Дисертації з теми "Natural flavours"
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Santos, Luísa Ferreira dos. "Metabolic engineering of actinobacteria for the production of flavours." Thesis, université Paris-Saclay, 2022. http://www.theses.fr/2022UPASL034.
Повний текст джерелаThis thesis was carried out in collaboration with ENNOLYS, a French biotechnology company specialised in the production of biomass, enzymes, and natural aromatic molecules. In this context, the main objective of this thesis project is the metabolic engineering of actinobacteria, including those of the genus Amycolatopsis, for the development and improvement of bioproduction processes for natural aromatic molecules, including vanillin, the most used flavouring agent in the world. To this end, we sequenced the genome of the industrial strain Amycolatopsis ZYL926 in order to better understand the potential of this bacterium in the production of specialised metabolites and in the biosynthesis of vanillin. Furthermore, we were able to identify genes involved in the degradation of vanillin (or of its biosynthetic intermediates) by sequence comparison analysis. Secondly, we have identified genetic tools (including vectors and promotors) for the stable insertion and efficient expression of heterologous genes in Amycolatopsis. In addition, we have developed tools for marker-free deletion of genes or large genomic regions in these bacteria. These genetic tools are versatile and could be used in many species of the genus Amycolatopsis. Finally, in order to implement a vanillin biosynthetic pathway from a low-cost substrate, we selected and studied a few candidate enzymes for each new biosynthetic step. These studies enabled us to identify among the candidate enzymes those which are active in Amycolatopsis under the bioconversion conditions used industrially. In addition, we were able to study a limiting step and suggest ways to improve the efficiency of the studied biosynthetic pathway
Sluss, Randi Jasmine. "Comparison of Artificial Flavors in Commercial Products and Actual Natural Flavor via Gas Chromatography Mass Spectroscopy Data." Digital Commons @ East Tennessee State University, 2009. https://dc.etsu.edu/etd/1804.
Повний текст джерелаWest, Rebecca. "Natural Flavors: Rhetorical Stories of Food Labels." Diss., North Dakota State University, 2017. https://hdl.handle.net/10365/28363.
Повний текст джерелаBouges, Hélène. "Modifications enzymatiques de la composition de mélanges naturels complexes utilisés en parfumerie." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4024.
Повний текст джерелаIn the field of flavor and fragrance industry, the optimization of natural flavoring essential oils and extracts’ properties by biocatalysis is really interesting. In a context of sustainable chemistry, this research project is dedicated to the development of pure compounds, extracts and essential oils by enzymatic modifications. In this way, a bibliographic study has been carried out on the composition of the natural raw materials, their properties and the main biosynthetic pathways of the compounds present in the natural complex substances and some regulation elements. In the first place, according to a process of sustainable chemistry, the goal is to make healthier natural products while keeping their properties and their "naturalness". The detoxification in atranol and chloroatranol of the oak moss extract was carried out with the oak moss absolute by biocatalysis preserving their olfactory quality. Through an academic /industrial collaboration, protocols for monitoring biocatalytic transformations were established and implemented. In a third part, sustainable chemistry methodologies were used to propose new ingredients through the use of biotechnological processes based on the circular economy principle. The natural character has been preserved and the method allowed targeted transformations to develop interesting olfactory facets
Oliveira, Fernanda de Carvalho. "Produção de lipase por Penicillium roqueforti e sua aplicação na obtenção de aroma de queijo." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-27092012-110159/.
Повний текст джерелаNot avaliable.
Valverde, Pellicer Laura. "Comparison of sensory characteristics, and instrumental flavor compounds analysis of milk produced by three production methods." Diss., Columbia, Mo. : University of Missouri-Columbia, 2007. http://hdl.handle.net/10355/5057.
Повний текст джерелаThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 6, 2007 Includes bibliographical references.
Azevedo, Orlando Delfim Carvalho Couto de. "Avanços metodológicos na síntese de novos derivados de flavonas." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14509.
Повний текст джерелаAs estirilflavonas poli-hidroxiladas são compostos heterocíclicos de natureza polifenólica que suscitam interesse devido à atividade biológica que possuem atuando, por exemplo, como antioxidantes. O desenvolvimento de novas rotas de síntese de estirilflavonas constitui um desafio e é neste contexto que se têm efetuado vários estudos sobre a aplicação de reações de acoplamento cruzado catalisadas por paládio, como a reação de Heck, na preparação deste tipo de compostos. Nesta dissertação reporta-se a síntese de (E)-8-estirilflavonas através da reação de Heck de 8-iodoflavonas com derivados de estireno com rendimentos excelentes, descrevendo-se um estudo no qual se optimizaram as condições experimentais desta reação. Adicionalmente, descrevem-se duas tentativas de desmetilação da (E)-8-[2-(4-metoxifenil)vinil]-4’,5,7-trimetoxiflavona. As 8- iodoflavonas foram preparadas com elevada regiosseletividade através da ciclização oxidativa/iodação das (E)-2’-hidroxicalconas correspondentes por aplicação do sistema de reagentes I2/DMSO. A propósito, descreve-se um estudo de ciclização oxidativa/iodação da (E)-2’-hidroxi-4,4’,6’- trimetoxicalcona, no qual se testou a aplicação do sistema de reagentes I2/DMSO na síntese de iodoflavonas em reações one-pot. As (E)-2’- hidroxicalconas foram sintetizadas através da condensação aldólica catalisada por base entre a 2’-hidroxi-4’,6’-dimetoxiacetofenona, previamente preparada, e derivados de benzaldeído. A caraterização estrutural da maioria dos compostos obtidos neste trabalho foi efetuada com base em estudos de espetroscopia de ressonância magnética nuclear (RMN), nomeadamente de 1H e 13C, e, sempre que possível, em estudos bidimensionais de correlação espetroscópica heteronuclear (HSQC e HMBC), bem como em estudos de espetrometria de massa (EM).
Polyhydroxylated styrylflavones are heterocyclic compounds of polyphenolic nature that have gained interest due to their biological activity, e.g., acting as antioxidants. The development of new synthetic routes of styrylflavones is a challenge, therefore several studies have been conducted on the application of palladium catalysed cross-coupling reactions, such as Heck reaction, in the synthesis of these compounds. In this work it is reported the synthesis of (E)-8-sytrylflavones through the Heck reaction of 8-iodoflavones with styrene derivatives with excellent yields. A study to optimize the experimental conditions of the Heck reaction is performed and described. Additionally, it is described two demethylation assays of (E)-8-[2-(4- methoxyphenyl)vinyl]-4',5,7-trimethoxyflavone. The 8-iodoflavones were prepared with high regioselectivity by cyclodehydrogenation/iodination of (E)-2'- hydroxychalcones with I2/DMSO. It is also described a study of the cyclodehydrogenation/iodination of (E)-2'-hydroxy-4,4',6'-trimetoxychalcone using I2/DMSO as the reagent system in the synthesis of iodoflavones in onepot reactions. The (E)-2'-hydroxychalcones were synthesized by basecatalyzed aldol reactions of 2'-hydroxy-4',6'-dimethoxyacetophenone, previously prepared, with benzaldehyde derivatives. The structural characterization of most of the compounds obtained in this work was based on studies of nuclear magnetic resonance spectroscopy (NMR), namely 1H and 13C and, when possible, on two-dimensional heteronuclear studies (HSQC and HMBC), as well as on mass spectrometry studies (MS).
Scanavini, Helena Finardi Alvares. "Destilação em batelada de aroma natural de caju e oleo essencial de manjericão : investigação via simulação computacional." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255111.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-08T15:25:45Z (GMT). No. of bitstreams: 1 Scanavini_HelenaFinardiAlvares_M.pdf: 3144443 bytes, checksum: f6733d6ff56270059b3021e96e08e996 (MD5) Previous issue date: 2006
Resumo: O aroma de um alimento é o resultado da combinação de diversas substâncias voláteis, de diferentes classes químicas, sendo que nenhuma delas é individualmente responsável pelo aroma, mas sim a combinação entre elas. Atualmente, os aromatizantes são amplamente utilizados na indústria alimentícia, seja para conferir um determinado aroma a um produto, ou para reforçar o aroma característico já existente, como de um suco, por exemplo. A concentração de sucos de frutas reduz o volume, sendo importante para o armazenamento, embalagem e transporte. Porém, durante o processo convencional de concentração, a maioria dos componentes aromatizantes é perdida, sendo necessário recuperar a fração aromatizante do suco de fruta durante a concentração. Existem vários processos utilizados para a recuperação de aroma e concentração de suco. O aroma concentrado pode, então, ser reincorporado no suco concentrado para obter uma bebida com aroma natural e característico da fruta. O mercado internacional tem demonstrado grande interesse nos sucos de frutas tropicais, entretanto parcela das indústrias nacionais ainda não alcançou desenvolvimento tecnológico para competir em um mercado no qual os produtos obtidos devem apresentar certas características de qualidade. No caso do óleo essencial de manjericão, ele tem atraído a atenção de pesquisadores por possuir grande quantidade de linalol, uma substância de largo emprego na indústria de aromas e perfumes, também encontrada no pau-rosa, árvore amazônica em extinção. Assim, neste trabalho foram estudadas, através da simulação computacional, condições operacionais e construtivas (número de estágios) de colunas de destilação em batelada de aroma natural de caju e de óleo essencial de manjericão. No caso do aroma natural de caju, foram investigadas as condições que garantissem uma maior recuperação dos compostos voláteis desejáveis, para serem reincorporados ao suco concentrado ou utilizados na formulação de outros produtos alimentícios e também a purificação deste aroma em relação ao ácido 2-metil butanóico, considerável indesejável, devido ao seu odor desagradável. Enquanto que para o óleo essencial de manjericão, foram estudadas as melhores condições para o fracionamento de seus componentes de maior interesse comercial, visando a obtenção destes com o maior grau de pureza possível, para a utilização pela indústria alimentícia, de perfumaria ou farmacêutica
Abstract: The flavor is a combination of some volatile substances, of different chemical classes. However none of them is individually responsible for a specific flavor, but a combination of them. Nowadays flavor compounds are widely used in the food industry, either to confer one definitive flavor to a product, or to strengthen an existing characteristic flavor, as of a juice, for example. The fruit juice concentration reduces the volume, being important to the storage, packing and transportation. However, during the conventional concentration process, the majority of the flavor components is lost, being necessary to recover the juice flavor fraction lost during the concentration. There are some information of different processes used for the flavor recovery and juice concentration. The concentrated flavor can then be reintroduced in the concentrated juice to get a beverage with the natural and characteristic flavor of the fruit. The international market has demonstrated a great interest in tropical fruit juices. However, a share of the domestic industries still has not developed technologies to compete in a market in which the products must present certain quality characteristics. In the case of the essential oil of basil, it has attracted the attention of researchers for containing a large amount of linalool, a substance with high ability of setting odors, also found in the wood-rose, an Amazonian tree in extinguishing. Therefore, in this work, it had been studied, through computer simulation, operational and design conditions of a batch distillation column of the natural flavor of cashew fruit and essential oil of basil. In the case of the cashew natural flavor, it was investigated the conditions that guarantee a larger recovery of desirable volatile compounds, to be reintroduced to the concentrated juice or used in the formulation of other nourishing products and also the purification of this flavor in relation to the 2-methylbutanoic acid, considered undesirable and of unpleasant odor. For the essential oil of basil, the best conditions for the purification of its components of larger commercial interest had been studied, aiming at obtaining them with the largest degree of possible purity, for the nourishing, cosmetic or pharmaceutical industry uses
Mestrado
Mestre em Engenharia de Alimentos
Nardella, Flore. "Flavones substituées : une nouvelle classe de composés pour le traitement du paludisme : optimisation vers un candidat médicament." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF018.
Повний текст джерелаMalaria was responsible for 438.000 deaths in 2015. The increasing proportion of P. falciparum parasites resistant to artemisinin, the most potent antimalarial, is a major concern in Southeast Asia. Fast acting drugs with unaltered activity versus the current multi-drug resistant strains are urgently needed to replace artemisinin. This thesis deals with a new antimalarial series based on the structure of an active natural biflavonoid called lanaroflavone. The lead compound, MR27770, displays interesting properties: it acts throughout the blood cycle faster than artemisinin, its pharmacokinetic properties are promising, and it exhibits a partial in vivo antimalarial activity. Plus, it has no cross-resistance with artemisinin or other antimalarials. Its mode of action is unknown and could imply an osmotic stress. This promising compound has however a mild in vitro activity which motivated the topological study of its structure and led to optimized derivatives
Greene, Jeffrey Lynnette. "Characterization of Naturally Occurring Fruity Fermented Off-flavor in Peanuts Using Descriptive Sensory, Consumer, and Instrumental Analyses." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-06192007-175623/.
Повний текст джерелаSlabizki, Petra [Verfasser], and Hans-Georg [Akademischer Betreuer] Schmarr. "Identification and quantification of cork off-flavor compounds in natural cork stoppers by multidimensional gas chromatographic methods / Petra Slabizki. Betreuer: Hans-Georg Schmarr." Duisburg, 2016. http://d-nb.info/1101343516/34.
Повний текст джерелаAbdulmalik, Takiyah. "Use of plant-derived essential oil compounds and naturally-occurring apple flavor compounds to control foodborne pathogens in apple juice." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77367.
Повний текст джерелаPh. D.
Vu, Michael, and Sofie Holmberg. "Ett doft- och smakbibliotek avseende hampfrö-presskaka, gula mjölmasklarver, texturerad veteprotein, ärtproteinisolat och ärtprotein koncentrat : En sensorisk undersökning av alternativa proteinkällor." Thesis, Högskolan Kristianstad, Fakulteten för naturvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hkr:diva-22333.
Повний текст джерелаThe purpose of the study is to construct a fragrance- and flavour library for sensory analyses for hemp seed press cake, yellow mealworms, textured wheat protein, pea protein isolate and pea protein concentrate. The methods pilot study, consensus test and inhouse intensity test are used to be able to execute the study. The purpose of the pilot study is to gain an increased understanding of the fragrance- and flavour of the pre-products. The consensus test is a central point for the structure of the fragrance- and flavour library, since predominant attributes generated during the test are used for the product description in the fragrance- and flavour library. The purpose of the inhouse intensity test is to verify the validity of the attribute generation from the consensus test. The results from the pilot study contribute with references to the consensus test. There are also common attributes for the products' fragrance- and flavour in the pilot study and in the consensus test. The results from the consensus test show that it is difficult to distinguish between taste and mouthfeel. For example, can oil from hemp seed press cake be determined as a flavour. The result from the inhouse intensity test has a large statistical error, which makes it difficult to determine the attributes due to the differential in the minimum- and maximum value. Attributes that gave a descriptive text to the library show that hemp seed press cake has a scent of grass and seaweed where the taste is reminiscent of the scent. Pea protein isolate mainly smells of grain, the taste is reminiscent of seeds and corn. Yellow mealworms smell like cereals and walnuts where the taste is based on the basic taste umami. Textured wheat protein has a scent that can remind of roasted wheat puffs and oatmeal, where the taste is reminiscent of the scent. The last product is pea protein concentrate, which has a scent of pea shoots, and the taste is bitter.
Rahmouni, Hidayat. "Stress oxydant et sensibilisation à l'ischémie/reperfusion myocardique dans le syndrome métabolique et le diabète chez le rat. Evaluation de l'apport de composés antioxydants et à visée antidiabétique, naturels ou de synthèse." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4795.
Повний текст джерелаCardiovascular disorders related to metabolic syndrome or diabetes are a direct consequence of the installation of oxidative stress, which progress is associated with free radicals overproduction and increase of biomolecules degradation, in parallel with lowered antioxidant defenses. These pathologies represent a considerable public health problem, and research to improve prevention and treatment is strongly encouraged. In this context, our 1st objective was to develop two models in vivo, mimicking on rats metabolic syndrome and diabetes conditions, one by administration of a fructose-enriched diet or drink, the second being chemically induced. Our 2nd objective was to prepare phycocyanine-rich extracts of spirulina, a natural antioxidant, and to evaluate their properties on the two experimental animal models. Results showed the beneficial effect of spirulina on glycemia decrease, insulinemia improvement and lipid profile, accompanied by and increase of the antioxidant defenses and an improvement of myocardial functional recovery after ischaemia/reperfusion. Our 3rd objective was of to evaluate the antioxidant and cardioprotective capacities of new polyphenol derivatives. Around thirty new flavonols have been isolated in our Laboratory; best results were obtained with molecules bearing an ionizable group in C6 position, and methoxy groups in C3' and C5', leading to better solubility and lower cytotoxicity. Finally, the 4th objective was to quantify the therapeutic and cardioprotective potential of hybrid compounds, associating an antioxidant pattern with an antidiabetic molecule
Valente, Inês Maria Afonso. "Desenvolvimento de metodologias analíticas para a determinação de off-flavours em bebidas." Tese, 2014. https://repositorio-aberto.up.pt/handle/10216/75680.
Повний текст джерелаValente, Inês Maria Afonso. "Desenvolvimento de metodologias analíticas para a determinação de off-flavours em bebidas." Doctoral thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/75680.
Повний текст джерелаFerreira, Inês Filipa Mourão. "Chemical Changes and off-flavours development in beer during storage." Doctoral thesis, 2021. https://hdl.handle.net/10216/139306.
Повний текст джерелаTeixeira, Samira Patricia dos Reis Borges. "Compostos Responsáveis pelo "Off-Flavour" da Cerveja. Caracterização e Impacto Sensorial." Dissertação, 2016. https://repositorio-aberto.up.pt/handle/10216/85356.
Повний текст джерела"Comparison of Artificial Flavors in Commercial Products and Actual Natural Flavor Via Gas Chromatography Mass Spectroscopy Data." East Tennessee State University, 2009. http://etd-submit.etsu.edu/etd/theses/available/etd-0430109-153628/.
Повний текст джерелаLin, Chilong, and 林志隆. "Type III natural flavour-conserving model." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/50076462725030281721.
Повний текст джерелаTeixeira, Samira Patricia dos Reis Borges. "Compostos Responsáveis pelo "Off-Flavour" da Cerveja. Caracterização e Impacto Sensorial." Master's thesis, 2016. https://repositorio-aberto.up.pt/handle/10216/85356.
Повний текст джерелаFerreira, Miguel Coelho. "Adding flavor degrees of freedom to the AdS/CFT correspondence." Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/77350.
Повний текст джерелаFerreira, Miguel Coelho. "Adding flavor degrees of freedom to the AdS/CFT correspondence." Master's thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/77350.
Повний текст джерелаPeixoto, Ana Paula Pereira. "Search for tZ production via Flavour Changing Neutral Currents with the ATLAS experiment at the LHC." Master's thesis, 2016. http://hdl.handle.net/1822/56022.
Повний текст джерелаThe subject of the present dissertation is the search for tZ event production by Flavour Changing Neutral Currents (FCNC) through the analysis of data collected by the ATLAS detector of the Large Hadron Collider located in CERN. The FCNC processes are very rare in the Standard Model of Particle Physics since they are not allowed at tree-level and extremely suppressed at loop-level. However, this processes have a higher probability to occur in several models beyond the Standard Model. In this thesis, a search for the production of a top quark and a boson Z via FCNC in a trileptonic topology is discussed. The final state of the tZ production consists in a pair of leptons with opposite sign and same flavour having a mass compatible with the decay of a Z boson, a charged lepton and a neutral lepton classified as coming from the decay of a top quark and finally a jet coming from a bottom quark (b-tagged jet). The analyzed data coming from proton-proton collisions at the centre-of-mass energy of √s = 13 TeV was collected in the data-taking period between July and November of 2015 corresponding to an integrated luminosity of 3.21 fb−1. A complementary study of possible discriminant variables is presented. Through this study, expected upper limits at 95% confidence level on the cross-section of tZ production via FCNC were obtained. An interpretation of these limits in terms of branching ratios for t → qZ and the tZq coupling is also presented.
A presente dissertação tem como objectivo a pesquisa da produção de eventos tZ através de processos de mudança de sabor por correntes neutras recorrendo a uma análise de dados colectados pelo detector ATLAS do Large Hadron Collider localizado no CERN. Os processos de mudança de sabor por correntes neutras são muito raros no Modelo Padrão da Física de Partículas, sendo ausentes a tree-level e extremamente suprimidos a loop-level. No entanto, estes processos têm uma maior probabilidade de ocorrer em vários modelos para além do Modelo Padrão. Neste trabalho é estudada a produção de um quark top e de um bosão Z através de processos de mudança de sabor por correntes neutras numa topologia trileptónica. O estado final desta pesquisa consiste num par de leptões de carga oposta e sabor idêntico com uma massa compatível com o decaimento de um bosão Z, um leptão carregado em conjunto com um leptão neutro provenientes do decaimento de um quark top e finalmente um jacto proveniente de um quark bottom (b-tagged jet). Os dados analisados, relativos a colisões protão-protão a uma energia de centro de massa de √s = 13 TeV, foram obtidos no período de Julho a Novembro de 2015 correspondendo a uma luminosidade integrada de 3.21 fb−1. Um estudo complementar de possíveis variáveis discriminantes é apresentado. Através deste estudo, são obtidos limites superiores esperados com um nível de confiança de 95% na secção eficaz de produção deste processo. Estes limites são interpretados em termos do acoplamento tZq e da fracção de decaimento t → qZ.
Laboratório de Instrumentação e Física Experimental de Partículas, FCT/MEC (Fundação Ciência e Tecnologia /Ministério da Educação e da Ciência), FEDER (Fundo Europeu de Desenvolvimento Regional) for funding my activities this past year, as established by the partnership PT2020 partnership with COMPETE2020 (Autoridade de Gestão do Programa Operacional Competitividade e Internacionalização), by providing me with a research scholarship (Reference LIP/BI-26/2015).
Mendes, Inês Isabel Moreira Moutinho Vieira. "Systems biology approaches for the design of novel Saccharomyces cerevisiae winemaking strains for enhanced flavour compounds synthesis." Doctoral thesis, 2015. http://hdl.handle.net/1822/40427.
Повний текст джерелаWine flavour and aroma are the result of yeast metabolism and must compounds interactions. During must fermentation thousands of volatile aroma compounds are formed, with higher alcohols, acetate esters and ethyl esters being the main aromatic compounds contributing to a floral and fruity aroma. The action of yeast, in particular of Saccharomyces cerevisiae strains, on the must components will build the architecture of the wine flavour and their fermentation bouquet. Only a holistic approach based on systems biology, an inter-disciplinary area combining the study of biology, chemistry, physics and mathematics, based on data-driven and model-based elucidation of complex biological systems, will allow the complete understanding on the vast and dynamical relationships between genomics, phenomics and metabolomics. In this work a S. cerevisiae collection was constituded comprising 172 strains of worldwide geographical origins and different technological applications. This collection was characterized regarding 30 physiological traits that are important mostly from an oenological point of view. From the different traits studied, growth in the presence of potassium bisulphite, growth at 40 ºC, and resistance to ethanol contributed the most to strain variability, as shown by the principal component analysis. Computational methods were developed in order to assess the importance of phenotypic features to identify candidate strains to be used commercially in winemaking. In particular, the probability of a strain to be assigned to the group of commercial strains was 27% using the entire phenotypic profile and increased to 95%, when only results from the three tests suggested by the model were considered. Results show the usefulness of the mentioned approaches to simplify strain selection procedures. In addition to the phenotypic characterization, we undertook genetic typing of the 172 S. cerevisiae strains, using 11 polymorphic microsatellites. We found 280 alleles, whereas microsatellite ScAAT1 contributed the most to intra-strain variability, together with the alleles 20, 9 and 16, from microsatellites ScAAT4, ScAAT5 and ScAAT6, respectively. These microsatellite allelic profiles are characteristic for both the phenotype and origin of yeast strains. Data were computationally related with the previously obtained results of the 30 phenotypic tests, and the phenotypes associated with higher number of alleles were the capacity to resist to sulphur dioxide (tested by the capacity to grow in the presence of potassium bisulphite) and the presence of galactosidase activity. Our study demonstrated the utility of computational modelling to estimate a strain technological group and phenotype from microsatellite allelic combinations as tools for preliminary yeast strain selection. To better understand the molecular and metabolic bases of aroma production during a fermentation process, we used comparative transcriptomic and metabolic analysis of four yeast strains from different origins and/or technological applications (cachaça, sake, wine, and laboratory), to rationally identify new targets for improving aroma production. Results showed that strains from cachaça, sake and wine presented a higher production of acetate esters, ethyl esters, acids and higher alcohols, in comparison with the laboratory strain S288c. At fermentation time T1 (5 g/L of CO2 released), comparative transcriptomics of these three S. cerevisiae strains from different fermentative environments in comparison with the laboratory yeast S288c, showed an increased expression of genes related with tetracyclic and pentacyclic triterpenes metabolism, involved in sterol synthesis. Sake strain showed also an upregulation of genes ADH7 and AAD6, involved in the formation of higher alcohols in the Ehrlich pathway. For fermentation time point T2 (50 g/L CO2 released), again sake strain, but also wine strain, showed an increased expression of genes involved in formation of higher alcohols in the Ehrlich pathway, namely ADH7, ADH6 and AAD6, which is in accordance with the higher levels of methionol, isobutanol, isoamyl alcohol and phenylethanol observed. Our approach revealed successful to integrate data from several technologies (HPLC, GC-MS and microarrays) and using different data analysis methods (PCA, MFA). The results obtained, increased our knowledge on the association of genes with the formation of metabolic compounds that contribute to the wine aroma and flavour, and showed differences in the metabolism of cachaça, sake and wine strains not yet addressed, and mainly explained by the production of fatty acids, and ethyl and acetate esters.
This work was supported by FCT I.P. through the strategic funding UID/BIA/04050/2013 and the project PTDC/AGR-ALI/121062/2010, and Inês Mendes was recipient of a fellowship from the Portuguese Science Foundation, FCT (SFRH/BD/74798/2010).
O aroma e o sabor do vinho resultam das interações entre o metabolismo das leveduras e os compostos presentes no mosto. Durante a fermentação do mosto formamse milhares de compostos voláteis, sendo que os álcoois superiores, os esteres de acetato e os esteres de etilo são os compostos que mais contribuem para o aroma floral e frutado. A ação das leveduras, em particular das estirpes de Saccharomyces cerevisiae, nos componentes do mosto contribui para a arquitetura do cheiro do vinho e do seu bouquet fermentativo. Apenas uma visão holística baseada na biologia de sistemas, uma área interdisciplinar que combina o estudo da biologia, química, física e matemática, baseada na elucidação de dados e modelos de sistemas biológicos complexos, permitirá uma completa compreensão das vastas e dinâmicas relações entre genómica, fenómica e metabolómica. No presente trabalho uma coleção de 172 estirpes de S. cerevisiae foi constituída com isolados provenientes de diferentes origens geográficas e diferentes aplicações tecnológicas. O seu fenótipo foi avaliado considerando 30 testes fenotípicos, selecionados de forma a avaliar características importantes do ponto de vista enológico. O crescimento na presença de bissulfito de potássio, crescimento a 40 ˚C e resistência ao etanol foram os fenótipos que mais contribuíram para a variabilidade entre estirpes, de acordo com o revelado pela análise de componentes principais. Foram desenvolvidos métodos computacionais com o objetivo de avaliar a importância das características fenotípicas na identificação de estirpes candidatas para serem usadas comercialmente na produção de vinho. Em particular, a probabilidade de uma estirpe pertencer ao grupo das estirpes comerciais foi de 27% usando o perfil fenotípico completo e aumentou para 95% quando foram apenas considerados os 3 testes sugeridos pelo modelo. Os resultados mostraram a utilidade dos métodos mencionados para simplificar os procedimentos de seleção de estirpes. Além da caracterização fenotípica, fez-se a tipagem genética das 172 estirpes de S. cerevisiae, usando para isso 11 microssatélites polimórficos. A caracterização genética identificou 280 alelos, sendo o microssatélite ScAAT1 o que mais contribuiu para a variabilidade entre estirpes, em conjunto com os alelos 20, 9 e 16 dos microssatélites ScAAT4, ScAAT5 e ScAAT6, respetivamente. Este perfil alélico de microssatélites revelou-se como característico tanto para o fenótipo como para a origem da estirpe de levedura. Estes dados foram relacionados computacionalmente com os resultados obtidos previamente para os 30 testes fenotípicos e os fenótipos associados com o maior número de alelos foram a capacidade de resistir ao dióxido de enxofre (testado pela capacidade de crescer na presença de bissulfito de potássio) e a presença de atividade da galactosidase. Este estudo demonstrou a utilidade da modelação computacional para fazer uma estimativa do grupo tecnológico de uma estirpe e do seu fenótipo a partir de combinações alélicas de microssatélites como ferramentas para seleção preliminar de estirpes de leveduras. De forma a contribuir para uma melhor compreensão das bases moleculares e metabólicas da produção de aroma durante o processo fermentativo, fez-se transcritómica comparativa e análise metabólica de quatro estirpes de levedura com diferentes origens e /ou aplicações tecnológicas (cachaça, saké, vinho e laboratório), para identificar novos alvos para o melhoramento da produção de aroma. Os resultados mostraram que as estirpes de cachaça, saké e vinho apresentaram uma maior produção de esteres de acetato, esteres de etilo e álcoois superiores, em comparação com a estirpe laboratorial S288c. No tempo de fermentação T1 (5 g/L de CO2 libertado), a transcritómica comparativa das três estirpes de S. cerevisiae obtidas em diferentes ambientes fermentativos em comparação com a estirpe laboratorial S288c, mostrou um aumento da expressão de genes relacionados com o metabolismo dos triterpenos tetracíclicos e pentacíclicos, envolvidos na síntese de esteróis. A estirpe de saké mostrou também um aumento na regulação dos genes ADH7 e AAD6, envolvidos na formação de álcoois superiores na via de Ehrlich. Para o tempo de fermentação T2 (50 g/L de CO2 libertado), mais uma vez a estirpe de saké, mas também a estirpe vínica, mostraram um aumento da expressão de genes envolvidos na formação de álcoois superiores na via de Ehrlich, nomeadamente ADH7, ADH6 e AAD6, o que está de acordo com elevados níveis de metionol, isobutanol, álcool isoamilico e feniletanol observados. A nossa abordagem revelou-se bem-sucedida para integrar dados de diferentes plataformas (HPLC, GC-MS e microarrays) e usando diferentes métodos de análise de dados (PCA, MFA). Os resultados obtidos aumentaram o conhecimento sobre a associação de genes com vias de formação de compostos que contribuem para o aroma e sabor do vinho, e mostraram diferenças no metabolismo das estirpes de cachaça, saké e vinho que não tinham ainda sido investigadas, e principalmente explicadas pela produção de ácidos gordos, e esteres de etilo e de acetato.
Βλάχος, Παναγιώτης. "Ανάπτυξη εναλλακτικών διεργασιών για την απολύμανση και απόσμηση των φυσικών φελλών". Thesis, 2007. http://nemertes.lis.upatras.gr/jspui/handle/10889/618.
Повний текст джерелаNovel processes for sterilization and deodorization of cork stoppers and cork barks have been developed and evaluated. Cork sterilization targets to microbial load reduction, either for bacteria or yeasts-moulds, while the reduction of rapidly releasable 2,4,6-trichloroanisole (2,4,6-TCA) of cork is achieved via their deodorization. The application of the plain ozonation process proved to be particularly efficient in cork barks treatment, while similar results were achieved using their plain or pulsed steam exposure. In the case of naturally or artificially contaminated cork stoppers, the steam pulsed process (SPP) was chosen as the optimum, based on techno economical criteria. The detailed description of cork deodorization was based on an appropriate mathematical model and the determination of its critical parameters was carried out via the simulation of the obtained experimental results. In the second part, the cork deodorization using commercially available adsorption materials via gas or liquid phase was studied and the polymer Tygon was chosen as the optimum. Finally, the management of 2,4,6-TCA, as a waste from cork deodorization in liquid and gas phase was tested using various oxidizing agents.
Aguiar, Dayana Nataly de Menezes. "Evolution of staling aldehydes on lager beer stability: impact of maritime transport and storage condidtions." Master's thesis, 2021. http://hdl.handle.net/10400.13/4055.
Повний текст джерелаThe flavour stability of bottled beer is the main challenge of the brewing industry. Carbonyl compounds, in particular aldehydes, are responsible for the unfavourable and perceptible changes detected by consumers. Those modifications are favoured by unrefrigerated temperatures, prolonged storage, transport-induced vibrations, among other factors. Currently, there are few data in the scientific literature on the impact of real transport conditions, namely vibrations and unrefrigerated temperatures, on beer stability. The aim of this study was to evaluate the evolution of 10 aldehydes in bottled Lager beer during maritime exportation and storage at the destination. To this end, the real conditions that the locally produced beer is subjected to, namely temperature (19-30ºC), vibration (1.7 Hz) and time (up to 120 days) were simulated. The analysis of the compounds under study was performed by solid-phase microextraction followed by gas chromatography coupled with mass spectrometry. The results revealed that the conditions of transport and storage simulated i) promoted an average increase in the concentration of Strecker aldehydes of 65%, ii) while the aldehydes formed from lipid oxidation as well as acetaldehyde, in general, do not present significant variations. The increase described in i) presented two patterns: bottles with traditional cap had mean values of 131.6±9.9 and 190.3±9.4 µg/L while bottles with a ring pull cap had 190.5±10.0 and 180.3±9.5 µg/L, after transport and storage respectively. Phenylacetaldehyde was the compound with the greatest variation, increasing from 94.7±7.3 (fresh beer) to 143.6±8.0 and 168.9±8.9 µg/L, after transport and considering an additional storage period, respectively. Additionally, it was found that the forced ageing procedure typically adopted may have limitations in reproducing the real conditions. Benzaldehyde stands out, which in any period of forced ageing, 7, 14 and 28 days, presented concentrations, on average, lower, of 5.3±0.3 µg/L, 5.4±0.3 µg/L and 5.4±0.3 µg/L, respectively, compared to the actual content after 120 days, of 6.4±0.4 µg/L.