Optimization of pretreatment methods for N-nitrosamine compounds in ready-to-eat aquatic products / 预防医学

Objective@#To optimize the pretreatment method of N-nitrosamine compounds in ready-to-eat aquatic products. @*Methods@#Market-sold ready-to-eat aquatic products were collected, homogenized and distilled by steam. The samples were extracted for 10 minutes using dispersive liquid-liquid microextraction (DLLME) with ethanol, trichloromethane and sodium chloride (3.0 g). After centrifugation, the organic phase in the lower layer was collected and subjected to gas chromatography-tandem mass spectrometry (GC-MS/MS). The six common N-nitrosamine compounds were determined in ready-to-eat aquatic products using multiple reaction monitoring mode (MRM) and quantified by the internal standard method. @*Results@#The optimized method exhibited a good linear relationship at concentrations of 10.0 to 500 μg/L for determination of 6 N-nitrosamine compounds (correlation coefficient of greater than 0.999), with 0.05 to 0.60 μg/kg limit of detection, 0.15 to 1.60 μg/kg limit of quantitation, mean spiked recovery rates of 71.8% to 108.9%, and relative standard deviations of 1.4% to 8.6%. N-Nitrosodimethylamine showed the highest detection rate in 20 market-sold ready-to-eat aquatic products (90%), and the detection rates of N-Nitrosopyrrolidine, N-Nitrosodiethylamine and N-dibutylnitrosamine were 15%, 10% and 10%, respectively. @*Conclusion@#Steam distillation combined with DLLME may optimize the pretreatment method of N-nitrosamine compounds in ready-to-eat aquatic products and meet the measurement requirements.

Optimization of extraction technology of volatile oil from Blumea balsamifera and analysis on its compositions / 中国药房

OBJECTIVE To opti mize the supercritical CO 2 extraction technology of volatile oil from Blumea balsamifera ，and compare the components of the volatile oil from B. balsamifera obtained by supercritical CO 2 extraction and steam distillation. METHODS The volatile oil of B. balsamifera was extracted by supercritical CO 2 extraction. Using extraction rate of volatile oil as index，extraction temperature ，extraction pressure and extraction time as factors ，based on single-factor experiment ，orthogonal experiment was used to optimize the supercritical CO 2 extraction technology. Gas chromatography-mass spectrometry was used to identify the components of volatile oil from B. balsamifera . Peak area normalization was used to calculate the relative contents of each component. Taking the volatile oil obtained by steam distillation as a reference ，the extraction rates ，components and contents of volatile oil by the two methods were compared. RESULTS The optimal supercritical CO 2 extraction technology of volatile oil from B. balsamifera included extraction pressure of 30 MPa，extraction temperature of 50 ℃ and extracting for 50 min. After 3 times of validation tests ，average extraction rate of volatile oil was 4.64％（RSD＝0.54％，n＝3）. Thirty-nine components such as tritriacontane，stigmasterol，squalene were identified in the volatile oil of B. balsamifera obtained by supercritical CO 2 extraction； and 51 components such as triacontane ，ledol，humulene epoxide Ⅰ were identified by steam distillation. The extraction rate of volatile oil from B. balsamifera obtained by 2 methods were 4.64％ and 0.99％. A total of 26 common components were obtained ， such as xanthoxylin ，L-borneol，β-caryophyllene. Except for xanthoxyline （34.829％ by supercritical CO 2 extraction，30.676％ by steam distillation method ）and phytol （2.401％ by supercritical CO 2 extraction，1.273％ by steam distillation ），the relative contents of the components of volatile oil obtained by supercritical CO 2 extraction were lower than those of steam distillation. CONCLUSIONS The optimal supercritical CO 2 extraction technology is stable and feasible ；the components and contents of volatile oil obtained by two methods varies greatly ，and main compounds are aldehydes and ketones ，alkenes，alcohols and other components.

Comparison of Different Extraction Techniques of Zingiber officinale Essential Oil

Abstract This study aims to find the best conditions for the extraction of Zingiber officinale essential oil using the supercritical fluid extraction (SFE), steam distillation (SD) and hydrodistillation (HD) techniques, regarding the maximum oil yield. For the HD technique is evaluated the best ratio between plant mass and water volume and for SFE and SD the pressure condition was investigated. Principal Component Analysis (PCA) was used to evaluate the similarity between the composition of the essential oil in different pressures and extraction methods. The experimental extraction curve was plotted and three different mathematical models were used to fit the data for SD and SFE methods, obtaining the relevant mass transfer parameters. The essential oil compounds were identified by gas chromatography coupled with mass spectrometry (GC-MS), being α-zingiberene the main component with different contents (from 11.9 to 28.9%). The best condition for the SFE was 100 bar, 40 °C (0.0508 goil/gplant) with 19.34% of α-zingiberene; for the SD, 3 bar (133 °C) (0.00616 goil/gplant) with 28.9% of α-zingiberene; and HD, the volume of 750 mL (0.006988 goil/gplant) with 15.70% of α-zingiberene, all measured on a dry basis.

GC-MS analysis of extraction kinetics of volatile oil from Acori Tatarinowii Rhizoma by steam distillation / 中草药

Objective: The experiment was designed to reveal the extraction, distribution and influencing factors of volatile components in the extraction process of volatile oil from Acori Tatarinowii Rhizoma (ATR). Methods: Volatile oil of ATR was extracted by steam distillation and the extract was collected every 30 min to separate the aromatic water and volatile oil. Results: A total of 56 volatile compounds were determined, of which β-asarone, methyleugenol, cis-methylisoeugenol and γ-asarone were the main characteristic constituents. There were 41 kinds of components distributed only in water, four components only in oil and 11 kinds in both oil and water. Correlation analysis showed that the specific components in water were positively correlated with the dissolution/diffusion of the main components in water, but negatively correlated with the main components in volatile oil. The water solubility of the unique components in water was the highest. The results of radar and PCA showed that the water solubility and boiling point of the specific components in water were very high, the vapor pressure of the common components of oil and water was the highest, and the polar surface areas of the special components in oil were high. Conclusion: Affected by the physical and chemical properties of volatile component, some components specifically distributed in water increased the content of main components in the aromatic water, may resulting in volatile oil extraction process easy to "emulsification", in turn, leading to an important reason for the declining quality of volatile oil.

Comparative study on volatile oil in Rhizoma chuanxiong by steam distillation and supercritical fluid extraction / 药学实践杂志

Objective To clarify the influence of the extraction process on its active ingredients by comparing the volatile oils of Rhizoma Chuanxiong obtained under different processes. Methods The volatile oil of Rhizoma Chuanxiong was extracted by supercritical CO2 extraction (SFE) and steam distillation. The main chemical components and relative contents were identified by gas chromatography-mass spectrometry (GC-MS). Results A total of 18 common components were identified in the volatile oil samples of Chuanxiong from the two methods. In steam distillation samples, main components included phthalides (61%), monoterpenoids (25%) and sesquiterpenes (10%). In SFE samples, phthalides (97%) were major components, followed by monoterpenoids (1%),sesquiterpenes (0.4%) and other minor components. Conclusion The steam distillation retains highly volatile components in Rhizoma chuanxiong such as monoterpenoids and sesquiterpenes. For SFE approach, the phthalides were extracted more efficiently compared with other components. The effect of the extraction process on the active ingredients should be fully considered in obtained products of Rhizoma chuanxiong since the difference in constituents may result in varied effects.

Effect of seven antioxidants on thermal stability improvement of volatile oil from curcuma longa l / 中国药学杂志

OBJECTIVE: Thermal stability of Curcuma longa L. was studied by GC-MS- analysis. The affect to Curcuma longa L.by seven antioxidants were explored. METHODS: Volatile oil of Curcuma longa L. were extracted by steam extraction and heated at different temperature. The compounds of Curcuma longa L. were analysis by GC-MS. Volatile oil were heated in different temperature and the temperature which make volatile oil most obvious changing were selected. The volatile oil was heated at 100 ℃ in different time and the time which make volatile oil most obvious changing were selected. The affect to Curcuma longa L.by seven antioxidants were explored and the antioxidant which improved thermal stability of Curcuma longa L. was selected. RESULTS: The compounds of volatile oil from Curcuma longa L. was changed most significant by heated 8 h and heated at 20 ℃.The upward trend of α-turmerone was appropriate inhibited by thymol. The downward trend of ar-curcumen was better inhibited by tocopherol. CONCLUSION: The volatile oil from Curcuma longa L. shown obvious thermal instability. The volatility compounds from volatile oil of Curcuma longa L. was changed most by heated. The thermal stability of volatile oil from Curcuma longa L. can improve by antioxidants.

The investigation of key factors influencing the extraction process of chuanxiong oil by steam distillation / 中国药学杂志

OBJECTIVE: To investigate the key process parameters that affect the extraction of essential oil from Ligusticum chuanxiong by steam distillation. METHODS: Volatile oil and emulsified aromatic water are the products of the extraction process of volatile oil. The nature of volatile oil will directly affect the formation of emulsified aromatic water. The influence of extraction temperature, the ratio of liquid to medicine, medicinal material granularity process parameters on the stability of the emulsified fragrance water and the yield of volatile oil were analyzed, furtherly the corresponding extraction process control model of volatile oil was established to reveal the key technology and parameter during the process of volatile oil extraction and separation. RESULTS: The relative viscosity, relative density, surface tension and contact angle of Ligusticum chuanxiong oil decreased gradually with the increase of temperature, while the interfacial tension increased with the increase of temperature. The liner model of aromatic water TSI and process parameters was TSI = 0. 877 + 0. 230 × extraction temperature - 0. 024 × comminution particle size + 0. 010 × liquid ratio + 0. 292 × condensation temperature + 0. 776 × collection temperature. The liner model of the physicochemical properties of TSI and volatile oil was TSI = 0. 877 - 0. 170 × density + 0. 098 × viscosity - 0. 301 × surface tension + 0. 695 × interfacial tension - 0. 060 × contact angle. The liner model of volatile oil yield and process parameters was that yield = 5. 065 + 0. 258 × extraction temperature + 0. 127 × particle size + 0. 016 × liquid ratio + 0. 264 × condensation temperature + 0. 264 × collection temperature + 0. 502 × TSI. The liner model with the physicochemical properties of volatile oil was the yield = 5. 065 - 0. 196 × density - 0. 167 × viscosity - 0. 201 × surface tension + 0. 153 × interfacial tension - 0. 065 × contact angle. CONCLUSION: TSI and yield of aromatic water of Ligusti-cum chuanxiong are directly proportional to the extraction temperature and comminution particle size of medicinal materials. The yield of volatile oil shows a significant positive correlation with the TSI value, which can reflect the yield of volatile oil and is a specific index that can evaluate the process parameters objectively.

Comparison of Volatile Components in Citri Sarcodactylis Fructus from Guangdong Province Before and After Being Steamed by GC-MS / 中国实验方剂学杂志

Objective:To compare volatile components in raw products and steamed products of Citri Sarcodactylis Fructus. Method:Volatile oil in different batch of raw products and steamed products of Citri Sarcodactylis Fructus was extracted by steam distillation, and volatile components were identified by GC-MS.The determination was performed with injector temperature of 280℃, high pure helium(≥ 99.999%) as carrier gas, split ratio of 10:1, and sample size of 3 μL with temperature programming.Mass spectrum conditions included electron bombardment ion source, electron bombardment energy of 70 eV, ion source temperature of 230℃, acceleration voltage of 34.6 V, resolution of 2 500, scanning range of m/z 40-350.Peak matching, cutting and noise filtering were used in analyzing data based on GC-MS combined with orthogonal partial least square-discriminant analysis(OPLS-DA). Result:A total of 58 components were separated and identified from the different batches of raw Citri Sarcodactylis Fructus and their processed products, and 27 differential chemical components were identified by multivariate statistical analysis, among them, 15 common differential components presented different changing laws.The relative contents of α-pinene, β-pinene, p-cymene, β-linalool, L-4-terpinenol, α-terpineol, nerol, β-cyclocitral, geraniol and α-citral in raw products were higher than that of their corresponding processed products.The relative contents of β-caryophyllene, cis-α-bergamotene, γ-muurolene, γ-elemene and β-bisabolene in processed products were higher than that of their corresponding raw products. Conclusion:The content and composition of volatile components in Citri Sarcodactylis Fructus from Guangdong province have changed after being steamed.The results can provide experimental basis for expounding the processing principle and quality evaluation of Citri Sarcodactylis Fructus, and have positive significance for promoting the research and development of this Lingnan characteristic decoction pieces.

Optimization of the Extraction Technology of Volatile Oil from Schizonepeta tenuifolia and Forsythia suspensa / 中国药房

OBJECTIVE： To establish the method for content determination of volatile oil of Schizonepeta tenuifolia and Forsythia suspensa， and to optimize the extraction technology of the volatile oil. METHODS： The contents of β-pinene and pulegone were determined by GC method. The determination was performed on Hp-5 capillary column. The detector was hydrogen flame ion detector with programmed temperature. The sample size was 0.5 μL， the split ratio was 70 ∶ 1， the carrier gas was nitrogen， the inlet temperature was 250 ℃， the detector temperature was 280 ℃， the air flow rate was 390 mL/min， the hydrogen flow rate was 36 mL/min， the tail flow rate was 15 mL/min， and the nitrogen flow rate was 1 mL/min. Based on single factor test， orthogonal test combined with information entropy method were used to optimize the extraction technology of S. tenuifolia and F. suspensa using soaking time， extraction time， material-liquid ratio and forsythia grain size as factors， with the extraction amount of volatile oil， the content of β-pinene and pulegone and their comprehensive score as indexes.  RESULTS： The linear range of β-pinene and pulegone 1.575-7.875（r＝0.999 9） and 1.892-9.46 μg（r＝0.999 7）， respectively. The limits of quantitation were 0.10 and 0.25 μg； the limits of detection were 0.03 and 0.08 μg； RSDs of precision， stability and reproducibility tests were less than 2％ （n＝6）； the recoveries were 97.77％-100.01％ （RSD＝0.93％，n＝9） and 96.47％-99.00％（RSD＝0.89％， n＝9）. The optimal extraction technology was soaking 2 h， extracting for 6 h， 10-fold water （mL/g）， half a clove of granularity. Under this condition， the extraction amount of volatile oil， the contents of β-pinene and pulegone were 3.6 mL， 1 450.4 mg， 127.6 mg， respectively. RSD were 1.62％， 0.20％， 1.42％. CONCLUSIONS： Established method is simple， accurate and reproducible， and the optimal extraction technology is stable and feasible.

Extraction kinetics of volatile components from Foeniculum vulgare by steam distillation / 中草药

Objective To reveal the dissolution rule of volatile oil in the extraction processfrom Foeniculum vulgare by GC-MS analysis. Methods The volatile oil of F. vulgare was extracted by steam distillation; The volatile oil/perfume system was collected at fixed time interval (30 min); The volatile oil part and perfume part were separated. Using N-docosane and methyl myrisate as double internal standard, GC-MS was selected for analysis and quantification. The main components were extracted by thermography, and the distribution regularity of components was definited. The principal components with the impact on the composition distribution were investigated according to the physical and chemical properties of the molecular weight, melting point, boiling point, and density of the compounds. Results The GC-MS analysis results concluded 123 volatile components. The main components were estragole, anethole, and (R)-(+)-limonene. There were 60 and 27 endemic components in aromatic aqueous solution and volatile oil, respectively, in which 27were common composition. The content of anethole in water was positively related to the endemic components in aromatic water, and even had a positive correlation with anethole artemisia content and (R)-(+)-limonene content. The specific components in the oil were positively related to the content of the main components (R)-(+)-limonene in the volatile oil. The principal component analysis showed that the physical and chemical properties of the compounds were important factors affecting the distribution of components; PC1 (molecular weight and positive correlation of melting point), PC2 (refractive index positive correlation), and PC3 (water-soluble negative correlation) were the principal components that lead to differences in component distribution. Conclusion In the process of extracting volatile oil from F. vulgare, steam distillation is affected by the physical and chemical properties of volatile components. Some components are specifically distributed in aromatic perfume and volatile oil system. The endemic components of aromatic water increase the content of the main components in the water system, which may lead to theproduction of "emulsification" during the extraction process of volatile oil and reduce the yield and quality of volatile oil.

Optimization of the Extraction Technology of Garlic Oil by Box-Behnken Response Surface Method / 中国药房

OBJECTIVE:To optimize the extraction technology of garlic oil. METHODS:Using extraction rate of garlic oil as index,based on single factor test,Box-Behnken response surface method was used to optimize conditions of steam distillation method for the extraction of garlic as fermentation time,solid to liquid ratio,fermentation temperature and the verification test were made for the optimized technology. RESULTS:The optimal extraction technology was as follows as fermentation time of 4.5 h,solid to liquid ratio of 1:7,fermentation temperature of 55 ℃. The average extraction rate of garlic oil in verification test was 0.32%(RSD=1.43%,n=3);the relative error between the measured value and predicted value was 0.06%. CONCLUSIONS:Box-Behnken response surface method is simple,reasonable and feasible to optimize the extraction technology of garlic oil,which can provide a scientific basis for industrial production.

Optimization of solvent-free microwave extraction for Acori Tatarinowii Rhizoma and analysis on volatile components by GC-MS / 中草药

Objective: To study the solvent-free microwave extraction for oils of Acori Tatarinowii Rhizoma and analyze the volatile components. Methods: The paper selected the best technological conditions by L9(34) orthogonal test, with the index of α-asarone, volume of volatile oils, and sum of the percentage, The essential oils in Acori Tatarinowii Rhizoma were analyzed with GC-MS. Results: The percentage of volatile oils was calculated according to peak area normalization method. The results showed similar amount of volatile oil components by two methods, and the extraction rates of α-asarone, β-asarone, and γ-asarone accounted for 4.12%, 55.11%, and 10.54% on the method of solvent-free microwave extraction, while the steam distillation was 5.39%, 47.03%, and 9.15%. To compare with two methods, solvent-free microwave extraction extracted volatile oil 0.235 mL and α-asarone 31.99 mg for 5 min, while steam distillation extracted volatile oil 0.175 mL and α-asarone 29.09 mg for 1 h. The method of solvent-free microwave extraction had the advantage of short reaction time and high yields. Conclusion: Solvent-free microwave extraction is a new method with shorter extracting time and better extracting efficiency.

Analysis of the Volatile Constituents of the Compound Extract from 3 Medicinal Materials in Siji Ganmao Tablet by Supercritical CO2 Fluid Extraction / 中国药房

OBJECTIVE:To study the volatile constituents of the compound extract from Folium Perillae,Pericarpium Citri and Herb Schizonepetae in Siji Ganmao tablet by supercritical CO2 fluid extraction (SFE-CO2). METHODS:Supercritical CO2 ex-traction technology was used to extract the volatile constituents of 3 medical material in Siji Ganmao tablet. The chemical constitu-ents of the compound extract from 3 medicinal materials were analyzed by GC-MS. RESULTS:The extracting rate of SFE-CO2 was 2.21%,21 compounds in the compound extract were separated and 16 compounds were identified with the major components of si-nensetin(36.56%)and linolic acid(19.52%). The extracting rate of water steam distillation(SD)was 1.035%,51 compounds in the compound extract were separated and 32 compounds were identified with the major components of D-limonene(62.40%) and thujone(15.49%). CONCLUSIONS:The volatile constituents of F. perillae,P. cCitri and H. Schizonepetae can be compound ex-tracted by SFE-CO2,however,it is different from the constituents of the compound volatile oil by SD.

Analysis of Volatile Oils in Leaves of Tibetan Medicine Juniperus Formosana Hayata from Two Different Regions by GC-MS / 中国药师

Objective:To analyze and compare the volatile oil in the leaves of Juniperus formosana Hayata from Yuzhong and Lu-qu. Methods:The volatile oil from Juniperus formosana Hayata was extracted by steam distillation, and then identified by gas chroma-tography-mass spectrometry ( GC-MS) . Results:The average yield of the volatile oil from the leaves of Juniperus formosana Hayata from Yuzhong and Lugu was 0. 21% and 1. 45%(w/w), respectively. Between the two areas of the volatile oil from the leaves of Juniperas formsana, totally 40 peaks were separated from the volatile oil from Gansu with 38 ones (95%) were identified. Totally 51 peaks were separated from the volatile oil from Xizang with 47 ones (92%) were identified. The maln constituents in the former volatile oil wereα-pinene(44.92%),l-caryophyllene(9.23%),( -)-isoledene(6. 50%),a-caryophyllene(5.60%),myrcene(4.54%) and d-cadinene(3. 37%), and those in the latter were di-epi-cedrene(31. 87%),cyclohexene(15. 28%),γ-elemene(10. 05%), lanceol (5. 80%) and α-pinene(5. 79%). Conclusion:The constituents in the volatile oil in the leaves of Juniperus formosana Hayata from the two different regions are various, and the differences in the yield and compounds are notable. The method provides reference for the establishment of quality standard for Juniperus. formosana Hayata.

Comparison of Steam Distillation and Supercritical CO2 Method in the Extraction of Volatile Constituents from Compound Kuhuang Prescription by GC-MS / 中国药师

Objective:To compare the steam distillation( SD) and supercritical CO2 ( SFE-CO2 ) method in the extraction of vola-tile constituents from such 3 traditional Chinese drugs as cnidium monnieri, radix sileris and atractylodes lancea in compound Kuhuang prescription. Methods:Essential oil was extracted from the 3 traditional Chinese drugs by SD and SFE-CO2 method, respectively. The components were identified by GC-MS, and their relative contents were calculated with peak area normalization method. Results:To-tally 36 components were isolated and identified using SD extraction and 31 components were identified using SFE-CO2 extraction, a-mong them, 22 components were the same and their relative molecular weight mainly concentrated within 200-230. Conclusion: SFE-CO2 method can extract effective components from the 3 traditional Chinese drugs in compound Kuhuang prescription with higher selec-tivity, which is the more suitable extraction method for essential oil from the prescription.

Determinação de óleos essenciais de alfavaca (Ocimum gratissimum L. ), orégano (Origanum vulgare L. ) e tomilho (Thymus vulgaris L.) / Determination of essential oils of basil (Ocimum gratissimum L. ), oregano (Ocimum gratissimum L. ) and thyme (Thymus vulgaris L.)

O presente trabalho teve como objetivo a caracterização de plantas frescas e secas (comerciais) de alfavaca, orégano e tomilho, a obtenção dos óleos essenciais através do método de arraste a vapor e a quantificação dos compostos químicos por CG/EM. As plantas frescas e as secas comerciais foram submetidas às análises de umidade, extrato etéreo, proteína, fibra bruta, cinzas, extrato não nitrogenado, valor calórico, teor de óleo essencial e identificação dos compostos majoritários através da cromatografia gasosa-espectrometria de massas. Dentre a caracterização obtida os resultados na base seca mostraram-se promissores, sendo o teor de proteína e de cinzas na alfavaca seca comercial com 17,34 g 100 g-1 e 8,12 g 100 g-1, respectivamente; a fibra bruta no orégano seco comercial com 15,65 g 100 g-1; o extrato etéreo, o extrato não nitrogenado e o valor calórico no tomilho seco comercial com 9,30 g 100 g-1, 52,72 g 100 g-1 e 356,74 Kcal 100 g-1, respectivamente. Obteve-se o maior rendimento de óleo essencial na alfavaca seca comercial com 1,02%, enquanto a alfavaca fresca apresentou o menor rendimento, com apenas 0,13%. Na alfavaca fresca encontrou-se 87,38% de eugenol e 6,27% de timol, enquanto na alfavaca seca comercial observou-se redução no eugenol (71,12%) e aumento do timol (13,28%). No orégano fresco foram quantificados quatro picos o γ-terpineno (33,45%), 4-terpineol (25,59%), timol (14,21%) e carvacrol (2,30%). Já no óleo essencial de orégano seco comercial houve redução no γ-terpineno (28,73%) e aumento no 4-terpineol (27,58%), timol (19,71%) e carvacrol (3,67%). No óleo essencial do tomilho fresco foram quantificados três picos o borneol (66,66%), timol (13,41%) e linalol (3,24%). Por outro lado, no óleo essencial do tomilho seco comercial houve redução no borneol (37,90%) e aumento no timol (20,61%) e linalol (10,34%). Pode-se concluir que as folhas secas comerciais analisadas de alfavaca, orégano, e tomilho apresentam potencial para o enriquecimento dos alimentos ou para a obtenção dos óleos essenciais.

This study aimed to characterize commercial fresh and dry medicinal plants (basil, oregano and thyme), to obtain essential oil by the steam distillation method and to quantify chemical compounds by means of GC/MS. The fresh and dry plants were subjected to the following analyses moisture, ether extract, protein, crude fiber, ash, non-nitrogenous extract, caloric value, essential oil content and identification of major compounds by gas chromatography-mass spectrometry. Considering the obtained characterization, the following results on dry basis proved promising: protein and ash content in commercial dry basil with 17.34 g 100 g-1 and 8.12 g 100 g-1, respectively; crude fiber in commercial dry oregano with 15.65 g 100 g-1; ether extract, non-nitrogenous extract and caloric value in commercial dry thyme with 9.30 g 100 g-1, 52.72 g 100 g-1 and 356.74 Kcal 100 g-1, respectively. The highest essential oil yield was obtained for commercial dry basil with 1.02% and the lowest yield was obtained for fresh basil with only 0.13%. Chromatography indicated 87.38% eugenol and 6.27% thymol in fresh basil. For commercial dry basil, the chromatogram showed a reduction in eugenol (71.12%) and an increase in thymol (13.28%). Four peaks were quantified for fresh oregano the γ-terpinene (33.45%), 4-terpineol (25.59%), thymol (14.21%) and carvacrol (2.30%). For the essential oil of commercial dry oregano, there was a decrease in γ-terpinene (28.73%) and an increase in 4-terpineol (27.58%), thymol (19.71%) and carvacrol (3.67%). In the chromatogram of the essential oil of fresh thyme, three peaks were quantified: borneol (66.66%), thymol (13.41%) and linalool (3.24%). On the other hand, in the chromatogram of the essential oil of commercial dry thyme, there was a decrease in borneol (37.90%) and an increase in thymol (20.61%) and linalool (10.34%). It can be concluded that commercial dry leaves of basil, oregano and thyme are feasible to enrich foods or to obtain essential oils.

Comparative Study of Volatile Oil Extraction Process from Flowers of Elaeagnus angustifolia L.with Steam Distillation and Supercritical CO_2 Extraction / 中国中医药信息杂志

Objective To optimize the extraction process by determing the volatile oil yield of steam distillation and supercritical CO2 extraction from flowers of Elaeagnus angustifolia L..Methods Orthogonal test was carried out to compare two extraction effects between steam distillation and supercritical CO2 extraction by detecting the extraction ratio from flowers of Elaeagnus angustifolia L..Results Steam distillation time on volatile oil extraction has the greatest impaction,and the best condition of supercritical CO2 extraction was extraction pressure of 20 MPa,extraction temperature of 40 ℃,and flux of CO2 is 10 L/h.Conclusion Compared with steam distillation,supercritical CO2 extraction spends less time,has higher efficiency and less harm to the materiel after extracting.It adapts to batch process and is convenient for subsequent extraction technology.

Determination of chemical constituents of essential oil from flower of Dendrobium candidum Wall.ex Lind1 / 中华中医药杂志

Objective: To study the chemical constituents of volatile oil from flower of Dendrobium candidum Wall. ex Lind1. Methods: The chemical compositions of volatile oil of the plant which were obtained by steam distillation with hexane were analyzed by GC-MS equipped with a elastic quartz capillary column-HP-5MS5% Phenyl Methyl Siloxane (30 m? 0.25 mm ?0.25 ?m). The constituents were identifi ed by their mass spectra. The relative percentage of the oil constituents was calculated from the GC peak areas. Results: Eighty-nine kinds of chemical constituents in Dendrobium candidum Wall.ex Lind1.flower were separated; of which fifty-nine compounds representing 76.51% of the oil were characterized. Relative contents that were more than 2.0% were determined as Nonanal 9.21%, Eudesma-5,11-dien-8,12-olide 5.55%, (E)-2-Decenal 4.63%, 2,3-Dehydro- 1,8-cineole 4.39%, Pentacosane 4.03%,?-Cedrol 3.69%, Isoalantolactone 3.65%, (E)-2-Heptenal 3.60%, E,E-2,4-Decadienal 2.14%,?-Phorone 2.03%.Conclusion: This paper reports, for the first time, the composition of volatile oils of Dendrobium candidum Wall.ex Lind1.flower by GC/MS.