Literatura académica sobre el tema "Volatile component"
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Artículos de revistas sobre el tema "Volatile component"
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Chuntonov, K. A., V. G. Postovalov, and A. G. Kesarev. "Evaporation of volatile component from intermetallic granule with non-volatile component shell." Vacuum 55, no. 2 (1999): 101–7. http://dx.doi.org/10.1016/s0042-207x(99)00134-7.
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Yu, T., H. Yao, S. Qi, and J. Wang. "GC-MS analysis of volatiles in cinnamon essential oil extracted by different methods." Grasas y Aceites 71, no. 3 (2020): 372. http://dx.doi.org/10.3989/gya.0462191.
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Cinnamon essential oil (CEO) was extracted by three different methods: steam distillation (SD), ultrasound-assisted steam distillation (UASD) and microwave-assisted steam distillation (MASD). The volatiles in CEO were separated and identified by gas chromatography–mass spectrometry (GC-MS), and the differences in volatiles among the three different methods were further analyzed through principal component analysis. The results showed that 36 individual volatile components were present in the CEO from the three different methods. In general, the numbers of aldehydes, esters, alcohols, terpenes, aromatics and ketones were 6, 3, 7, 17, 2, and 1, respectively. The most abundant volatile component was determined to be cinnamic aldehyde. The content of total cinnamic aldehydes, which determines the price of CEO, was the highest among the three methods in the UASD sample (85.633%). Moreover, the highest yield (8.33‰) of essential oil was extracted by the UASD method. Therefore, UASD was the best way for CEO extraction in this research and was recommended for future industrial applications.
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Zhao, Yongqi, Zhenling Zhang, Hongwei Zhang, Yanbang Shi, and Yiming Wang. "Gas Chromatographic-Ion Mobility Spectrometry Combined with Chemometrics to Study the Changes in Characteristic Odor Components of Galli gigerii Endothelium Corneum in Different Processing Methods." Journal of Analytical Methods in Chemistry 2023 (August 7, 2023): 1–11. http://dx.doi.org/10.1155/2023/2259280.
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Galli gigerii endothelium corneum (GGEC) is a traditional Chinese medicine commonly used in clinical practice to treat various conditions such as indigestion, vomiting, spermatorrhea, and enuresis. In this study, the volatile components of different concoctions of GGEC were examined by gas chromatography-ion mobility spectrometry (GC-IMS), and the changes of the components were compared by fingerprinting, combined with principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) to analyze the main volatile components and find out the different markers that can distinguish the different concoctions of GGEC. In the result, the GC-IMS fingerprints of GGEC and its different concoctions showed differences in their volatile components, of which 49 volatiles were clearly characterized, with some components including monomers and dimers. The characteristic volatile components of raw GGEC (SP) were n-nonanal, (E)-2-octenal, beta-ocimene, 2-ethyl-1-hexanol, etc. The characteristic volatile components of stir-fried GGEC (QC) are heptanal, 2-octanol, (E)-2-heptenal, etc. The characteristic volatile components of sand ironing GGEC (ST) are isoamyl acetate, decanal, cyclohexanone, 2-ethyl pyrazine, etc. The characteristic volatile components of stir-fried GGEC with vinegar (CZ) are thiazole, linalool, 2,3,5-trimethylpyrazine, etc. The characteristic volatile components of stir-fried GGEC with milk (FH) are 2-methylbutanoic acid, ethyl acetate, ethyl 2-hydroxypropanoate, butyl acetate, etc. By chemometric analysis, components such as n-nonanal, (E)-2-octenal, 2-pentyl-furan, butanal, 1,4-dioxane, and 2-methylpropanoic acid could be used as difference markers to distinguish different concoction products of GGEC. Furthermore, by analyzing different volatile compounds, we can examine the changes in volatile components during processing of GGEC, which can provide experimental data for the identification and establishment of quality standards.
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Xiang, Nan, Yihan Zhao, Bing Zhang, Qiuming Gu, Weiling Chen, and Xinbo Guo. "Volatiles Accumulation during Young Pomelo (Citrus maxima (Burm.) Merr.) Fruits Development." International Journal of Molecular Sciences 23, no. 10 (2022): 5665. http://dx.doi.org/10.3390/ijms23105665.
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As widely planted fruits with high nutritional and medical values, pomelos are managed systematically to achieve the largest economic benefits. But the annual shedding of young pomelos, which could be applied as feedstocks for essential oil extraction with their abundant volatiles, leads to a waste of source. The present study selected two commonly planted pomelo (Citrus maxima (Burm.) Merr.) varieties in Southern China, to investigate the volatile profiles during young pomelo fruits development. Combing transcriptomic analysis, this study aimed at identifying the prominent volatile components in young pomelo fruits in order to preferably extract profitable volatiles, as well, increasing the knowledge concerning regulatory roles of transcription factors (TFs) on volatiles accumulation in young pomelos. Totally 29 volatiles were identified, including 14 monoterpenoids and 13 sesquiterpenoids. Diprene was the principal component with the highest amount. Volatiles were generally decreased during fruits development but preferable stages were figured out for volatile collections. 12 and 17 TFs were related to developing time while ERF003 and MYC2 were highly correlated to monoterpenoids. These findings put forward the comprehensive usages of young pomelos and enriched the regulatory roles of TFs on both fruit development and volatiles metabolism.
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Aschariyaphotha, Wattana, Chalermchai Wongs-Aree, Kitti Bodhipadma, and Sompoch Noichinda. "Fruit Volatile Fingerprints Characterized among Four Commercial Cultivars of Thai Durian (Durio zibethinus)." Journal of Food Quality 2021 (September 4, 2021): 1–12. http://dx.doi.org/10.1155/2021/1383927.
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Ripe durian fruits produce unique volatiles of pungent odor comprising esters, alcohols, ketones, and sulfur-containing compounds. Recently, “Chanthaburi 1” hybrid bred from 2 famous commercial cultivars of “Chanee” and “Monthong” claimed to be less fragrant during ripening, but there was no report. The present study compared the volatile profiles from 3 Thai commercial cultivars of “Kanyao,” “Chanee,” and “Monthong” compared to “Chanthaburi 1”, and the relationships of the cultivars were organized using the volatile fingerprints. Out of 41 volatile compounds detected by SPME/GC-MS in ripe durian flesh, 33 compounds were esters, but only 14 esters were found in “Chanthaburi 1.” Ripe flesh of most durian cultivars contains ethyl-2-methyl butanoate and ethyl hexanoate as the active volatiles. “Chanthaburi 1” contained fewer components with low odor activity value (OAV) of the volatiles. “Chanee” ripe flesh exhibited the strongest durian smell among the four varieties, whereas “Monthong” exhibited a strong apple-like fruity odor and “Kanyao” was more green fruity. Diethyl disulfide and 3, 5 dimethyl-1, 2, 4-trithiolane contributing pungent smells of garlic or onion were found only in “Chanthaburi 1” and “Monthong.” In terms of detected volatiles, “Kanyao” and “Chanee” were highly close when “Monthong” was apart. PCA analysis revealed that “Chanthaburi 1” contained ester compounds ancestrally related to the parents, “Chanee” in the component I and “Monthong” in the component II. These data could be beneficial for managing the status of Thai durians in global markets.
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Zatolokina, K. I., A. A. Tomilenko, T. A. Bul’bak, and G. G. Lepezin. "Volatile Components in Cordierite and Coexisting Tourmaline and Quartz from Pegmatites of the Kuhilal Deposit (Pamir, Tajikistan)." Russian Geology and Geophysics 62, no. 10 (2021): 1157–74. http://dx.doi.org/10.2113/rgg20204224.
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Abstract —The compositions of volatile components in cordierite, tourmaline, and quartz from pegmatites of the Kuhilal deposit were studied by pyrolysis-free gas chromatography–mass spectrometry (GC–MS), IR and Raman spectroscopy, and microthermometry, and their comparative analysis was performed. Capillary GC–MS was applied to determine the component composition and relative contents (rel.%) of volatiles from different zones of crystals and fractions of cordierite. It has been established that water and carbon dioxide prevail among them. Among hydrocarbons, aliphatic, cyclic, and oxygenated ones are predominant. Heterocyclic, nitrogenated, and sulfonated compounds have also been found. In tourmaline and quartz, volatile components are present in gas–liquid inclusions; in cordierites, they are localized both in structural cavities and in nonstructural positions.
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Xi, Jiapei, Ping Zhan, Honglei Tian, and Peng Wang. "Effect of Spices on the Formation of VOCs in Roasted Mutton Based on GC-MS and Principal Component Analysis." Journal of Food Quality 2019 (September 10, 2019): 1–11. http://dx.doi.org/10.1155/2019/8568920.
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Peppertree prickly ash, Amomum tsao-ko, cumin, and ginger have long been used in Asian countries to modify the flavor and to partially neutralize any unpleasant odors present in roast lamb. The purpose of this study was to evaluate the change in the amount of volatile components present in roast lamb compared to meat added with peppertree prickly ash, Amomum tsao-ko, cumin, and ginger. Principal component analysis was carried out on the 27 initially selected from 88 volatile substances, and 15 substances with a projection of more than 0.25 in the load matrix were used as indicators to study the different contents in roasted mutton and lamb prepared by adding peppertree prickly ash, Amomum tsao-ko, cumin, and ginger. The types of VOCs (volatile organic compounds) detected in roast meat without adding spices were the least. Roast meat with the addition of cumin leads to the strongest content of aldehydes, followed by the addition of Amomum tsao-ko. Additionally, roast meat with the addition of Chinese prickly ash leads to the strongest content of terpenes, followed by the addition of ginger. Moreover, with the addition of spices, the content of volatiles responsible for the presence of a mutton odor (such as hexanal, heptanal, pentanal, (z)-4-decenal, benzaldehyde, p-propyl-anisole, and dimethyl ether) was not significantly decreased, and in fact some volatiles increased in amount such as pentanal, hexanal, octanal, and (z)-4-decenal. In conclusion, the effect of addition of spices on the volatile profile of roasted mutton and lamb can be attributed to the generation of flavor volatiles mainly derived from raw spices’ hot action, with few additional volatiles formed during boiling.
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Bruce, Toby J. A., Charles A. O. Midega, Michael A. Birkett, John A. Pickett, and Zeyaur R. Khan. "Is quality more important than quantity? Insect behavioural responses to changes in a volatile blend after stemborer oviposition on an African grass." Biology Letters 6, no. 3 (2009): 314–17. http://dx.doi.org/10.1098/rsbl.2009.0953.
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Plants subjected to insect attack usually increase volatile emission which attracts natural enemies and repels further herbivore colonization. Less is known about the capacity of herbivores to suppress volatiles and the multitrophic consequences thereof. In our study, the African forage grass, Brachiaria brizantha , was exposed to ovipositing spotted stemborer, Chilo partellus , moths. A marked reduction in emission of the main volatile, ( Z )-3-hexenyl acetate ( Z 3HA), occurred following oviposition but the ratio of certain other minor component volatiles to Z 3HA was increased. While further herbivore colonization was reduced on plants after oviposition, the new volatile profile caused increased attraction of an adapted parasitoid, Cotesia sesamiae . Our results show that insect responses are dependent on the quality of volatile emission rather than merely the quantity in this multitrophic interaction.
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Zhang, Wei, and Xianrui Liang. "Headspace Gas Chromatography-Mass Spectrometry for Volatile Components Analysis in Ipomoea Cairica (L.) Sweet Leaves: Natural Deep Eutectic Solvents as Green Extraction and Dilution Matrix." Foods 8, no. 6 (2019): 205. http://dx.doi.org/10.3390/foods8060205.
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In this study, natural deep eutectic solvents (NADESs) were used as both the extraction and dilution matrix in static headspace gas chromatography-mass spectrometry (SHS-GC-MS) for the analysis of volatile components in Ipomoea cairica (L). Sweet (ICS) leaves. Six NADESs were prepared and the NADESs composed of choline chloride and glucose with a 1:1 molar ratio containing 15% water were preferred due to the better peak responses. A total of 77 volatiles in ICS leaves were detected and tentatively identified by mass spectral matching with the US National Institute of Standards and Technology (NIST, 2014) Mass Spectral Library and the retention index-assisted qualitative method. These 77 volatile components were mainly terpenoids, aromatics, and aliphatics. Among them, β-elemene, β-caryophyllene, α-humulene, and 2, 4-di-tert-butylphenol were found to be the main components. This investigation verified that the use of NADESs is an efficient green extraction and dilution matrix of the SHS-GC-MS method for direct volatile component analysis of plant materials without extra extraction work.
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Kostic, Emilija, Dusanka Kitic, Maja Vujovic, Marija Markovic, Aleksandra Pavlovic, and Gordana Stojanovic. "A chemometric approach to the headspace sampled volatiles of selected Salvia species from Southeastern Serbia." Botanica Serbica 46, no. 2 (2022): 285–94. http://dx.doi.org/10.2298/botserb2202285k.
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Headspace sampling is a fast, simple and economical way to prepare plant samples for analysis by gas chromatography. For the first time, the composition of the head space volatiles (HSV) of six Salvia species (S. verticillata, S. glutinosa, S. nemorosa, S. aethiopis, S. amplexicaulis and S. officinalis) in the flowering stage and two (S. glutinosa and S. sclarea) in the fruiting stage from Southeastern Serbia was analysed using the GC-FID-MS technique after headspace sampling. The chemical composition of the highly volatile compounds of the analysed species varies considerably. Monoterpene hydrocarbons represented the dominant class of volatile compounds in all the Salvia species, except for S. sclarea and S. aethiopis. The content of sesquiterpenes was the highest in S. aethiopis (96.9%) and S. glutinosa in the flowering phase (29.5%), while in all the other samples that percentage was below 10%. Oxygenated monoterpenes were the most abundant in S. sclarea, where the main component was oxygenated monoterpene linalyl acetate (97.7%). The main component of S. verticillata was ?-phellandrene, and its content varied depending on the plant location and sampling time. The main component of S. glutinosa in the flowering phase was limonene (16.6%), and in the fruiting phase sabinene (87.1%). Headspace analysis of the volatile components of S. aethiopis was carried out for the first time and the most abundant detected components were sesquiterpenes: (E)- caryophyllene (36.8%), ?-copaene (33.4%) and ?-elemene (7.3%). The analysis of the principal components was performed to interpret the grouping patterns, as well as to analyse the similarities and differences between the samples in terms of the composition of the volatile components. The samples were grouped into three clusters. The first cluster consisted of samples of S. verticillata (S1, S4 and S5) from different locations, the second comprised samples of S. glutinosa (S3), S. aethiopis (S8), S. amplexicaulis (S9) and S. officinalis (S10), while samples of S. nemorosa (S7) made up the third cluster. The HS-GC-FID-MS technique can be successfully used for the qualitative and quantitative analysis of volatile compounds of different Salvia species. The obtained results are important for evaluating the possibility of using different types of sage.
Tesis sobre el tema "Volatile component"
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Tomi, Kenichi. "Relationships between aroma component composition of herbs and its aromachology effects." Kyoto University, 2016. http://hdl.handle.net/2433/215986.
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Kyoto University (京都大学)<br>0048<br>新制・論文博士<br>博士(農学)<br>乙第13034号<br>論農博第2835号<br>新制||農||1044(附属図書館)<br>学位論文||H28||N5007(農学部図書室)<br>32992<br>京都大学大学院農学研究科農学専攻<br>(主査)教授 坪山 直生, 教授 黒木 裕士, 教授 妻木 範行<br>学位規則第4条第2項該当
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Barnard, Carla. "Investigating the effect of various film-forming polymers on the evaporation rate of a volatile component in a cosmetic formulation." Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1498.
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The topical application of many substances, including drugs, enzymes, moisturizers and fragrances, contributes largely to the cosmetic and pharmaceutical industries. These components are often volatile in nature and dissipate in a matter of hours. When considering the different types of slow release systems, an overwhelming variety of these systems is available. Each one of the systems is unique in a way, and is designed to perform a particular function, whether it facilitates the controlled release of an active into the body via the skin surface (transdermal delivery) or whether it reduces the rate of loss of an active from the skin surface to the surrounding environment. For the purpose of this study, a previously existing fixative formulation which is believed to reduce the rate of loss of an active component to the environment, through film formation on the skin surface, was investigated. Alternative ingredients or components were incorporated together with the original fixative formulation ingredients into an experimental design which investigates the effect of each group of the components present. 18 formulations with various concentrations of the components within the groups and specified upper and lower limits for each component were formulated. The fixative properties of the formulations were analysed through the incorporation of a fixed amount of a simple fragrance molecule, 4- methoxybenzaldehyde, into each formulation and evaporation studies were conducted in an environmental room at 28±1° C over a period of 5 hours followed by gas chromatography analysis and finally data analyses using statistical methods. The most efficient fixative formulation was established using regression analysis. The fragrance compound in this formulation was found to evaporate at a rate of 0.47 g/L per hour. The least efficient fixative formulation lead to the loss of 0.78 g/L of the fragrance component per hour. From the calculated fragrance concentrations, the rate constant for each individual fixative formulation could be calculated and response surface 8 modelling by backward regression was used in order to determine how each component contributes to the rate of loss of the fragrance compound. Since the sum of the original ingredient and its alternative was constant, each of the original ingredients was coupled directly to its alternative and no conclusion could be made about the contribution of individual components. By increasing the concentration of Hydroxypropylcellulose (HPC) 100K and its alternative HPC 140K, while keeping the effects of the other components constant, a decrease in the rate of fragrance loss was observed. The same conclusion could be made when increasing the concentrations of PEG-12 Dimethicone and its alternative cetyl dimethicone (decreases the evaporation rate). An interaction took place between HPC 100K and PEG-12 dimethicone and their alternatives. The negative effect was, however, not as strong as the combined positive effect on the rate of fragrance loss of the individual components HPC and PEG-12 dimethicone. Evidence suggested that the removal of the components polyvinylpyrrolidone and its alternative, polyurethane-32 (Baycusan® C1003), would improve the effectiveness of the fixative formulation in terms of its slow release properties. A confirmation experiment established that the exclusion of these components from the fixative formulation does improve the “slow release” properties thereof. A larger, more intricate design is required to investigate the effect of each one of the individual components and where the sum of the components (original and its alternative) is not constant.
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Nahan, Keaton. "Principal Component Analysis Approach for Determination of Stroke Protein Biomarkers and Modified Atmospheric Pressure Chemical Ionization Source Development for Volatile Analyses." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491817651627161.
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Brito, Givanilton. "Tipificação de méis do estado de Sergipe através do perfil químico dos compostos voláteis obtidos por headspace dinâmico seguido por cromatografia em fase gasosa acoplada a espectrometria de massas (CG/EM)." Universidade Federal de Sergipe, 2012. https://ri.ufs.br/handle/riufs/6037.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Among the products of the hive, honey is considered the principal, standing out as natural food and for having multiple pharmacological applications. Honey can be produced
by honey bees (Apis mellifera, L.) from the nectar, fruit, plant secretions and excretions of aphids or other sweetened solutions.Their nutritive power, pharmacologic and commercial
value depends on its botanical origin, which can be obtained through classical methods as sensory evaluation, physicochemical analyses or melissopalynology. Although, these methods require much experience of the analyst and are costly.In view of the current difficulties in conducting these analyses, methods based on the study of volatile constituents have emerged as an alternative in the search for the source of compound markers of floral honeys. For the identification of these compounds, techniques such as solid in solid phase (SPME) and dynamic headspace (HSD) followed by analysis on gas chromatography coupled to mass spectrometer (GC-MS) are suggested. In this work, different honeyproducing regions in the State of Sergipe were studied, as well as samples of honey originated from other states of Brazil, purchased in local supermarkets. Analyses of volatile
components were obtained by dynamic headspace using Porapak Q® and Peat in natura as adsorbent materials. For both, parameters such as amount of sample, salt addition, time and temperature of extractionhave been optimized. Optimization, made possible the identification of 112 different compounds belonging to classes of aliphatic alcohols,
aliphatic aldehydes, benzene derivatives, monoterpene hydrocarbons, oxygenated hydrocarbons, norisoprenoids, sesquiterpenes, oxygenated sesquiterpenes, carboxylic acids
and others. Among these, a group of senior compounds were studied by principal components analysis and hierarchical cluster analysis. With these analyses was likely to
identify the components with biggest weights in the samples and cluster them into five groups with a similarity of 48% based on Euclidean distance. Among the weighty compounds are furfuraldehyde, benzaldehyde, cis-linalool oxide (furanoid), trans-linalool oxide (furanoid), linalool, hotrienol, 4-ketoisoforone, aldehyde lilac (isomer I), cis-linalool oxide (pyranoid) and -terpineol.<br>Dentre os produtos apícolas o mel é considerado o principal por se destacar como alimento natural e ter várias aplicações farmacológicas, podendo ser produzido por abelhas Apis mellifera a partir do néctar, secreções das plantas e frutos, excreções de afídeos e outras soluções adocicadas. Seu poder nutritivo, farmacológico e valor comercial dependem de sua origem botânica, a qual pode ser obtida através de métodos clássicos como a avaliação sensorial, a melissopalinologia ou análises físico-químicas, porém estes métodos exigem muita experiência do analista e são dispendiosas. Em virtude das dificuldades atuais em realizar essas análises os métodos baseados no estudo dos constituintes voláteis têm surgido como uma alternativa na procura de compostos marcadores da origem floral de méis. Para a identificação destes compostos, técnicas como a microextração em fase sólida (SPME) e headspace dinâmico (HSD) seguido de análise em cromatógrafo em fase gasosa/espectrômetro de massas (CG/EM) são sugeridas. Neste trabalho foram estudados méis de diferentes regiões produtoras do estado de Sergipe, bem como amostras de méis adquiridos em supermercado de Aracaju oriundas de outros estados do Brasil através da análise dos componentes voláteis
obtidos por headspace dinâmico utilizando Porapak Q® e Turfa in natura como materiais adsorventes. Para tanto foram otimizados parâmetros como quantidade de amostra, adição de sal, tempo e temperatura de extração. Nas condições otimizadas foi possível identificar 112 diferentes compostos pertencentes às classes dos álcoois alifáticos, benzenóides, aldeídos alifáticos, hidrocarbonetos lineares, monoterpenos,
monoterpenos oxigenados, sesquiterpenos, sesquiterpenos oxigenados, norisoprenóides, ácidos carboxílicos e outros. Dentre estes, um grupo de compostos majoritários foram
estudados por análise de componentes principais e análise de agrupamento hierárquico. Com estas análises foi possível identificar os componentes de maiores pesos das
amostras e agrupá-las em cinco grupos com uma similaridade de 48%, tendo como base a distância Euclidiana. Dentre os compostos de maiores pesos estão o furfural, benzaldeído, cis-óxido de linalol (furanóide), trans-óxido de linalol (furanóide), linalol, hotrienol, 4-ceto-isoforona, lilac aldeído (isômero I), cis-óxido de linalol (piranóide) e o -terpineol.
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Jalal, Ahmed Hasnain. "Multivariate Analysis for the Quantification of Transdermal Volatile Organic Compounds in Humans by Proton Exchange Membrane Fuel Cell System." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3886.
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In this research, a proton exchange membrane fuel cell (PEMFC) sensor was investigated for specific detection of volatile organic compounds (VOCs) for point-of-care (POC) diagnosis of the physiological conditions of humans. A PEMFC is an electrochemical transducer that converts chemical energy into electrical energy. A Redox reaction takes place at its electrodes whereas the volatile biomolecules (e.g. ethanol) are oxidized at the anode and ambient oxygen is reduced at the cathode. The compounds which were the focus of this investigation were ethanol (C2H5OH) and isoflurane (C3H2ClF5O), but theoretically, the sensor is not limited to only those VOCs given proper calibration.
Detection in biosensing, which needs to be carried out in a controlled system, becomes complex in a multivariate environment. Major limitations of all types of biosensors would include poor selectivity, drifting, overlapping, and degradation of signals. Specific detection of VOCs in multi-dimensional environments is also a challenge in fuel cell sensing. Humidity, temperature, and the presence of other analytes interfere with the functionality of the fuel cell and provide false readings. Hence, accurate and precise quantification of VOC(s) and calibration are the major challenges when using PEMFC biosensor.
To resolve this problem, a statistical model was derived for the calibration of PEMFC employing multivariate analysis, such as the “Principal Component Regression (PCR)” method for the sensing of VOC(s). PCR can correlate larger data sets and provides an accurate fitting between a known and an unknown data set. PCR improves calibration for multivariate conditions as compared to the overlapping signals obtained when using linear (univariate) regression models.
Results show that this biosensor investigated has a 75% accuracy improvement over the commercial alcohol breathalyzer used in this study when detecting ethanol. When detecting isoflurane, this sensor has an average deviation in the steady-state response of ~14.29% from the gold-standard infrared spectroscopy system used in hospital operating theaters.
The significance of this research lies in its versatility in dealing with the existing challenge of the accuracy and precision of the calibration of the PEMFC sensor. Also, this research may improve the diagnosis of several diseases through the detection of concerned biomarkers.
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Hu, Lin Feng. "Chemical analysis studies on the volatile components of Herba Pogostemonis." Thesis, University of Macau, 2005. http://umaclib3.umac.mo/record=b1445816.
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González, Martínez María. "Woody and agricultural biomass torrefaction : experimental study and modelling of solid conversion and volatile species release based on biomass extracted macromolecular components." Thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/24326/1/gonzalez_martinez.pdf.
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Nowadays, there is an increasing awareness on the importance of biomass waste as a renewable source of energy, materials and chemicals. In this context, the European project MOBILE FLIP aims at developing and demonstrating mobile conversion processes suitable with variousunderexploited agro- and forest based biomass resources in order to produce energy carriers, materials and chemicals. One of these processes is torrefaction, which consists in a mild thermal treatment, occurring typically between 200 and 300°C during a few tens of minutes in a defaultoxygen atmosphere. The solid product obtained has thermal and processing properties closer to coal, and thus is suitable as fuel for combustion or gasification. During torrefaction, condensable coproducts are released, that may also be source of “green” chemicals. It is therefore crucial to characterize them to optimize the torrefaction process and design industrial units. Up to now, only few works have been focused on characterizing and modelling both solid and condensable species during torrefaction versus operating conditions and feedstock type. Furthermore, these studies typically include a reduced number of biomasses. Cellulose, hemicellulose and lignin,which constitute biomass macromolecular composition, are determining properties to predict biomass behaviour during torrefaction. However, torrefaction tests on these constituents are rare and always based on commercial compounds, which were proved as little representative of the native biomass. The objective of this study is to analyse the influence of biomass characteristics, mainly represented by the macromolecular composition in cellulose, hemicellulose and lignin, on the global behaviour of biomass in torrefaction, both in terms of solid mass loss and of productionprofiles of the volatile species released, in function of the operating conditions.14 biomasses from the main biomass families (deciduouswood, coniferous wood, agricultural byproductsand herbaceous crops) were selected for this study. An optimized extraction procedure was proposed to recover cellulose, hemicellulose and lignin fractions from 5 reference biomasses. Experiments were performed on a thermogravimetric analyzer coupled to a gas chromatography mass spectrometer device through a heated storage loop system (TGA-GC/MS). Solid degradation kinetics and volatile release profiles were followed during torrefaction experiments combining non-isothermal (200 to 300°C at 3°C/min) and isothermal (300°C, 30 min) conditions, ensuring the chemical regime thanks to the appropriate operating conditions. The results obtained with the raw materials demonstrated that biomass macromolecular composition is a main factor influencing biomass behavior in torrefaction. Consequently, the heterogeneity of the resource results in a diverse behavior in torrefaction, particularly in the case of agricultural biomasses. The results with the extracted components evidenced their very different behavior compared to thecommercial compounds, particularly in the case of cellulose. This suggests that a limitation could be induced by the common use in literature of commercial components for torrefaction modelling. The impact on the characterization of macromolecular components was also shown to be prevailing in their behavior in torrefaction, especially in the case of hemicellulose sugar composition and cellulose crystallinity. Furthermore, differences in release kinetics of volatile species during torrefaction were observed, even for volatiles belonging to the same chemical family (acids, furans, ketones). Derived from these results, a torrefaction model based on the additive contribution of extracted cellulose, hemicelluloses and lignin to the global behavior of biomass in torrefaction was proposed, and this for the 5 representative biomasses.
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Tronson, Deidre A., of Western Sydney Hawkesbury University, of Science Technology and Environment College, and of Science Food and Horticulture School. "Volatile compounds in some eastern Australian Banksia flowers." THESIS_CSTE_SFH_Tronson_D.xml, 2001. http://handle.uws.edu.au:8081/1959.7/140.
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This project was the very beginning of research into the chemistry of eastern Australian banksia flowers. Using dynamic headspace sampling (DHS) analysis, differences in volatile components, consistent with detection of differences in odour, were detected among three different species and one commercial cultivar. Infraspecific variation was also observed between two known subspecies of Banksia ericifolia and between differently coloured forms of Banksia spinulosa var. collina. The cultivar, Banksia 'Giant Candles', was shown to have some of the chemical components of each of its supposed ancestors. The absence of known wound-response chemicals indicated that this DHS method was successful in leaving the inflorescences undamaged throughout the sampling procedure. The Likens-Nickerson modification of classical hydrodistillation methods was useful. The static headspace method (SHS) was easily automated and was shown to be chemically robust and sufficiently sensitive to detect volatile compounds from only a few flowers. The milder DHS method, which minimised mechanical and heat damage to the plant tissue, produced a different set of results. From the results of this project, a suite of volatile compounds has been proposed that may be useful in future behavioural studies to help determine whether animals are attracted to components of banksia odours. These candidates include some compounds that have been reported in animal secretions, wound-response chemicals that may be produced by the plant to aid its communication with other organisms, and a compound (suggested to be sulfanylmethyl acetate) not previously reported from natural sources. The mildest of the three analytical methods used, dynamic headspace sampling, was shown to be suitable for the potential chemotaxonomic evaluation of some members of the Banksia genus.<br>Doctor of Philosophy (PhD)
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Munch, Ryan Nicholas. "Deodorization of Garlic Breath Volatiles by Food and Food Components." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1383566379.
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Guardiano, Carmelo. "Livelli di pascolo, componenti volatili, antiossidanti e qualità del latte." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/1018.
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The aim of this study was to evaluate the effect of pasture feeding and cow s breed on milk volatiles fingerprint and to examine the effects of pasture feeding and dairy cattle breed on fat-soluble antioxidant, vitamin content in milk. Four Sicilian dairy farms were selected, two with both Holsteins and Brown Swiss cows and two with only local breed Modicana cows. Bulk milk of each breed per farm was sampled four times per experimental period (spring, summer, and autumn). Samplings within period occurred with weekly intervals. Pasture was available in spring and autumn but not in summer. Spring and autumn differed by botanical composition and plant maturity. During summer cows were grazing stubble. Additional hay and concentrate was supplemented during all periods. Milk samples were analyzed by SMart Nose®: data were statistically evaluated by Principal Component Analysis. Volatiles profiles of samples from spring and autumn compared to summer were discriminated, but not between spring and autumn. There was less variation in volatiles during autumn compared to spring. Milk volatile profiles collected at the last sampling day (spring), except for volatiles composition from Modicana milk, were similar to all samples from summer. At this day, plants were mature and almost dry and chemical composition might have been similar to stubble composition. In all periods, also when pasture was not available during summer, volatiles composition of Modicana milk was different from Holsteins and Brown Swiss milk. Differences during spring and autumn might be explained, at least in part, by the higher average pasture intake of Modicana relative to the Brown Swiss and Holsteins. Pasture benefits relative to vitamin content milk content might be obtained only after a minimum necessary exposure period of cows to pasture. Milks from Modicana had the same levels of beta-carotene of Brown Swiss compared to Holsteins cows, whereas significant higher levels of alfa-tocopherol of Modicana relative to Brown Swiss and Holsteins. As a difference to Holsteins and Brown Swiss cows who had similar feeding regimen, Modicana cows had significant higher pasture intake. Differences in vitamin content contents in milk from Modicana relative to Brown Swiss and Holsteins cows cannot be exclusively explained by breed effects but may mainly be attributed to different levels of pasture intakes.
Libros sobre el tema "Volatile component"
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Volatile components and continental material of planets. National Aeronautics and Space Administration, 1986.
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Luginbühl, Martin, and Arvi Yli-Hankala. Assessment of the components of anaesthesia. Edited by Antony R. Wilkes and Jonathan G. Hardman. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199642045.003.0026.
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In modern anaesthesia practice, hypnotic drugs, opioids, and neuromuscular blocking agents (NMBAs) are combined. The introduction of NMBAs in particular substantially increased the risk of awareness and recall during general anaesthesia. Hypnotic drugs such as propofol and volatile anaesthetics act through GABAA receptors and have typical effects on the electroencephalogram (EEG). During increasing concentrations of these pharmaceuticals, the EEG desynchronization is followed by gradual synchronization, slowing frequency, and increasing amplitude of EEG, thereafter EEG suppressions (burst suppression), and, finally, isoelectric EEG. Hypnotic depth monitors such as the Bispectral Index™, Entropy™, and Narcotrend® are based on quantitative EEG analysis and translate these changes into numbers between 100 and 0. Although they are good predictors of wakefulness and deep anaesthesia, their usefulness in prevention of awareness and recall has been challenged, especially when inhalation anaesthetics are used. External and patient-related artifacts such as epileptiform discharges and frontal electromyography (EMG) affect the signal so their readings need careful interpretation. Their use is recommended in patients at increased risk of awareness and recall and in patients under total intravenous anaesthesia. Monitors of analgesia and nociception are not established in clinical practice but mostly remain experimental although some are commercially available. Some use EEG changes induced by noxious stimulation (EEG arousal) or quantify the frontal EMG in relation to EEG, while others are based on the sympathoadrenergic stress response. Various other devices are also discussed in this chapter.
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Rai, Mahendra, and Kateryna Kon. Fighting Multidrug Resistance with Herbal Extracts, Essential Oils and Their Components. Elsevier Science & Technology Books, 2013.
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Rai, Mahendra, and Kateryna Kon. Fighting Multidrug Resistance with Herbal Extracts, Essential Oils and Their Components. Elsevier Science & Technology Books, 2013.
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Larson, Donald F. Food Prices and Food Price Volatility. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190656010.003.0022.
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This chapter examines food prices from 1900 to 2015. Despite growing populations, rising incomes, new technologies, globalization, and the emergence of commodities as an asset class, no trends are evident in food price levels or volatility. Still, food prices have averaged higher since 2010, harming the poor and raising fears that agricultural productivity growth has slowed. Consistently since 1900, food prices have been more volatile than the prices of manufactured goods and most other commodity groups. This relation drives terms-of-trade volatility, which slows economic growth. At the farm level, price volatility impedes investment and technology adoption, and encourages low-income livelihood strategies. Past policies to manage food prices have not worked and governments have shifted to policies aimed at mitigating the consequences of high and volatile food prices. Extending the reach of risk markets, warehouse receipt systems, index insurance, and contract farming can be useful policy components.
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Barth, Winfried. Pulp Production by Acetosolv Process. Technische Universität Dresden, 2021. http://dx.doi.org/10.25368/2022.415.
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Cellulose is the most abundant organic polymer on Earth and a fascinating compound for a vast variety of applications. It is mostly received from wood, thus it is a renewable resource and a CO2 storing material. One of the most important cellulose products are pulp and paper. The major goal of this work was to obtain a material with a high amount of cellulose through a pulping process of wood. Therefore, it is necessary to separate the wood bers and to remove a component of wood, which is called lignin (deligni cation). The conventional way to delignify wood is the Kraft process that causes serval problems like contamination of lignin with sulfur and the emission of toxic volatile sulfur compounds. Hence, there are alternative processes without sulfur, such as the Acetosolv process. It uses simple chemicals like acetic acid and is easy to handle. After cutting a spruce tree (Picea abies L. Karst.), debarking and chipping, the wood chips were cooked in the laboratory. The research included the chemical analysis of the obtained pulp and the manufacturing and testing of paper sheets. The yield of pulp ranged widely due to the di erent parameters of the cooking. FT-IR and Raman spectroscopy were used to observe the decrease of aromatic substances (lignin) and the acetylation of the pulp. With the means of Design of Experiments and statistical analysis the most important factors were identi ed and a mathematical regression model was calculated. The manufactured paper sheets showed good mechanical properties and high transparency. Finally, the Acetosolv process could be considered as a contribution to the upcoming bio-based economy because, in addition to the cellulose bers, the industry would be capable of adding value utilization of the separated lignin. It could be one step to a more sustainable paper and pulp production.
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Toledano, Roulhac D. Physiological changes associated with pregnancy. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780198713333.003.0002.
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Pregnant patients pose several challenges to anaesthetists and other healthcare providers. Significant systemic and organ-specific changes accompany each stage of pregnancy, culminating during labour and delivery and in the early postpartum period. While healthy parturients tolerate these physiological adaptations to pregnancy well, patients with coexisting disease or pregnancy-related medical conditions may experience acute decompensation, with potential long-term sequelae. Alternatively, symptoms of a disease state may be obscured by pregnancy or mistaken for physiological changes of pregnancy. Anaesthetic management of pregnant patients is further complicated by concerns regarding difficulty with airway management, aspiration of gastric contents, haemodynamic effects of aortocaval compression, maternal obesity, and the effects of volatile agents on uterine tone; reference ranges for laboratory results that differ from those of the non-pregnant population; fears of fetal exposure to antibiotics, analgesics, and anaesthetics; and concerns that more than one patient must be taken into consideration. This chapter reviews the systemic and organ-specific physiological changes that occur during different stages of pregnancy, with a focus on how these adaptations to pregnancy affect anaesthetic management. Familiarity with updated, evidence-based practices and a firm understanding of the physiological changes of pregnancy are essential components of the anaesthetic management of obstetric patients at any gestational age.
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Trieloff, Mario. Noble Gases. Oxford University Press, 2017. http://dx.doi.org/10.1093/acrefore/9780190647926.013.30.
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This is an advance summary of a forthcoming article in the Oxford Encyclopedia of Planetary Science. Please check back later for the full article.Although the second most abundant element in the cosmos is helium, noble gases are also called rare gases. The reason is that they are not abundant on terrestrial planets like our Earth, which is characterized by orders of magnitude depletion of—particularly light—noble gases when compared to the cosmic element abundance pattern. Indeed, such geochemical depletion and enrichment processes make noble gases so versatile concerning planetary formation and evolution: When our solar system formed, the first small grains started to adsorb small amounts of noble gases from the protosolar nebula, resulting in depletion of light He and Ne when compared to heavy noble gases Ar, Kr, and Xe: the so-called planetary type abundance pattern. Subsequent flash heating of the first small mm to cm-sized objects (chondrules and calcium, aluminum rich inclusions) resulted in further depletion, as well as heating—and occasionally differentiation—on small planetesimals, which were precursors of larger planets and which we still find in the asteroid belt today from where we get rocky fragments in form of meteorites. In most primitive meteorites, we even can find tiny rare grains that are older than our solar system and condensed billions of years ago in circumstellar atmospheres of, for example, red giant stars. These grains are characterized by nucleosynthetic anomalies and particularly identified by noble gases, for example, so-called s-process xenon.While planetesimals acquired a depleted noble gas component strongly fractionated in favor of heavy noble gases, the sun and also gas giants like Jupiter attracted a much larger amount of gas from the protosolar nebula by gravitational capture. This resulted in a cosmic or “solar type” abundance pattern, containing the full complement of light noble gases. Contrary to Jupiter or the sun, terrestrial planets accreted from planetesimals with only minor contributions from the protosolar nebula, which explains their high degree of depletion and basically “planetary” elemental abundance pattern. Indeed this depletion enables another tool to be applied in noble gas geo- and cosmochemistry: ingrowth of radiogenic nuclides. Due to heavy depletion of primordial nuclides like 36Ar and 130Xe, radiogenic ingrowth of 40Ar by 40K decay, 129Xe by 129I decay, or fission Xe from 238U or 244Pu decay are precisely measurable, and allow insight in the chronology of fractionation of lithophile parent nuclides and atmophile noble gas daughters, mainly caused by mantle degassing and formation of the atmosphere.Already the dominance of 40Ar in the terrestrial atmosphere allowed C. F v. Weizsäcker to conclude that most of the terrestrial atmosphere originated by degassing of the solid Earth, which is an ongoing process today at mid ocean ridges, where primordial helium leaves the lithosphere for the first time. Mantle degassing was much more massive in the past; in fact, most of the terrestrial atmosphere formed during the first 100 million years of Earth´s history, and was completed at about the same time when the terrestrial core formed and accretion was terminated by a giant impact that also formed our moon. However, before that time, somehow also tiny amounts of solar noble gases managed to find their way into the mantle, presumably by solar wind irradiation of small planetesimals or dust accreting to Earth. While the moon-forming impact likely dissipated the primordial atmosphere, today´s atmosphere originated by mantle degassing and a late veneer with asteroidal and possibly cometary contributions. As other atmophile elements behave similar to noble gases, they also trace the origin of major volatiles on Earth, for example, water, nitrogen, sulfur, and carbon.
Capítulos de libros sobre el tema "Volatile component"
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Dart, S. K., and H. E. Nursten. "Volatile Components." In Coffee. Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-4948-5_7.
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Mojzes, I., B. Kovács, I. Kun, L. Máté, M. Schuszter, and L. Dobos. "Surface Pattern Formation and the Volatile Component Loss of Heat Treated Pd/InP and Au/Inp Samples." In Multichip Modules with Integrated Sensors. Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-0323-4_32.
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Ariga, Toyohiko, Asobu Takeda, Sachiyuki Teramoto, and Taiichiro Seki. "Inhibition Site of Methylallyl Trisulfide: A Volatile Oil Component of Garlic, in the Platelet Arachidonic Acid Cascade." In Food Factors for Cancer Prevention. Springer Japan, 1997. http://dx.doi.org/10.1007/978-4-431-67017-9_46.
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Beck, John J., and Bradley S. Higbee. "Plant- or Fungal-Produced Conophthorin as an Important Component of Host Plant Volatile-Based Attractants for Agricultural Lepidopteran Insect Pests." In ACS Symposium Series. American Chemical Society, 2015. http://dx.doi.org/10.1021/bk-2015-1204.ch009.
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Watanabe, Ichiro, Osamu Takazawa, Yasuhiro Warita, and Ken-ichi Awano. "Volatile Components of Apricot Flowers." In ACS Symposium Series. American Chemical Society, 1993. http://dx.doi.org/10.1021/bk-1993-0525.ch016.
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Zhang, Nanqi, Qinghai Dong, Qingxi Wang, and Jinping Liu. "Analysis of Volatile Oils in Ginseng." In Ginseng Nutritional Components and Functional Factors. Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4688-4_4.
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Kobayashi, Akio, Kikue Kubota, and Motoko Yano. "Formation of Some Volatile Components of Tea." In ACS Symposium Series. American Chemical Society, 1993. http://dx.doi.org/10.1021/bk-1993-0525.ch005.
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Buttery, Ron G. "Volatile Aroma/Flavor Components of Raisins (Dried Grapes)." In Handbook of Fruit and Vegetable Flavors. John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470622834.ch30.
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Buttery, Ron G., and Louisa C. Ling. "Volatile Components of Tomato Fruit and Plant Parts." In ACS Symposium Series. American Chemical Society, 1993. http://dx.doi.org/10.1021/bk-1993-0525.ch003.
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Kameoka, H. "GC-MS Method for Volatile Flavor Components of Foods." In Gas Chromatography/Mass Spectrometry. Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82612-2_11.
Texto completoActas de conferencias sobre el tema "Volatile component"
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Grasser, T., K. Rott, H. Reisinger, et al. "Hydrogen-related volatile defects as the possible cause for the recoverable component of NBTI." In 2013 IEEE International Electron Devices Meeting (IEDM). IEEE, 2013. http://dx.doi.org/10.1109/iedm.2013.6724637.
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Webster, James D., Christian Huber, and Olivier Bachmann. "INSIGHTS ON MAGMATIC FLUID EXSOLUTION AND EVOLUTION FROM CHLORINE THE UNDER-APPRECIATED MAGMATIC VOLATILE COMPONENT." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-302941.
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Malygin, A. P., and I. G. Nizovtseva. "The stefan problem on evaporation of a volatile component in the gas-melt-solid system." In PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2014 (ICNAAM-2014). AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4913163.
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Debabhuti, Nilava, Swarnali Neogi, Abhishek Dhar, et al. "Identification of The Important Volatile Organic Component in Cardamom based on Silica-Modified Piezoelectric Resonator." In 2020 IEEE International Conference for Convergence in Engineering (ICCE). IEEE, 2020. http://dx.doi.org/10.1109/icce50343.2020.9290496.
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Lee, Szer Ming, Min Huey Ong, Robert Harrison, and Andrew A. West. "The Need for a Component-Based Approach to Automation Systems for Agile Manufacturing." In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58346.
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Manufacturing enterprises are facing new challenges caused by unprecedented changes due to volatile market demands. Such changes have direct impact to the design, implementation and operation of automation systems in the domain of automotive production. An in-depth study in the activities of building and operating automation systems in the domain of automation manufacturing has revealed weaknesses in current practices and in particular an inability to cope effectively with production changes. It is envisaged that a component-based approach will enable an automation system to be designed, implemented and modified quickly and effectively, thereby increasing the agility, responsiveness and changeability of the system. This paper investigates the impact of market demands on the lifecycle of automation systems in the automotive manufacturing and proposes a novel component-based approach suitable for automation system design and implementation.
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Kaya, Durmuş Alpaslan, and Musa Türkmen. "Comparing of Eucalyptus (Eucalyptus camaldulensis and Eucalyptus grandis) Essential Oil Compositions Growing in Hatay Ecological Conditions." In The 9th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2022. http://dx.doi.org/10.24264/icams-2022.ii.14.
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Essential oils obtained by hydrodistillation of Eucalyptus camaldulensis and Eucalyptus grandis from Hatay (Turkey), were analyzed by GC/MS. The total ratio of twenty-three components in Eucalyptus camaldulensis volatile components with 98.15%. This ratio is seen as forty-seven components and 99.66% in Eucalyptus grandis. Eucalyptol, limonene and α-pinene were identified as the main components of the essential oils of Eucalyptus camaldulensis. Cymene, α-pinene, isoborneol, trans-pinocarveol and eucalyptol were identified as the main components of the essential oils of Eucalyptus grandis. When compare the components of E. camaldulensis and E. grandis essential oils, the main component was determined as eucalyptol with 74.11% and cymene with 31.67% respectively.
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Reichardt, G. "A study on economic tooling concepts for dry deep-drawing using environmentally benign volatile lubricants." In Sheet Metal 2023. Materials Research Forum LLC, 2023. http://dx.doi.org/10.21741/9781644902417-50.
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Abstract. Dry processes represent promising approaches in forming technology to improve environmental aspects and human health by avoiding harmful substances and additives of conventional lubricants. Among many different approaches for dry forming investigated within the priority program SPP 1676, this paper addresses the use of volatile media as lubricants such as CO2 or N2. These volatile media are introduced directly into the interstice between sheet metal and tool surface via microinjectors. Indeed, this does not contradict the principle dry forming approach, as dry forming is defined as a process in which no residues are left on the surfaces [1]. This is ensured by the complete evaporation of the volatile media. The general feasibility of this novel tribological system has already been demonstrated in previous research work. However, despite good tribological results, the manufacturing costs of the required tool inserts and the media consumption per component are not yet economically competitive with conventional tribological systems. Therefore, this paper focuses on new designs of dry deep-drawing tools utilising volatile lubricants, considering the economics of different manufacturing processes.
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MONNEYRON, P., M. H. MANERO, and J. N. FOUSSARD. "SINGLE AND MULTI COMPONENT ADSORPTION OF VOLATILE ORGANIC COMPOUNDS ONTO HIGH SILICA ZEOLITES - DISCUSSION OF ADSORBED SOLUTION THEORY." In Proceedings of the Third Pacific Basin Conference. WORLD SCIENTIFIC, 2003. http://dx.doi.org/10.1142/9789812704320_0044.
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Güzel, Yelda, Durmuş Alpaslan Kaya, and Musa Türkmen. "Essential Oil Composition of Teucrium montbretii Subsp. montbretii Benth. (Lamiaceae)." In The 9th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2022. http://dx.doi.org/10.24264/icams-2022.ii.8.
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Essential oils obtained by hydrodistillation of Teucrium montbretii subsp. montbretii Benth. (Lamiaceae) from Hatay (Turkey), were analyzed by GC/MS. Forty-four volatile components were identified in the oils, representing 98.12 % of the total oils. The sample was yielded 0.24% of yellowish oil (w/w), with a pleasant smell. The main essential oil compounds of the plant were trans-caryophyllene, germacrene-D and caryophyllene oxide, representing 66.7%. Trans-caryophyllene, which has the highest ratio (36.78%), also known as β-caryophyllene, is a component that is the main constituent of many plants included in the sesquiterpene chemical class. Second main component germacrene-D (19.87%) is also sesquiterpene and detected in the essential oil of many plants. α-Copaene, humulene, aromadendrene and globulol were the other components detected at ratio of 5.45%, 4.29%, 3.99% and 3.35%, representing 17.08%, respectively.
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Alonso, Dominique, Ghislain Genin, David Heller, Brice Chabrier, and Michel Molie`re. "Evaporation of Volatile Liquid Pools Under Forced Convection: Experimental Approach for Multi-Component Liquids and Validation of a Vaporization Model." In ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/gt2011-45560.
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The evaporation of pools of volatile liquids under dynamic conditions is gaining interest as an engineering subject. Indeed there is an increasing need to optimize the control of thermal or chemical processes and to cope with more and more stringent Environmental, Health and Safety (EHS) regulations applicable to the handling of hazardous liquids, especially those relating to stationary gas turbine installations. A specific issue, tied with flammable substances, comes from the fact that the transition from a flame to an explosion is not sufficiently well controlled due to the difficulty in modeling complex installations. Therefore, the current approach used to address explosion risks consists in quantifying the flux of vapors emitted by the pool and evaluating the mechanical effect entailed by a potential ignition of the flammable cloud generated. It is therefore of paramount importance to accurately know, under variable vaporizing conditions, how much of the volatile matter is extracted by the ventilation stream from the liquid pool and how these vapors get diluted downstream of the source. A survey of the literature shows that while pool evaporation of water has been extensively covered by experimentation, most organic liquids including hydrocarbons, alcohols, ethers, etc. have been insufficiently studied. In order to fill this gap, the authors have combined an experimental approach enabling to quantify the source of vapors with a dedicated Computational Fluid Dynamics (CFD) approach describing the mixing/dilution phenomena in the gas phase. This dual approach has proved very fruitful as it leads to realistic spatial distributions of the species downstream of the source. Therefore it has been utilized to develop experimentally verified data for the evaporation rate of single and multicomponent liquids. This paper presents the original experimental rig developed to quantify the vaporization rates. The elaboration of the CFD model and the results obtained when coupling both approaches will be the matter of a next paper.
Informes sobre el tema "Volatile component"
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Ibdah, Mwafaq, Dorothea Tholl, and Philipp W. Simon. How temperature stress changes carrot flavor: Elucidating the genetic determinants of undesired taste in carrots. United States Department of Agriculture, 2014. http://dx.doi.org/10.32747/2014.7598171.bard.
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Global climate change and warming temperatures represent the greatest future challenge for global food production and quality. In this project, we will define the genetic factors of climate-associated taste deficiencies in carrot. Carrot is considered one of the leading horticultural crops in the world in terms of its nutritional value, health benefits, and unique flavor based on its high content of carotenoids and volatile aroma compounds. In recent years, carrot genotypes of different color with improved nutraceutical attributes have been developed. When exposed to high growth temperatures, carrots develop an undesired harsh and bitter taste caused by the accumulation of terpene metabolites. This taste deficiency represents a quality defect to carrot breeders and large- scale growers and needs to be minimized for successful marketing of carrot crops. Surprisingly, the genetic determinants of bitter and harsh flavor in carrot and their response to temperature stress are not well characterized. We started to elucidate these factors in different carrot cultivars by investigating the biosynthesis of volatile terpenes, which represent the predominant flavor compounds in carrots. Also, up to date we identified and characterized two terpenesynthase enzymes, one of which produces (E)-β- caryophyllene, a major terpene component in carrot root. Both TPSs may contribute to the observed variation in volatile terpene formation.
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Smith, R. A. Volatile Components from Packing Matrials, Rev. 2. Office of Scientific and Technical Information (OSTI), 2006. http://dx.doi.org/10.2172/974247.
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Dahlke, Garland R., and Beth E. Doran. Volatile Components of Wet and Modified Corn Distillers Grains—A Survey. Iowa State University, 2016. http://dx.doi.org/10.31274/ans_air-180814-553.
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Tappan, D. V., D. R. Knight, E. Heyder, and P. K. Weathersby. Volatile Organic Components of Air Samples Collected from Vertical Launch Missile Capsules. Defense Technical Information Center, 1988. http://dx.doi.org/10.21236/ada218153.
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Rouseff, Russell L., and Michael Naim. Characterization of Unidentified Potent Flavor Changes during Processing and Storage of Orange and Grapefruit Juices. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7585191.bard.
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Citrus juice flavor quality traditionally diminishes after thermal processing and continuously during storage. Our prior studies found that four of the five most potent off-aromas formed during orange juice storage had not been identified. The primary emphasis of this project was to characterize and identify those potent flavor degrading aroma volatiles so that methods to control them could be developed and final flavor quality improved. Our original objectives included: 1 Isolate and characterize the most important unidentified aroma impact compounds formed or lost during pasteurization and storage. 2. Determination of thiamine and carotenoid thermal decomposition and Strecker degradation pathways in model solutions as possible precursors for the unidentified off-flavors. 3. Evaluate the effectiveness of an "electronic nose" to differentiate the headspace aromas of from untreated and heat pasteurized orange and grapefruit juices. 4. Use model systems of citrus juices to investigate the three possible precursor pathways (from 2) for flavor impact compounds formed or lost during pasteurization or storage. RESULTS - The components responsible for citrus storage off flavors and their putative precursors have now been identified. Certain carotenoids (b-carotene) can thermally degrade to produce b-ionone and b-damascenone which are floral and tobacco smelling respectively. Our GC-O and sensory experiments indicated that b-damascenone is a potential storage off-flavor in orange juice. Thiamine (Vitamin B1) degradation produces 2-methyl-3-furan thiol, MFT, and its dimer bis(2- methyl-3-furyl) disulfide which both produce meaty, savory aromas. GC-O and sensory studies indicated that MFT is another storage off-flavor. Methional (potato aroma) is another off flavor produced primarily from the reaction of the native amino acid, methionine, and oxidized ascorbic acid (vitamin C). This is a newly discovered pathway for the production of methional and is more dominant in juices than the classic Maillard reaction. These newly identified off flavors diminish the flavor quality of citrus juices as they distort the flavor balance and introduce non-typical aromas to the juice flavor profile. In addition, we have demonstrated that some of the poor flavor quality citrus juice found in the market place is not only from the production of these and other off flavors but also due to the absence of desirable flavor components including several potent aldehydes and a few esters. The absence of these compounds appears to be due to incomplete flavor volatile restoration after the making of juice concentrates. We are the first to demonstrate that not all flavor volatiles are removed along with water in the production of juice concentrate. In the case of grapefruit juice we have documented which flavor volatiles are completely removed, which are partially removed and which actually increase because of the thermal process. Since more that half of all citrus juices is made into concentrate, this information will allow producers to more accurately restore the original flavor components and produce a juice with a more natural flavor. IMPLICATIONS - We have shown that the aroma of citrus juices is controlled by only 1-2% of the total volatiles. The vast majority of other volatiles have little to no direct aroma activity. The critical volatiles have now been identified. The ability to produce high quality citrus juices requires that manufacturers know which chemical components control aroma and flavor. In addition to identifying the critical flavor components (both positive and negative), we have also identified several precursors. The behavior of these key aroma compounds and their precursors during common manufacturing and storage conditions has been documented so manufacturers in Israel and the US can alter production practices to minimize the negative ones and maximize the positive ones.
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Sloan, Jr., Richard Charles. Development and application of a mass spectrometric system to study volatile components of fluid inclusions. Office of Scientific and Technical Information (OSTI), 1992. http://dx.doi.org/10.2172/10152018.
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Sloan, R. C. Jr. Development and application of a mass spectrometric system to study volatile components of fluid inclusions. Office of Scientific and Technical Information (OSTI), 1992. http://dx.doi.org/10.2172/5148689.
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Naim, Michael, Gary R. Takeoka, Haim D. Rabinowitch, and Ron G. Buttery. Identification of Impact Aroma Compounds in Tomato: Implications to New Hybrids with Improved Acceptance through Sensory, Chemical, Breeding and Agrotechnical Techniques. United States Department of Agriculture, 2002. http://dx.doi.org/10.32747/2002.7585204.bard.
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The tomato, a profitable vegetable crop in both the USA and Israel, has benefited significantly from intensive breeding efforts in both countries, and elsewhere (esp. Holland). : Modem hybrids are highly prolific and resistant to a variety of major pests. They produce attractive, firm fruit for both processing and fresh-marketing. In all cases, however, reduction in flavor and aroma have occurred concomitantly with the increase in yield. Sugars-acids ratio dominate fruit taste, whereas aroma volatiles (potent at minute ppb and ppt levels) contribute to the total characteristic tomato flavor. An increase in sugars (1-2%) contributes significantly to tomato fruit taste. However, because of energy reasons, an increase in fruit sugars is immediately compensated for by a decrease in yield. Our main objectives were to: (a) pinpoint and identify the major impact aroma components of fresh tomato; (b) study the genetic and environmental effects on fruit aroma; (c) determine precursors of appealing (flavors) and repelling (off-flavors) aroma compounds in tomato. Addition of saturated salts blocked all enzymatic activities prior to isolation of volatiles by dynamic and static headspace, using solvent assisted flavor evaporation (SAFE) and solid phase micro-extraction (SPME) from highly favored (FA-612 and FA-624) and less preferred (R 144 and R 175) tomato genotypes. Impact aroma components were determined by gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC- MS) and aroma extract dilution analysis (AEDA). The potent odorant (Z)-1,5-octadien-3-one, was identified for the first time in fresh tomato. From the ca. 400 volatile compounds in the headspace of fresh tomato, the following compounds are proposed to be impact aroma compounds: (Z)-3-hexenal, hexanal, 1-penten-3-one, 2-phenylethanol, (E)-2-hexenal, phenyl acetaldehyde, b-ionone, b-damascenone, 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (FuraneolR), (Z)-l,5-octadien-3-one, methional, 1-octen-3-one, guaiacol, (E,E)- and (E,Z)- 2,4-decadienal and trans- and cis-4,5-EPOXY -(E)-2-decenal. This confirms the initial hypothesis that only a small number of volatiles actually contribute to the sensation of fruit aroma. Tomato matrix significantly affected the volatility of certain impact aroma components and thus led to the conclusion that direct analysis of molecules in the headspace . may best represent access of tomato volatiles to the olfactory receptors. Significant differences in certain odorants were found between preferred and less-preferred cultivars. Higher consumer preference was correlated with higher concentrations of the following odorants: l-penten-3-one, (Z)-3-hexenal, (E,E)- and (E,Z)-2,4-decadienal and especially Furaneol, whereas lower consumer preference was associated with higher concentrations of methional, 3-methylbutyric acid, phenylacetaldehyde, 2-phenylethanol, and 2-isobutylthiazole. Among environmental factors (salinity, N source, growth temperature), temperature had significant effects on the content of selected aroma compounds (e.g., 3-methylbutanal, 1- penten-3-one, hexanal, (Z)-3-hexenal, (E)-2-hexenal, 2-isobutylthiazole, 6-methyl-5-hepten- 2-one, 1-octen-3-one, methional, 2-phenylethanal, phenyl acetaldehyde, and eugenol) in fresh tomatoes. Salt stress (20 mM NaCl) increased the content of odorants such as (Z)-3-hexenal, 2-phenylethanol and 3-methylbutanal in the R-144 cultivar whereas salinity had minor effects on 1-pentene-3-one, 2-isobutylthiazole and b-ionone. This fundamental knowledge obtained by comprehensive investigation, using modem chemical, sensory and agrotechnical methodology will assist future attempts to genetically modify the concentrations of key odorants in fresh tomatoes, and thus keep the tomato production of Israel and the USA competitive on the world market.
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Lewinsohn, Efraim, Eran Pichersky, and Shimon Gepstein. Biotechnology of Tomato Volatiles for Flavor Improvement. United States Department of Agriculture, 2001. http://dx.doi.org/10.32747/2001.7575277.bard.
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The main objectives of the research project were: 1. The manipulation, by genetic engineering techniques, of the terpenoid pathway in tomato fruit. Specifically, to test the hypothesis whether overexpression of linalool synthase in tomato fruits will result in the diversion of intermediates of the carotene biosynthetic pathway to linalool, demonstrating that linalool synthase is a key regulatory enzyme, and possibly improving tomato flavor. 2. The elucidation of the biochemical pathway leading to eugenol and methyl eugenol, and the manipulation of this pathway to determine key enzymes and to improve flavor in tomato. Background, conclusions and implications The different proportions of volatile components present in foods often determine their flavor properties. Two of the ten most important flavor compounds in tomatoes, linalool and eugenol, are emitted by the flowers of Clarkia breweri, (Onagraceae), a plant native to California, and are also present in sweet basil (Ocimum basilicum, Lamiaceae). We have studied the key enzymes and genes involved in the production of these flavorants. Linalool synthase, the key enzyme in linalool biosynthesis and its corresponding gene were isolated and characterized from Clarkia breweri. The gene was coupled to a fruit-specific tomato promotor (E8) and was used to transform tomatoes. The transgenic tomatoes produced S-linalool and 1-hydroxylinalool, compounds absent from the fruits of controls. The transgenesis did not adversely affect the overall appearance of the plants nor the levels of other terpenoids present such as carotenoids and vitamin E. Our work has proven that the terpenoid pathway in tomatoes can be modified by the introduction and expression of foreign genes coding for the enzymes controlling the production of monoterpenoid flavor compounds. We have also isolated novel enzymes and genes that are involved in the formation of eugenol and methyl eugenol from Clarkia breweri and basil. An EST library of basil glandular trichomes (the site of eugenol and methyl eugenol biosynthesis) was prepared. More than 1,200 genes have been preliminary characterized and a few of them have been confirmed by functional expression, to be involved in eugenol and methyl eugenol biosynthesis. These genes have augmented the still small repertoire of genes that are available to modify the aroma of agricultural produce by genetic engineering.
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Christensen, Earl, Jack Ferrell, Mariefel V. Olarte, and Asanga B. Padmaperuma. Quantification of Semi-Volatile Oxygenated Components of Pyrolysis Bio-Oil by Gas Chromatography/Mass Spectrometry (GC/MS). Laboratory Analytical Procedure (LAP). Office of Scientific and Technical Information (OSTI), 2016. http://dx.doi.org/10.2172/1241093.
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