Extraction of Cinnamomum longepaniculatum deciduous leaves essential oil using solvent-free microwave extraction: Process optimization and quality evaluation

The optimal process conditions for solvent-free microwave extraction(SFME)of essential oils from Cinnamomum longepaniculatum deciduous leaves after moisture conditioning were established by response surface methodology(RSM).A Box-Behnken design(BBD)was applied to evaluate the effects of three independent variables:moisture content(A:54%–74%),microwave power(B:300–500 W)and microwave time(C:20–40 min),on the extraction yield of essential oil.The compounds of the essential oils obtained by SFME,hydro-distillation and microwaveassisted hydro-distillation(MADE)were identified by gas chromatography-mass spectrometry(GC-MS),and the total lipids of C.longepaniculatum fresh leaves and deciduous leaves were analyzed.The correlation analysis of the response regression model indicated that quadratic polynomial model could be employed to optimize the extraction of essential oil.The optimal extraction condition was A:58%,B:400 W and C:28 min.In the optimal condition,the maximum extraction yield was 4.475 mL/100 g dw and higher than that by MADE.The main compound of the essential oil was eucalyptol(63.54%),and total oxygenated compounds was 78.95%,mainly caused by SFME and the metabolism of endophytic bacteria with decreasing content of phospholipids and fatty acids.Analysis of variance under the extraction condition illustrated high fitness of the model and the success of RSM for optimizing and reflecting the expected process condition.SFME combined with moisture regulation was an effective method for extracting essential oil from C.longepaniculatum deciduous leaves.

Antioxidant and Antimicrobial Activities of Essential Oils Extracted from Laurus nobilis L.Leaves by Using Solvent-Free Microwave and Hydrodistillation

In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial activity. Extraction time was reduced by about 43% in SFME at 622 W and 67% in SFME at 249 W compared to hydrodistillation. Essential oil of laurel was extracted by SFME at 622 W (100%) and 249 W (40%) power levels and HD inhibited oxidation generated by ABTS radical by 93.88%, 94.13% and 92.06%, respectively. Trolox equivalent antioxidant capacities (TEAC) of essential oils were 0.18 mM/mL oil for SFME at 622 W, 1.36 mM/mL oil for SFME at 249 W and 2.40 mM/mL oil for HD (p < 0.05). Essential oils of L. nobilis were extracted by SFME at 100% and 40% power levels and HD inhibited linoleic acid peroxidation by 70.57%, 63.53% and 89.18% respectively. Inhibition effects of laurel essential oils obtained by SFME at different power levels and HD on DPPH radical cation oxidation were not significantly different. The strongest antioxidant activity against DPPH radical was found in the essential oil obtained by SFME at 100% power level. Essential oils displayed antimicrobial activity against Staphylococcus aureus 6538P, Escherichia coli O157:H7 and Salmonella typhimurium NRRL E 4463 except for Listeria monocytogenes. The inhibitory effect on Staphylococcus aureus 6538P survival of laurel oil obtained from SFME by using lower power level was found to be lower than that obtained from SFME at 100% power level and HD

Rapid Extraction and Analysis of Essential Oil from Cinnamomum Cassia Presl.

An improved solvent-free microwave extraction（ISFME） was used for the extraction of essential oil from dried Cinnamomum cassia Presl. Two kinds of solid microwave absorption media[carbonyl iron powder（CIP） and graphite powder（GP）] were used. When ISFME was applied, the heating rate was enhanced and the extraction time was obviously shorter than that consumed in conventional solvent-free microwave extraction（CSFME）. Twenty-eight kinds of compounds in the essential oil were identified, and the total content fractions of the compounds obtained by CIP-ISFME, GP-ISFME, CSFME, and hydrodistillation（HD） were 96.65%, 96.06%, 97.22%, and 96.29%, respectively. The compounds in the essential oil obtained from Cinnamomum cassia Presl. by ISFME, CSFME, and HD were compared and the quantity of the essential oil was almost the same. The ISFME has been proved to be a feasible way to extract essential oil from dried samples, and there are several obvious advantages in ISFME over those of HD and CSFME, for example, shorter extraction time（30 min） and lower energy consumption.

自制微波辅助无溶剂萃取装置及GC／MS分析白玉兰花挥发油

利用普通的家用微波炉改装和自制微波辅助无溶剂萃取装置,采用微波辅助无溶剂萃取法和传统水蒸气蒸馏法提取白玉兰花挥发油,用气相色谱-质谱(GC/MS)法分析鉴定,并用GC/MS总离子流色谱峰的峰面积归一化法确定挥发油成分的相对百分含量。实验结果表明,微波辅助无溶剂萃取法与水蒸气蒸馏法所得的挥发油成分基本相同,但微波无溶剂萃取挥发油的收率(0.80%)高于水蒸气蒸馏法的收率(0.68%)。自制的微波辅助无溶剂萃取装置具有价格便宜、容易推广使用等优点,同时在该装置基础上进行的微波无溶剂萃取法是一种真正意义上的无污染、快速、高收率的提取鲜活香料植物挥发油的萃取技术。

莪术中挥发性成分的微波辅助固相顶空气相色谱法分析

将微波无溶剂提取(SFME)与顶空气相色谱(HS-GC)在线联用,建立了中药材的微波辅助固相顶空气相色谱法(MASP-HSGC),并用该方法快速直接分析了莪术药材中的挥发性成分。研究中对色谱条件、微波作用时间、微波作用功率等因素进行了考察,并以莪术醇为标准品考察了回收率和检出限,同时测定了莪术醇在莪术药材中的含量。对采用水蒸气蒸馏法(HD)和SFME法获得的莪术挥发油进行了气相色谱-质谱(GC-MS)分析,所得结果与所建立方法的结果进行对比。结果表明:HD-GC、SFME-GC和MASP-HSGC法所测得的化合物分别为35、33和40种;3种方法测得的莪术醇含量分别为(0.294±0.015)、(0.331±0.023)和(0.297±0.009)mg/g。该法简便快速,可用于莪术中挥发性成分的分离分析。

微波无溶剂萃取法提取野菊花精油工艺及成分分析

采用微波无溶剂萃取法(Solvent-free microwave extraction,SFME)分别提取野菊花鲜花精油和干花精油,对提取工艺进行了优化;并通过气相色谱-质谱联用技术(chromatograpy-mass spectrometry,GC-MS)分析两种精油化学成分,用峰面积归一法计算各组分相对含量。结果表明:野菊花鲜花精油的最佳提取条件为提取时间50 min,微波功率540 W,精油得率为鲜花重的0.1129%;干花精油的最佳提取条件为料液比1:5 g/mL,浸泡时间3 h,提取时间60 min,微波功率540 W,精油得率为干花重的0.1926%;经GC-MS分析,SFME提取野菊花鲜花精油的主要化学成分是单萜及单萜类含氧化合物,相对含量较多的化合物是乙酸桧酯(13.20%)、甲位侧柏酮(11.10%)、桧醇(9.70%)、菊醇(5.06%)、甲位水芹烯(3.87%)、荜澄茄油烯(3.78%)、桉叶油素(3.61%)、崖柏醇(3.37%)、2-侧柏烯(3.36%)。干花精油的主要化学成分是单萜含氧化合物及倍半萜,相对含量较多的化合物是菊醇(8.59%)、反式石竹烯(7.63%)、大根香叶烯(7.06%)、Α-合金欢烯(5.86%)、甲位侧柏酮(4.85%)、乙酸桧酯(4.34%)、乙酸菊醇酯(3.45%)、右旋樟脑(3.35%)。野菊花鲜花精油的含量比干花更高,单萜含氧化合物相对含量高于干花精油,更具有应用价值。

无溶剂微波萃取法提取野菊花精油及化学成分分析

采用无溶剂微波萃取法(Solvent-free microwave extraction,SFME)提取野菊花精油,考察了料液比、浸泡时间、微波功率和萃取时间对野菊花精油得率的影响,并通过气相色谱-质谱联用技术(Chromatograpy-mass spectrometry,GC-MS)分析精油化学成分,用峰面积归一法计算各成分相对含量。结果表明:野菊花精油最佳提取条件为料液比1:5 g/mL、浸泡时间3 h、微波功率600 W、提取时间50 min,精油得率达到0.2161%;SFME提取的野菊花精油经GC-MS检测分析出化学成分121种,主要为单帖类含氧化合物(38.25%)和倍半萜烯烃(28.59%),相对含量较多的化合物是右旋樟脑(12.01%)、甲位侧柏酮(6.95%)、Cubebene(6.05%)、反式石竹烯(4.09%)、冰片(3.93%)、乙位侧柏酮(3.72%)、Α-长叶蒎烯(3.67%)和乙酸龙脑酯(3.50%)。