Solubility of Jatropha and Aquilaria oils in supercritical carbon dioxide at elevated pressures

This study investigated experimental equilibrium solubilities of Jatropha curcas and Aquiliaria crassna oils dissolved in supercritical carbon dioxide at temperatures of 318 to 338 K and pressures of 20, 25, 30, 35 MPa. The highest solubility of Jatropha curcas and Aquiliaria crassna oil were 29.8 and 28.4 mg L−1, respectively, at 338 K and 35 MPa. The oil solubilities and the concentration of triglycerides both increased with increasing temperature and pressure. Triglyceride molecules surrounded by carbon dioxide molecules may be proposed since solubilities increased with the flux of supercritical carbon dioxide. The solubility of these two oils linearly increased with the density of supercritical carbon dioxide. Experimental data of the oil solubility were successfully correlated by the Chrastil equation

Supercritical carbon dioxide extraction of omega-3 oil compounds from Ficus awkeotsang Makino achenes

This work investigated the production of linolenic-rich oil from Ficus awkeotsang Makino achenes using supercritical carbon dioxide extraction. The 16 h Soxhlet n-hexane extraction of these achenes produced total yield of 12.91% and concentration of 686.3 mg/g of the extracted oil. Supercritical carbon dioxide extractions were performed with pressures ranged from 325 to 375 bar, temperatures ranged from 323 to 343 K, and solvent to solid ratios ranged from 80 to 160 by using a three-factor experimental designed response surface methodology. Three responses of total yield (TY), concentration of triglycerides (CTG) and recovery of triglycerides (RTG) were measured. Under a suitable condition, the values of TY, CTG, and RTG were 9.24%, 893.5 mg/g and 93.2%, respectively. This study demonstrated that environmental benign supercritical carbon dioxide extraction of linolenic-rich oil from F. awkeotsang M. achenes is a feasible and sustainable green process, alternative to traditional organic solvent extraction

Excess molar volumes, densities and P-T-x phase equilibria for binary mixtures of benzene + toluene, benzene + N-methylformamide (NMF), heptane + octane, toluene + m-xylene and toluene + NMF at 333.15 K and 353.15 K

Isothermal P-T-x phase equilibria at 333.15 K and 353.15 K for five binary mixtures of benzene + - toluene, benzene + N-methylformamide (NMF), heptane + octane, toluene + m-xylene and toluene + NMF were obtained at pressures from 0 kPa to 101.3 kPa over

Microalgae cultivation and purification of carotenoids using supercritical anti-solvent recrystallization of CO2 + acetone solution

Zeaxanthin is a type of xanthophyll found in carotenoids, which is produced as a food supplement frequently used for human retinal protection. These works investigated growth rate and harvest of the sea water algal species of Nannochloropsis oculata (N. oculata) by in-door and out-door cultivations; stirred ultrasonic acetone extraction of zeaxanthin from; employed column fractionation to obtain zeaxanthinrich elution; and then coupled it with supercritical carbon dioxide anti-solvent (SAS) precipitation to generate the highly pure submicron-sized zeaxanthin. The ultrasonic extract contained 38.2 mg/g of zeaxanthin and then the column elution fractionation increased the zeaxanthin content to 41% (410.3 mg/g) with a recovery of 82.3%. The SAS precipitation at 215 bar, 50 ◦C for 24 min of injection time enhanced the zeaxanthin content to 58% (582.4 mg/g) with a recovery of 67.2%. Experimental results showed that the amount of zeaxanthin increased with total SAS time and feed concentration had an effect of enlarging the precipitates due to agglomeration and accumulation. The SAS precipitation of the column purified algal solution demonstrated a production of micro/nano-sized lamellar particulates that contained high amounts of zeaxanthin

Green production of energetic Jatropha oil from de-shelled Jatropha curcas L. seeds using supercritical carbon dioxide extraction

This study examined the use of supercritical carbon dioxide (SC-CO2) in the extraction of triglycerides from de-shelled Jatropha curcas L. seeds. A central composite response surface methodology (RSM) was employed to evaluate the effects of pressure, temperature and solvent-to-solid ratio (SSR) on total yield (TY), concentration of triglycerides (CTG) and recovery of triglycerides (RTG). In the experiment, SC-CO2 extraction of 15 g ground, de-shelled Jatropha seeds at a CO2 flow rate of 25 mL/min was investigated under various pressure (250–350 bar), temperature (313–333 K) and SSR (60–100) conditions. The proposed quadratic model well fitted the RSM-designed data, and the statistical analyses showed that both pressure and SSR are important parameters that will significant affect the quality of extracted oil. Under a pressure of 350 bar, a temperature of 325 K and a SSR of 82, the values of TY, CTG and RTG were 43.0%, 936.2 mg/g, and 98.1%, respectively

Recovery of vitamins B from supercritical carbon dioxide-defatted rice bran powder using ultrasound water extraction

This study investigates the ultrasonic water extraction of vitamins B from supercritical carbon dioxide-defatted rice bran powder. Experimental data show that when the vitamins B content in the defatted extract reached 0.63% (wt), the extract was healthy. The effects of the solvent to solid ratio and the extraction time on the total yield, extraction efficiency, purification factor and purity of vitamins B in the extract were also determined. A two-factor center composite response surface method was adopted to optimize the condition for ultrasonic water extraction. Both parameters are important. The solvent to solid ratio has a greater influence on total yield than the extraction time. However, the extraction time is the most important in increasing the efficiency of extraction of vitamins B. Given an appropriate solvent to solid ratio, the vitamins B content in the defatted rice bran extract increased substantially with extraction time, exceeding that of the raw rice bran extract. Ultrasonic water extraction at a solvent to solid ratio of 10.0 at 323 K for 1.5 h yields a vitamin B content of 0.63%, a purification factor of 4.55 and a recovery rate of vitamins B of 92.8% in the dried defatted rice bran extract

Preparation of highly pure zeaxanthin particles from sea water-cultivated microalgae using supercritical anti-solvent recrystallization

Xanthophylls, including zeaxanthin, are considered dietary supplements with a potentially positive impact on age-related macular degeneration. Using pilot-scale column fractionation coupled with supercritical anti-solvent (SAS) recrystallization, highly pure zeaxanthin particulates were prepared from ultrasonic extracts of the microalgae, Nannochloropsis oculata, grown in sea water. Column partition chromatography increased the concentration of zeaxanthin from 36.2 mg/g of the ultrasonic extracts to 425.6 mg/g of the collected column fractions. A response surface methodology was systematically designed for the SAS process by changing feed concentration, CO2 flow rate and anti-solvent pressure. Zeaxanthin-rich particles with a purity of 84.2% and a recovery of 85.3% were produced using supercritical anti-solvent recrystallization from the column eluate at a feed concentration of 1.5 mg/mL, CO2 flow rate of 48.6 g/min and pressure of 135 bar

Supercritical carbon dioxide anti-solvent precipitation of anti-oxidative zeaxanthin highly recovered by elution chromatography from Nannochloropsis oculata

Zeaxanthin, a kind of xanthophylls, rich in Marigold flowers and a few micro algae, acts as a strong antioxidant capable of protecting human eye-sight from age-related macular degeneration. This study examined elution chromatography coupled with supercritical anti-solvent precipitation applied for generation of zeaxanthin-rich particulates from micro-algal Nannochloropsis oculata species. Crude of the ultrasonic acetone extract subjected to the column fractionation successfully yields a fraction containing 303.02 mg/g (30%) of zeaxanthin with recovery of 90%. Supercritical anti-solvent precipitation of the algal solution at 200 bar and 313 K was used in producing submicron-sized particulates of 50% zeaxanthin. These extracts were subjected to tests of antioxidant capacities in 2,2-diphenyl-2-picrylhydrazyl hydrate free-radical assay and human adult retinal pigment epithelium-19 cells. This work provided a fast and environmental benign process to generate anti-oxidative capable algal micronized powders from the N. oculata

Solvent Selection and Optimization of a-Chymotrypsin-Catalyzed Synthesis of N-Ac-Phe-Tyr-NH2 Using Mixture Design and Response Surface Methodology

A peptide, N-Ac-Phe-Tyr-NH2, with angiotensin I-converting enzyme (ACE) inhibitor activity was synthesized by an a-chymotrypsin-catalyzed condensation reaction of N-acetyl phenylalanine ethyl ester (N-Ac-Phe-OEt) and tyrosinamide (Tyr-NH2). Three kinds of solvents: a Tris–HCl buffer (80 mM, pH 9.0), dimethylsulfoxide (DMSO), and acetonitrile were employed in this study. The optimum reaction solvent component was determined by simplex centroid mixture design. The synthesis efficiency was enhanced in an organic-aqueous solvent (Tris-HCl buffer: DMSO: acetonitrile ¼ 2:1:1) in which 73.55% of the yield of N-Ac- Phe-Tyr-NH2 could be achieved. Furthermore, the effect of reaction parameters on the yield was evaluated by response surface methodology (RSM) using a central composite rotatable design (CCRD). Based on a ridge max analysis, the optimum condition for this peptide synthesis included a reaction time of 7.4 min, a reaction temperature of 28.1 C, an enzyme activity of 98.9 U, and a substrate molar ratio (Phe:Tyr) of 1:2.8. The predicted and the actual (experimental) yields were 87.6 and 85.5%, respectively. The experimental design and RSM performed well in the optimization of synthesis of N-Ac-Phe-Tyr-NH2, so it is expected to be an effective method for obtaining a good yield of enzymatic peptide

Countercurrent flow of supercritical anti-solvent in the production of pure xanthophylls from Nannochloropsis oculata

This study examined pilot scaled elution chromatography coupled with supercritical anti-solvent precipitation (using countercurrent flow) in generating zeaxanthin-rich particulates from a micro-algal species. Ultrasonic agitated acetone extract subjected to column fractionation successfully yielded a fraction containing 349.4 mg/g of zeaxanthin with a recovery of 85%. Subsequently, supercritical anti-solvent (SAS) precipitation of the column fraction at 150 bar and 343 K produced submicron-sized particulates with a concentration of 845.5 mg/g of zeaxanthin with a recovery of 90%. Experimental results from a twofactor response surface method SAS precipitation indicated that purity, mean size and morphology of the precipitates were significantly affected by the flow type configuration, feed flow rate and injection time