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gamma-Lactones in wine: Synthesis, quantification and sensory studiesBrown, Rachel Christine, rcbrown@adam.com.au January 2007 (has links)
gamma-Lactones are found in a wide variety of food and beverage products, in particular grapes and wine. This thesis details the work completed on some gamma-lactones in wine: their synthetic preparation, development of quantification methodologies and sensory studies.
Chapter 1 outlines the history of the Australian wine industry from the arrival of the first vines on the First Fleet in 1788 with Captain Arthur Philip. This chapter provides: an overview of Australias position in the world of grape and wine production; an analysis of the export arm of the industry; and a look at the different wine producing regions around the country. The latter part of the chapter focuses on the different volatile compounds found in wine.
Part A:
Chapter 2 provides an overview on the history of barrel manufacture and the use of oak wood in cooperage, with an emphasis on oaks well known ability to impart desirable characteristics to wine through the extraction of volatile aroma compounds. This chapter provides a summary of these odorants with a particular emphasis on the oak lactones. Previous sensory studies and synthetic work are discussed. Of great importance to this work are the recent advancements in 1,2-dioxine chemistry, highlighted in this chapter.
Chapter 3 details the synthetic work completed for the preparation of all four possible oak lactone stereoisomers. A suitably substituted racemic 1,2-dioxine featured as the common intermediate and enabled preparation of the gamma-lactone moiety upon reaction with a chiral malonate diester and separation of the diastereomers by column chromatography. A key step involved the decarboxylation of the ester cleaved gamma-lactone diastereomers, which could be directed to give either the cis- or trans-products. Standard chemical transformations were then utilised to produce the desired stereoisomers of oak lactone.
Chapter 4 describes the results from the sensory studies that were completed on the synthetic oak lactone samples. Odour detection thresholds were measured in both a white and a red wine. The thresholds in the former medium were calculated to be 24 ug/L, 172 ug/L, 132 ug/L and 305 ug/L, while in the latter medium the thresholds were calculated to be 57 ug/L, 380 ug/L, 175 ug/L and 285 ug/L, for (4S,5S)-cis-, (4S,5R)-trans-, (4R,5R)-cis- and (4R,5S)-trans-oak lactone, respectively. Difference testings were completed on the pairs of enantiomers and also on mixtures of the nature-identical isomers: between the cis-enantiomers a significant difference was found at the 99% confidence level, while between the trans-enantiomers and also the mixtures of cis- and trans-isomers little difference was observed.
Chapter 5 contains the experimental procedures for Part A.
Part B:
Chapter 6 discusses the sensory properties of some gamma- and delta-lactones, with the focus on a series of five-alkyl substituted gamma-lactones: gamma-octalactone, gamma-nonalactone, gamma-decalactone and gamma-dodecalactone. Topics covered in this chapter include chirality, biosynthetic pathways and quantification results in wine from previous studies for these gamma-lactones.
Chapter 7 concerns the method development for the quantification of gamma-lactones in wine using a stable isotope dilution assay (SIDA). Deuterated analogues were prepared from commercially available racemic gamma-lactones for use as internal standards. Initially a head space solid-phase microextraction (HS SPME) method was developed using d5-standards; however, analysis of bottled wine samples revealed the presence of co-eluting compounds that contained several of the selected ions. Thus an alternative method was developed using d7-standards, with a specific focus on sample clean-up, via solid-phase extraction (SPE). Using this procedure, 44 white and 120 red wines were analysed for their gamma-lactone content. The lactones were found to be significantly more common in the red wines, with gamma-nonalactone the most abundant lactone in this series.
Chapter 8 deals with the extension of the SIDA method, as developed in Chapter 7, for use with a chiral gas chromatography column. Optically pure standards were prepared, from either L- or D-glutamic acid, and used to determine the order of elution of the enantiomers. A method was developed for the quantification of the individual enantiomers of gamma-octalactone, gamma-nonalactone, gamma-decalactone and gamma-dodecalactone. The enantiomeric distribution of gamma-nonalactone was investigated in 34 red wines; the (R)-stereoisomer was found to be dominant with an average of 59%, although there were wines analysed that did contain the (S)-stereoisomer in greater amounts.
Chapter 9 describes the results from the sensory studies that were completed on the individual enantiomers of the gamma-lactones. Odour detection thresholds were measured in a red wine. The thresholds were calculated to be 238 ug/L, 285 ug/L, 34 ug/L and 8 ug/L for the (R)-enantiomers, while the thresholds were calculated to be 135 ug/L, 91 ug/L, 47 ug/L and 39 ug/L for the (S)-enantiomers, of gamma-octalactone, gamma-nonalactone, gamma-decalactone and gamma-dodecalactone, respectively.
Chapter 10 contains the experimental procedures for Part B.
Chapter 11 contains the appendices, followed by the references in Chapter 12.
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Pour une "dé-scription" des sens :L'oeuvre de Jean-Marie Gustave Le Clézio / For a "De-scription" of the Senses: Jean-Marie Gustave Le Clézio's WorkFeyereisen, Justine 11 September 2015 (has links)
J.M.G. Le Clézio a été plébiscité par le jury du Nobel en sa qualité d’écrivain de « l’extase sensuelle ». Les sens seraient-ils le filtre sémantique de « cet explorateur d’une humanité au-delà et en-dessous de la civilisation régnante » ?D’un point de vue diégétique, sémiotique et stylistique, la prose leclézienne illustre de diverses manières (entre mots, typographie, photographies ou techniques cinématographiques) un univers physique, où les perceptions sensorielles forment un prisme de significations sur l’époque contemporaine. Comme un sismographe à l’affût des pulsations du monde, l’écrivain enregistre, tous sens ouverts, les mouvements, les formes, et les idées des XXe et XXIe siècles. Telle est l’hypothèse centrale de cette étude. Le concept polysémique de « sens » est ainsi appréhendé depuis le monde perceptuel de l’auteur jusqu’aux strates les plus profondes du texte. La démarche repose sur l’étude de la description, en tant que clé de déchiffrement – ou de « dé-scription » selon le concept foucaldien –, à partir d’une analyse linguistico-textuelle puisant dans le champ élargi des sensory studies (phénoménologie de la sensation, philosophie du corps, sociologie de la perception, etc.). La finalité ultime est d’éclairer sous un nouvel angle la quête ontologique d’un homme de lettres pour lequel la littérature ne peut plus feindre d’être détachée du corps des hommes. J.M.G. Le Clézio was hailed by the Nobel jury as the author of “sensual ecstasy.” Would the senses be the semantic filter of this “explorer of a humanity beyond and below the reigning civilization?” From a diegetic, semiotic and stylistic viewpoint, the Leclezian prose depicts in many ways (through words, typography, photos or cinematic techniques) a physical universe, where sensory perceptions form a prism of meanings of the contemporary era. As a seismograph records the world’s pulse, the writer registers, with his senses fully attuned, the movements, shapes and ideas of the twentieth and twenty-first centuries. This is the central hypothesis of the research. The polysemous concept of “senses” is thus apprehended from the writer’s world beneath to the deepest strata of his texts. The approach relies on the study of description, as the key to deciphering – or to “de-scribing” according to Foucault’s concept –, from a linguistic-textual analysis drawing on the broader field of sensory studies (phenomenology of sensation, philosophy of the body, sociology of perception, etc.). The ultimate purpose is to enlighten from a new angle the ontological quest of a man of letters, according whom literature can no longer pretend to be detached from the body of human beings. / Doctorat en Langues et lettres / info:eu-repo/semantics/nonPublished
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Senses In Synthesis: Imaginative Sensing In The 19th CenturyHernandez, Jesse 21 April 2014 (has links)
During the late 19th century, arts and literature had a surge of sensory awareness, made manifest through sensory analogy, intersensory metaphor, and synaesthesia. This dissertation explores this phenomenon through a study of five poets and artists: Charles Baudelaire, Arthur Rimbaud, Dante Gabriel Rossetti, John Barlas, and Julia Margaret Cameron. Using imaginative sensing, these artists transformed the relationship between artist and observer, assigning greater responsibility to their audience while simultaneously asserting artistic control of their work. Their fascination with sensory mixing and multisensory awareness demonstrates unique ideas about perception and embodiment, ideas that have sparked both controversy and imitation. I begin with a brief history of the condition known as synaesthesia, considering its position as an “abnormal” clinical condition, a desired artistic state of transcendence, and a simple transfer of metaphor. Chapter 1 describes how two French poems brought synaesthesia to public consciousness and prompted a literary movement. In Chapter 2, I explore how poet-painter Dante Rossetti used “acts of attention” and unheard music to demand viewers’ embodied participation. Chapter 3 introduces John Barlas, a relatively obscure British poet who crafted exotic, sensory-laden environments that hovered between the actual and imagined, insisting that the reader use his sensory imagination to participate. Moving to the realm of photography in Chapter 4, I consider Julia Margaret Cameron, whose “out-of-focus” pictures changed photography from a mechanistic technology to high art by incorporating the sense of touch. Historically, the senses have been ranked and separated, with priority given to vision, the sense most associated with reason. I argue that considering the senses as bundles of interconnected experiences and through imagination rather than as isolated methods of physical perception can show how the senses function culturally and give us a much greater understanding of how we process the world. While no time period has regarded the senses with the intensity of the late 19th century, the embodied approach of the era can be applied to our current “sensory revolution” and can impact how we regard technology, cultural studies, and interdisciplinarity. Evaluating how 19th century artists blended the senses through imaginative constructs gives a more thorough explanation of the characteristic sensuality of the period and provides a model for how sensing can function more fully in current endeavors.
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Pour une "dé-scription" des sens : l’œuvre de Jean-Marie Gustave Le Clézio / For a "De-scription" of the senses : Jean-Marie Gustave Le Clézio's workFeyereisen, Justine 11 September 2015 (has links)
J.M.G. Le Clézio a été plébiscité par le jury du Nobel en sa qualité d'écrivain de « l'extase sensuelle ». Les sens seraient-ils le filtre sémantique de « cet explorateur d'une humanité au-delà et en-dessous de la civilisation régnante » ? D'un point de vue diégétique, sémiotique et stylistique, la prose leclézienne illustre de diverses manières (entre mots, typographie, photographies ou techniques cinématographiques) un univers physique, où les perceptions sensorielles forment un prisme de significations sur l'époque contemporaine. Comme un sismographe à l'affût des pulsations du monde, l'écrivain enregistre, tous sens ouverts, les mouvements, les formes, et les idées des XXe et XXIe siècles. Telle est l'hypothèse centrale de cette étude. Le concept polysémique de « sens » est ainsi appréhendé depuis le monde perceptuel de l'auteur jusqu'aux strates les plus profondes du texte. La démarche repose sur l'étude de la description, en tant que clé de déchiffrement – ou de « dé-scription » selon le concept foucaldien –, à partir d'une analyse linguistico-textuelle puisant dans le champ élargi des sensory studies (phénoménologie de la sensation, philosophie du corps, sociologie de la perception, etc.). La finalité ultime est d'éclairer sous un nouvel angle la quête ontologique d'un homme de lettres pour lequel la littérature ne peut plus feindre d'être détachée du corps des hommes. / J.M.G. Le Clézio was hailed by the Nobel jury as the author of “sensual ecstasy.” Would the senses be the semantic filter of this “explorer of a humanity beyond and below the reigning civilization?” From a diegetic, semiotic and stylistic viewpoint, the Leclezian prose depicts in many ways (through words, typography, photos or cinematic techniques) a physical universe, where sensory perceptions form a prism of meanings of the contemporary era. As a seismograph records the world's pulse, the writer registers, with his senses fully attuned, the movements, shapes and ideas of the twentieth and twenty-first centuries. This is the central hypothesis of the research. The polysemous concept of “senses” is thus apprehended from the writer's world beneath to the deepest strata of his texts. The approach relies on the study of description, as the key to deciphering – or to “de-scribing” according to Foucault's concept –, from a linguistic-textual analysis drawing on the broader field of sensory studies (phenomenology of sensation, philosophy of the body, sociology of perception, etc.). The ultimate purpose is to enlighten from a new angle the ontological quest of a man of letters, according whom literature can no longer pretend to be detached from the body of human beings.
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