挤压膨化糙米香气物质的顶空固相微萃取条件优化

该研究应用顶空-固相微萃取(headspace-solid phase microextraction,HS-SPME)与气相色谱-质谱(gas chromatograph-mass spectrometer,GC-MS)技术对挤压膨化糙米的香气物质进行萃取条件优化,以期更好地检测分析其香气物质。采用50/30μm二乙烯基苯/羧基/聚二甲基硅氧烷(divinylbenzene/carboxen/polydimethylsiloxane,DVB/CAR/PDMS)萃取头,首先对料液比(饱和NaCl溶液)、萃取温度、平衡时间和吸附时间进行单因素试验,得到初步优化条件,进一步运用响应面分析法探究萃取温度、平衡时间及吸附时间3个因素对挤压膨化糙米中主要香气物质的离子色谱总峰面积的影响。优化得到的HS-SPME提取挤压膨化糙米香气物质的最佳条件为萃取温度51.11℃,平衡时间19.94 min,吸附时间43.99 min。最佳固相微萃取条件根据实际操作情况调整为样品量3.0 g,料液比1∶7(g/mL),萃取温度51℃,平衡时间20 min,吸附时间44 min,该条件下实际测得的香气物质离子色谱总峰面积为3.215×10~8,与预测值的相对误差为0.78%,且高于单因素试验中最大值3.157×10~8,说明该萃取条件参数合理可行,且具有实用价值,有利于挤压膨化糙米中香气物质的进一步定性、定量分析。     

HS-SPME结合GC-MS测定白腐乳中挥发性风味成分

采用顶空固相微萃取(HS-SPME),结合GC-MS联用技术分析了某品牌白腐乳的挥发性风味成分.并对萃取条件:萃取头、预热时间、萃取时间及萃取温度进行了优化,确定了较佳的萃取条件:采用100μm PDMS萃取头,在60℃,预热10min,萃取40min.通过GC-MS检测,在腐乳块及汤汁中共鉴定出90种物质,其中腐乳块中鉴定出62种,汤汁57种,但腐乳块中风味物质并不能囊括汤汁中的所有风味成分,样品预处理方式对腐乳风味成分的准确测定也具有重要作用.     

红枣白兰地中香气成分的顶空固相微萃取条件优化

采用顶空固相微萃取-气相色谱质谱联用技术分析红枣白兰地中的香气成分,并且通过单因素实验和正交实验对香气成分的萃取条件进行优化。以峰个数和面积为指标比较不同的因素对香气成分的影响,并且对萃取条件进行4因素3水平正交优化实验。实验结果表明:最佳的萃取条件为萃取温度50℃、萃取时间40 min,乙醇含量10%, NaCl添加量1.0 g、解析时间6 min。在该萃取条件下,检测到红枣白兰地中的香气成分共81种,确定结构的有59种,其中包括酯类物质34种(85.47%),醇类物质7种(3.67%),酸类物质4种(4.61%),醛类物质6种(4.51%),其它种类物质8种(1.74%)。     

HS-SPME-GC-MS法分析即墨黄酒陈酿过程中香气成分的变化

即墨黄酒是采用黍米酿制的特色黄酒,其香气成分和陈酿过程中香气的变化目前研究较少。本研究采用顶空-固相微萃取(HS-SPME)结合气相色谱-质谱联用技术(GC-MS)分析即墨黄酒的挥发性香气成分。通过优化萃取探针、萃取温度、萃取时间以及NaCl添加量,确定即墨黄酒香气成分的最佳提取条件:ACAR/PDMS/DVB复合涂层的萃取探针在50℃条件下萃取60 min,NaCl添加量为0.15 g/mL。从2009年、2012年、2013年、2015年酒样中分别检测出16,15,15,19种香气物质。苯乙醇、苯乙酸乙酯、苯丙酸乙酯、丁二酸二乙酯在4份酒样中均有检出。苯乙醇和丁二酸二乙酯的相对含量随陈酿年份的增加逐年减少。2012年酒样中苯乙酸乙酯和苯丙酸乙酯的相对含量最高。     

新疆库尔勒香梨果醋香气萃取条件优化研究

采用HS-SPME/GC-MS联用方法对经发酵优化后的新疆库尔勒香梨果醋挥发性香气成分进行了初步分析,初步建立了库尔勒香梨果醋挥发性香气组分分析的方法。结果表明:采用50/30μm DVB/CAR/PDMS萃取头,在磁力搅拌条件下,萃取温度为45℃,添加电解质的量为0.2g/mL,萃取时间为20min时梨醋中的挥发性风味物质能最大程度地挥发、吸附;经HS-SPME/GC-MS分析,从梨醋中共检测出来的挥发性成分有35种,主要包括4种烷烃类、3种醛类、2种酮类、8种醇类、7种酸类、9种酯类以及2种其他物质,其中,酯类、醇类和酸类占已鉴定出总挥发性成分的73.6%,分析效果良好。     

优化GC检测欧李酒香气成分的萃取条件

香气物质的组成表征果酒的特色,利用响应面法优化顶空固相微萃取(HS-SPME)欧李果酒中香气物质的条件,使气相色谱法检测香气物质的结果更精确。本文采用HS-SPME结合GC-FID检测欧李发酵酒中的香气物质,在单因素实验的基础上,以加盐量、萃取温度、萃取时间为影响因素,出峰面积为响应值,运用Box-Benhnken中心组合实验设计原理进行响应面分析,优化了HS-SPME的萃取条件。结果表明,HS-SPME萃取欧李发酵酒中香气成分的适宜条件为:加盐量0.226g/mL、萃取温度29℃、萃取时间36min。该条件下萃取,结合GC-FID测得欧李发酵酒中32种香气成分,对其中10种进行了定性和定量分析,含量较高的有:异戊醇110.734mg/L、己酸乙酯11.568mg/L、异丁醇8.7725mg/L、苯乙醇47.178mg/L、乙酸异戊酯15.655mg/L、丙醇1.7032mg/L。     

葡萄蒸馏酒香气成分顶空固相微萃取条件优化

香气成分对葡萄蒸馏酒的风味和品质具有重要作用。为了有效地分析葡萄蒸馏酒中香气成分的种类和含量,对影响萃取效果的顶空固相微萃取(headspace solid-phase microextraction, HS-SPME)条件进行优化。采用HS-SPME与GC-MS相结合的方法对葡萄蒸馏酒中香气成分进行定性、定量分析,对萃取条件进行单因素分析和响应面优化。结果表明,葡萄蒸馏酒中香气成分顶空固相微萃取的较优条件为萃取温度30℃、解析时间6 min、平衡时间10 min、萃取时间30 min、NaCl添加量0.20 g/mL、乙醇体积分数10%。在优化条件下得到香气成分的总峰面积与峰个数分别为3.494×10⁸、34,从葡萄蒸馏酒中成功鉴定出酯类物质16种,醇类6种,醛类1种、酚类1种。该研究为葡萄蒸馏酒香气成分的分析提供了一种简单、快速的测定方法,也可为其他酒类香气成分的测定提供参考。     

顶空固相微萃取-气质联用测定樱桃酒中的挥发性成分

采用顶空固相微萃取(HS-SPME)与气质联用技术(GC-MS)测定樱桃酒中的挥发性成分,通过对萃取参数的优化,建立快速、准确测定樱桃酒中香气物质的方法。优化后的最佳分析条件为65μm PDMS/DVB萃取头、萃取温度40℃、萃取时间30min、酒精度(体积分数)12%。在此条件下测定中樱狄墨尔樱桃酒中的挥发性成分,共鉴定出65种挥发性物质,其中酯类是樱桃酒中种类最多和含量最多的一类挥发性物质。     

HS-SPME结合GC-MS分析着色香葡萄中挥发性香气成分

利用顶空固相微萃取(HS-SPME)结合气相色谱-质谱联用(GC-MS)分析着色香葡萄中的挥发性香气成分。优化后的HS-SPME条件为:样品超声20 min,采用50/30μm PDMS/CAR/DVB萃取头,样品量8 mL,加盐3 g,40℃萃取40 min。此条件下GC-MS测出36种挥发性香气物质,主要为醇类、醛类、酯类和酮类化合物,其中决定其特征香气的物质包括己醛、2-己烯醛、(E)-2-己烯醇、芳樟醇、脱氢芳樟醇及α-萜品醇等。     

顶空固相微萃取分析苹果酯类香气

酯类是苹果香气成分中的重要组成之一。应用顶空固相微萃取、气相色谱和质谱联用技术分析了苹果酯类香气成分的组成。对HS-SPME的萃取条件如萃取头的选择、萃取时间、萃取温度进行了优化,建立了适合苹果酯类香气成分萃取的最优组合-采用纤维头65μm PDMS/DVB在50℃下吸附30 min。使用该方法在成熟金冠苹果中鉴定出18种酯类香气成分。     

顶空固相微萃取法快速测定苹果酒中的香味物质

以顶空固相微萃取法 (HeadSpaceSolid PhaseMicro Extractions,HS SPME)和气相色谱质谱 (GasChromatgraphy MassSpectrometry ,GC MS)联用 ,2 辛醇为内标 ,研究了萃取头、萃取时间、加盐质量浓度、萃取温度对苹果酒中香气物质萃取的影响 ,优化了分析条件 ,建立了快速测定苹果酒中香气物质的方法 .该方法在苹果酒中常见香气物质的质量浓度范围内有良好的线性关系 ,对常见香气物质的定量比较准确     

Headspace In-Tube Microextraction Coupled with Capillary Electrophoresis for Detection of Bromophenols in Water and <Emphasis Type="Italic">Trachypenaeus curvirostris</Emphasis>

A rapid, simple, and sensitive method has been developed for the analysis of bromophenols in tap water and Trachypenaeus curvirostris by using headspace in-tube microextraction (HS-ITME) coupled with capillary electrophoresis (CE). In the newly developed method, simply by placing a capillary filled with a basic run buffer in the HS above an acidic donor solution, volatile acidic analytes were extracted into the acceptor phase in the capillary. After extraction, electrophoresis of the extracts in the capillary was carried out. Extraction parameters such as the extraction temperature, extraction time, pH of the sample solution, ionic strength, and volume of the sample solution were systematically investigated. Under the optimized conditions, enrichment factors for three bromophenols were 812, 685, and 568, respectively. The proposed method provided a good linearity, low limits of detection (below 5.25 ng/mL), and good repeatability of the extractions (RSDs below 7.8 %, n?=?6). The tap water and T. curvirostris samples were analyzed by the proposed method, and the obtained results indicated that the proposed method provides acceptable recoveries and precisions.     

顶空固相微萃取- 气质联用法测定哈尔滨红肠的挥发性风味物质

为进一步探明烟熏灌肠类食品的风味特征,以哈尔滨红肠为对象,采用顶空固相微萃取制备样品,联合气质联用测定其主要挥发性物质。通过比较不同萃取头、萃取温度以及萃取时间对萃取效果的影响,获得较适的萃取条件：50/30μm DVB/CAR/PDMS萃取头、萃取温度50℃、萃取时间50min。采用气质联用对解吸物进行测定的结果表明,其挥发性风味物质的主要成分中醛类占17.59%、酮类占7.01%、酚类占7.27%、醇类占12.29%、烯萜类占9.39%、烷烃类占6.14%、含硫化合物占27.38%、杂环化合物占7.01%。     

EFFECT OF SUPERCRITICAL CO2 EXTRACTION OF OIL ON PHYSICOCHEMICAL PROPERTIES OF RESIDUAL ATLANTIC MACKEREL (Scomber scombrus) PROTEINS

Protein residue of Atlantic mackerel, an underutilized fish species, was investigated following extraction of oil with supercritical CO₂. Spring mackerel was extracted at 35–55C and 34.5–62.1 MPa for 5 h whereas extraction time of 1–6 h was applied to fall mackerel at 35C/34.5 MPa. Water binding potential of fall mackerel proteins increased with extraction time as oil was removed and that for spring mackerel reached a maximum of 2.2 g H₂O/g protein at 55C and 62.1 MPa. Sarcoplasmic proteins (SAR) became less soluble with increasing extraction temperature and pressure. This change occurred during the first hour of extraction of fall mackerel. Analysis of the SAR by capillary electrophoresis showed that proteins with a molecular weight of 50–100 kDa decreased, while MW> 100 kDa proteins increased with extraction pressure and time for spring and fall mackerel, respectively, suggesting aggregation of proteins. Supercritical CO₂ extraction of lipids from fish muscle shows potential for development of high quality functional proteins.     

Determination of bioactive constituents in Flos Sophorae Immaturus and Cortex Fraxini by capillary electrophoresis in combination with far infrared-assisted solvent extraction

A method based on far infrared-assisted solvent extraction (FIASE) and capillary electrophoresis–amperometric detection (CE–AD) has developed for the rapid determination of rutin and quercetin in Flos Sophorae Immaturus and esculin and esculetin in Cortex Fraxini. The effects of the irradiation time and the voltage applied on the infrared generator were investigated to acquire the optimum extraction conditions. It was demonstrated that far IR radiation substantially enhanced the extraction efficiency and the extraction time was significantly reduced from 3 h for conventional hot solvent extraction to 6 min for FIASE. The obtained extracts were subsequently analysed by CE–AD. The detection electrode was a 300-μm-diameter carbon disc electrode at a detection potential of +0.90 V (vs. saturated calomel electrode). The relation between peak current and analyte concentration was linear over about three orders of magnitude. The proposed method has been applied to determine the bioactive constituents in real samples.     

超高压处理对香荚兰豆中香兰素提取率的影响

为研究超高压处理对香英兰豆中香兰素提取率的影响,文章利用毛细管气相色谱-质谱归一化法测定香兰素含量,以香兰素含量为考察指标,研究了在80％浓度乙醇为提取剂条件下,不同压力和保压时间对香英兰豆中香兰素提取效率.实验结果表明:超高压处理后对香英兰豆提取物中香兰素含量有较明显影响,在200MPa,20 min超高压的提取条件下,香兰素含量的可达72％,比传统的提取方法增加17.5％.     

Extraction and purification of free cholesterol from some egg-containing food by on-line supercritical fluid extraction – solid-phase extraction

Two methods for the extraction and determination of free cholesterol in some egg-containing food samples were compared: the classical Soxhlet method and a supercritical carbon dioxide extraction (at 338 bar and 40vv°C) coupled on-line with solid-phase extraction (SPE with a solid trap packed with an ODS stationary phase). Egg noodles, biscuits and sweet snacks were homogenised and added to the internal standard and anhydrous sodium sulphate. Part of each sample was extracted by on-line supercritical fluid extraction - solid-phase extraction (SFE-SPE) and the remaining part was extracted by the classical method using petroleum ether. A further purification after the Soxhlet extraction was performed by SPE. Free cholesterol was determined in both the off-line Soxhlet-SPE fraction and the on-line SFE-SPE extract with capillary gas chromatography after silylation. The two extraction methods gave similar results. However, on-line SFE-SPE represents a valid alternative to the Soxhlet method because it shows important advantages, such as a short analysis time and low solvent consumption.     

Determination of PAEs by Integrative Coupling Method of Headspace in-Tube Microextraction and Reverse-Flow Micellar Electrokinetic Capillary Chromatography

An integrative coupling approach of headspace in-tube microextraction (HS-ITME) and reverse-flow micellar electrokinetic capillary chromatography (RF-MECC) was proposed for determination of phthalic acid esters (PAEs). In the novel method, by placing a capillary filled with background electrolyte (BGE) of RF-MECC in the HS above the sample solution, the PAEs were extracted into the acceptor phase in the capillary. Then, the extracts were separated and determined by RF-MECC. The influence of some essential BGE components such as sodium dodecyl sulfate (SDS) and organic modifier concentrations were investigated. Extraction parameters were also systematically investigated, including the extraction temperature, extraction time, salt concentration, and volume of the sample solution. Under the optimized conditions, enrichment factors for three PAEs were 169, 2534, and 1526, respectively. The proposed method provided a good linearity, low limits of detection, and good repeatability (RSDs below 5.44%, n = 5). This method was then utilized to analyze the three PAEs in tap water, seawater, and beverage samples. The results indicated that the developed method is an excellent alternative for the PAE routine analysis in the food field.     

正交法优化HS-SPME甜面酱挥发性成分的条件

建立一种方便快捷地测定甜面酱挥发性成分的顶空固相微萃取-气相色谱-质谱法,对萃取时间、萃取温度、离子强度进行了优化,最终确定了用50/30μm DVB/CAR/PDMS萃取头,在3 g样品及6 mL水中加入1.5 g固体NaCl,萃取温度60℃,萃取时间60 min,进样口温度250℃,解析5 min为最佳分析条件。     

Headspace solid-phase micro-extraction gas chromatography method for the determination of methanol in aspartame sweeteners

A headspace solid-phase micro-extraction (HS-SPME) method for the extraction and determination of residual methanol in artificial sweeteners by capillary gas chromatography with flame ionization detection (GC-FID) is described. A manual SPME holder with an 85-µm polyacrylate fibre was used. The optimized conditions for methanol extraction by SPME were: sample agitation, absorption temperature of 30°C, absorption time of 10 min, desorption time of 2 min and sample volume in the vial of 400.0 µl. Under these conditions the calibration graphs were linear in the range 2.50-31.60 mg l^-1, and the precision was good (relative standard deviation 4.9%). The detection limit was 0.40 mg l^-1; the quantification limit was 2.06 mg l^-1.