Rapid screening of antioxidant activity of sage (Salvia officinalis L.) extracts obtained by supercritical carbon dioxide at different extraction conditions.

Sage herb (Salvia officinalis L.) was extracted at supercritical fluid extraction (SFE) conditions with carbon dioxide at different parameters and the extracts tested on their antioxidant activity (AA). SFE of sage herb at 35 MPa pressure was found to be an effective method to obtain pure extracts. The yields of the extracts were substantially increased by using 1% of entrainer solvent ethanol. The fractionation of sage extract was a complex procedure in terms of extract distribution between separators operating at various pressure and temperature conditions. It was also proved by testing the AA of the extracts in rapeseed oil. The effect of the extracts on the rapeseed oil weight gain varied in a wide range (from 'very low' to 'high') depending on the fractionation conditions. Preliminary results showed that to obtain more effective antioxidant fractions separation steps should be started at 10 MPa lower pressure than that used for the extraction.     

Rapid screening of antioxidant activity of sage (Salvia officinalis L.) extracts obtained by supercritical carbon dioxide at different extraction conditions

Sage herb (Salvia officinalis L.) was extracted at supercritical fluid extraction (SFE) conditions with carbon dioxide at different parameters and the extracts tested on their antioxidant activity (AA). SFE of sage herb at 35 MPa pressure was found to be an effective method to obtain pure extracts. The yields of the extracts were substantially increased by using 1% of entrainer solvent ethanol. The fractionation of sage extract was a complex procedure in terms of extract distribution between separators operating at various pressure and temperature conditions. It was also proved by testing the AA of the extracts in rapeseed oil. The effect of the extracts on the rapeseed oil weight gain varied in a wide range (from ‘very low’ to ‘high’) depending on the fractionation conditions. Preliminary results showed that to obtain more effective antioxidant fractions separation steps should be started at 10 MPa lower pressure than that used for the extraction.     

超临界CO2提取葛缕子精油及其成分分析

目的:优化葛缕子精油的提取工艺并对其成分进行分析。方法:以葛缕子籽粒为原料,采用超临界CO₂技术提取葛缕子精油,并通过气相色谱—质谱(GC-MS)对精油挥发性成分进行分析。结果:超临界CO₂提取葛缕子精油的最佳工艺条件为提取釜温度50℃,分离釜温度40℃,提取釜压力30 MPa,分离釜压力0.4 MPa,二氧化碳流速20 g/min,提取时间90 min,此条件下精油得率为4.79%。与同时蒸馏萃取(SDE)法相比,超临界CO₂流体能快速扩散到样品颗粒内部并充分溶解其中的精油成分,具有提取时间短、得率高、无溶剂残留的优点。超临界CO₂法制备的葛缕子精油中,主要成分为D-柠檬烯(50.96%)和香芹酮(46.65%),挥发性成分种类及含量均高于同时蒸馏萃取法的。结论:超临界CO₂法比同时蒸馏萃取法更适合葛缕子精油的提取。     

Central composite design for the optimization of supercritical carbon dioxide fluid extraction of fatty acids from Borago officinalis L. flower

Abstract: In the present study, fatty acids and essential oils of the flower of borage (Borago officinalis L.) were obtained by supercritical carbon dioxide fluid extraction under different conditions. The extracts obtained were compared to oils of borage flower oil isolated by hydrodistillation. The obtained oils were analyzed by gas chromatography mass spectrometry. The compounds were identified according to their retention indices and mass spectra. The experimental parameters of supercritical fluid extraction (SFE) were optimized using a central composite design after a full factorial experimental design. Extraction yields based on SFE varied in the range of 0.02% to 1.96% (w/w), and the oil yield based on the hydrodistillation was 0.05% (v/w). The optimum conditions of SFE were obtained at a pressure of 350 atm, a temperature of 65 °C, a methanol modifier volume of 100 μL, and static and dynamic extraction time of 10 min. Main components of the extracts under optimum SFE conditions were palmitic acid, linoleic acid, γ‐linolenic acid, and oleic acid. The results indicated that by using the suitable extraction conditions, SFE is more effective than the conventional hydrodistillation method in the extraction of fatty acids and the preservation of its quality. Practical Application: SFE is a good technique for the extraction of oils from plants. The extraction yields by SFE are more than the conventional method. SFE is used on a large scale for production of essential oils and pharmaceutical products from plants.     

SUPERCRITICAL CARBON DIOXIDE SELECTIVITY TO FRACTIONATE PHENOLIC COMPOUNDS FROM THE DRY ETHANOLIC EXTRACT OF PROPOLIS

The global yield and composition of extracts obtained by supercritical carbon dioxide (SC-CO₂) extraction from a dry ethanolic extract of propolis were measured in order to determine the possibility of using SC-CO₂ to fractionate components of interest present in these extracts. The global yield extraction was measured, and also the concentrations of the following phenolic compounds in the resulting supercritical fluid extracts (SFEs): 3,5-diprenyl-4-hydroxycinnamic acid (known as artepillin C), 3-prenyl-4-hydroxycinnamic acid, 4-hydroxycinnamic acid ( p- coumaric acid) and 4-methoxy-3,5,7-trihydroxyflavone (kaempferide), of which artepillin C was the target component of greatest interest. The results showed extraction yields between 3.82 (at 150 bar) and 13.07% (at 350 bar), which could be highly correlated with the density of the SC-CO₂ at a constant temperature of 60C. The resulting concentrations in the SFE indicated that the selectivity of the carbon dioxide could be manipulated, and it was more selective at lower pressures, although with lower extraction yields.

PRACTICAL APPLICATIONS

Supercritical fluid extraction is an interesting process for the production of natural extracts because it is a clean process, and extractions using carbon dioxide (CO₂) as the solvent have been gaining attention in recent years. This study presented important aspects with respect to the fractionation of a dry ethanolic extract of propolis using supercritical carbon dioxide, and it is important to explore the potential applications of propolis extracts and the biological properties of its fractions in the food, pharmaceutical and cosmetic industries, such as in dental hygiene products, wound healing creams and antibacterial soaps.     

Extraction of resveratrol from the pomace of Palomino fino grapes by supercritical carbon dioxide

Resveratrol is a phenolic compound that is present in grapes and has significant benefits for human health. The development of methods to obtain concentrates of this compound is currently a major challenge in the food industry. In the work described here, resveratrol from grape seeds, stems, skin and pomace of the Palomino fino grape variety was extracted by supercritical carbon dioxide extraction. The effect of pressure (100, 400 bar), temperature (35, 55 °C) and the addition of modifier (5% v/v of ethanol) was evaluated to identify optimal resveratrol extraction from this by-product. Extraction yields and concentrations of resveratrol in the extracts were determined. The best results were obtained on working at high pressure and low temperature using 5% v/v ethanol as a co-solvent.     

Optimisation of supercritical fluid extraction of flavonoids from Pueraria lobata

Supercritical carbon dioxide extraction was employed to extract flavonoids from Pueraria lobata. The optimal conditions for flavonoid extraction were determined by response surface methodology. Box–Behnken design was applied to evaluate the effects of three independent variables (pressure, temperature and co-solvent amount) on the flavonoid yield of P. lobata. Correlation analysis of the mathematical-regression model indicated that a quadratic polynomial model could be employed to optimise the supercritical carbon dioxide extraction of flavonoids. From response surface plots, pressure, temperature and co-solvent amount exhibited independent and interactive effects on the extraction of flavonoids. The optimal conditions to obtain the highest flavonoid yield of P. lobata were a pressure of 20.04 MPa, a temperature of 50.24 °C and a co-solvent amount of 181.24 ml. Under these optimal conditions, the experimental values agreed with the predicted values, using analysis of variance, indicating a high goodness of fit of the model used and the success of response surface methodology for optimising supercritical carbon dioxide extraction of flavonoids from P. lobata.     

超临界CO2萃取小茴香油的初步研究

本文介绍从小茴香子中采用超临界CO2萃取和分级分离富含精油和富含脂油两种产品的工艺可行性，探讨了采用不同规模的超临界萃取过程对萃取物组成，风味和CO2消耗量的影响以及第一分离罐的分离压力对两种产品产率的影响。对超临界CO2萃取法，索氏萃取法和水蒸气蒸馏法所制备的茴香精油或萃取物的产率和主要挥发性成分进行了比较和分析。     

Extraction of ewe's milk cream with supercritical carbon dioxide

The extraction of ewe's milk cream by supercritical carbon dioxide in the pressure range 9–30 MPa (90–300 bar) and at temperatures of 40 °C and 50 °C was studied. The solubility of total fat increased with pressure at both temperatures until a plateau was reached. The extraction of cholesterol also increased with pressure until a plateau was reached and it was higher at 50 °C than at 40 °C when the pressure was ≥15 MPa (150 bar). The triglyceride composition of each extract, determined by GC, showed that extracts obtained at lower pressures were enriched in short-chain triglycerides and their concentration decreased as the pressure increased. In the other hand, long-chain triglycerides were enriched in the extracts obtained at higher pressures and their concentration rose with increasing pressure.     

Selective extraction of oxygenated compounds from oregano with sub-critical water

BACKGROUND: The essential oil of oregano is composed of numerous substances that exhibit various properties (e.g. antioxidants). The innovative and promising method of extraction with sub‐critical water (subcH₂O) has been applied to the Greek oregano. RESULTS: The sub‐critical water extraction experiments were performed at various conditions of pressure, temperature and water flow rate. Extracts collected at different extraction times were examined by gas chromatography. The oil has been processed by super‐critical carbon dioxide (scCO₂) followed by steam distillation or sub‐critical water extraction. The conventional method of steam distillation was also performed. The main component of the plant is carvacrol. The favourable oxygenated compounds (carvacrol, thymol, borneol and thymoquinone) have been extracted preferentially and faster with sub‐critical water. This method was selective for thymoquinone, which was not present in the oil from steam distillation. The oil yield obtained was much higher in the case of sub‐critical water extraction compared to the one of super‐critical carbon dioxide. The latter method resulted in oil with the highest concentration in carvacrol. CONCLUSION: Compared to the classical steam distillation, the sub‐critical water extraction is superior in terms of higher yields, less energy consumption (as it was a faster process), and better composition/selectivity of the extracts controlled by the extraction parameters. Copyright © 2011 Society of Chemical Industry     

枇杷叶熊果酸超临界流体萃取工艺的研究

采用超临界CO2流体萃取技术萃取枇杷叶中的熊果酸,并用高效液相色谱法测定萃取物中熊果酸含量;通过L9(34)正交试验对萃取条件进行优化,确定适宜的工艺参数。结果表明,枇杷叶熊果酸超临界CO2萃取的各因素影响程度为A>D>C>B(A为萃取温度,B为萃取压力,C为携带剂的添加量,D为萃取时间),最佳参数:萃取温度30℃,萃取压力15MPa,携带剂的添加量50ml,萃取时间90min。在最佳组合条件下进行萃取,粗提物含熊果酸15.66mg,含量为7.83%。     

红辣椒中辣椒红色素的提取工艺研究

分别采用有机溶剂法与超临界二氧化碳萃取法对通辽市开鲁县盛产的红辣椒进行了辣椒红色素的提取分离。通过分光光度法对产品品质进行了分析鉴定。采用两种方法分别得到了色价为68．4与289．3的油状辣椒红色素。结果表明：超临界二氧化碳萃取法具有产品回收率大、产率高、色价高等优点而更适于辣椒红色素的提取。     

超临界CO2杀菌过程中萃取机制研究

在相同工艺条件下对大肠杆菌菌悬液作超临界CO2 处理,对不同时间段萃取液的成分进行分析。结果表明,萃取物主要有两大类：非极性脂肪酸类及极性较弱的小分子氨基酸类物质,均为细胞的功能性物质。证实在超临界CO2 杀菌过程中确实发生了萃取作用。     

超临界CO2萃取杭白菊挥发油的工艺研究

采用超临界CO2 技术萃取杭白菊挥发油,以杭白菊挥发油得率为指标,采用正交试验考察萃取温度、萃取压力、CO2 流量、萃取时间4 个因素对杭白菊挥发油的超临界CO2 流体萃取的影响。结果表明萃取压力20MPa、萃取温度55℃、CO2 流量10kg/h 的条件下萃取2h 为最佳工艺,杭白菊挥发油得率达5.92%。     

Extraction of Oleoresin from Dao-Kou Roasted Chicken Flavor Spice Blends Using Supercritical Carbon Dioxide

In this paper, the supercritical carbon dioxide extraction of oleoresin from Dao-kou roasted chicken flavor spice blends was optimized under particular conditions of extraction temperature, pressure, and time by response surface methodology (RSM). On the basis of single-factor experiments, the Box-Behnken design with three factors and three levels was applied to obtain the optimum process parameters for good extraction ratio. The optimum extraction conditions are as follows: extraction temperature 48 °C, pressure 39 MPa, and time 134 min. Under such conditions, the oleoresin extraction ratio reached 3.68 % experimentally. The flavor effect of that extracted by supercritical fluid extraction (SFE) on chicken sausage base was compared with that extracted by steam distillation, alcohol, and water, and the composition of essential oils were analyzed by GC-MS/MS. The results showed that 65 compounds could be extracted by SFE; it was better than that extracted by traditional methods of 63, 46, and 34 compounds; and the flavor effect was nicer than that extracted by other three methods.     

Extraction Conditions and Moisture Content of Canola Flakes as Related to Lipid Composition of Supercritical CO2 Extracts

Canola flakes obtained before and after conventional cooking were extracted with supercritical carbon dioxide (SC-CO₂) at 35–75°C and 20.7–62.0 MPa. Moisture content was adjusted to 12.7–42.5% (w/w, moisture-and oil-free basis). Moisture content of residual flakes after extraction was monitored. Amount of extract recovered increased with increasing temperature and pressure, except at 20.7 MPa pressure it decreased with temperature indicating a crossover of the solubility isotherms. Some water was co-extracted with canola oil. Free fatty acid (FFA) concentration of the extracts increased with decreasing pressure due to a decrease in triglyceride (TG) solubility. Oleic and linolenic acids had highest concentrations in the FFA fractions of all extracts. The lowest TG content of extracts was attained at 20.7 MPa and 75°C. The effect of extraction conditions was more pronounced than seed pre-treatments on yield and composition of SC-CO₂ extracts.     

LIQUID CO2 AND ETHANOL EXTRACTION OF HOPS

The time-course of liquid carbon dioxide extraction of fresh and deteriorated hops was compared. The process of extraction becomes more difficult as hops deteriorate, which is reflected by the reduction in the LCV yield (g LCV/kg liquid carbon dioxide used). The extracts derived from deteriorated hops contain higher levels of uncharacterised soft resin. The pattern of elution of the latter does not allow the production of extracts low in uncharacterised soft resins and rich in alpha-acids.     

超临界CO2萃取菊花秸秆中总黄酮的研究

采用超临界CO2萃取技术,研究了从菊花秸秆中萃取总黄酮的工艺条件.在CO2流量为20L／h的条件下,对影响超临界CO2萃取总黄酮的各种因素,包括原料粒径、压力、温度、时间等进行了考察,得到较佳的萃取工艺条件为：原料。粒径60目、萃取温度50℃、萃取时间100min、萃取压力25MPa。     

超临界CO2萃取竹叶中总黄酮的研究

采用超临界CO2萃取技术,在CO2流量为25L／h的条件下,对影响竹叶中总黄酮提取率的4个因素（温度、时间、压力和夹带剂用量）进行了研究。运用正交试验得出了最佳的萃取工艺条件为温度为40℃,时间为3h,压力为30MPa,夹带剂用量为4．5mL／g。     

Recovery of Wine-Must Aroma Compounds by Supercritical CO2

The fractionation of wine musts (the fermentation broth that leads from grape juice to wine) of highly aromatic grape varieties was performed with supercritical carbon dioxide at pressures between 11 and 18 MPa and temperatures between 308 and 318 K. Different configurations of the separation devices were tested after the extraction step to improve the fractionation process. Headspace chromatography and Karl Fisher analyses were used to measure the composition of the extracts. A significant enrichment of the supercritical extracts on aromatic compounds was observed. The recovery of the aromatic compounds from the high pressure solvent stream poses technical problems that must be solved before the process can be feasible in an industrial scale.