A further study of the kinetics and optimization of the essential oil hydrodistillation from lavender flowers

Hydrodistillation has commonly been used to recover essential oil from various plant materials, including lavender (Lavandula officinalis) flowers. The main objectives of the present study were to model the kinetics of the lavender essential oil (LEO) hydrodistillation using a phenomenological model, to evaluate the statistical significance of the hydromodule and hydrodistillation time on LEO yield combining a 4² full factorial design with the response surface methodology, to model statistically LEO yield by multiple non-linear regression and to determine the optimal process conditions that provided the maximum LEO yield. The fast-essential oil distillation (washing stage) in the initial period and the slow diffusion stage until the saturation occurring simultaneously were observed, justifying the use of the phenomenological model. With increasing the hydromodule, the saturation LEO yield and the washable fraction of the LEO decreased while the washing and diffusion rate constants increased. Knowledge of the LEO oil yield and the hydrodistillation kinetics is important from the techno-economical point of view.     

A new kinetic model for the common juniper essenstial oil extraction by microwave hydrodistillation

The main objective of the present study was to model the kinetics of essential oil extraction from swelled ground juniper berries by classic hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD). A new phenomenological kinetic model was developed on the basis of the juniper essential oil extraction mechanism that assumed three mass transfer processes occurring simultaneously: washing, unhindered diffusion and hindered diffusion. The new model was compared to the existing kinetic models. Among the tested models, the new model had the smallest mean relative percentage deviation and the highest corrected Akaike information criterion value. In addition, that, the new model was verified for HD and MAHD of essential oils from some other plant materials. On the basis of the above-mentioned facts, the new model can be recommended for modeling the kinetics of essential oil extraction by both HD and MAHD.     

Supercritical carbon dioxide extraction of spearmint oil from mint-plant leaves

Spearmint oil (essential oil of Mentha spicata) was extracted from Turkish mint-plant leaves using supercritical CO₂ in a basket-type extractor. Effects of temperature, pressure, extraction time, amount of CO₂, and entrainer (ethanol) concentration on composition of essential-oil extracts and oil yield, relative to hydro-distillation, were investigated. Relative yields were as high as 80%. Monoterpenes fraction in extracts was inversely correlated with relative oil yields. Monoterpenes were preferentially extracted by CO₂ due to their high vapor pressure, low molar mass and low polarity. Supercritical extraction presented advantages over the conventional hydro-distillation by yielding extracts lower in monoterpenes fraction and by enabling high yields at temperatures safe for the heat-sensitive essential oil.     

Solvent Extraction: Kinetic Study of Major and Minor Compounds

The effects of temperature and contact time on lipid extraction from sunflower collets was investigated in a batch extractor with hexane as solvent. The total removed material varied in quantity and composition due to changes in temperature and contact time. Higher temperatures enhanced oil extraction as well as increased the tocopherol and phospholipid contents of the oil. The kinetic data for triglycerols, phospholipid and tocopherols extraction were interpreted by using an equation that considers extraction as the sum of two components: diffusion and washing. Effective diffusion coefficients for oil, tocopherols and phospholipid at different temperatures were determined. Control of temperature and contact time are essential to obtain good quality oil and reduce refining costs. Extraction at 60 °C and short contact times (30 min) obtained high oil yield (98%) accompanied by significant tocopherol extraction (>99%) and reduced phospholipid extraction (66%).     

Dual Bioactivities of Essential Oil Extracted from the Leaves of Artemisia argyi as an Antimelanogenic versus Antioxidant Agent and Chemical Composition Analysis by GC/MS

The study was aimed at investigating the antimelanogenic and antioxidant properties of essential oil when extracted from the leaves of Artemisia argyi, then analyzing the chemical composition of the essential oil. The inhibitory effect of the essential oil on melanogenesis was evaluated by a mushroom tyrosinase activity assay and B16F10 melanoma cell model. The antioxidant capacity of the essential oil was assayed by spectrophotometric analysis, and the volatile chemical composition of the essential oil was analyzed with gas chromatography-mass spectrometry (GC/MS). The results revealed that the essential oil significantly inhibits mushroom tyrosinase activity (IC₅₀ = 19.16 mg/mL), down-regulates B16F10 intracellular tyrosinase activity and decreases the amount of melanin content in a dose-dependent pattern. Furthermore, the essential oil significantly scavenged 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline- 6-sulphonic acid) ABTS radicals, showed an apparent reduction power as compared with metal-ion chelating activities. The chemicals constituents in the essential oil are ether (23.66%), alcohols (16.72%), sesquiterpenes (15.21%), esters (11.78%), monoterpenes (11.63%), ketones (6.09%), aromatic compounds (5.01%), and account for a 90.10% analysis of its chemical composition. It is predicted that eucalyptol and the other constituents, except for alcohols, in the essential oil may contribute to its antioxidant activities. The results indicated that essential oil extracted from A. argyi leaves decreased melanin production in B16F10 cells and showed potent antioxidant activity. The essential oil can thereby be applied as an inhibitor of melanogenesis and could also act as a natural antioxidant in skin care products.     

向日葵盘精油的化学成分及抗氧化活性

为明晰采收后向日葵盘精油的成分及其体外抗氧化活性，应用水蒸气蒸馏法提取采收后向日葵盘精油，利用气相色谱-质谱联用法（GC-MS）分析其化学成分，通过DPPH自由基和ABTS自由基清除法对精油的体外抗氧化活性进行测定。结果显示：从向日葵盘精油中共鉴定出49种化学成分（占精油总量91.16%），其中α-蒎烯（28.22%）、柠檬烯（6.55%）、α-蛇麻烯（4.99%）、反式-β-金合欢烯（3.58%）和莰烯（3.39%）为其主要成分。向日葵盘精油具有一定的体外抗氧化活性，其清除DPPH自由基、ABTS自由基的半数有效浓度（EC₅₀）值分别为0.47、0.30 g/L，明显高于阳性对照BHT的EC₅₀值（分别为8.21和6.16 mg/L）。     

东北连翘鲜花精油的GC-MS分析

采用同时蒸馏萃取(SDE)法提取东北连翘鲜花精油,气相色谱-质谱法(GC-MS)分析精油的化学组分,考察不同溶剂对结果的影响。结果表明,SDE石油醚萃取得到的东北连翘鲜花精油得率为0.69%,鉴定得到28种成分,GC含量最高的化合物为二十五烷(28.65%),其次是Z-9-二十三烯(27.82%)。SDE正己烷萃取得到的东北连翘鲜花精油得率为0.81%,鉴定得到44种成分,GC含量最高的化合物为Z-9-二十三烯(47.16%),其他香料化合物如肉豆蔻醛(0.97%)、石竹烯(0.05%)等。两种精油的共有成分Z-9-二十三烯可用作家蝇性引诱剂。     

Chemical Composition and Antimicrobial Activity of the Essential Oil of Kumquat (Fortunella crassifolia Swingle) Peel

The aim of this study was to determine the main constituents of the essential oil isolated from Fortunella crassifolia Swingle peel by hydro-distillation, and to test the efficacy of the essential oil on antimicrobial activity. Twenty-five components, representing 92.36% of the total oil, were identified by GC-MS analysis. The essential oil showed potent antimicrobial activity against both Gram-negative (E. coli and S. typhimurium) and Gram-positive (S. aureus, B. cereus, B. subtilis, L. bulgaricus, and B. laterosporus) bacteria, together with a remarkable antifungal activity against C. albicans. In a food model of beef extract, the essential oil was observed to possess an effective capacity to control the total counts of viable bacteria. Furthermore, the essential oil showed strongly detrimental effects on the growth and morphological structure of the tested bacteria. It was suggested that the essential oil from Fortunella crassifolia Swingle peel might be used as a natural food preservative against bacteria or fungus in the food industry.     

蓝桉叶挥发油化学成分分析研究

采用乙醚为溶剂提取云南产蓝桉干叶的挥发油,经气相-质谱联用仪分析,得到57种组分,确定了其中54个化合物的结构,主要成分是1,8-桉叶素(68.61%),α-蒎烯(10.24%),别香橙烯(5.27%),乙酸松油酯(4.05%),香橙烯(1.45%),(-)-蓝桉醇(1.26%),α-松油醇(1.02%)等。采用峰面积归一法计算各组分的相对含量,所鉴定成分占总馏出峰面积的99.69%。     

Constituents of essential oil from the dried fruits and stems of Akebia quinata (THUNB.) DECNE

The compositions of the essential oil from AKEBIAE FRUCTUS and AKEBIAE CAULIS, the dried fruits and stems of Akebia quinata (THUNB.) DECNE. (Lardizabalaceae), have been investigated by GC and GC/MS. As a result, the fruits oil was revealed the presence of 86 components, representing 98.4% of the total oil. The major compounds of the fruits oil were limonene, eugenol, octanal and p-cymene. The monoterpenoids and saturated short-chain aldehyde (C6 approximately C10) were main volatile fractions of the oil. Ninety components accounting for 90.5% of constituents of stems oil were identified, and the main compounds of the oil were hexanoic acid, palmitic acid, (2E, 4E)-decadienal and hexanol. The oil had high content of saturated fatty acids (C6 approximately C16), and unsaturated short-chain aldehyde (C6 approximately C10).     

Qualitative and Quantitative Changes in the Essential Oil of Lemon Verbena (Lippia citriodora) as Affected by Drying Condition

The objective of this study was to evaluate the effect of drying air temperature and air flow rate on the quantity and quality of the essential oil of lemon verbena. A completely randomized design was applied with a factorial arrangement of two factors: temperature (30, 40, and 50°C) and air flow rate (0.5, 1, and 1.5 m/s). The leaves were harvested in full blooming stage and placed in the drying machine at different temperatures and air flow rates. The essential oil of leaves was extracted by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). The results showed that the interaction between different temperatures under various air flow rates had a significant effect on the content and chemical composition of the essential oil. Seventeen compounds were identified in essential oil of lemon verbena, of which geranial, neral, and limonene were the major components. The maximum oil content and majority compounds of essential oil were obtained at 50°C and a 0.5 m/s air flow. Finally, seven mathematical models of thin-layer drying such as correlation coefficient (R ²), sum of square errors (SSE), and root mean square error (RMSE) were evaluated and the modified Page model was found to be the best drying model for lemon verbena.     

蒜头果挥发油化学成分研究

采用同时蒸馏萃取及水蒸气蒸馏方法分别提取新鲜蒜头果果皮中的挥发性成分,挥发油通过气相色谱-质谱联用法进行分离和鉴定,采用峰面积归一化法确定百分含量。从水蒸气蒸馏中分别鉴定出9种成分,分别占总量的96.62%和99.80%,这些成分主要是为苯甲醛、α-羟基-苯乙腈、苯甲醇、4-羟甲基苯甲酸甲酯和2-羟基-丙烷腈等成分。结果表明,采用同时蒸馏萃取法得到的挥发油得率(为1.23%)较水蒸气蒸馏方法 (为0.92%)高,所鉴定出来的挥发性成分含量占总量的比例较水蒸气蒸馏方法高,因此采用同时蒸馏萃取方法更适用于蒜头果果皮精油的提取。     

素心蜡梅和红心蜡梅鲜花挥发油成分分析

用同时蒸馏萃取法(SDE)提取了素心蜡梅和红心蜡梅鲜花的挥发油,用气相色谱-质谱(GC-MS)联用技术对其挥发油的化学成分进行了分析鉴定。从素心蜡梅挥发油中鉴定出38种化学成分,占挥发油色谱总峰面积的92.214%;红心蜡梅中鉴定出42种化学成分,占挥发油色谱总峰面积的93.689%。素心蜡梅挥发油中相对质量分数较高的成分是z-木罗烯(18.128%)、z-榄香烯(13.640%)、L-乙酸龙脑酯(8.577%)、tau-杜松醇(7.771%)、β-荜澄茄烯(6.588%)等;红心蜡梅挥发油中相对质量分数较高的是榄香醇(16.171%)、z-榄香烯(12.758%)、β-荜澄茄烯(11.501%)、tau-杜松醇(4.649%)、石竹烯(3.947%)等。     

响应面法优化微波辅助水蒸气蒸馏法提取油樟精油工艺

为了解决油樟精油传统提取工艺时间长、效率低、耗能高和成本高等问题，本文遵循绿色提取理念，采用微波辅助水蒸气蒸馏法提取油樟精油并优化最佳提取工艺。根据单因素试验并结合响应面法建立二次回归模型进行方差分析和诊断，考察物料粒度、微波提取时间和微波提取功率对油樟精油得率的影响，确定最佳提取工艺并对理论结果进行实验验证。结果表明，在油樟精油得率相似的情况下，与传统的水蒸气蒸馏法（2h）相比，微波辅助水蒸气蒸馏法（10min）具有提取时间更短、效率更高和更节约能源的优势。通过二次多项式回归模型极显著（P<0.01），失拟项不显著（P>0.05），决定系数为R²=0.989等分析结合诊断图表明该模型对数据拟合良好。微波辅助水蒸气蒸馏法提取油樟精油最佳提取工艺为：物料粒度10目，微波提取时间11min，微波提取功率630W，此条件下油樟精油得率为4.479%，与实验验证结果（4.442%±0.16%）基本一致，验证了二次回归模型的可靠性。该技术较传统工艺提取时间短、效率高、耗能少、成本低，更加绿色安全且容易实现产业化，有望提高油樟精油在日化、美容、医药等各个领域的应用价值。     

Extraction,Chemical Composition,and Antifungal Activity of Essential Oil of Bitter Almond

The essential oil from the powder residual of dried bitter almond, a novel and environmentally-friendly fungicide, was successfully extracted in a 0.7% yield by hydro-distillation under optimized conditions. The chemical composition of bitter almond essential oil (BAEO) was analyzed by gas chromatography–mass spectrometry (GC–MS). Twenty-one different components representing 99.90% of the total essential oil were identified, of which benzaldehyde (62.52%), benzoic acid (14.80%), and hexadecane (3.97%) were the most abundant components. Furthermore, the in vitro and in vivo antifungal activities of BAEO against common plant pathogenic fungi were evaluated by the mycelium linear growth rate method and pot test, respectively. It was documented that 1 mg/mL of BAEO could variously inhibit all tested pathogenic fungi with the inhibition rates of 44.8%~100%. Among the tested 19 strains of fungi, the median effective concentration (EC₅₀) values of BAEO against Alternaria brassicae and Alternaria solani were only 50.2 and 103.2 μg/mL, respectively, which were higher than those of other fungi. The in vivo antifungal activity of BAEO against Gloeosporium orbiculare was much higher than Blumeria graminis. The protective efficacy for the former was up to 98.07% at 10 mg/mL and the treatment efficacy was 93.41% at 12 mg/mL. The above results indicated that BAEO has the great potential to be developed as a botanical and agricultural fungicide.     

Fractioning of orange (Citrus sinensis L.) essential oil using vacuum fractional distillation

Citrus essential oil has many uses in food, cosmetics, and pharmaceuticals industries, especially the minor compounds present in the oil. This work aimed to evaluate the distillation patterns of the components of the peel essential oil of Citrus sinensis using vacuum fractional distillation. The performed tests show that the separation of the compounds occurs with the leaving of the lighter terpenes, followed by the heavier terpenes and part of the oxygenated functions. Most of the oxygenated functions remained in the bottom of the column, being concentrated in this fraction. Many trace compounds were found in the bottom products. The limonene mass percentage reduced from 96.68% to 52.81% in the bottom products. Linalool had its mass percentage increased from 0.37% in the raw oil to 4.22% in the bottom. It was also observed in the operation conditions of the column (10 kPa and 70°C), there was no evidence of thermal degradation of the raw oil, neither of the obtained fractions during the process.     

重庆含笑鲜花挥发油的化学成分分析

采用水蒸气蒸馏法(SD)和同时蒸馏萃取法(SDE)分别提取了重庆地区含笑鲜花的挥发油,并用气相色谱-质谱联用技术对其挥发油的化学成分进行了分离鉴定。从含笑鲜花水蒸气蒸馏和同时蒸馏萃取所得挥发油中,分别鉴定出38种和36种化合物,分别占挥发油色谱总峰面积的92.928%和90.555%。两种方法提取的含笑鲜花挥发油提取率分别为0.12%和0.26%,主要成分均为萜烯类、萜烯醇类、酯类化合物,相对质量分数较高的成分有τ-榄香烯、石竹烯、β-榄香烯、大根香叶烯D、α-布藜烯、(Z)-5,11,14,17-二十碳四烯酸甲酯等。     

赤桉和本泌桉叶精油的化学成分研究

用水蒸气蒸馏法提取了赤桉叶和本泌桉叶精油,通过气相色谱-质谱(GC-MS)联用法分析鉴定了二者的化学成分及质量分数。赤桉叶精油共鉴定出57种化合物,占总离子流出峰面积的94.81%,主要成分为w(1,8-桉叶油素)=50.17%,其后依次是w(α-蒎烯)=8.53%、w(蓝桉醇)=5.65%、w(乙酸松油酯)=3.69%、w(α-松油醇)=3.58%;本泌桉叶精油共鉴定出45种化合物,占总离子流出峰面积的90.93%,主要成分为w(α-蒎烯)=31.00%、w(蓝桉醇)=15.34%、w(香树烯)=13.80%和w(表蓝桉醇)=4.86%。     

落叶松鲜针叶精油的化学成分及杀虫活性研究

采用同时蒸馏萃取(SDE)法以正己烷为溶剂提取落叶松鲜针叶精油,并对其进行了气相色谱-质谱(GC-MS)分析,研究了落叶松鲜针叶精油与松木屑木醋液复配物对舞毒蛾2龄幼虫的杀虫活性。结果表明:落叶松鲜针叶精油得率为0.93%,共鉴定出63种成分,总GC含量为98.11%,GC含量最高的化合物为3-蒈烯(12.13%),其次是2,4-二(1-甲基-1-苯基乙基)苯酚(10.71%)。雌舞毒蛾引诱剂(+)-(7R,8S)-7,8-环氧-2-甲基十八烷的GC含量为0.10%。落叶松鲜针叶精油-木醋液(体积比1:9,稀释至原体积5倍)对舞毒蛾2龄幼虫喷雾法杀虫活性实验的校正死亡率24 h达到83.33%,优于木醋液5倍稀释液,且72h内无变化。落叶松鲜针叶精油与松木屑木醋液复配能起到增效作用。