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Academic literature on the topic 'Odourants'

Author: Grafiati
Published: 4 June 2021
Last updated: 4 February 2022

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Journal articles on the topic "Odourants"

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Schubert, Marco, Jean-Christophe Sandoz, Giovanni Galizia, and Martin Giurfa. "Odourant dominance in olfactory mixture processing: what makes a strong odourant?" Proceedings of the Royal Society B: Biological Sciences 282, no. 1802 (March 7, 2015): 20142562. http://dx.doi.org/10.1098/rspb.2014.2562.

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The question of how animals process stimulus mixtures remains controversial as opposing views propose that mixtures are processed analytically, as the sum of their elements, or holistically, as unique entities different from their elements. Overshadowing is a widespread phenomenon that can help decide between these alternatives. In overshadowing, an individual trained with a binary mixture learns one element better at the expense of the other. Although element salience (learning success) has been suggested as a main explanation for overshadowing, the mechanisms underlying this phenomenon remain unclear. We studied olfactory overshadowing in honeybees to uncover the mechanisms underlying olfactory-mixture processing. We provide, to our knowledge, the most comprehensive dataset on overshadowing to date based on 90 experimental groups involving more than 2700 bees trained either with six odourants or with their resulting 15 binary mixtures. We found that bees process olfactory mixtures analytically and that salience alone cannot predict overshadowing. After normalizing learning success, we found that an unexpected feature, the generalization profile of an odourant, was determinant for overshadowing. Odourants that induced less generalization enhanced their distinctiveness and became dominant in the mixture. Our study thus uncovers features that determine odourant dominance within olfactory mixtures and allows the referring of this phenomenon to differences in neural activity both at the receptor and the central level in the insect nervous system.
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Natsch, Andreas, and Roger Emter. "The specific biochemistry of human axilla odour formation viewed in an evolutionary context." Philosophical Transactions of the Royal Society B: Biological Sciences 375, no. 1800 (April 20, 2020): 20190269. http://dx.doi.org/10.1098/rstb.2019.0269.

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Human body odour is dominated by the scent of specific odourants emanating from specialized glands in the axillary region. These specific odourants are produced by an intricate interplay between biochemical pathways in the host and odour-releasing enzymes present in commensal microorganisms of the axillary microbiome. Key biochemical steps for the release of highly odouriferous carboxylic acids and sulfur compounds have been elucidated over the past 15 years. Based on the profound molecular understanding and specific analytical methods developed, evolutionary questions could be asked for the first time with small population studies: (i) a genetic basis for body odour could be shown with a twin study, (ii) no effect of genes in the human leukocyte antigen complex on the pattern of odourant carboxylic acid was found, and (iii) loss of odour precursor secretion by a mutation in the ABCC11 gene could explain why a large fraction of the population in the Far East lack body odour formation. This review summarizes what is currently known at the molecular level on the biochemistry of the formation of key odourants in the human axilla. At the same time, we present for the first time the crystal structure of the N α -acyl-aminoacylase, a key human odour-releasing enzyme, thus describing at the molecular level how bacteria on the skin surface have adapted their enzyme to the specific substrates secreted by the human host. This article is part of the Theo Murphy meeting issue ‘Olfactory communication in humans’.
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Ömür-Özbek, P., J. C. Little, and A. M. Dietrich. "Ability of humans to smell geosmin, 2-MIB and nonadienal in indoor air when using contaminated drinking water." Water Science and Technology 55, no. 5 (March 1, 2007): 249–56. http://dx.doi.org/10.2166/wst.2007.186.

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The most common compounds responsible for off flavours are geosmin, 2-MIB, and nonadienal which are poorly removed by conventional water treatment operations and hence result in customer complaints. Because these odourants are moderately volatile and have very low odour threshold values, it is necessary to determine their concentrations in air when water is used indoors. If the detectable aqueous concentrations for these odourants are known, the utilities may take action to treat their water at times when the concentration of the raw water exceeds the threshold concentration. To predict the concentration in the shower stall and bathroom air after showering, recently published Henry's law constants for the selected odourants and a model developed to determine the volatilization of the odourous compounds by applying two-resistance theory were used. Then the results were compared with the odour threshold concentration data to determine under which conditions the odourants become detectable. For parameters representing a typical bathroom and shower stall setting, the results showed that the odourants become detectable when the aqueous concentration of geosmin and nonadienal exceed 10 ng/L at 42 °C. As the aqueous concentration increases, geosmin and nonadienal become detectable at lower temperatures, however 2-MIB is only detectable above 20 ng/L and at 42 °C.
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Jones, R. B., and P. Redman. "The presence of a familiar odourant increases social affiliation when pairs of unfamiliar chicks are tested in a novel environment." Proceedings of the British Society of Animal Science 2002 (2002): 216. http://dx.doi.org/10.1017/s1752756200008723.

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Chickens can differentiate between cagemates and strangers and they are often exposed to unfamiliar birds in novel environments under modern farming practice; this can lead to xenophobia, aggression and distress (Rajecki et al., 1976; Jones, 1996). Chickens form olfactory memories and regulate their behaviour in response to naturally occurring and artificial odours (Jones & Roper, 1997). The presence of a familiar odourant (vanillin) increased social dispersal and feeding when familiar pairs of chicks from the same cage were tested in a novel environment (Jones et al., 2001); suggesting that familiar odourants can be reassuring. Here, we asked if the presence of a familiar odour (vanillin) would increase social affiliation when two unfamiliar pairs of chicks were placed in a novel test arena.
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Mercer, E., C. J. Davey, P. Campo, D. Fowler, L. Williams, A. Kolios, A. Parker, et al. "Quantification of liquid phase faecal odourants to evaluate membrane technology for wastewater reuse from decentralised sanitation facilities." Environmental Science: Water Research & Technology 5, no. 1 (2019): 161–71. http://dx.doi.org/10.1039/c8ew00693h.

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Krång, Anna-Sara, Markus Knaden, Kathrin Steck, and Bill S. Hansson. "Transition from sea to land: olfactory function and constraints in the terrestrial hermit crab Coenobita clypeatus." Proceedings of the Royal Society B: Biological Sciences 279, no. 1742 (June 6, 2012): 3510–19. http://dx.doi.org/10.1098/rspb.2012.0596.

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The ability to identify chemical cues in the environment is essential to most animals. Apart from marine larval stages, anomuran land hermit crabs ( Coenobita ) have evolved different degrees of terrestriality, and thus represent an excellent opportunity to investigate adaptations of the olfactory system needed for a successful transition from aquatic to terrestrial life. Although superb processing capacities of the central olfactory system have been indicated in Coenobita and their olfactory system evidently is functional on land, virtually nothing was known about what type of odourants are detected. Here, we used electroantennogram (EAG) recordings in Coenobita clypeatus and established the olfactory response spectrum. Interestingly, different chemical groups elicited EAG responses of opposite polarity, which also appeared for Coenobita compressus and the closely related marine hermit crab Pagurus bernhardus. Furthermore, in a two-choice bioassay with C. clypeatus, we found that water vapour was critical for natural and synthetic odourants to induce attraction or repulsion. Strikingly, also the physiological response was found much greater at higher humidity in C. clypeatus , whereas no such effect appeared in the terrestrial vinegar fly Drosophila melanogaster . In conclusion, our results reveal that the Coenobita olfactory system is restricted to a limited number of water-soluble odourants, and that high humidity is most critical for its function.
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Farkaš, P., J. Sádecká, M. Kováč, B. Siegmund, E. Leitner, and W. Pfannhauser. "Key odourants of pressure-cooked hen meat." Food Chemistry 60, no. 4 (December 1997): 617–21. http://dx.doi.org/10.1016/s0308-8146(97)00042-3.

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Daly, Kevin C., Sathees Chandra, Michelle L. Durtschi, and Brian H. Smith. "The generalization of an olfactory-based conditioned response reveals unique but overlapping odour representations in the moth Manduca sexta." Journal of Experimental Biology 204, no. 17 (September 1, 2001): 3085–95. http://dx.doi.org/10.1242/jeb.204.17.3085.

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SUMMARY Most highly derived olfactory systems, such as the insect antennal lobe, discriminate among a wide array of monomolecular odourants and blends of odourants. Given the relatively limited number of neurons used to code these odours, this ability implies that neural representations for odours overlap in a cross-fiber coding scheme. Here we use the generalization of a conditioned feeding response in the sphinx moth, Manduca sexta, to quantify three geometry-based dimensions of odour space in which monomolecular odours may be assessed. In a series of experiments we show that generalization of a conditioned response from one monomolecular odour to another is a function of differences in length and shape of the carbon chain as well as the functional group on the molecule. When moths were conditioned to 2-hexanone or 1-decanol and tested with a number of alcohols and ketones, we found that the generalization of the conditioned response decreased as a function of the chain length and functional group. In contrast, when conditioned to 1-hexanol, moths failed to distinguish alcohols from ketones of the same chain length. In all of these cases, chain length did not interact with functional group, thus indicating the independence of these dimensions. Differential conditioning of alcohols and of alcohols and ketones revealed interaction of excitatory and inhibitory generalization gradients within an odour ‘dimension’. When odourants were sufficiently distinct, the peak of the generalization gradient was shifted away from the conditioning odour and in an opposite direction from the unreinforced odour. Altogether, these data substantiate the claim that these molecular characteristics are relevant coding dimensions in the moth olfactory system. These data are consistent with a cross-fiber coding scheme in which odours are coded by spatio–temporally overlapping sets of neurons, both in the periphery and in the antennal lobes.
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Parker, W. J., and G. H. Wu. "Modifying ADM1 to include formation and emission of odourants." Water Science and Technology 54, no. 4 (August 1, 2006): 111–17. http://dx.doi.org/10.2166/wst.2006.532.

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A mathematical model that is based upon the ADM1 structure has been developed to describe the formation and emission of odourous compounds in anaerobic sludge digestion. Special emphasis is given to the general mechanisms for the formation of common odorous sulfur compounds that are found in anaerobic digesters: methyl mercaptan, dimethyl sulfide and hydrogen sulfide, as well as volatile fatty acids and ammonia. The model includes multiple-reaction stoichiometry, microbial growth kinetics and conventional material balances for an ideally mixed reactor. Simulations that were performed with the model revealed that changes in common operational parameters such as temperature, HRT and sludge metal content can dramatically impact upon the gas phase concentrations of odourants. Additional research is required to reduce uncertainty in the model formulation.
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Czesnik, Dirk, Wolfgang Rössler, Friedrich Kirchner, Arne Gennerich, and Detlev Schild. "Neuronal representation of odourants in the olfactory bulb ofXenopus laevistadpoles." European Journal of Neuroscience 17, no. 1 (January 2003): 113–18. http://dx.doi.org/10.1046/j.1460-9568.2003.02448.x.

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Dissertations / Theses on the topic "Odourants"

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Peres, Maria de Fátima Pratas. "Influence of enzymes and technology on the composition of Cobrançosa and Galega vulgar virgin olive oils." Doctoral thesis, ISA-UL, 2015. http://hdl.handle.net/10400.5/12050.

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Gluyas, Josef Bheinn George [Verfasser], and Reinhold [Akademischer Betreuer] Tacke. "Synthesis of Silicon-Based Drugs and Odourants / Josef Bheinn George Gluyas. Betreuer: Reinhold Tacke." Würzburg : Universitätsbibliothek der Universität Würzburg, 2012. http://d-nb.info/1025223837/34.

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Drevermann, Britta, and britta79@gmail com. "Marine Fragrance Chemistry: Synthesis, Olfactory Characterisation and Structure-Odour-Relationships of Benzodioxepinone Analogues." RMIT University. Applied Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080805.102446.

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Calone 1951® (7-methyl-2H-1,5-benzodioxepin-3(4H)-one) is renowned in the fragrance industry for its distinct marine odour and offers an interesting molecular framework for structure-odour-relationship (SOR) research. Limited olfactory reports on 7-membered benzodioxepine analogues with modification influenced by functionality, polarity, and ring size, prompted us to construct a range of aromatic and C-3 substituted structures for olfactory evaluation. Incorporation of a diverse range of functionality contributes valuable information on the molecular aspects that determine the archetypal marine character of Calone 1951®. Here we present the preparation of Calone 1951® analogues including spectroscopic and olfactory details to contribute to the sparse marine fragrance arena. In these studies pertaining to the odour properties of benzodioxepinone systems, we considered the modification of substitution and functionality on the aromatic ring in the context of qua litative olfactory analysis. Application of the patented Williamson and Dieckmann reaction pathways resulted in construction of the benzodioxepinone molecule. Preparation of aryl-substituted benzodioxepinones required introduction of an alternate broadly applicable synthetic pathway due to the diverse nature of the introduced substituents. Limitations of the patented approach led to incorporation of a simple but novel methodology applied to the same range of substituted catechol reagents for synthesis of the benzodioxepinone skeleton and an overview of comparable yields. Single-step mechanisms were also successfully applied to contribute to the repertoire of benzodioxepin(on)e structures prepared for olfactory analysis. Semi-empirical models of the synthesised data set were generated and evaluated in light of previous research undertaken by Archer and Claret and related to the olfactory characteristics of each compound. Evaluation of the models with corresponding olfactory information revealed that functionality and ring size contribute significantly to the conformation adopted by the benzodioxepinone species and therefore the olfactory character of the molecule. It is evident from our observations that aromatic ring substitution and functional alteration of the cyclic ketone modifies the perceived odour of Calone 1951®. Structural modification overall led to a decrease in odour potency. The presence of the aromatic methyl substituent in Calone 1951® reinforces, but is not critical for, the marine tonality. Modification of the ketone of Calone 1951® led to significant deviation in character from the prototypical marine odour.
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Sjöström, Desirée. "Behavioural responses in mice exposed to predator odour components." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-108103.

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It is essential for prey species to be able to detect predators to avoid them. The sense of smell is used by a number of prey species for this purpose. The aim of the present study was to assess if one of the odourants that make up a predator odour is sufficient to induce a behavioural response in mice (Mus musculus). Two predator odourants were used, 2,2-dimethylthietane and methyl-2-phenylethyl sulfide, which are both found in the secretions of natural predators of mice. An odourant found in fruits, n-pentyl acetate, was also used. All three odourants were presented at a concentration that was a factor of 100 above the olfactory detection threshold of mice. Ten adult predator-naïve CD-1 mice were individually put in a two-compartment chamber one of which contained an odourant while the other contained a near-odourless solvent (diethyl phthalate). The results indicated that methyl-2-phenylethyl sulfide was actively avoided by the mice. Towards 2,2-dimethylthietane and n-pentyl acetate, in contrast, the mice behaved indifferent. Further, the results suggest a significant correlation between the number of switches between the two compartments of the test chamber and the test sessions when the animals were presented with n-pentyl acetate, but not when they were presented with the predator odourants. The results support the notion of an innate fear response towards the predator odourant methyl-2-phenylethyl sulfide in mice, but further studies with more animals and different concentrations of the odourants are necessary.
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Ropkins, K. "Flavour generation in wheatflakes." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310834.

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Ödmar, Emma. "Analysis of odourant compounds in wine : - With headspace solid-phase microextraction and gas chromatography- mass spectrometry." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-69081.

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Wine is a drink that can enhance the flavour experience of food, which is why it is important that the wine’s sensory profile is explained correctly to the consumers. In this study, headspace solid-phase microextraction gas chromatography mass spectrometry was used to characterise odourant compounds in wine to find chemical markers to explain wine sensory profiles instead of sensory analysis. The study included 16 different wines, red, white, orange and sparkling, where the nine most abundant peaks in each wine sample were evaluated. Homologue patterns based on areas were used to compare profiles between different wines. When studying homologue patterns for each wine and comparing within wine groups, differences and similarities can be seen. All wine samples contained isoamyl alcohol and the majority of them also contained ethyl decanoate, octanoic acid and decanoic acid. Six out of eight red wines contained ethyl succinate and five of them also contained ethyl hexanoate. All white wine samples showed presence of ethyl octanoate and ethyl hexanoate. The orange wines also contained ethyl octanoate and ethyl hexanoate, along with pentanoic acid. Both sparkling wines contained ethyl octanoate and ethyl hexanoate in addition with phenylethyl alcohol. However, a more thorough study covering more compounds to identify the less obvious differences of wine would have to be performed for a more precise explanation of the wine’s characterisation and sensory profile. It should be noted that the method of this study does leave room for improvements to improve the quality of the results. For example, since the most abundant compounds are not necessarily the ones with the most powerful odours, quantification based on response of an internal standard would strengthen the study. Additional compounds in the samples could also be further investigated. Statistically the method would also need improvement for satisfactory results regarding reproducibility of the samples.
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Gluyas, Josef Bheinn George. "Synthesis of Silicon-Based Drugs and Odourants." Doctoral thesis, 2012. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-72182.

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This thesis concerns (i) the synthesis and olfactory characterisation of silicon-containing analogues of the musk odourant phantolide, (ii) the synthesis and pharmacological investigation of silicon-containing analogues of retinoids of the EC23 and TTNN type and (iii) the attempted syntheses of silicon-containing analogues of the antipsychotic penfluridol and the antidiarrhoeal agent loperamide. All target compounds and intermediates were characterised by multinuclear NMR studies (1H, 13C, 15N, 19F, 29Si) and elemental analyses or high-resolution mass spectrometry. Additionally, some of these compounds were characterized by single crystal X-ray diffraction studies
Die vorliegende Arbeit beschreibt (i) die Synthese und olfaktorische Charakterisierung von siliciumhaltigen Derivaten des Moschus-Riechstoffes Phantolid, (ii) die Synthese und pharmakologische Charakterisierung siliciumhaltiger Derivate von Retinoiden des EC23- und TTNN-Typs, und (iii) die Versuche zur Darstellung siliciumhaltiger Analoga der Wirkstoffe Penfluridol und Loperamid. Die Charakterisierung der Zielverbindungen sowie aller auftretenden Zwischenstufen erfolgte durch NMR-Spektroskopie (1H, 13C, 15N, 19F, 29Si) und Elementaranalyse bzw. hochaufgelöste Massenspektrometrie. Außerdem wurden einige der Verbindungen durch Kristallstrukturanalyse charakterisiert
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Botelho, Goreti Maria dos Anjos. "Characterisation of the aroma components of clonal grapes and wines from Aragonez and Trincadeira Vitis vinifera L. cultivars." Doctoral thesis, 2008. http://hdl.handle.net/10348/128.

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Tese de Doutoramento em Ciências Alimentar
A grande variabilidade e diversidade dos vinhos tintos produzidos em Portugal provenientes de castas nacionais Vitis vinifera L. justificam a sua caracterização aromática e físico-química. Essa caracterização, tem por objectivos, preservar a qualidade e a tipicidade dos vinhos de diferentes regiões, bem como, contribuir para aprofundar o conhecimento de castas que proliferam no mundo vitivinícola. Além disso, a caracterização do aroma de vinhos clonais apresenta um interesse inegável para a indústria vitivinícola, devido à importância que assume nos diversos aspectos qualitativo, produtivo e financeiro. De entre algumas centenas de compostos voláteis pertencentes a diversas famílias químicas e existentes em diferentes gamas de concentração, apenas uma parte contribui efectivamente para o aroma, aumentando a sua intensidade e complexidade no vinho. O conhecimento sobre a identidade e a concentração de tais compostos é fundamental para uma melhor compreensão do seu papel no aroma do vinho. Esta abordagem deverá ser complementada com a análise sensorial descritiva, para que se possa obter uma visão mais abrangente do aroma dos vinhos e da apreciação da sua qualidade. O programa Português de Selecção Clonal, criado em 1978, cujos objectivos são os de conhecer e seleccionar as melhores castas, visando aumentar a qualidade dos vinhos produzidos em Portugal, possui actualmente diversos clones certificados que são cultivados por viticultores. As castas Aragonez e Trincadeira estão entre as oito variedades tintas mais plantadas em Portugal, encontrando-se já certificados 7 e 6 clones, respectivamente. O conhecimento sobre as relações entre o papel individual de cada composto odorante e o papel global dos compostos responsáveis pelo aroma, são metas específicas a alcançar, de modo a ser possível realizar a escolha dos melhores clones para produzir vinhos de elevada qualidade. Este estudo teve como objectivo, contribuir para a caracterização dos componentes do aroma de vinhos tintos clonais e dos respectivos mostos e uvas, das castas Aragonez e Trincadeira Vitis vinifera L O desenvolvimento e a aplicação de um método de cromatografia em fase gasosa – olfactometria (GC-O), designado método de intensidade posterior, permitiu, pela primeira vez, estabelecer os perfis odorantes de cada casta e, simultaneamente, diferenciar os vinhos clonais de ambas as castas e os mostos dos clones de Aragonez. Assim, em todos os vinhos clonais foram detectados diversos compostos odorantes, tendo apresentado intensidades médias mais elevadas: o ácido 3-metilbutanóico, o 2-feniletanol, o Furaneol™ e o 4-vinilguaiacol. A quantificação de alguns compostos odorantes utilizando a cromatografia em fase gasosa acoplada ao detector de ionização de chama (GC-FID) encontrados nos vinhos clonais e respectivos mostos e uvas, demonstrou a existência de diversas diferenças estatísticas entre os clones. Os compostos Furaneol™ e homofuraneol, caracterizados com os descritores de odor a açúcar queimado (tipo caramelo) e algodão doce, foram identificados nos vinhos clonais de Aragonez e Trincadeira bem como nas fracções livres e ligadas dos mostos de Aragonez, indicando a sua origem varietal. Demonstrou-se por GC-O, GC-FID e análise sensorial descritiva que o ano de vindima apresentou uma influência relevante nos vinhos clonais da casta Trincadeira. A análise discriminante linear aplicada aos dados obtidos, revelou a existência de algumas variáveis discriminantes que poderão ser utilizadas para se obter uma correcta classificação dos vinhos clonais provenientes das duas vindimas em estudo. Os atributos de aroma, adocicado, herbáceo, animal, frutos secos, frutos vermelhos, especiarias e madeira, utilizados pelo painel sensorial, foram úteis para a obtenção do perfil de aroma dos vinhos clonais de Aragonez e de Trincadeira. A não quantificação de compostos monoterpénicos e a escassez de norisoprenóides em C13 nas uvas e nos mostos são indicadores de que as castas Aragonez e Trincadeira podem ser classificadas como castas neutras. A informação obtida por GC-O e pela análise sensorial descritiva sugere uma elevada utilidade destas “ferramentas sensoriais” para o controlo da qualidade dos vinhos.
The large variability and diversity of red wines produced in Portugal with Portuguese Vitis vinifera L. cultivars fully justify their chemical and aroma characterisation. The objectives of this characterisation are to preserve the quality and tipicity of the wines from different regions and to contribute to the deeper knowledge of grape varieties in the world. Furthermore, the characterisation of the aroma of clonal wines is of undeniable interest to the winemaking industry, due to its productive, financial and qualitative aspects. Among hundreds of volatile compounds of distinct classes and a wide range of concentrations present in red wines, only a part contribute effectively to the aroma, enhancing the intensity and complexity of the wine flavour. Knowing the identity and the concentration of such compounds in wines is crucial for a better understanding of their role in defining wine aroma. This approach should be complemented with descriptive sensory analysis in order to give an overview of the aroma of wines and appreciation of the general quality of wines. The Portuguese Clonal Selection Program was created in 1978 with the objectives of getting to know and select our best varieties of grapes and to increase the quality of wines produced in Portugal. Nowadays it has several certified clones commonly used by grape-growers. Aragonez and Trincadeira are among the eight more planted red grape varieties in Portugal and respectively seven and six clones of both cultivars have already been certified. The knowledge of the relationships between the individual role of each odourant compound and the global role of the overall aroma compounds are specific targets that we need to know in order to be able to choose the best clones to produce the best wines. The aim of this study was to contribute for the characterisation of the aroma of distinct clonal red wines, musts and grapes, from Vitis vinifera L. cultivars Aragonez and Trincadeira. The development and application of a gas chromatography-olfactometry (GC-O) posterior intensity method allowed, for the first time, the establishment of the odourant profiles of each cultivar and, simultaneously, the differentiation of the clonal wines among Aragonez and Trincadeira varieties and clonal musts from Aragonez. Several odourant compounds were detected, having the highest average intensities in all clonal wines: 3-methylbutanoic acid, 2-phenylethanol, Furaneol™, and 4-vinylguaiacol. The quantification by gas chromatography-flame ionization detector (GC-FID) of some of the odourant compounds found in the clonal wines as well as those found in musts and grapes showed several statistical differences among clones Furaneol™ and homofuraneol, described with a burnt sugar (caramel-like) and candy-cotton odour descriptors, were identified in Aragonez and Trincadeira clonal wines as well as in both free and bound fractions of Aragonez musts, indicating their grape-derived origin. Vintage had a significant influence on Trincadeira clonal wines, as was demonstrated by GC-O, GC-FID and by descriptive sensory analysis. Stepwise linear discriminant analysis applied to data obtained from the previous analyses revealed some discriminating variables that can be used to obtain a correct classification of the clonal wines from the two distinct vintages. The aroma attributes sweet, herbaceous, animal, dried fruits, red fruits, spicy and woody, used by the sensory panel, were useful in obtaining the aroma profile of the Aragonez and Trincadeira clonal wines. The inexistence of quantified monoterpenic compounds and the poorness in C13-norisoprenoids found in musts and grapes indicated that Aragonez and Trincadeira can be classified as neutral cultivars. The information obtained by GC-O and descriptive sensory analysis suggested the usefulness of these “sensory tools” for controlling wine quality.
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Book chapters on the topic "Odourants"

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Chen, Chao, Arash Zamyadi, Tsair-Fuh Lin, and Daniel Gallagher. "Removal of odourants from drinking water." In Taste and Odour in Source and Drinking Water: Causes, Controls, and Consequences. IWA Publishing, 2019. http://dx.doi.org/10.2166/9781780406664_0167.

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Van Langenhove, H., B. Bendinger, R. Oberthür, and N. Schamp. "Organic sulfur compounds: persistent odourants in the biological treatment of complex waste gases." In Studies in Environmental Science, 177–82. Elsevier, 1992. http://dx.doi.org/10.1016/s0166-1116(08)70693-9.

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Delahunty, C. M., F. Crowe, and P. A. Morrissey. "THE INFLUENCE OF ODOURANT BALANCE ON THE PERCEPTION OF CHEDDAR CHEESE FLAVOUR." In Flavour Science, 339–43. Elsevier, 1996. http://dx.doi.org/10.1533/9781845698232.6.339.

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"emission of dust-borne odourants like volatile fatty acids (VFA) and simple phenols and indoles from piggeries, the impor­ tance of particle-borne odours, and the possibilities of con­ trolling dust-borne odours. 2. ORIGIN, NATURE AND RELEASE OF THE DUST It is estimated that the dust in animal houses originates mainly from the feed (15 ), (16 ), (17 ), the bedding material (18), (19), the manure (20) and the animals themselves (21),(22). Relevant values are rare. Table I shows that feed and bedding, when used, are the predominant sources of dust in pig and hen houses. Dust from animal houses consists mainly of organic matter (23). The preferred technique for investigating both the mate­ rial composition of the dust and feed stuff is the WEENDER An­ alysis Technique (24). Table II shows the composition of dust from pig and hen houses compared to the feed fed. The differ­ ences in the protein content between dust and feed support the opinion that an important part of the dust originates from feathers, hairs, and skin cells of the animals. The release of the dust is caused by the activity of ani­ mals or man or the function of technical equipments in the an­ imal house. Feeding, particularly dry feeding (25), as well as bedding and cleaning activities, the use of different systems of feed distribution, manure removal and ventilation (26) can increase the dust level in the air of animal houses consider­ ably (27). Figure 1 gives an example of the relation between the amount of dust in the air and different activities based on values as reported by CERMAK and ROSS (27) for poultry houses. In the course of a day the dust level in animal houses varies considerably. Mostly feeding increases the dust concen­ tration in the air as demonstrated in Figure 2 (22). However, within 30 to 120 min the "normal" background level is reached again (16),(22). The figure shows that even before the feed is distributed, the activity of the animals increases the dust concentration in the air considerably. Table III shows the influence of rel . humidity, pen vol­ ume, feeding system and air flow on the number of dust parti­ cles and weight of settled dust in an experimental piggery.The essential influence of animal activity on the formation of dust is shown by the fact that self-feeding results in significant­ ly greater atmospheric dust concentration (particles/volume of air) than does floor-feeding. However, a significantly greater amount of settled dust is associated with floor feeding. Prob­ ably, the self-fed pigs spend much more time eating than the floor-fed pigs. The intense activity of the pigs during floor feeding results in a great deal of visible dust for only a pe­ riod of time, while the self-fed pigs may play with the excess feed (28),(17). These studies indicate that the factors deter­ mining the amount of dust in confinements include animal ac­ tivity, temperature, relative humidity, ventilation rate,stock­ ing density and volumetric air-space per animal, feeding method, and nature of feed. This dust originating from various sources can carry gases, vapours and odours (7)." In Odour Prevention and Control of Organic Sludge and Livestock Farming, 336. CRC Press, 1986. http://dx.doi.org/10.1201/9781482286311-130.

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