柠檬香茅精油的提取及抗氧化活性研究

文中采用水蒸汽蒸馏法对海南产柠檬香茅进行精油提取,研究了提取时间、料液比、香茅粗细、香茅部位、提取液成分等因素对精油收率及主要成分存在影响,精油提取率为0.09-1.06%,50g 长2cm的干柠檬香茅在1400mL含8 g NaCl的水溶液,提取时间180min时精油出油率最高,为1.06%;随提取条件不同,精油成分有所变化,但主要成分无明显差异,主要为芳樟醇、橙花醛、香叶醛、香叶醇和香叶酸,此五种主要成分的含量约占精油总量的86-96%。电子自旋共振法（ESR）测试结果表明1%香茅精油乙醇溶液对羟基自由基具有一定清除活性,清除率32%。     

采收和存放时间对柠檬香茅得油率及其挥发油主成分的影响

为了研究在不同的采收月份和存放时间条件下柠檬香茅得油率及其挥发油主成分的变化情况,采用水蒸气蒸馏法对不同采收月份、不同存放时间的柠檬香茅测定得油率,利用气相色谱-质谱法(GC-MS)对柠檬香茅油的化学成分进行分析,峰面积归一化法定量,观察采收月份以及存放时间对柠檬香茅挥发油成分的影响。试验结果表明:柠檬香茅中的挥发油含量(以绝干计)在9月和12月较高,以9月为最高。柠檬香茅油中的主要成分为月桂烯、橙花醛和香叶醛,相对质量分数均大于10%;橙花醛和香叶醛的总相对质量分数从3月(68.02%)到9月(76.16%)呈增加趋势;柠檬香茅草存放30~40 d时,绝干得油率以及柠檬香茅油中的香叶醛和橙花醛含量相对较高。     

枯萎霉变对柠檬型香茅草精油得率和主成分含量的影响北大核心

采集广西防城港种植的柠檬醛型香茅草,对刚收割下来的香茅草枯萎叶稍、新鲜茎、新鲜全草、干燥全草的精油得率和成分进行分析,并考察自然存放霉变对香茅草精油得率和精油主要化学成分的影响。结果表明:在湿热环境下,随着存放时间的延长,香茅草腐烂程度加重,其精油得率降低,精油主要成分橙花醛和香叶醛总含量也降低。新鲜全草与干燥全草的含油率基本相同,新鲜香茅草精油中柠檬醛GC含量约为71.028%,得油率为0.483%,经过7天的自然腐烂后,霉变的香茅草精油中柠檬醛的GC含量降为66.1%,得油率为0.317%。新鲜茎精油柠檬醛GC含量78.766%为最高,枯萎叶稍精油得率最低为0.174%。     

枯萎霉变对柠檬型香茅草精油得率和主成分含量的影响

采集广西防城港种植的柠檬醛型香茅草,对刚收割下来的香茅草枯萎叶稍、新鲜茎、新鲜全草、干燥全草的精油得率和成分进行分析,并考察自然存放霉变对香茅草精油得率和精油主要化学成分的影响。结果表明:在湿热环境下,随着存放时间的延长,香茅草腐烂程度加重,其精油得率降低,精油主要成分橙花醛和香叶醛总含量也降低。新鲜全草与干燥全草的含油率基本相同,新鲜香茅草精油中柠檬醛GC含量约为71.028%,得油率为0.483%,经过7天的自然腐烂后,霉变的香茅草精油中柠檬醛的GC含量降为66.1%,得油率为0.317%。新鲜茎精油柠檬醛GC含量78.766%为最高,枯萎叶稍精油得率最低为0.174%。     

从山苍子中提取柠檬醛及其测定研究

采用微波辐照从山苍子中提取柠檬醛 ,精油的得率较传统的直接水蒸气蒸馏法平均提高2 48%以上。用程序升温毛细管柱气相色谱归一化法测定山苍子精油中的柠檬醛 ,获得的山苍子精油柠檬醛质量分数为 6 8 6 4% ,回收率为 10 1 3% ,相对标准偏差为 0 2 8% ,线性相关系数为0 9997,准确性与内标法相一致 ,而且操作较内标法和GB 1142 4— 89法更为方便。     

六种香茅属植物资源及精油成分

西双版纳栽培有六种香茅属(CymboPoeon)植物,从它们的叶片中可提取芳香油,鲜叶出油为0.43—0.87%,主要成分分别为柠檬醛、香茅醛、香叶醇、胡椒酮、榄香树脂等,具有发展种植和开发利用的价值。     

香茅挥发油组分的GC-MS分析

目的:研究香茅挥发油的组成成分,为该药材的应用提供理论依据.方法:通过蒸馏法对香茅药材进行挥发油的提取,用气相色谱-质谱联用法(GC-MS)分析香茅挥发油的主要成分.结果:香茅挥发油提取率为1.56％,分析出22个成分,主要化学成分为:2-甲氧基乙基乙烯基醚、(E)-3,7-二甲基-2,6-辛二烯醛(即(E)-柠檬醛)...     

不同产地香茅草挥发性成分的GC-MS分析

采用水蒸气蒸馏法提取不同产地的4种香茅草挥发油,并利用GC-MS技术进行分离鉴定,以面积归一化法测定各成分的相对含量(峰面积相对百分比),鉴定出34种主要挥发性成分,其中相对含量最高的为香茅醛,在4种挥发油中分别为19.48%、36.15%、28.49%和27.09%,其次为香叶醇,分别为30.65%、21.49%、19.52%和22.56%。不同产地的香茅草挥发性成分有所差异,但均含有柠檬烯、香茅醛、香茅醇、香叶醇、乙酸香茅酯、α-榄香醇、桉叶油醇等主要化学成分,总相对含量超过85%,此结果可为香茅草的质量评价、质控标准制定和合理选择植物种植地提供数据参考。     

提取山苍子油及柠檬醛的工艺研究

用水中蒸馏法、水上蒸馏法和超声波水中蒸馏法提取山苍子精油,通过化学法分离出柠檬醛,用正交实验探索提取柠檬醛的最佳条件。结果表明,超声波水中蒸馏法能更好的提取山苍子油,最佳条件为:超声时间25 min,温度100℃;分离柠檬醛的最优条件为(以1 mL山苍子油为原料基准):控制温度0℃,静置60 min,NaHSO3饱和溶液6 mL,NaOH(10%)溶液30 mL,提取率达90%。     

季节对柠檬香茅草油得油率和成分的影响研究

采用传统水蒸气蒸馏通过对不同季节的柠檬香茅草进行得油率测定,利用气相色谱-质谱(GC-MS)分析柠檬香茅油的化学成分,采用GC峰面积归一化法定量,考察了季节对柠檬香茅挥发油成分的影响。实验结果表明:柠檬香茅挥发油含量(绝干计)在9月和12月较高,其中9月的挥发油含量最高。柠檬香茅油中主要组分为月桂烯、橙花醛和香叶醛,含量均大于10%;橙花醛和香叶醛含量从3月到10月呈增加趋势。     

亚临界水提取干花椒中精油的研究

采用亚临界水提取技术从干花椒中提取花椒精油.考察了原料颗粒度、提取时间、提取温度等因素对花椒精油提取得率的影响.确定亚临界水提取花椒精油的最佳工艺为:原料颗粒度0.5 mm、提取时间40 min、100～150℃的连续程序升温、压力5 Mpa,在此条件下花椒精油的提取得率为5.42%.同时,对亚临界水提取所得的花椒精油进行了抗氧化实验,并与常用抗氧化剂BHT和BHA进行了对比.结果表明,亚临界水提取所得的花椒精油具有较好的抗氧化性.用亚临界水提取技术提取花椒精油具有效率高、能耗低的优点.     

芫荽籽精油成分分析及消除亚硝酸钠能力研究

研究了黑龙江产芫荽籽精油成分和精油、残渣溶剂萃取物消除NaNO2的能力。用水蒸气蒸馏法提取黑龙江产芫荽籽,以0.50%的产率获得精油。用GC-MS对精油进行了成分分析,检测出31个成分,解析鉴定了占精油质量99.726%的29个成分。主要成分芳樟醇占73.614%(质量分数)。对NaNO2的消除作用结果显示:当精油用量为0.05～0.35mL时,消除率为47.0%～74.2%。水蒸气蒸馏后残渣的甲醇、乙醇、丙酮萃取物溶液用量为0.6～1.0mL时,对NaNO2的消除率为38.8%～42.2%。     

侧柏叶挥发油提取工艺及其抑菌活性研究

采用水蒸气蒸馏法提取侧柏叶挥发油,以减重法测定挥发油质量,并用薄层色谱法及气相色谱法进行成分分析,通过测量侧柏叶挥发油的抑菌圈大小考察其抑菌活性.正交实验确定侧柏叶挥发油的最佳提取工艺条件为:侧柏叶粉碎度20～30目,加6倍量水,浸泡时间12 h,提取时间5 h;侧柏叶挥发油对金黄色葡萄球菌、四联球菌、大肠杆菌和产气杆菌均有明显的抑制作用,对枯草杆菌的抑菌作用不明显.     

Microwave Assisted Extraction of Essential Oil From Cymbopogon Flexuosus (Steud.) Wats.: A Parametric and Comparative Study

Microwave assisted extraction was employed for efficient and rapid extraction of essential oil from leaves of Cymbopogon flexuosus (Steud.) Wats. (lemongrass). Parametric study was carried out to examine the effect of various parameters like solid loading, volume of water, rehydration time, extraction time, and power on yield and composition of essential oil. Hydrodistillation was performed for comparative analysis. Kinetic modelling of experimental data was attempted. Microscopic analysis of treated and untreated leaves was performed to observe the surface morphology. The results obtained can further be utilized for optimization of parameters as well as designing the process.     

SFE法和SD法提取木贼挥发油化学成分的比较分析

分别采用超临界CO2萃取(SFE)法和水蒸气蒸馏(SD)法提取木贼挥发油,用GC-MS法进行成分鉴定,用归一法测其相对含量。SFE法提取木贼挥发油的出油率为2.10%,SD法提取木贼挥发油的出油率为0.86%。超临界CO2萃取法提取物鉴定出61个成分,占总成分的22.2%;水蒸气蒸馏法提取物鉴定出43个成分,占总成分的19.6%。超临界CO2萃取法提取植物挥发油具有产率高、产品质量好、提取速度快等特点,适用于中草药挥发油的化学成分分析。     

Chromenes from Ageratum conyzoides: Steam distillation,supercritical extraction,and mathematical modeling

The chromenes extraction processes from Ageratum conyzoides by steam distillation and supercritical fluid extraction (SFE) were studied. Essential oil was extracted by saturated steam at 1.0 to 2.0 bar and the SFE was performed at 40ºC and 90 to 200 bar to obtain non-volatile extracts. The essential oil presented two major compounds—precocene I (28.24%) and precocene II (28.55%). At 90 bar, the SFE resulted in higher yield and selectivity for precocene I and II (65.06%). The yield of chromenes varied according to pressure of SFE; however, this behavior was not observed in extracts obtained by steam distillation.     

芹菜籽精油成分以及清除亚硝酸钠作用研究

水蒸汽蒸馏法提取黑龙江产芹菜籽,以1．18％产率获得精油。用GC—MS联机分析精油共检测出23个成分,鉴定出占总精油91．375％的18种成分,主要成分为柠檬烯（31．149％）,β-蛇床烯（22．281％）,对甲苯基异戊酸酯（14．944％）,α-2-丙烯基苯甲醇（9．872％）,β-月桂烯（4．324％）和α-蛇床烯（4．322％）。精油对亚硝酸钠的清除作用研究结果显示：芹菜籽精油具有明显的清除亚硝酸盐作用,当精油用量0．4mL时,清除率最大为71．28％。     

Optimization of Supercritical CO2 Extraction of Fish Oil from Viscera of African Catfish (Clarias gariepinus)

Fish oil was extracted from the viscera of African Catfish using supercritical carbon dioxide (SC-CO₂). A Central Composite Design of Response Surface methodology (RSM) was employed to optimize the SC-CO₂ extraction parameters. The oil yield (Y) as response variable was executed against the four independent variables, namely pressure, temperature, flow rate and soaking time. The oil yield varied with the linear, quadratic and interaction of pressure, temperature, flow rate and soaking time. Optimum points were observed within the variables of temperature from 35 °C to 80 °C, pressure from 10 MPa to 40 MPa, flow rate from 1 mL/min to 3 mL/min and soaking time from 1 h to 4 h. However, the extraction parameters were found to be optimized at temperature 57.5 °C, pressure 40 MPa, flow rate 2.0 mL/min and soaking time 2.5 h. At this optimized condition, the highest oil yields were found to be 67.0% (g oil/100 g sample on dry basis) in the viscera of catfish which was reasonable to the yields of 78.0% extracted using the Soxhlet method.     

Effects of supercritical CO2 extraction parameters on chemical composition and free radical-scavenging activity of pomegranate (Punica granatum L.) seed oil

Pomegranate (Punica granatum L.) seed oil (PSO) was prepared by supercritical CO₂ (SC-CO₂) extraction technology. Changes in the yield, chemical composition and free radical-scavenging activity of PSO under different extraction parameters were investigated. The results of SC-CO₂ extraction revealed that extraction pressure was the dominant factor to affect the oil yield. PSO was characterized by a high content of punicic acid (approximately 60%) and γ-tocopherol (more than 300 mg/100 g oil). A slight increase in the contents of punicic acid, arachidic acid and gadoleic acid was observed under higher extraction pressure and temperature. At lower pressure or shorter extraction time, PSO with high amount of total tocopherols was obtained. PSO extracted by SC-CO₂ showed strong free radical-scavenging activity towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenz-thiazoline-6-sulfonic) diammonium salt (ABTS) radicals and its scavenging ability was correlated with the level of tocopherols in extracted oils.