coefficients (R²) of 0.9593. The optimum ultrasound-assisted conditions were as follows: solvent to solid ratio of 15:1 (g/g), ultrasound power density of 4.7?W·mL^?1, and extraction time of 54?min. Compared with the conventional UAE method, the yields were basically the same, but the presented method had higher purity. The structure of UA did not change between pure UA and UA in the upper phase using UV–vis and FT-IR. This approach using ChCl-based DES-ATPS as a novel extraction system and ultrasound as a source of energy provided a better choice for the separation of active components from other natural products.     

琼榄果实油提取工艺优化及其脂肪酸成分分析

比较了索氏提取法、超声提取法、加速溶剂萃取法对南药琼榄果实油的提取率。通过正交实验优化了超声提取法的工艺条件,气质联用(GC-MS)法测定了3种方法所提油脂的脂肪酸的成分及相对质量分数。优化后的最佳工艺条件为:每1 g琼榄果实粉溶于9 mL石油醚中(即料液比为1∶9,下同),超声时间10 min,超声功率400W,超声温度70℃。在该条件下,得油率可达31.32%。GC-MS分析表明,3种方法提取的琼榄油中分别含有7、9、8种脂肪酸,其中相对质量分数最高的是13-十八碳烯酸(70.86%、68.71%、69.92%),其次是十六酸(棕榈酸)(17.58%、19.95%、18.73%),再次是十八碳二烯酸(5.12%、6.00%、5.96%)。不饱和脂肪酸占脂肪酸总量达80.61%、78.68%、79.88%。     

A minor source of vernolic,malvalic, and sterculic acids inPithecollobium dulce (syn.Inga dulcis) seed oil

Pithecollobium dulce, Benth (syn.Inga dulcis, Willd) seed oil, belonging to the Leguminosae plant family, contains minor amounts of vernolic acid (12,13-epoxy-octadec-cis-9-enoic acid, 10.0%), malvalic acid [7-(2-octacyclopropen-1-yl)heptanoic acid, 3.2%], and sterculic acid [8-(2-octacyclopropen-1-yl)octanoic acid, 2.0%]. The other normal fatty acids are palmitic (12.1%), stearic (4.2%), behenic (10.6%), oleic (34.1%), and linoleic (23.8%). These fatty acids have been characterized by Fourier transform infrared,¹H nuclear magnetic resonance, mass spectrometry and gas-liquid chromatography techniques and by chemical degradations.     

Modeling and optimization of the process parameters in vacuum drying of culinary banana (Musa ABB) slices by application of artificial neural network and genetic algorithm

The influence of drying temperature, sample slice thickness, and pretreatment on quality attributes like rehydration ratio, scavenging activity, color (in terms of nonenzymatic browning), and texture (in terms of hardness) of culinary banana (Musa ABB) has been evaluated in the present study. A comparative approach was made between artificial neural network (ANN) and response surface methodology (RSM) to predict various parameters for vacuum drying of culinary banana. The effect of process variables on responses during dehydration were investigated using general factorial experimental design. This design was used to train feed-forward back-propagation ANN. The predictive capabilities of these two methodologies for optimization of process parameters were compared in terms of relative deviation (R_d). Results revealed that a properly trained ANN model is found to be more accurate in prediction as compared to RSM. The optimum condition selected from ANN/GA responses on the basis of highest fitness value revealed that culinary banana slices of 6 mm thickness pretreated with 1% citric acid and dried at 76°C resulted in a maximum rehydration ratio of 6.20, scavenging activity of 48.63% with minimum nonenzymatic browning of 25%, and hardness of 43.63 N. Results further revealed that, in the case of rehydration ratio, temperature and pretreatment showed a positive effect while thickness had a negative effect. On the contrary, for scavenging activity, temperature showed the highest negative effect followed by slice thickness and positive effect with pretreatment. For nonenzymatic browning, thickness showed the highest negative effect but temperature and pretreatment showed a positive effect. Similarly, for hardness, all three parameters showed a negative effect.     

Adsorption of FFA in crude catfish oil onto chitosan,activated carbon,and activated earth: A kinetics study

The feasibility of using chitosan, activated carbon, and activated earth to remove FFA from crude catfish visceral oil, and the adsorption kinetics of the procedure were evaluated. The effect of adsorbents on water activity and the 18∶3 and 22∶6 content of crude catfish visceral oil was also studied. The initial adsorption kinetic coefficients of FFA (mL g⁻¹ min⁻¹) were 0.1, 0.07, and 0.03 for chitosan, activated carbon, and activated earth, respectively. The external film mass-transfer coefficient (0.001 mL s⁻¹) was similar for the three adsorbents. The adsorption capacity of FFA at saturation (mg g⁻¹) was 71.2 for chitosan, 65.5 for activated carbon, and 57.0 for activated earth. The intraparticular diffusion coefficients (mg mL⁻¹ min^−0.05) were 0.14, 0.12, and 0.09 for chitosan, activated carbon, and activated earth, respectively. Water activity of the crude oil decreased with increased contact time of the adsorbents. Results indicated that chitosan was a better adsorbent than activated carbon and activated earth for FFA removal from crude catfish visceral oil.     

Empirical modeling development for integrated process optimization of poly(3-hydrxybutyrate-co-3-hydroxyvalerate) production

The optimization of P(3HB-co-3HV) synthesis was investigated using response surface methodology (RSM). Primary experiments showed different concentrations of 1-pentanol, agitation rates, and incubation times were the main factors influencing the production of this copolymer. To test the influence of the process parameters, two statistical experimental designs were performed. The first step of optimization used two-level factorial designs to determine the significant variables affecting the growth and production. The RSM model was experimentally validated yielding a maximum of 65 wt % PHA content and 10.2 g/L cell dry weight, which represent 12.1% increase in PHA content in comparison to the non-optimized condition using oleic acid and 1-pentanol as the carbon source and carbon precursor, respectively. The experimental results showed that the RSM was a useful tool as the utilization of 1-pentanol by Cupriavidus sp. USMAA2-4 was reduced by 33%. A second-order polynomial equation was obtained by multiple regression analysis to explain the combined effect of the three parameters with the coefficient of determination, R², greater than 0.9. The optimum process conditions and interactions were determined by analyzing three-dimensional surfaces. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012