微波水蒸气法提取八角茴香挥发油

采用微波水蒸气蒸馏法提取八角茴香挥发油,并与水蒸气蒸馏法进行比较.结果表明,微波水蒸气蒸馏法的提取率与水蒸气蒸馏法相等,但提取时间为水蒸气蒸馏法的一半.气相色谱质谱联用(GC/MS)对所提取的挥发油进行化学成分分析,微波水蒸气蒸馏法所得挥发油成分与水蒸气蒸馏法相同,但含有较多的单萜类含氧化合物,挥发油的主要成分反式-茴香脑的含量为水蒸气蒸馏法的1.5倍.     

龙须菜挥发油的提取及抗菌抗虫活性研究

分别采用直接水蒸气蒸馏法和溶剂提取-水蒸气蒸馏法提取龙须菜(Gracilaria lemaneiformis)挥发油,并进行气相色谱-质谱法(GC-MS)分析和抗菌抗虫活性研究。结果显示:相比于直接水蒸气蒸馏法,溶剂提取-水蒸气蒸馏法提取的龙须菜挥发油中气味阈值较低的醛类成分相对含量低至0.20%,而营养保健价值高的羧酸及酯类含量达到21.54%。龙须菜挥发油对大肠杆菌O157(Escherichia coli O157)、金黄色葡萄球菌(Staphylococcus aureus)、沙门氏菌(Salmonella enterica)、单增李斯特菌(Listeria monocytogenes)和副溶血性弧菌(Vibrio parahemolyticus)5种常见致病菌均有一定的抗菌活性;溶剂提取-水蒸气蒸馏法和直接水蒸气蒸馏法提取的龙须菜挥发油对卤虫的半数致死量(LD50)分别为0.126,0.162mg/mL。     

木蝴蝶挥发性化学成分的气相色谱-质谱分析

采用普通水蒸气蒸馏萃取法,对木蝴蝶中挥发油进行提取,测得木蝴蝶挥发油含量为1.99%;并用气相色谱-质谱联用技术进行分析鉴定,结合计算机质谱图库检索技术对分离的化合物进行结构分析,鉴定出13种化学组分,占挥发性物质总含量的96.63%。应用峰面积归一化法确定了各成分的相对含量。结果表明普通水蒸气蒸馏萃取法提取的挥发油中主要含有苯乙酮(72.29%)、二苯酮(7.81%)、丁化羟基甲苯(4.85%)等。     

不同辅助提取方式对玳玳花精油挥发性成分的影响

采用传统水蒸气蒸馏(HD)、超声辅助水蒸气蒸馏(UAHD)和微波辅助水蒸气蒸馏(MAHD)3种方法提取玳玳花精油,使用气相色谱-质谱联用技术分析比较了精油挥发性成分。结果表明:使用HD、UAHD、MAHD技术提取的精油,可以鉴定出的化合物种类分别为30种、33种、50种,主要成分为芳樟醇、柠檬烯、乙酸芳樟酯、β-蒎烯、α-松油醇等。由于提取工艺不同,各种挥发性物质的含量和成分有一定的差异。与HD和UAHD相比,MAHD方法制备的精油得率较高,处理时间较短,可以作为一种高效、快速、节能的提取技术进行推广。     

麦冬挥发油成分的提取与GC-MS分析

麦冬是名贵中药,挥发油是麦冬的主要活性成分。本文采用水蒸气蒸馏法提取麦冬挥发油,用气相色谱-质谱联用(GC-MS)法定性定量分析了麦冬的挥发油。通过质谱库检索得到其中37种主要组分的定性定量结果,占挥发油总含量的93.65%。     

辛夷挥发油GC-MS分析及其抗氧化、抗菌活性

采用水蒸气蒸馏（hydrodistillation,HD）法、同时蒸馏萃取（simultaneous distillation extraction,SDE）法、静态顶空（static headspace,SH）法3 种方法对辛夷挥发油进行提取,通过气相色谱结合标准品获得保留指数,气相色谱-质谱联用结合数据库检索进行定性,确定不同方法提取的挥发油的成分和相对含量,并采用1,1-二苯基-2-三硝基苯肼自由基清除法、普鲁士蓝法和新铜试剂法比较HD法和SDE法挥发油的抗氧化能力,以及滤纸片扩散法和96 孔板法测定抗菌活性。结果表明,3 种方法共鉴定出66 种化学成分,其中17 种共有成分。从HD法和SDE法挥发油中分别鉴定出47 种和43 种化合物,SH法对辛夷粉末分析检测到26 种化合物。其中,HD和SDE提取的化合物成分较接近,而SH法获得的挥发成分最少,三者相同成分的相对含量也存在较大差异。HD法和SDE法挥发油均表现出一定的抗氧化活性,对供试菌（金黄色葡萄球菌、单增李斯特氏菌、大肠杆菌、鼠伤寒沙门氏菌）均有抑制作用,对其中的革兰氏阴性菌的抑制效果较好。辛夷挥发油的抗氧化和抗菌研究显示其具有药学研究价值和作为食品天然抗菌剂和食品防腐剂的潜能。     

水蒸汽蒸馏、溶剂萃取、同时蒸馏萃取法提取花椒挥发油的效果比较

对水蒸气蒸馏法、溶剂萃取法以及同时蒸馏萃取发提取花椒挥发油的效果进行了比较,并通过气相色谱质谱法对3种方法的提取物种类进行了比较。结果显示水蒸气蒸馏法虽然花椒挥发油提取物种类达到了30种,但对挥发油的提取率只有6.66%;溶剂萃取法使得花椒挥发油的提取率达到了8.37%,但提取物种类只有17种;采用同时蒸馏萃取法提取花椒挥发油时,其提取率达到了11.6%,提取物的种类达到了77种,该方法提取花椒挥发油的效果理想,对于花椒挥发油的成分分析以及定量检测也十分有助。该比较结果将为花椒挥发油的提取以及对挥发油的成分分析和定量检测提供实验依据。     

黄花菜挥发油成分分析

利用水蒸气蒸馏法从黄花菜中提取挥发油,运用气相色谱- 质谱技术,对其化学成分进行分离和鉴定,用色谱峰面积归一化法计算各组分的相对含量。色谱分离了100 个组分,鉴定了其中36 个组分,占总含量的95.68%,其中含量最高的是3- 呋喃甲醇,为76.17%。     

湖南刨花楠树叶挥发油的成分分析

利用水蒸气同时蒸馏萃取法提取产自湖南株洲的刨花楠新鲜树叶中的挥发油,对刨花楠树叶中挥发性成分的分析鉴定采用的是气相色谱-质谱联用技术。从中分析鉴定出了40种化学成分,占挥发性成分总含量的98.91%。应用峰面积归一化法确定了各成分的相对百分含量。结果表明:应用普通水蒸气蒸馏萃取法提取的刨花楠树叶挥发油中含量最高的化合物组分为癸醛(51.67%),其余含量相对较高的化合物组分分别为十氢-1,1,7-三甲基-4-亚甲基-氢-环丙薁(11.23%)、罗勒烯(5.67%)、γ-榄香烯(5.25%)、10-十一烯醛(4.58%)、十二醛(2.87%)、β-罗勒烯(2.56%)、3-己烯-1-醇(1.90%)、十氢-1,1,4,7-四甲基-1H-环丙薁醇-(4)(1.59%)、金合欢烯(1.31%)以及α-桉叶醇(1.17%)。本研究为湖南地区的刨花楠植物资源的研究开发和高效利用提供了实验参考依据。     

微波辅助水蒸气蒸馏调味香料肉豆蔻挥发油化学成分的研究

对云南产调味香料肉豆蔻挥发油进行了成分分析。采用微波水蒸气蒸馏法(MHD,300 W,料液比1∶10,蒸馏时间1 h)及水蒸气蒸馏法(HD)提取了肉豆蔻挥发油,利用气相色谱/质谱(GC/MS)联用技术和保留指数比较法分析了该挥发油的化学成分。从MHD肉豆蔻挥发油中鉴定了48种化合物,占挥发油总量的99.81%。主要成分为肉豆蔻醚(36.53%)、4-萜品醇(12.47%)、肉豆蔻酸(8.27%)、榄香素(4.96%)、黄樟素(4.75%)、γ-松油烯(4.56%)和甲基丁香酚(4.38%)。     

Comparison of microwave-assisted hydrodistillation withthe traditional hydrodistillation method in the extractionof essential oils from Thymus vulgaris L.

Microwave-assisted hydrodistillation (MAHD) is an advanced hydrodistillation (HD) technique utilizing a microwave oven in the extraction process. MAHD of essential oils from the aerial parts (tops) of Thymus vulgaris L. (common thyme) was studied and the results were compared with those of the conventional HD in terms of extraction time, extraction yield/efficiency, chemical composition, quality of the essential oils and cost of the operation. MAHD was superior in terms of saving energy and extraction time (75 min, compared to 4 h in HD). Scanning electron microscopy (SEM) of thyme leaves undergone HD and MAHD provided evidences as to a sudden rupture of essential oil glands with MAHD. Gas chromatography–mass spectrometry analysis of the extracted essential oils indicated that the use of microwave irradiation did not adversely influence the composition of the essential oils. MAHD was found to be a green technology.     

Representativeness of Apple Aroma Extract Obtained by Vacuum Hydrodistillation: Comparison of Two Concentration Techniques

ABSTRACT: Vacuum hydrodistillation, which is a very gentle work-up procedure, has never been used for the extraction of apple aroma. During the concentration of aroma that follows vacuum hydrodistillation, some very volatile components can be lost. The aim of this study was to compare 2 different concentration techniques, liquid-liquid extraction and solid phase extraction, to obtain an apple aroma extract as close as possible to fresh apple. After the elimination of solvent from the extract by gas chromatography, the study of the odor characteristics of solvent-free extracts was made possible. Vacuum hydrodistillation was convenient for fresh apples.     

Hydrodistillation and in situ microwave‐generated hydrodistillation of fresh and dried mint leaves: a comparison study

BACKGROUND: Hydrodistillation (HD) has been used since ancient times for the extraction of essential oils (EO). Despite the intrinsic limitations of this technique, it remains the most common method both in the laboratory and on an industrial scale. The main drawbacks are the long extraction time involved and the risk of thermal degradation. Over the last decade, microwave‐assisted extraction (MAE) and in situ microwave‐generated hydrodistillation (MGH) have been shown to be the most promising techniques in improving plant extraction and hydrodistillation. RESULTS: In this study we compare HD with MGH in the extraction of several mint species cultivated in Piedmont: Mentha spicata L. var. rubra, Mentha spicata L. var. viridis and Mentha piperita L. MGH requires either fresh plant or rehydrated material, it is extremely fast and allows a reduction in energy consumption and overall cost. All the EO have been analyzed by gas chromatography‐mass spectrometry. A mechanism of microwave‐generated essential oil extraction has been proposed to explain the differences in the composition of the oil obtained from this environmentally friendly technique. CONCLUSIONS: The yields and composition percentages of the EO obtained by HD and in situ MGH of fresh and dried mint leaves lie in a relatively narrow range, although MGH is faster. MW polarization effects and the water solubility of the components influence extract composition Copyright © 2012 Society of Chemical Industry     

Antioxidant Activities of the Supercritical and Conventional Satureja montana Extracts

ABSTRACT:  The antioxidant activities of the volatile and the nonvolatile fractions from  Satureja montana  obtained by supercritical fluid extraction (SFE) and by conventional techniques, hydrodistillation (HD) and soxhlet extraction (SE), were compared. A good agreement between DPPH and rancimat methods was obtained showing that the extracts were able to scavenge free radicals and to inhibit lipid oxidation. The volatile oil (obtained by SFE at 90 bar/40 °C) was the most effective extract, presenting the lowest EC₅₀ (0.06 g/L) and the highest protector factor (PF = 2.03). These results demonstrated the advantages of SFE over conventional techniques by avoiding thermodegradation and hydrolysis reactions. Furthermore, volatile oil is 15 times richer in thymoquinone than the essential oil (HD). This compound is of great importance due to its antioxidant, neuroprotective, and anti-cancer activities. The combination of carvacrol + thymol + thymoquinone in volatile oil may be responsible for the increase in the antioxidant activity when compared to HD, which demonstrates that, in this case, SFE improves value to the final product.     

冲泡条件对‘修水化红’甜橙皮茶总黄酮含量的影响及茶的挥发性风味成分分析

目的:旨在研究冲泡条件对‘修水化红’甜橙皮茶中总黄酮含量及挥发性风味成分的影响。方法:研究冲泡料水比、水质、冲泡温度、冲泡时间、冲泡次数对‘修水化红’皮茶总黄酮含量的影响,并采用顶空固相微萃取-气相色谱-质谱连用技术(HS-SPME-GC-MS)测定‘修水化红’皮冲泡后茶的挥发性风味成分。结果表明,随着冲泡温度、冲泡时间的增加,茶汤中总黄酮含量逐渐增加;但冲泡次数越多,每次冲泡后总黄酮含量降低,在冲泡2~3次后,皮中的大部分总黄酮浸出到茶汤中。在料水比1:125 g/mL,水质为矿泉水,100 ℃沸水下冲泡‘修水化红’皮茶8~10 min,茶汤中总黄酮含量最高。‘修水化红’皮茶中共鉴定出39种挥发性风味成分,D-柠檬稀相对含量最高,挥发性风味成分包括萜烯烃类、烷烃类、醇类、醛类、酯类及酮类等6类化合物,主要是萜烯烃类和醇类。结论:不同冲泡条件的‘修水化红’皮茶中总黄酮含量均有一定的差异,精确控制‘修水化红’皮茶的冲泡条件可获得高总黄酮含量的皮茶,同时皮茶中的多种挥发性成分为其整体风味和感官属性起关键性作用。     

Ohmic‐assisted hydrodistillation of essential oils from Zataria multiflora Boiss (Shirazi thyme)

Ohmic‐assisted hydrodistillation (OAHD) is a combination of ohmic heating and distillation, and could be considered as a novel method for the extraction of essential oils. Major problems with traditional methods are long extraction time and lower purity of the extract. In this study, OAHD was applied as an economic and green technology for the extraction of essential oils from Zataria multiflora Boiss. (Shirazi thyme) aerial parts and the results were compared to those obtained from hydrodistillation (HD) as a conventional method. The results showed that OAHD method had the extraction time of 32.21 ± 2.59 min while this value was about 57.21 ± 2.33 min for hydrodistillation (HD). Scanning electron micrographs of thyme leaves showed a sudden eruption of essential oil glands and their surrounding area for OAHD samples. GC–MS analysis indicated that both methods of OAHD and HD can extract the same compounds.     

Essential oil composition and antibacterial activity of the grapefruit (Citrus Paradisi. L) peel essential oils obtained by solvent‐free microwave extraction: comparison with hydrodistillation

The chemical composition of the essential oil (EO) obtained by solvent‐free microwave extraction (SFME) and hydrodistillation (HD) from the peel of grapefruit (Citrus Paradisi. L) was analysed by gas chromatography/mass spectrometry (GC/MS). Totally, twenty‐five components were identified in the EO. Limonene was observed as dominant (91.5–88.6%) for two extraction methods, SFME and HD, respectively. β‐Pinene (0.8–1.2%), linalool (1.1–0.7%), α‐terpinene (0.7–1.0%) and the other minor components were also detected. Disc diffusion method was applied to determine the antibacterial properties of the EO. The results showed that the EO of grapefruit peel had a wide spectrum of antimicrobial activities against Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Escherichia coli, Salmonella typhimurium, Serratia marcescens and Proteus vulgaris, with their inhibition zones ranging from 11 to 53 mm.     

顶空- 气质联用法测定柚子皮绿茶挥发性成分

采用顶空-气质联用法测定柚子皮绿茶、柚子皮和绿茶原料中的挥发性香气成分,通过对各样品成分的比较,探讨柚子皮绿茶成品香气成分的来源及成因。结果：柚子皮绿茶、柚子皮和绿茶原料的主要成分均为柠檬烯和月桂烯,表明柠檬烯和月桂烯不是由柚子皮转移至绿茶原料的新香气成分;在柚子皮绿茶中检测出几种含氧化合物,占柚子皮绿茶总挥发性成分的5%左右,是区别于绿茶原料和柚子皮的特异性香味物质;并将本方法提取的香气成分与同时蒸馏法进行对比,发现同时蒸馏法提取物含氧化合物比例较高,可能是因为同时蒸馏萃取法高温下长时间反复萃取,样品中的烯烃类物质被氧化所致,而顶空提取法条件较为温和,得到的挥发性成分与样品自然释放的香气成分更为接近。     

Fresh squeezed orange juice odor: a review

Fresh orange juice is a highly desirable but unstable product. This review examines analytical findings, odor activity, and variations due to cultivar, sampling methods, manner of juicing, plus possible enzymatic and microbial artifacts. Initial attempts to characterize orange juice odor were based on volatile quantitation and overemphasized the importance of high concentration volatiles. Although over 300 volatiles have been reported from GC-MS analytical studies, this review presents 36 consensus aroma active components from GC-olfactometry studies consisting of 14 aldehydes, 7 esters, 5 terpenes, 6 alcohols, and 4 ketones. Most are trace (microg/L) components. (+)-Limonene is an essential component in orange juice odor although its exact function is still uncertain. Total amounts of volatiles in mechanically squeezed juices are three to 10 times greater than hand-squeezed juices because of elevated peel oil levels. Elevated peel oil changes the relative proportion of several key odorants. Odor active components from solvent extraction studies differ from those collected using headspace techniques as they include volatiles with low vapor pressure such as vanillin. Some reported odorants such as 2,3-butanedione are microbial contamination artifacts. Orange juice odor models confirm that fresh orange aroma is complex as the most successful models contain 23 odorants.