SOLUBILITY OF HOP α- AND β-ACIDS IN LIQUID CARBON DIOXIDE*: ADDENDUM: SOLUBILITY OF PESTICIDES IN LIQUID CARBON DIOXIDE

A procedure is described for determining the solubility of hop α- and β-acids in liquid carbon dioxide. Results have shown that the optimum temperature range for the extraction of hops with liquid carbon dioxide is +5 to +10°C. A number of pesticides used by hop growers are appreciably soluble in liquid carbon dioxide.     

超临界CO2萃取胡麻油及其自氧化性质研究

研究旨在优化超临界CO2技术提取胡麻油的工艺条件并研究贮藏温度时间对其品质的影响。以胡麻籽为试验原料,在单因素试验的基础上,采用响应曲面分析法建立了超临界CO2萃取胡麻油出油率的二次多元回归方程,探讨了压力、温度、萃取时间等关键因素对出油率的作用规律,而后采用Schaal烘箱法,研究了温度时间对所提取胡麻油的影响。结果表明:在条件萃取温度46.3℃、萃取压力31.5 Pa、萃取时间80 min下,胡麻油的出油率为41.24%;温度和时间对所提取胡麻油的氧化有显著的影响,且温度的影响更加明显。     

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%。     

QUALITY OF APPLE FRUIT IN RIGID FILM CONTAINERS

The storage quality of‘Delicious’ apples individually packaged in rigid film containers was investigated. Objective quality attributes (internal and external color, firmness, soluble solids and titratable acidity) were measured as a function of storage time with and without packaging in a rigid container. Overall firmness, acidity and soluble solids content decreased over a 70-day storage period. Significant effects of rigid film packaging and storage included: superior skin color, decreased weight loss, slight decrease in soluble solids content and increased firmness loss during ripening when compared to control fruit. Upon examination of the atmosphere surrounding individual fruit in these containers, increased levels of carbon dioxide and ethylene were found. Conversely, packaged fruit contained significantly less internal carbon dioxide than control samples. It was concluded that the atmosphere modified by the rigid film container hastened ripening of‘Delicious’ apples, thus deteriorating eating quality. An adequately ventilated packaged would probably alleviate this condition.     

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提取辣椒油树脂工艺的研究

以红辣椒粉为原料,采用超临界CO2萃取法提取辣椒油树脂。以辣椒油树脂的收率为评价指标,确定最佳工艺条件为:萃取压力25MPa,萃取温度30℃,萃取时间3h,此条件下辣椒油树脂收率为10.09%±0.29%。对比实验结果显示:超临界CO2法所得的辣椒油树脂的色价为303±5,辣椒素质量浓度为3.7%±0.7%,均明显优于传统的索氏提取法。对超临界CO2法所得的辣椒油树脂进行二次超临界萃取,可将辣椒红色素和辣椒素进行初步分离。     

超临界CO2流体萃取红花籽油研究

通过超临界CO2流体萃取红花籽油试验,研究物料粉碎度、萃取压力、萃取温度、萃取时间对红花籽油萃取效果影响。结果表明,超临界CO2流体萃取红花籽油最佳工艺条件为:粉碎度30目、萃取压强30 MPa、萃取温度40℃、萃取时间2 h．     

THE STABILITY OF HOP OILS IN LIQUID CARBON DIOXIDE EXTRACTS OF HOPS

Portions of extracts obtained by treating three varieties of hops with liquid carbon dioxide were stored in the cold and at ambient temperature for 18 months. During this period the composition of nop oils remained stable, except for the formation of two terpene methyl sulphides in extracts from all three varieties. Ales were ‘dry-hopped’ using portions of the stored extracts and, despite formation of the two sulphur compounds, the resulting hop character was satisfactory in all cases.     

Supercritical carbon dioxide extraction of lycopene: A review

Lycopene is a powerful antioxidant and potential high-value compound for the nutraceutical and pharmaceutical sectors. Its low solubility in water and high solubility in toxic organic solvents has led to a number of studies being carried out on using supercritical carbon dioxide to extract lycopene, with a majority of the studies focusing on extraction from tomatoes or tomato-derived preparations. Parameters such as temperature, pressure, flow rate, extraction time, sample moisture content and sample particle size influence the yield of lycopene via the exertion of different mechanisms. The use of co-solvents and modifiers can greatly enhance the lycopene yield beyond optimization of the parameters previously mentioned, while the co-extraction method offers a new way of enhancing lycopene yields. The scope of this review covers the effects of various parameters on lycopene extraction by supercritical carbon dioxide.     

超声波液态CO2提取分离芹菜籽油工艺条件优化的研究

目的：优选超声波液态CO2 提取分离芹菜籽油的工艺条件。方法：通过单因素试验和正交试验考察提取压力、超声时间、超声功率和料液比对芹菜籽油得率的影响。结果：以液态CO2 提取芹菜籽油各因素对芹菜籽油得率的影响大小依次为超声时间＞超声功率＞提取压力＞料液比,优化的提取工艺参数为超声时间30min、超声功率100W、提取压力4MPa、料液比1:7(m/V),在此操作条件下,芹菜籽油得率2.8%。结论：超声波液态CO2提取分离芹菜籽油是一种有效的新型分离技术。     

超声强化亚临界CO_2萃取小球藻中叶黄素的研究

采用超声强化亚临界CO2技术研究了从小球藻中萃取叶黄素的工艺条件,并初步分析了超声强化的机理。实验中考察了萃取温度、萃取压力、流体流量、夹带剂用量、萃取时间及超声功率对叶黄素萃取率的影响,得到了最佳的工艺条件:萃取温度25℃,萃取压力11MPa,流体流量30kg/h,夹带剂用量为1.5mL/g的无水乙醇,萃取时间3h,超声功率750W。     

罗布麻中黄酮的超临界CO2萃取及其抗菌性

为解决传统脱胶工艺罗布麻韧皮纤维中黄酮化合物的浪费问题,对罗布麻韧皮纤维采取超临界脱胶预处理的同时,利用超临界CO2 提取其黄酮有效成分,研究分析影响罗布麻中黄酮萃取的4个主要因素,然后对萃取液进行了高效液相色谱分析和抗菌实验。结果表明：助溶剂主要影响超临界流体的极性,随着助溶剂含量的增加,超临界流体极性的增加提高了黄酮萃取率,但助溶剂含量过高时,过多水分易造成萃取管路堵塞,使黄酮的萃取效率降低;在45 ℃、20 MPa时黄酮萃取率较高,升高或降低压力与温度均会影响黄酮萃取效果;随着超临界CO2流量的增加,黄酮萃取率逐渐增加,但对萃取设备要求更高;罗布麻中黄酮化合物具有良好的抗菌效果,是罗布麻纤维具有抗菌性能的原因之一。     

The Oxygenated Sesquiterpenoid Fraction of Hops in Relation to the Spicy Hop Character of Beer

Hop‐derived sesquiterpenoid‐type oxidation products have been associated with a spicy or herbal hoppy beer character. However, the flavour threshold values of hitherto identified oxygenated sesquiterpenes are generally much higher than their estimated levels in beer. By applying two‐step supercritical fluid extraction of hop pellets using carbon dioxide, followed by chromatographic purification of the enriched sesquiterpenoid fraction, highly specific varietal hop oil essences containing all main oxygenated sesquiterpenes were obtained. Post‐fermentation addition (at ppb levels) of these purified sesquiterpenoid essences from various European aroma hops led to distinctive spicy or herbal flavour notes, reminiscent of typical ‘noble’ hop aroma. It is concluded that a spicy hop flavour impression in beer depends significantly on minor constituents of the natural sesquiterpenoid hop oil fraction.     

RESPONSE OF 'TOP RED DELICIOUS' APPLES TO DAMINOZIDE

Daminozide was applied at 2.2, 4.5, 6.7 or 9.0 kg/ha to ‘Top Red Delicious’ apple trees 86 days after full bloom the first year and at 2.2, 3.4 or 4.5 kg/ha, 80 days after full bloom the second year. At commercial harvest, after 2 and 4 months regular cold storage, and after 6 and 10 months of controlled atmosphere (CA) storage apples were evaluated for carbon dioxide, ethylene production, flesh firmness, external color, soluble solids, acids, subjective appearance and daminozide residue. Ethylene production was reduced as daminozide application was increased. Delay in onset of the climacteric ranged from 3 to 21 days depending on chemical rate used. Firmness, red color, acids, subjective appearance and number of days to reach climacteric were significantly improved by all rates of daminozide. Quality differences due to daminozide were evident following both types of storage. Daminozide residues were directly related to rate and did not dissipate during storage. There was no detectable daminozide carry-over in fruit from year to year.     

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。     

INVESTIGATION OF SUPERCRITICAL FLUID EXTRACTION OF PUERARIN FROM PUERARIA LOBATA

Puerarin, which is the most abundant isoflavone in Pueraria lobata , has many pharmacological effects. In this study, supercritical carbon dioxide extraction was employed as a novel and efficient technique to extract puerarin from Pueraria lobata. Effects of four variables (pressure, temperature, time and co-solvent amount) on the puerarin yield of Pueraria lobata were investigated. Up to a certain value, the puerarin yield increased with increasing pressure; thereafter, puerarin yield decreased as pressure increased. A similar effect of temperature was also found. When the temperature was at 50C or the pressure was at 20 MPa, the highest puerarin yield obtained was 5.8  ±  0.3 mg/g. Positive effects of time and co-solvent amount were observed on the puerarin yield. However, when the time was longer than 100 min or the co-solvent amount was greater than 120 g, no significant improvement was detected in the puerarin yield. It was therefore important to define the level of each variable for an efficient preparation of puerarin. From the results obtained, supercritical carbon dioxide extraction was proved to be an efficient technique for extraction of puerarin from Pueraria lobata.

PRACTICAL APPLICATIONS

Pueraria lobata is a famous Chinese traditional medicinal herb which has been consumed by many people all over the world. Puerarin is the most abundant isoflavone in this herb, and it has been proven to have some important pharmacological properties. In this study, a novel technique called supercritical carbon dioxide extraction was employed to prepare puerarin from Pueraria lobata . Effects of pressure, temperature, time and co-solvent amount on the puerarin yield were evaluated. The results were helpful in understanding the extraction process of puerarin and could give evidence for further developments on this special medicinal herb.     

Determination of 105 antibiotic,anti-inflammatory,antiparasitic agents and tranquilizers by LC-MS/MS based on an acidic QuEChERS-like extraction

A procedure for screening 105 veterinary drugs in foods by liquid chromatography tandem mass-spectrometry (LC-MS/MS) is presented. Its scope encompasses raw materials of animal origin (milk, meat, fish, egg and fat) but also related processed ingredients and finished products commonly used and manufactured by food business operators. Due to the complexity of the matrices considered and to efficiently deal with losses during extraction and matrix effects during MS source ionisation, each sample was analysed twice, that is ‘unspiked’ and ‘spiked at the screening target concentration’ using a QuEChERS-like extraction. The entire procedure was validated according to the European Community Reference Laboratories Residues Guidelines. False-negative and false-positive rates were below 5% for all veterinary drugs whatever the food matrix. Effectiveness of the procedure was further demonstrated through participation to five proficiency tests and its ruggedness demonstrated in quality control operations by a second laboratory.     

Coumarin Extraction from Cuscuta reflexa using Supercritical Fluid Carbon Dioxide and Development of an Artificial Neural Network Model to Predict the Coumarin Yield

Coumarin found in Cuscuta reflexa (a medicinal herb) is a phytochemical that possesses blood-thinning, anti-fungicidal and anti-tumor activities, and increases the blood flow in the veins and decreases capillary permeability. Supercritical fluid carbon dioxide extraction is an effective method for extraction and separation of organic compounds. Coumarin was extracted using supercritical fluid carbon dioxide associated with a small amount of a co-solvent methanol to increase the selectivity of carbon dioxide and identified by high-performance liquid chromatography comparing with authentic coumarin standard. Determination of proper extracting temperature, time, and pressure is essential for the maximum extract of coumarin yield. Coumarin was extracted under different extraction conditions of temperature (35–75 °C), time (30–150 min), and pressure (15,160–34,450 kPa). Central composite rotate design was used to plan the experimental extraction conditions. The highest yield of coumarin was 90.13 ± 0.11 (μg/g), while extraction was done at 55°C for 150 min under 24,805 kPa. A feed-forward multilayer backpropagation artificial neural network (ANN) model was developed for the prediction of coumarin yield (μg/g), where input variables were temperature, time, and pressure. Several configurations were evaluated while developing the optimal ANN model. The optimal ANN model consisted of one hidden layer and five neurons. This model was able to predict coumarin yield quantitatively. Prediction of coumarin yields using the ANN model was proven to be a simple, convenient, and accurate method.     

大戟科木薯皮矿物质及化学成分的波谱分析

首次利用电感耦合等离子体发射光谱研究木薯皮的矿物质的种类及含量,又利用超临界及传统提取方法得到木薯皮不同极性部位的化学成分,并通过气—质联用、红外光谱、核磁共振技术等波谱分析方法对木薯皮化学成分做了初步定性分析。结果表明:木薯皮中矿物质含量最高的是K,含量最高为1 453.29 mg/100 g干重,Ca含量次之,Na含量位居第三;微量元素中Ni含量最高,为87.22 mg/kg干重;木薯皮中检索匹配度大于90%的化学成分中检测出7-氨基-3-苯基香豆素和东莨菪内酯2种香豆素类物质,其它重要的化学成分有β-谷甾醇、乙酰愈创木酮、N,N’-羰基二咪唑、亚硝酸异戊酯等,以上化学成分均为首次在木薯皮中发现。     

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。