超临界二氧化碳精制辣椒红色素的研究

采用超临界二氧化碳萃取技术对有机溶剂萃取的辣椒红粗提物进行提纯、精制,制备高色价、高质量的辣椒红色素产品。研究了萃取压力、萃取时间等因素对产品色价及收率的影响,添加夹带剂对萃取效果的影响,得到较佳的工艺条件为：萃取压力17MPa(添加夹带剂)、14MPa(添加夹带剂),萃取时间4h。结果：未添加夹带剂产品色价由原来的60提高到150,产品收率为93％;加有夹带剂的产品比未加夹带剂的产品色价高出20,产品收率高2％;辣素含量更低,基本无法检出：溶解性更好,无不溶物：脱辣、脱臭效果好,不含任何异味、杂味。     

A STUDY ON SUPERCRITICAL FLUID EXTRACTION OF L-PROLINE

The extraction of L-proline from the fermentation broth filtrate with the supercritical fluid was studied. It has been proved that L-proline and most amino acids are hardly dissolved in the pure supercritical carbon dioxide fluid. When the methyl alcohol was added as an entrainer in L-proline solution or carbon dioxide fluid, the solubility of L-proline in the supercritical fluid would be greatly increased, but ethyl alcohol was unsatisfactory as an entrainer.The influences of extraction pressure, temperature, time, flow rate of fluid, concentrations of L-proline and entrainer on the yield of L-proline have been investigated for searching the optimal extraction conditions.     

Co-solvent-Modified Supercritical Carbon Dioxide Extraction of 10-Deacetylbaccatin III from Needles of Taxus baccata L

Abstract

10-Deacetylbaccatin III was extracted from the ground needles of Taxus baccata L. growing in Turkey using sub- and supercritical carbon dioxide with and without co-solvents by using two different methods (as an entrainer and modifier) and compared to Soxhlet extraction. SFE applications were carried out in the pressure range between 10 to 40 MPa and temperature ranges between 35 to 45°C. Recovery of the target compound increased with increasing temperature and pressure. The highest quantity of 10-deacetylbaccatin III obtained from needles of Taxus baccata L. was about 718 mg/kg when 200 µL of methanol was used as an entrainer at 45°C.     

Selective Extraction of Lutein from Alcohol Treated Chlorella vulgaris by Supercritical CO2

A pretreatment process using alcohol for the removal of chlorophyll a, b and β‐carotene from Chlorella vulgaris was developed to improve the yield and selectivity of lutein in the extract obtained by supercritical carbon dioxide extraction. Supercritical carbon dioxide extraction was carried out after pretreatment in the pressure range of 20 to 40 MPa and the temperature range of 40 to 80 °C. Ethanol and methanol were selected as elution solvents, of which ethanol was found most suitable for the elution, or pretreatment, process. The amounts of lutein and other compounds were analyzed by HPLC with the mixture of methanol and THF as the mobile phase. The amount of lutein in the extract increased with pressure, but decreased with extraction temperature. The highest recovery percentage and the selectivity of lutein were around 52.9 ± 0.02 % and 43.1 ± 0.02 %, respectively, obtained from supercritical carbon dioxide extraction with pretreatment and ethanol entrainer at 40 MPa and 40 °C.     

Supercritical carbon dioxide extraction of astaxanthin from Paracoccus NBRC 101723: Mathematical modelling study

Astaxanthin (AX) is a secondary metabolite that accumulates inside the cell during Paracoccus fermentation. The fermentation biomass was extracted using supercritical carbon dioxide (SC-CO₂). The solubility parameter of AX, CO₂ and entrainer solvents was calculated and validated with experimental results. The pressure and particle size of the biomass had a significant effect on the extraction of AX. A maximum recovery of 963.33 μg/g of AX was obtained after SC-CO₂ extraction at 40ºC, 350 bar and a run time of 60 min with ethanol (20% v/w) as an entrainer. Further, the experimental data has been modelled using non-linear regression analysis method.     

超临界萃取油茶多酚的研究

研究了以油茶籽为原料、采用夹带剂超临界CO₂萃取油茶多酚的工艺。通过单因素实验分别考察了萃取温度、萃取压力、夹带剂浓度（乙醇水溶液）、夹带剂流速及萃取时间对油茶多酚提取率的影响。研究确定最适宜提取条件为：萃取温度55 ℃、萃取压力30 MPa、夹带剂为75%乙醇水溶液,夹带剂流速1.5 mL/min、萃取时间1.5 h,此时油茶多酚的提取率为1.26%。研究表明,超临界萃取油茶多酚具有工艺简单、溶剂用量少、提取率高和生产周期短等优点。     

超临界二氧化碳萃取喜树种子中喜树碱

用超临界CO2流体萃取技术从喜树种子中提取喜树碱。在CO2流量20 L/h的条件下,探讨了夹带剂、萃取压力、萃取温度和萃取时间对喜树种子中喜树碱提取率的影响。通过正交实验设计验证并确定了超临界CO2萃取喜树种子中喜树碱的最佳工艺条件为:萃取压力25 MPa,萃取温度50℃,萃取时间120 min,夹带剂乙醇体积分数90%。在该条件下,喜树碱平均提取率为76.98%,所得到的萃取物中喜树碱的质量分数达43.68%。     

Supercritical fluid extraction of sunflower seed oil with CO2-ethanol mixtures

The effect of ethanol addition to supercritical carbon dioxide (SC-CO₂), up to 20%, on sunflower seed oil extraction over the range of 150 to 350 bars and 42 to 80°C was studied. A nonrecirculating home-made bench-scale system was used as extraction equipment. The oil-SC-CO₂-ethanol mixture was reduced to atmospheric pressure in a test tube, where two phases, oil and ethanol, were obtained and ethanol-saturated CO₂ was liberated to the atmosphere. Results show that sunflower oil solubility in SC-CO₂ greatly increases with addition of ethanol as entrainer over the whole range of pressure and temperature conditions. Some phospholipids are co-extracted at levels directly proportional to the added ethanol. Moreover, a large amount of phospholipids was recovered in the ethanolic phase. Acidity of the extracted oil with ethanol as entrainer was lower than that without alcohol. Part of the free fatty acids was found in the ethanolic phase.     

Die Abtrennung von Ölsäuremonoglycerid aus einem Glyceridgemisch mit Hilfe eines überkritischen Extraktionsmittels

Separation of Glycerol-monooleate from a Mixture of Glycerides by Means of a Supercritical Extractant The continuous separation of pure monoglycerides out of a mixture of glycerides by means of supercritical fluid extraction was investigated. As supercritical extracting agent carbon dioxide containing propane as an entrainer was used. The phase equilibria concerning the process were measured and are discussed. In an extraction apparatus consisting of an extraction column and two separators the viability of the process was tested. At 40°C and 120 bar a product with 99.5 wt.% monoglycerides was manufactured out of a mixture of glycerides containing 59 wt.% monoglycerides.     

Supercritical CO2 extraction of egg yolk: Impact of temperature and entrainer on residual protein

Differential scanning calorimetry (DSC) was used to monitor changes in protein conformation resulting from supercritical carbon dioxide (SC-CO₂) extraction of lipids from egg yolk. Extraction temperatures of 65°C and lower had no effect on protein conformation as indicated by similar denaturation temperatures and enthalpies of denaturation (ΔH). An extraction temperature of 75°C resulted in a reduction in the ΔH value for ovalbumin present in the egg yolk. The use of 3% methanol as an entrainer during extraction at 36 MPa and 40°C resulted in a 50% reduction in the ΔH value for ovalbumin. The use of high temperatures and/or entrainers during SC-CO₂ extraction can result in significant protein denaturation.     

Experimental and Modeling Investigation of Supercritical Extraction of Mannitol from Olive Leaves

The experimental feasibility of mannitol extraction from olive leaves using supercritical carbon dioxide was investigated. The experimental data indicated that increasing the pressure from 200 to 350 bar and decreasing the temperature from 80 to 40 °C resulted in an enhancement of the extraction yield and reduced the partition coefficient significantly. In addition, increasing the extraction time from 10 to 90 min increased the extraction yield, while further increases up to 180 min did not cause any further change. Ethanol was utilized as an entrainer and the maximum extraction yield was obtained using 20 % of ethanol. Moreover, modeling of the supercritical fluid extraction was carried out with the relevant mass transfer mechanisms involved in the supercritical and solid phases, and the appropriate numerical method of finite difference. The numerical results show that the model with three adjustable parameters is capable of predicting the experimental data very well.     

Optimization of supercritical fluid extraction of phytosterol from roselle seeds with a central composite design model

Recovery of phytosterol from roselle (Hibiscus sabdariffa L.) seeds via supercritical carbon dioxide extraction modified with ethanol was investigated at pressures of 200–400 bar, temperatures from 40 to 80 °C and at supercritical fluid flow rates from 10 to 20 ml/min. It was found that an entrainer such as ethanol could enhance the solubility and extraction yield of roselle seed oil from the seed matrix, compared to values obtained using supercritical CO₂. After a typical run (holding period of 30 min, continuous flow extraction of 3 h), the results indicate that the oil recovery was optimal with a recovery of 108.74% and a phytosterol composition of 7262.80 mg kg^?1 at relatively low temperature of 40 °C, a high pressure of 400 bar and at a high supercritical fluid flow rate of 20 ml/min in the presence of 2 ml/min EtOH as entrainer. The solubility of roselle seed oil increased with temperature at the operating pressures of 200, 300 and 400 bar. Supercritical fluid extraction involved a short extraction time and the minimal usage of small amounts of entrainer in the CO₂.     

Supercritical CO2 extraction of pigment components with pharmaceutical importance from Chlorella vulgaris

BACKGROUND: Chlorella vulgaris is a green microalgae that contains various pigment components of carotenoids and chlorophylls. Supercritical CO₂ is widely used for extraction of pharmaceutical compounds because it is non‐oxic and easily separated from extracted material by simply depressurizing. In this work, pharmaceutical compounds from Chlorella vulgaris have been extracted using supercritical CO₂ with or without entrainer at various extraction conditions. RESULTS: Based on high performance liquid chromatography (HPLC) analysis, the extracts contained pigment components, such as lutein, β‐carotene, chlorophyll a and b. Higher extraction pressure and temperature promoted higher lutein extraction by supercritical CO₂. The optimum pressure and temperature for extraction were obtained as 50 MPa and 80 °C. Ethanol as an entrainer was more effective than acetone for the extraction of pigment components. Pigment components in the extract obtained by supercritical CO₂ with and without entrainer were compared with the extract obtained by a conventional extraction method. CONCLUSION: Supercritical CO₂ has been successfully applied for the extraction of pigment components from Chlorella vulgaris. Supercritical CO₂ enabled high selectivity for lutein extraction; however, the lutein yield was lower than that obtained by extraction using supercritical CO₂ with ethanol and soxhlet. Copyright © 2008 Society of Chemical Industry     

超临界CO2萃取黑胡椒中有效成分的研究

用超临界CO2萃取技术,首先在低压、低温的条件下选择性萃取黑胡椒精油,进而在高温、高压及极性夹带剂的协同作用下,萃取富含胡椒碱的黑胡椒油树脂。另外,利用分子蒸馏技术纯化超临界CO2萃取的黑胡椒精油,得到适用于日化行业的无色、无辛辣感的挥发油,并通过GC-MS对比分析其香气成分。研究结果表明,超临界CO2萃取黑胡椒精油的较优条件为:萃取压力10MPa、萃取温度35℃、萃取时间1.5h,在该条件下产物得率为3.01%;超临界CO2萃取黑胡椒油树脂的最佳条件为:m(原料)∶m(体积分数95%食用乙醇)=2∶1、萃取压力30MPa、萃取温度50℃、萃取时间4h,在该条件下油树脂得率为7.88%,油树脂中胡椒碱质量分数为65.79%。     

中草药挥发油提取新技术——亚临界水萃取

介绍一种中药挥发油提取的新技术,对亚临界水在中药挥发油提取方面的应用进行综述。探讨亚临界水在中药挥发油萃取过程中萃取温度、萃取压力、萃取时间、夹带剂等因素对萃取效果的影响,并将其与传统的水蒸气蒸馏、索氏提取及目前流行的超临界二氧化碳流体萃取进行对比。结果表明,使用亚临界水提取技术不仅挥发油收率高,提取时间更为迅速,是一种新型而更贴近传统的中药提取方式。     

使用含夹带剂的超临界CO2分离菜籽油中的芥酸

Separation of erucic acid from rape-seed oil using supercritical carbon dioxide with entrainer was carried on a pilot column with an inner diameter 14 mm and an effective total height 2.2m.Experiments were focused on the effects of entrainers.i.e.acetone.ethanol and ethyl acetate,on the extraction.It is showed that entrainers made selectivity lower,but separation time shorter.     

Liquefied gases and supercritical fluids in oilseed extraction

Soybean oil and numerous other vegetable oils can be extracted from crushed seeds by means of liquefied gases or supercritical fluids. The oils are recovered by lowering the pressure or increasing the temperature, or both. Supercritical carbon dioxide is ideally suited for the food industry as it is nontoxic and nonflammable. Moreover, it can be removed easily from the oil as well as the meal. The oils extracted with supercritical carbon dioxide contain much lower proportions of phospholipids than those obtained by conventional processing with hexane. The addition of acetone or another carrier or entrainer aids in the fractional extraction of lipids differing in polarity. The range of applicability of liquefied gases and supercritical fluids in the extraction and fractionation of lipids should be explored further to develop industrial processes using these solvents.     

Extraction of lipid-grown bacterial cells by supercritical fluid and organic solvent to obtain pure medium chain-length polyhydroxyalkanoates

A simple two-step process was developed to extract and purify medium chain-length polyhydroxyalkanoates (MCL-PHA) from bacterial cells (Pseudomonas resinovorans) grown on lard and tallow. The process consists of supercritical fluid extraction (SFE) of the lyophilized cells with carbon dioxide to remove lipid impurities, followed by chloroform extraction of the cells to recover the MCL-PHA. SFE conditions were varied as to temperature (40–100°C), pressure (2000–9000 psi), and carbon dioxide flow rate (0.5–1.5 L/min, expanded gas). Lipid material, usually 2–4%, but in some cases as high as 11%, was extracted from the dried cells by SFE. A pressure range (5000–9000 psi, increased stepwise), a temperature of 60°C, and a carbon dioxide flow of 1.5 L/min were routinely used to extract the bacterial cells (4–5 g) after 3 h. Higher flow rates could shorten the extraction time even more. SFE did not extract MCL-PHA from the cells. Yield of MCL-PHA after chloroform extraction at room temperature was a maximum of 42.4% based on dry cell weight. The results show that the two-step process saves time, uses much less organic solvent, and produces a purer MCL-PHA biopolymer than previous extraction and purification methods. A more environmentally friendly clean-up procedure based on SFE and organic solvent recovery was developed to remove contaminating lipid materials from the fermentation biomass, allowing for the recovery of higher purity MCL-PHA that are suitable for more demanding applications.     

含提携剂超临界二氧化碳中固体溶解度的BPANN计算

为了更好地预测含提携剂超临界二氧化碳(SCCO2)中固体的溶解度,用逆向人工神经网络(BPANN)优化模型对其进行了模拟。得到了恒温下282个训练数据点和71个预测数据点的相对误差(AARD)分别为8.04%和8.37%;变温下264个训练数据点和63个预测数据点的AARD分别为8.59%和10.01%,表明BPANN模型是一种固体在含提携剂SCCO2中溶解度的较好预测模型。     

超临界CO2萃取烟草中茄尼醇

研究了萃取时间、解析温度、萃取压力等因素对超临界CO2萃取烟草中茄尼醇萃取率的影响。结合皂化等预处理措施,并通过正交实验得到了提取茄尼醇的最佳工艺条件,即以体积分数90%的乙醇为夹带剂,在萃取压力为35 MPa、萃取温度为50℃、解析温度为40℃时,萃取3 h后,产品茄尼醇质量分数为40.14%,萃取率达到98.53%。