Micelle-Mediated Extraction and Cloud Point Preconcentration of Chlorophylls from Spinach

A micelle-mediated extraction and cloud point preconcentration of chlorophylls method was developed. Non-ionic surfactant (Genapol X-080) was employed as an alternative and effective extraction solvent. The optimal extraction parameters based on the micelle extraction technique were determined. Under optimal conditions, i.e., 5% Genapol X-080 (v/v), pH 9.0, liquid/solid ratio of 10:1 (mL g^?1), ultrasonic-assisted extraction for 30 min, extraction amount reached the highest value. For the preconcentration of chlorophylls by cloud point extraction (CPE), the solution was incubated at 50° for 30 min, and 0.1 g mL^?1 sodium chloride was added to the solution to facilitate the phase separation. The microstructure of coacervate phase after CPE was explored with transmitting electron microscopy. The preconcentration factor for chlorophylls was about 12.5, the extraction recovery approached 99.2%, and the loading capacity was about 1 mg mL^?1. Thus coupling of ultrasonic-assisted micelle extraction and cloud point extraction could be employed as a new and effective technique for the rapid extraction and preconcentration of chlorophylls from plants such as spinach.     

Extraction of Caffeine with Annular Centrifugal Contactors

Abstract

An extraction process for caffeine has been developed with annular centrifugal contactors. The caffeine distribution ratio in the mother solution effluent‐chloroform system was measured to be about 18.6. Both the pilot tests and the plant tests have been completed with Φ20 mm and Φ230 mm annular centrifugal contactors, respectively. The extraction rate higher than 99% was achieved in the pilot tests, when the rotor speed was 3000‐4500 r/min, the total flow was 20‐80 mL/min, and the flow ratio (A/O) was 2/1. When the rotor speed was 1800 r/min, the mother solution flow was 2000 L/h, and the chloroform flow was 1000 L/h; the extraction rate was also more than 99% in the plant tests.     

Influence of operating variables on yield and quality parameters of olive husk oil extracted with supercritical carbon dioxide

Supercritical fluid extraction is a viable alternative process for extracting oil from olive husk, a residue obtained in the olive oil production. We analyzed the effects of pressure (P) (100–300 bar), temperature (T) (40–60°C), solvent flow (1–1.5 L/min), and particle size (D) (0.30–0.55 mm) on extraction yield, and three oil-quality parameters: acidity (OA), PV, and phosphorus content (PC). A response surface methodology based on the statistical analysis of the experimental data permitted us to obtain mathematical expressions relating the operational variables and parameters studied. At the best extraction condition of the experimental range analyzed (P=300 bar, T=60°C, D=0.30 mm, and solvent flow=1.25 L/min at standard conditions), the oil yield was 80% (w/w) with respect to hexane extraction, whereas the quality parameters OA, PV, and PC were 14% (w/w), 8 meq/kg, and 2.3·10⁻³% (w/w), respectively. These results were compared to those obtained by hexane Soxhlet extraction. The quality of the supercritical extract was superior, requiring only simple refining. This advantage may result in improved economics of the supercritical process in relation to the conventional extraction with hexane.     

Natural Pigments Extraction from Basella rubra L. Fruits by Ultrasound-Assisted Extraction Combined with Box-Behnken Response Surface Design

In this study, natural pigments from Basella rubra L. were extracted by ultrasound-assisted extraction (UAE) technique using three levels, four factors (extraction temperature, ultrasonic power, extraction time and solid-liquid (SL) ratio) Box-Behnken response surface design. The optimal condition was found to be: extraction temperature of 54°C, ultrasonic power of 94 W, extraction time of 32 min and SL ratio of 1:17 g/mL respectively. Under this optimal condition, the experimental yield of (betacyanin of 1.42 ± 0.001 and betaxanthin of 5.35 ± 0.13 mg/g) pigments were well correlated with predicted values (betacyanin was 1.43 mg/g and betaxanthin was 5.37 mg/g).     

Cloud Point Extraction of Nitrobenzene using TX-100

Cloud point extraction (CPE) is carried out to extract nitrobenzene (NB) from aqueous solution using TX-100 as a nonionic surfactant. The effects of different operating parameters, like concentration of the feed mixture (both NB and surfactant), pH, temperature, and the presence of mono- and di-valent salts on the extraction of both the NB and surfactant have been studied in detail. The solubilization behavior of the NB in the surfactant micelle has been observed in the temperature range of 75°C to 90°C. Concentrations of surfactant and NB have been considered in the range of 0.03 M to 0.25 M and 100 mg/L to 400 mg/L, respectively. An optimum set of surfactant concentration, temperature, and salt concentration is obtained for the removal of NB from aqueous medium. The effects of temperature and concentrations of surfactants and NB on various thermodynamic parameters, like change in Gibbs-free energy (ΔG ⁰), change in enthalpy (ΔH ⁰), and change in entropy (ΔS ⁰) are observed and explained well. Experimental investigations have also been carried out for the recovery of the surfactant from the dilute phase applying solvent extraction (SE) in batch condition using heptane and hexane as the extracting medium.     

Cloud Point Extraction of Acetic Acid from Aqueous Solution

Abstract

A new acetic acid separation method was developed through a successful combination of cloud point extraction and complex extraction technology (CPE-SE), where an acetic acid complex compound formed and was solubilized in a surfactant micelle solution, instead of an organic solvent, and then concentrated into one phase by a phase separation process of the CPE technology. Since no organic solvent diluents were used, the new process was environmentally friendly and with a lower cost; meanwhile, the high selectivity of the complex extraction based on chemical complexation and high efficiency of CPE were also inherited as advantages over conventional solvent extraction process. In consideration of the compatibility and the related CPE characteristics, tributyl phosphate and PEG/PPG-18/18 Dimethicone were selected as complexing agent and surfactant of the CPE-SE system, respectively, and the extraction system was optimized by studying the effect of the main process parameters, including surfactant and complexing agent concentration, temperatures for the stirring and incubation steps, on the recovery and the distribution coefficient. A relative high recovery of 71.4% and a distribution coefficient of 1.4 were achieved simultaneously with the optimized process in the treatment of 0.1 M acetic acid solution. Based on its competitive extractability, high efficiency, low-cost, and environment friendlyness, the CPE-SE process was expected to be a potential separation method for a dilute acetic acid solution.     

Optimization of Microwave-Assisted Extraction of Cherry Laurel Fruit

Response surface methodology was used to optimize the influence of microwave power (300–600 W), plant material-to-solvent ratio (0.05–0.2 g/cm³), and extraction time (10–30 min) on the efficiency of microwave-assisted extraction of the cherry laurel (Prunus laurocerasus L.) fruit. From experimental data, a quadratic polynomial mathematical model (R² = 0.9949) was developed to predict the extract yield. All considered factors were statistically significant for extraction efficiency, while the most important factor was extraction time. Microwave power of 550 W, plant material-to-solvent ratio of 0.05 g/cm³, and time of 25 min were determined as optimal conditions with a maximum yield of 9.36 g/100 g fresh plant material, which was confirmed through laboratory experiments (9.12 ± 0.61 g/100 g fresh plant material). An economic condition for simultaneous maximum extract yield (7.58 g/100 g fresh plant material) with minimal energy and solvent consumption was determined by the desirability function method (18.2 min, 300 W, and 0.2 g/cm³). Additionally, the total phenol and flavonoid quantification and antioxidant activity of both extracts were tested. There is no statistically significant difference in the total flavonoid content in the extracts obtained under both proposed conditions, while the total phenolic content and antioxidant activity of the extract obtained under economic conditions were slightly lower.     

Cloud point and solvent extraction study of uranium(VI) by 8‐hydroxyquinoline

BACKGROUND: Cloud point extraction (CPE) is an attractive alternative to solvent extraction. However, comparisons between both techniques are lacking. In this paper, the extraction of uranium(VI) using 8‐hydroxyquinoline (HQ) as chelating agent was studied by CPE using Triton X‐114 as non‐ionic surfactant and by solvent extraction using CHCl₃ as diluent. RESULTS: Using CPE, a quantitative extraction was observed for pH higher than 4.5 with a HQ/U ratio of 10. Using solvent extraction an increase in the HQ/U ratio up to 50 is necessary to obtain a near quantitative extraction. Both extraction systems were then compared with respect to the nature of extracted species, and the extraction constants determined using log‐log analysis of the extraction data. In the solvent extraction system, the extracted species were identified as UO₂Q₂ and the corresponding extraction constant was found to be log k_ex = ? 3.6 ± 0.2 on the molar scale. Considering that UO₂Q₂ is also the extracted species in CPE, a slightly higher extraction constant, i.e. log k_ex = ? 2.5 ± 0.3, was found. CONCLUSION: Such a small difference in favour of the CPE system may arise from the combination of various phenomena, including effects of temperature and effects of ‘extractant environment’. However, a change in the nature of the extracted species, namely from UO₂Q₂ in the solvent extraction system to the formation of adducts, i.e. UO₂Q₂(HQ) and UO₂Q₂(HQ)₂ in the CPE system, due to higher HQ concentration in the surfactant‐rich phase compared with chloroform, cannot be precluded, but requires confirmation. Copyright © 2012 Society of Chemical Industry     

Kinetics of Ultrasound-Assisted Polyphenol Extraction from Spent Filter Coffee Using Aqueous Glycerol

Culinary filter coffee residues were utilized as raw material, with the aim of recovering functional polyphenolic components. The extraction was performed under ultrasonication using aqueous glycerol, and for this reason, the process was initially optimized with regard to glycerol concentration (C_gl) and extraction time (t), by implementing response surface methodology via a central composite (Box-Behnken) experimental design. The optimized conditions determined were C_gl = 3.6% (w/v) and t = 175 min. The comparative assessment, based on a kinetic assay, illustrated that the progression of the extraction was slower in aqueous glycerol than in water, yet aqueous glycerol was proven a more efficient extraction medium, providing 7.4% higher total polyphenol yield. Liquid chromatography-diode array-mass spectrometry analysis revealed that the major antioxidant phytochemicals in the aqueous glycerol extract were chlorogenic acids (caffeic acid derivatives), accompanied by some other polyphenolic metabolites.     

Cloud Point Extraction and Preconcentration for the Determination of Cu and Ni in Natural Water by Flame Atomic Absorption Spectrometry

Abstract

In this work, a new cloud point extraction (CPE) method was developed for the separation and preconcentration of copper and nickel. The analyte was complexed with 3‐[(8‐{[(E)‐2‐hydroxyimino‐1‐methylpropylidene] amino}‐1‐naphthyl) imino]‐2‐butanone oxime (H₂mdo) in the initial aqueous solution and octylphenoxy polyethoxy ethanol (Triton X‐114) was added as a surfactant. After phase separation, based on the cloud point in the mixture, and dilution of the surfactant‐rich phase with methanol containing 0.1 mol l^?1 HNO₃, the enriched analytes were determined by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions (i.e. pH=8.5, H₂mdo=3×10^?4 mol l^?1, Triton X‐114=0.1% (w/v)) the enhancement factors of 65 and 59 and detection limits of 0.14 and 0.2 ng ml^?1 were obtained for copper and nickel respectively. The proposed method was applied to the determination of copper and nickel in several natural water samples with satisfactory results.     

Response Surface Methodology to Supercritical Carbon Dioxide Extraction of Essential Oil from Amormum krevanh Pierre

Abstract

Response surface methodology was employed to investigate the effects of operating conditions and predict the optimal conditions for supercritical carbon dioxide extraction of essential oil from Amomum krevanh Pierre. The factors investigated were operating temperature (33–67°C), the operating pressure (91–259 bar), and the extraction time (20–70 min). The main effect of the operating pressure and the interaction effect between the operating temperature and the extraction time were found to be significant factors. From the response surface model, an optimal condition for essential oil content within the range of experimental study was found to be at 33°C, 175 bar, and 70 min, which gave the oil yield of 17.3 mg/g dry wt. The essential oil yield obtained at all conditions were higher than that obtained by organic solvent extraction (9.74 mg/g dry wt.) while the composition of the extract was similar, which were 1,8-cineole (70.87%), β-pinene (8.89%), and limonene (4.81%).     

Optimization of an Aqueous Extraction Process for Pomegranate Seed Oil

Response surface methodology employing a five-level, four-variable central composite rotatable design was applied to study the effects of extraction time, extraction temperature, pH and water/solid ratio on the extraction yield of pomegranate seed oil using an aqueous extraction approach. In addition, quality indices, fatty acid composition and antioxidant activity of the obtained oil were studied and compared with those of typical hexane-, cold press- and hot press-extracted oil. Aqueous extraction resulted in the maximum oil recovery of 19.3% (w/w), obtained under the following critical values: water/solid ratio (2.2:1.0, mL/g), pH 5.0, extraction temperature = 63 °C and extraction time = 375 min. This yield is lower than that obtained via hexane extraction (26.8%, w/w) and higher than the yields from cold press (7.0%, w/w) and hot press (8.6%, w/w) extraction. A comparison of the characteristics of the oils based on extraction method revealed that the unsaturated fatty acid content was highest for the oil obtained by aqueous extraction. In addition, higher levels of iodine and peroxide and lower levels of acid, p-anisidine and unsaponifiable matter were observed. The oil obtained with aqueous extraction also exhibited higher antioxidant activity than oils obtained by hexane or hot press extraction.     

Extraction of lipids from Yarrowia Lipolytica

BACKGROUND: Microorganisms have often been considered for the production of oils and fats as an alternative to agricultural and animal resources. Extraction experiments were performed using a strain of the yeast Yarrowia lipolytica (Y. lipolytica), a high‐lipid‐content yeast. Three different methods were tested: Soxhlet extraction, accelerated solvent extraction (ASE) and supercritical carbon dioxide (SCCO₂) extraction using ethanol as a co‐solvent. Also, high pressure solubility measurements in the systems ‘CO₂ + yeast oil’ and ‘CO₂ + ethanol + yeast oil’ were carried out. RESULTS: The solubility experiments determined that, at the conditions of the supercritical extractor (40 °C and 20 MPa), a maximum concentration of 10 mg of yeast oil per g of solvent can be expected in pure CO₂. 10% w/w of ethanol in the solvent mixture increased this value to almost 15 mg of yeast oil per g of solvent. Different pretreatments were necessary to obtain satisfactory yields in the extraction experiments. The Soxhlet and the ASE method were not able to complete the lipid extraction. The ‘SCCO₂ + ethanol’ extraction curves revealed the influence of the different pretreatments on the extraction mechanism. CONCLUSION: Evaluating the effectiveness of a given pretreatment, ASE reduced the amount of material and solvent used compared with Soxhlet. In all three cases, the best total extraction performance was obtained for the ethanol‐macerated yeast (EtM). Addition of ethanol to the solvent mixture enhanced the oil solubility. Oil can be extracted from Y. lipolytica in two different steps: a non‐selective ethanol extraction followed by TAG‐selective SCCO₂ purification. © 2012 Society of Chemical Industry     

Supercritical Carbon Dioxide Extraction of Marigold Lutein Fatty Acid Esters: Effects of Cosolvents and Saponification Conditions

Extraction of lutein fatty acid esters from marigold flower using supercritical carbon dioxide (SC-CO₂) with cosolvent was investigated. Without the cosolvent, the total xanthophylls yield increased with increasing temperature and pressure of SC-CO₂, and the optimal condition was found to be at 60°C and 40 MPa. At this condition, the highest total xanthophylls percent recovery was 74.4 ± 0.9%. Palm oil was found to be a more efficient cosolvent than soybean oil, olive oil, and ethanol, resulting in a 16% increase in the total xanthophylls recovery to 87.2 ± 4.4% when 10% (w/w) of palm oil was used. Furthermore, saponification of the oleoresin for 3 h at 75°C with 40% w/v KOH solution at the oleoresin to solution ratio of 1 g to 2 ml was found to suitably convert lutein fatty acid esters into free lutein.     

Pilot-Scale Multi-Stage Countercurrent Extraction of Scutellarein from Erigeron breviscapus (Vant.) Hand-Mazz

Abstract

A low-temperature, timesaving, lower solvent consumption, and energy cost and multi-stage countercurrent extraction (MCCE) technique was developed for pilot-scale production of scutellarein from Erigeron breviscapus (Vant.) Hand-Mazz. The optimum conditions of MCCE process were obtained using the orthogonal array design method, i.e., 70% (v/v) of ethanol water solution, 16 L/kg of solvent to herbal sample ratio, 45°C of extraction temperature and 30 min of extraction time. A comparison between the MCCE technique and single pot extraction (SPE) under respective optimized operation conditions was made and time courses of scutellarein of MCCE and SPE processes were plotted, indicating that the MCCE technique can lower the extraction temperature and decrease five-sixth of the extraction time and two-thirds of the solvent consumption at the equivalent extraction yield of scutellarein.     

Enzyme-assisted aqueous extraction of peanut oil

Enzyme-assisted aqueous extraction of oil from oilseeds is a relatively recent technique. In the present study, peanut oil was extracted under optimized aqueous extraction conditions using Protizyme^™, which is predominantly a mixture of acid, neutral, and alkaline proteases. The optimal conditions were: enzyme concentration of 2.5% (w/w) in 10 g of peanut seeds, pH 4.0, 40°C, and 18 h incubation with constant shaking at 80 rpm. Centrifuging the mixture at 18,000 × g for 20 min separated the oil with a recovery of 86–92%. The merits of this process over existing solvent extraction and/or mechanical pressing methods are discussed.     

Extraction of acetyl 11-keto-β-boswellic acids (AKBA) from Boswellia serrata using ultrasound

The present work establishes the application of ultrasund for intensification of extraction of acetyl 11-keto-β-boswellic acid (AKBA), a potent anti-inflammatory agent from Boswellia serrata. Ultrasound-assisted extraction (UAE) yield is also compared with Soxhelt and batch extraction techniques. The optimized batch extraction showed 4.8 ± 0.04 mg/g yield of AKBA with extraction time of 120 min. On the other hand, UAE required only irradiation time of 10 min for obtaining a highest extraction yield of 6.5 ± 0.05 mg/g AKBA under optimized conditions. UAE reduced operation time and enhanced extraction yield of AKBA. Therefore, UAE could be the best alternative to intensify extraction.     

Enzymatic and Mechanical Extraction of Virgin Coconut Oil

The effect of different processing methods namely enzymatic method using crude protease extract (CPE) from overripe pineapple, microwave‐assisted extraction (MAE) and ultrasound‐assisted extraction (UAE) methods on the recovery yield of virgin coconut oil (VCO) is evaluated. The physicochemical properties of VCOs namely color, iodine value (IV), refractive index, saponification value, moisture content, free fatty acid, p‐anisidine value, lipid peroxidation, fatty acid composition, triacylglycerol (TAG) composition, melting and crystallization profile are compared. The total phenolic compounds and scavenging activity of the extracted VCOs are also examined. Results reveal that enzymatic approach exhibits the highest VCO yield (77.7% ± 0.38) at 50 °C for 2 h, followed by MAE (58.6%±0.07), control without enzyme (24.1%±0.19) and UAE (24.1%±0.12). The physicochemical properties of the VCOs extracted are found to conform to APCC standards established except IV. The antioxidant activity of VCO extracted with CPE shows no significant difference with MAE and UAE methods (p > 0.05). Lauric acid appears to be the most abundant fatty acid detected in all VCO samples. Similar exotherms and endotherms are observed in both melting and crystallization profiles with two distinct peaks exhibited. The TAG compositions of the extracted VCOs are mainly LaLaLa, LaLaM, CLaLa, CCLa, and LaMM (C = Capric acid; La = Lauric acid; M = Myristic acid). Practical Applications: The results obtained from this study indicate that VCO extraction using CPE from overripe pineapple is feasible. The enzymatic extraction protocol presented here would be useful for VCO production at industrial scale with a promising oil yield.     

Pressurized Water Extraction of Hydrolysable Tannins from Phyllanthus niruri Linn

Pressurized water extraction (PWE) was studied for the extraction of hydrolysable tannins from Phyllanthus niruri Linn. The effects of operating conditions (pressure, temperature, and the water flow rate) on the extraction yields were investigated. The results showed that the extraction yields increased with increasing temperature and with decreasing water flow rate, whereas pressure gave no significant effect. At 100 bar, 100°C and 1.5 ml/min, the extract had higher component contents (%g/g extract) of gallic acid (0.65%), corilagin (4.11%), and ellagic acid (8.91%) than a commercial HEPAR-P? extract (0.21%, 2.64%, 4.17%, respectively). It was also found that the dynamic PWE had a faster extraction rate and lower solvent consumption (0.018 m³/kg) compared to the Soxhlet extraction and ultrasonication.     

Comparison of Extraction Methods for Recovery of Astaxanthin from Haematococcus pluvialis

Solvent extraction, ultrasound assisted extraction (UAE), and microwave assisted extraction (MAE) were examined for the extraction of astaxanthin from Haematococcus pluvialis. In all cases, acetone was found to give the highest astaxanthin recovery compared with other selected solvents, i.e., methanol, ethanol, and acetonitrile. Among the various methods, MAE at 75°C for 5 min resulted in the highest astaxanthin recovery (74 ± 4%).