Enrichment of tocopherols in modified soy deodorizer distillate using supercritical carbon dioxide extraction

Supercritical carbon dioxide (SC-CO₂) extraction of chemically modified Soy Deodorizer Distillate (DOD) at three levels of pressure (180–300 bar) and temperature (40–60 °C) to optimize the conditions for enrichment of tocopherols in the raffinate was carried out. After modification, soy DOD contained about 90% of fatty acid methyl esters (FAME), showed improved solubility in SC-CO₂, and better extraction rate. Since fatty acid methyl esters are more volatile, they are extracted preferentially over tocopherols and other high molecular weight compounds. Higher levels of pressure and temperature resulted in increased solubility of compounds with high molecular weight and tocopherols due to increased density of SC CO₂. So the extraction at higher pressures and temperatures resulted in a better yield of FAME along with tocopherols in the extract and this in turn decreased the degree of enrichment of tocopherols in the raffinate. However, specific level of pressure and temperature of extraction caused the increase in the solubility of FAME due to their volatility and results in enhanced enrichment of tocopherols in the raffinate. It was observed that the enrichment of tocopherols to ten times the original concentration of feed occurred at extraction pressure of 180 bar and temperature of 60 °C of SC-CO₂.     

Response surface methodology applied to supercritical carbon dioxide extraction of Piper nigrum L. essential oil

This study was conducted to optimize the supercritical carbon dioxide (SC-CO₂) extraction of Piper nigrum L. essential oil using response surface methodology (RSM). In order to obtain the maximum yield of the essential oil, experiments were carried out using a three-factor central composite design (CCD) under following conditions: pressure of 15–30 MPa, temperature of 40–50 °C and dynamic extraction time of 40–80 min. A second-order polynomial regression model expressing the total extraction yield as a function of main SC-CO₂ variables was significantly (p < 0.05) fitted, with high coefficient of determination value (R² > 0.985). The results showed that the best extraction yield (2.16%) was obtained at 30 MPa, 50 °C and 80 min. Pressure showed the most significant (p < 0.05) effect on the yield variation. The chemical composition of the essential oil was determined using GC-flame ionization detection (FID) and gas chromatography–mass spectrometry (GC–MS) analysis. The main constituents (concentration > 3.0%, calculated as % peak area) in the P. nigrum L. essential oil obtained through SC-CO₂ extraction were determined to be β-caryophyllene (24.34%), limonene (15.84%), sabinene (15.04%), 3-carene (9.44%), β-pinene (9.27%) and copaene (4.52%).     

Lycopene extraction from tomato peel by-product containing tomato seed using supercritical carbon dioxide

This work discusses the extraction of lycopene from tomato peel by-product containing tomato seed using supercritical carbon dioxide. The presence of tomato seed in the peel by-product improved the yield of extracted lycopene. Extraction was carried out at temperatures of 70-90 °C, pressures of 20-40 MPa, a particle size of 1.05 ± 0.10 mm and flow rates of 2-4 mL/min of CO₂ for 180 min extraction time. Oil from tomato seed was extracted under similar operating conditions and analyzed using GC-MS and GC-FID, while carotenoids extracted were analyzed by HPLC. The optimum operating condition to extract lycopene, under which 56% of lycopene was extracted, was found to be 90 °C, 40 MPa, and a ratio of tomato peel to seed of 37/63. The presence of tomato seed oil helped to improve the recovery of lycopene from 18% to 56%. The concentration of lycopene in supercritical carbon dioxide as a function of density at various temperatures was determined.     

同时蒸馏萃取-气质联用分析艾草挥发性成分

采用同时蒸馏萃取法,并结合气相色谱-质谱联用进行提取并分析艾草中的挥发性成分。实验结果表明,以乙醚为萃取溶剂时,使用DB-WAX型号毛细管色谱柱,鉴定出62种物质,而通过毛细管色谱柱HP-5鉴定出89种物质;以二氯甲烷为萃取溶剂时,在DB-WAX中经GC-MS鉴定出35种物质,在HP-5中鉴定出106种物质。使用两种萃取剂及两种不同极性的色谱柱共鉴定出159种物质,其中含量较大的有桉油精、石竹烯氧化物、石竹烯、3,3,6-三甲基-1,5-庚二烯-4-酮、3,3,6-三甲基-1,5-庚二烯-4-醇等。      

大麦虫油脂超临界二氧化碳萃取及其气相色谱–质谱分析

目的：研究金针菇菌糠饲养的大麦虫的油脂的超临界CO2萃取工艺及其脂肪酸组成。方法：采用超临界CO2萃取大麦虫油脂,探讨萃取压力、萃取温度对大麦虫油脂萃取率的影响,经甲酯化处理后用气相色谱-质谱联用仪分析大麦虫脂肪酸组成。结果：影响大麦虫油脂萃取因素的主次顺序依次为萃取压力＞萃取温度＞萃取时间,在大麦虫油中分离鉴定出11种脂肪酸,其中主要为油酸（40.26%）、棕榈酸（29.27%）、亚油酸（16.12%）、硬脂酸（7.38%）等。结论：生物转化农业生产废弃物的大麦虫具有较高的食用和药用价值,可以源源不断地提供食用、饲料用以及可再生能源的油脂资源。     

不同萃取方式结合GC-MS对本格烧酒中风味物质的分析

采用同时蒸馏萃取法（SDE）、顶空固相微萃取法（HS-SPME）和固相萃取捕集剂法（Mono Trap）对本格烧酒的风味成分进行提取,经气相色谱-质谱联用（GC-MS）技术对其风味物质进行定性分析,并结合保留指数法对定性结果进行验证。采用三种方法共鉴定出94种化合物,包括醇类10种、酯类38种、芳香类7种、萜烯类9种、酸类9种、烃类14种以及其他化合物7种。三种方法分别鉴定出风味物质56种（SDE）、47种（HS-SPME）和52种（Mono Trap）。比较三种方法可知,HS-SPME法有利于提取低沸点、挥发性化合物,SDE法则对高沸点化合物,如高级醇以及烃类的提取更加有效,Mono Trap法既能较多地提取到高沸点化合物,又能保证低沸点化合物的获得,是酒的风味物质提取的有效方法。      

陆英挥发油超临界CO2萃取工艺优化及其成分分析

以陆英为原料,采用单因素和响应面试验优化其挥发油的超临界CO_2萃取工艺,重点探讨CO_2流量、萃取压力、萃取时间、萃取温度对陆英挥发油得率的影响,并通过气相色谱-质谱(GC-MS)对陆英挥发油成分进行定性定量分析。结果表明,优化的陆英挥发油提取工艺条件为:CO_2流量25L/h、萃取压力30.5 MPa、萃取温度45.0℃、萃取时间2.8h,该条件下陆英挥发油得率为0.86%。从陆英挥发油中鉴定出了16个成分,占挥发油含量约93.87%,其中含量较多的有3-甲基戊酸(29.37%)、3-甲基丁酸(13.83%)、E-4-己烯-1-醇(8.27%)等,另外3-乙硫基丁醛(6.46%)含量也较多。     

不同方法提取艾纳香叶挥发性成分的气相色谱-质谱分析

采用气相色谱-质谱法(GC-MS)分析水蒸汽蒸馏法(SD)、同时蒸馏萃取法(SDE)和顶空固相微萃取法(HS-SPME)3种方法提取的艾纳香叶挥发性成分。结果表明:3种方法提取艾纳香叶挥发性成分中主要是醇类和烯类化合物,其中萜类物质占较大比例。3种方法的提取物中分别鉴定出化合物50种(SD)、24种(SDE)和49种(HS-SPME)。水蒸汽蒸馏法和同时蒸馏萃取法提取的油状挥发物中主要成分相似,水蒸汽蒸馏法提取油状挥发物与顶空固相微萃取法提取挥发性成分的种类和相对含量相似,同时蒸馏萃取法提取油状挥发物中低沸点化合物较少。     

In vitro antioxidant activities of Rosmarinus officinalis extracts treated with supercritical carbon dioxide

The leaves of Rosmarinus officinalis (rosemary) were subjected to supercritical CO₂ extraction (SFE). Different sources of variability, including location (Izmir, Canakkale and Mersin) and harvesting time (December, March, June and September), were considered. Among active constituents of rosemary, carnosic acid, carnosol and rosmarinic acid were analyzed by HPLC. Variability of the amounts of active constituents appears to be due to different geographical locations of growth and seasonal variations. The levels of the constituents were higher in the months of December 2003 and September 2004. In addition to this, 12 SFE extracts were screened for their radical-scavenging capacities and antioxidant activities by various in vitro assays, namely total phenol assay, DPPH radical-scavenging activity and trolox equivalent antioxidant capacity (TEAC).     

Comparison of dynamic headspace and simultaneous distillation extraction techniques used for the analysis of the volatile components in three European PDO ewes’ milk cheeses

This preliminary study aims to compare two different extraction and concentration methods often used for the gas chromatographic analysis of volatile components in food to determine the advantages and drawbacks of both for future routine investigation of PDO (protected designation origin) ewes’ milk cheeses. Roncal, Pecorino Sardo and Fiore Sardo were investigated at different ripening stages. The dynamic headspace technique using a Purge & Trap device (DHS) makes it possible to extract more highly volatile compounds than the simultaneous distillation extraction (SDE) method. Consequently, the latter is more efficient for extracting low-volatile components such as phenols, free fatty acids, lactones and longer-chain aldehydes, ketones, alcohols and esters. These two extraction methods are therefore complementary.     

Analysis of volatile compounds produced by different species of lactobacilli in rye sourdough using multiple headspace extraction

Profiles of volatile organic compound (VOC) produced by nine individual lactic acid bacteria (LAB) during rye sourdough fermentation were compared by automated SPME and GC/MS‐Tof. The dough samples were inoculated with individual strains, placed inside the headspace vials and incubated during next 24 h. The production or loss of VOC‐s was followed by adsorbing volatiles onto 85‐m Car/PDMS fibre in every 4 h. Volatile profiles differed among LAB species and divided LAB into two main groups – hetero‐ and homofermentative. Hetrofermentative LAB (Lactobacillus brevis; Leuconostoc citreum; Lactobacillus vaginalis, Lactobacillus panis) showed high production of acetic acid, CO₂, ethanol, ethylacetate, producing also hexyl acetate, ethyl hexanoate and isopentyl acetate. Whereas homofermentative LAB species (Lactobacillus helveticus; Lactobacillus casei; Lactobacillus sakei; Lactobacillus curvatus) produced a considerable amount of 2,3‐butanedione. Production of l ‐leucine methyl ester was unique for Lb. sakei, Lb. casei and Lb. curvatus strains. Lb. helveticus was the only LAB that produced benzaldehyde.     

Antioxidant activity of Spirulina platensis extracts by supercritical carbon dioxide extraction

Supercritical CO₂ extraction of antioxidants from Spirulina platensis was optimized using response surface methodology. About 10.26 g/kg of extracts from S. platensis could be obtained under the optimum conditions of 48 °C at 20 MPa over a 4 h period. The antioxidant activity of the extracts prepared under the optimized condition, determined by linoleic acid peroxidation inhibition method, was lower compared with BHT and Trolox, but significantly higher than α-tocopherol in 300 min and became similar to α-tocopherol after that. The components of the extracts were further analyzed, and the results showed that the extracts contained 85.1 g/kg of flavonoids, 77.8 g/kg of β-carotene, 113.2 g/kg of vitamin A and 3.4 g/kg of α-tocopherol, which may contribute greatly to their high antioxidant activity. The main fatty acids in the extracts were palmitic acid (35.32%), linolenic acid (21.66%) and linoleic acid (20.58%).     

液液萃取与顶空固相微萃取结合气相色谱-质谱法分析金种子馥合香白酒香气成分的比较

为明确不同前处理方法对白酒挥发性香气成分的提取效果,分别采用液液萃取法（Liquid-liquid extraction, LLE）和顶空固相微萃取法（headspacesolid phase microextraction, HS-SPME）作为酒样的前处理方法提取金种子馥合香白酒中的挥发性香气成分,再结合气相色谱-质谱法（GC-MS）进行定性与相对定量分析。结果表明：两种不同方法检出的共有组分有28种,特有组分分别有35种和18种。LLE对酯类、醇类、酸类以及其他物质具有很好的萃取效果,但是对于易挥发性物质萃取效果较差;HS-SPME对痕量、易挥发性的物质具有较好的萃取效果,但对难挥发性物质的萃取效果较差。LLE能富集到较多种类的香气物质,HS-SPME能富集到更高含量的香气成分。酒样的两种不同前处理方法各有特点,相互补充并结合分析可为白酒挥发性香气成分的检测提供更加全面完整的数据支持。     

‘白玉’枇杷花不同花期挥发性物质分析

目的 探究枇杷花发育过程中挥发性物质的组成及变化规律。方法 采用顶空固相微萃取-气相色谱-质谱法对幼蕾期、显露期、始展期、盛花期和谢花期枇杷花的挥发性成分进行定性定量分析,并利用主成分分析法(principalcomponentanalysis,PCA)和香气活性值(odoractivityvalue,OAV)分析枇杷花的主要香气成分。结果 5个时期共检测出96种挥发性物质,分为醛类、烃类、酯类、醇类、酮类、酚类以及其他共7大类,其中苯甲醛在各个时期含量均最高。对枇杷花发育过程中的16种主要挥发性物质进行主成分分析,可简化成3个主成分,累计贡献率达到95.400%。分析发现,第1主成分与己醛、苯甲醛、二十一烷、二十四烷、苯甲醇成高度正相关,与4-甲氧基苯甲醛、4-甲氧基苯甲酸甲酯、4-甲氧基苯甲酸乙酯和苯乙醇成高度负相关。第2主成分贡献较大的组分是十五烷、二十六烷和十九烷,属于烷烃类化合物。5个时期共检测出8种关键香气物质(OAV>1),共有的香气是己醛,具青草香,其在花发育过程香气的调控中扮演着至关重要的作用,对‘白玉’枇杷花香的形成有着极大的贡献。除了己醛以外,还有癸醛、4-...     

响应面法优化顶空固相微萃取条件结合气相色谱-质谱法测定四川红茶挥发性成分

目的 优化顶空固相微萃取技术(headspace solid phase microextraction, HS-SPME)对四川红茶挥发性成分的萃取条件。方法 通过单因素试验,研究了萃取时间、萃取温度和样品质量对萃取效果的影响,并通过Box-Benhnken中心组合试验及响应面分析法对萃取条件进行优化。结果 最佳萃取条件为萃取时间60 min、萃取温度65 ℃、样品质量1.00 g, 验证试验结果与预测值的相对误差为2.10%。在此条件下, 在四川红茶中共检出醇类、醛类、酮类等9类共计56种挥发性成分, β-紫罗酮、芳樟醇、橙花醇、苯乙醛、苯乙醇等9种高相对香气活度值(relative odor activity Value, ROAV)的成分, 可能是四川红茶的特征挥发性成分。结论 利用响应面法优化得到四川红茶挥发性成分的HS-SPME萃取技术, 并结合GC-MS进行分析, 方法可靠, 具有应用价值。     

Comparison of volatile components in raw and cooked green beans by GC-MS using dynamic headspace sampling and microwave desorption

 The effects of four culinary treatments (steaming and boiling in a covered pot, a pressure cooker or a microwave oven) on the volatile component profile of green beans were evaluated. Volatile compounds in raw and cooked beans were analysed by means of dynamic headspace sampling onto an adsorbent, followed by microwave desorption into a gas chromatograph equipped with a mass spectrometric detector. Twenty-seven compounds were identified, including alcohols, aldehydes, ketones, esters, terpenes, sulphur compounds and alkenes. All of the thermal treatments caused important changes in the volatile compound profile in particular an increase in carbonyl compounds and a decrease in alcohol compounds, most notably in the case of the covered pot. It is concluded that the change in aroma during the cooking of green beans depends on compounds from lipid oxidation as well as compounds from other types of reactions, for instance the Strecker degradation. Received: 8 March 1999 / Revised version: 23 April 1999     

Influence of defined milk products on the flavour of white coffee beverages using static headspace gas chromatography–mass spectrometry/olfactometry and sensory analysis

The influence of milk processing and ingredients on the sensory properties of white coffee beverages has, as yet, not been thoroughly investigated, so in this study analysed milk products processed in a defined manner were added to a standardized, fresh coffee beverage; the resulting odour, taste and retronasal odour perception were measured by intensity tests, and selected volatiles were analysed by static headspace gas chromatography/mass spectrometry. After adding pasteurized consumers’ milk, the effects of a different fat content (3.5 and 1.5%) and fat dispersion were studied. The milk with the lower fat content and with smaller fat globules, resulting from double homogenization (each 250/50 bar), induced a more intense coffee-related retronasal odour perception, whereas the milk-related impression was nearly the same. The addition of casein increased the creamy and milky retronasal odour perception and reduced the coffee-related taste and retronasal odour. These correlations may result in a custom-made development of milky coffee beverages controlled in their nasal and retronasal odour and taste by the defined processing of the milk component. With instrumental analysis it was observable that the effect of the addition of twice-homogenized, twice-pasteurized low-fat milk and of the addition of whole milk was similar. In both cases more volatiles were released from the beverage than with the addition of low-fat milk that was homogenized once. This is an unexpected result, because the whole milk has a higher fat content than the low-fat milk and therefore a greater retention of the flavour compounds was expected. Is it possible that the flavour compounds are not dissolved in fat and that interactions happen only with fat globule membrane constituents?     

顶空固相微萃取-气相色谱-质谱法分析脐橙中挥发性成分

目的 探究脐橙果皮和果肉中挥发性成分的种类、相对含量及其风味的差异。方法 将脐橙洗净后切分为果皮及果肉部分, 经粉碎后, 通过顶空固相微萃取(headspace solid phase microextraction, HS-SPME)技术分别富集果皮和果肉的挥发性成分, 再经气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)分析其挥发性成分的种类及相对含量, 同时计算各物质的相对气味活度值(relative odor activity value, ROAV)。结果 脐橙中鉴定出烯烃类、醛类、醇类、酮类、酯类和酸类等挥发性成分共82种, 果皮中有59种, 果肉中有51种, 两者共有成分28种, 其中果皮特有挥发性成分31种, 果肉23种; 对果皮风味起关键作用和修饰作用的挥发性成分分别有20种和7种, 果肉分别有9种和7种。脐橙果皮和果肉中相对含量最高的成分均为D-柠檬烯, 分别达到43.97%和41.25%, 果皮次主要成分为芳樟醇, 含量为5.38%, 果肉次主要成分为巴伦烯亚橘烯, 含量为18.50%; 对果皮风味贡献最高的物质为芳樟醇, 主要提供麻香、青香和花香, 对果肉贡献最高的物质为β-紫罗酮, 主要提供花香; 此外果皮和果肉的木调香和清香差异不大, 但果皮的果香、花香、甜香和脂香更加丰富。结论 脐橙果皮和果肉中挥发性成分的种类和含量差异较大, 且造成其关键香气的物质有明显区别。     

Optimization of supercritical carbon dioxide extraction of sea buckthorn (Hippophaë thamnoides L.) oil using response surface methodology

Response surface methodology (RSM) was employed to optimize the conditions of supercritical CO₂ extraction of the whole berry oil from sea buckthorn. The effects of pressure, temperature, CO₂ flow rate and extraction time on the yield of oil, vitamin E and carotenoids were investigated. Results showed that the data were adequately fitted into three second-order polynomial models. The independent variables, the quadratics of pressure and extraction time, the interactions between pressure and temperature, pressure and extraction time, temperature and extraction time, as well as flow rate and extraction time had a significant effect on the yield of the oil, vitamin E or carotenoids. It was predicted that the optimum extraction conditions within the experimental ranges would be the extraction pressure of 27.6 MPa and temperature of 34.5 °C with flow rate of 17.0 L/h and extraction time of 82.0 min. Under such parameters, the yields of oil, vitamin E and carotenoids were predicted to be 208.0 g/kg, 288.7 mg/kg and 620.0 mg/kg dry sea buckthorn berry, respectively. Monounsaturated fatty acids were predominant in the whole berry oil, accounting for over 62% of the total fatty acids.     

静态顶空进样-气质联用法测定玫瑰花香成分

采用静态顶空和气相色谱-质谱联用技术,对比分析\