Дисертації з теми "Sensory characterization of cheeses"
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1
Saltaji, Sabrina. "Étude de l’apport de flores microbiennes issues du lait cru, purifiées par le procédé Bionatif®, appliquées à une production fromagère." Thesis, La Rochelle, 2020. http://www.theses.fr/2020LAROS033.
Анотація:
Les ferments lactiques sont considérés comme un levier important de l’innovation pouvant apporter à la matrice fromagère de nouvelles propriétés organoleptiques, sensorielles et nutritionnelles. Cette thèse a eu pour sujet d’étude le procédé breveté Bionatif® qui purifie le lait cru de ses flores d’hygiène et d’altération de façon à restituer au fromager un ferment fonctionnel, composé d’une diversité bactérienne intra-spécifique propre au terroir de collecte (ferment indéfini). Ce travail s’est articulé autour de deux objectifs : i) caractériser la diversité des ferments indéfinis et étudier leur potentiel métabolique, ii) étudier l’expression des ferments en technologie fromagère pâte molle. Une diversité intra-spécifique des ferments indéfinis étudiés a été mise en évidence puisque plusieurs variants de L. lactis ont été découverts. Des isolats L. lactis du ferment indéfini présentaient des propriétés métaboliques supérieures et diversifiées notamment via l’expression de leur métabolisme des sucres (D-xylose, D-tagatose, etc.). Ce résultat a été confirmé par l’étude comparative de leur génome et pourrait être lié à leur origine environnementale. Les isolats L. lactis possèderaient également des ilots CRISPR-Cas particulièrement riches qui pourraient leur conférer une résistance accrue aux bactériophages. De plus, un potentiel antimicrobien a phénotypiquement été observé puis confirmé via l’étude génomique. En technologie fromagère pâte molle, la comparaison entre des ferments définis, conçus en conditions de laboratoire, et des ferments indéfinis, issus du procédé Bionatif®, a démontré que plus le consortium bactérien du ferment était complexe et diversifié, meilleures étaient les propriétés sensorielles et rhéologiques du fromageStarter cultures confer enhanced properties to improve organoleptic, sensory and nutritional attributes upon the cheese matrix. The subject of this PhD project was the patented Bionatif® process. That process purifies raw milk from hygiene and spoilage microflora. Then, it restores a functional Undefined Mixed Starter Culture (UMSC) to the cheesemaker. That unique UMSC is composed of an intra-specific bacterial diversity specific to the terroir where the raw milk is collected.This work fixed two goals: i) to characterize the diversity of the UMSC and study their metabolic potential, ii) to study the expression of the UMSC in soft cheese technology. The UMSC intra-specific diversity study highlighted some bacterial variants of the L. lactis species. UMSC's L. lactis isolates showed superior and diversified metabolic properties through the expression of their sugar metabolism (D-xylose, D-tagatose, etc.). A comparative genome study confirmed this result and could link these metabolic properties to an environmental origin. L. lactis isolates also possess rich CRISPR-Cas clusters. These clusters could confer them a high resistance against bacteriophages. Besides, an antimicrobial potential has been phenotypically observed and then confirmed through genomic studies. In soft cheese technology, the comparison between defined starter cultures designed under laboratory conditions and UMSC from the Bionatif® process demonstrated that the more complex and diversified the bacterial consortium of the UMSC, the better the sensory and rheological properties of the cheese
2
Polowsky, Patrick. "Analysis of surface crystals on soft washed rind cheeses using polarized light microscopy and their effect on the sensory perception of grittiness." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/864.
Анотація:
With the rising popularity of artisanal cheese in the United States, the soft washed rind category has emerged as a fast-growing segment of the marketplace. There is much anecdotal evidence to suggest a common sensorial defect in soft washed rind cheese is a gritty/sandy texture attributed to crystal growth on the rind of these cheeses
A preliminary study was undertaken to develop a set of criteria to visually identify crystals found on soft washed rind cheeses. Single crystal identities were presumptively determined using polarized light microscopy (PLM), and cross-checked using powder x-ray diffractometry (PXRD). Two distinct crystal groupings were determined based on these metrics. Group 1 crystals had high birefringent coloring, angle of extinction (AE) ≈ 90°, and were smaller and less circular than Group 2 crystals (P<0.05). Group 2 crystals had no birefringent coloring and AE ≈ 18°. Using established mineralogical data, Group 1 and Group 2 crystals were identified to be struvite and ikaite, respectively. These crystalline bodies are situated in an amorphous cheese matrix (i.e. smear), which create difficulties when examining via PLM and PXRD, leading to high background noise. To remedy these issues, a novel method for harvesting crystals was developed. Smear scrapings were immersed in NaOH (pH=10) to dissolve smear material, which resulted in improved PLM and PXRD performance.
A subsequent observational study was conducted to understand the prevalence of surface crystals and grittiness associated with washed rind cheeses sourced from the U.S.A. and Europe. Crystal types were identified via PXRD and PLM. Crystal size and shape (circularity) metrics were determined via PLM and image analysis. A descriptive sensory panel (n=12) was used to evaluate grittiness presence and intensity. Identified crystal types included ikaite, struvite, calcite, and brushite. Mean crystal length and area ranged from ~30μm to ~1100μm, and ~500μm2 to ~200,000μm2, respectively. Sensory perception threshold for grittiness occurred at a mean crystal length of ~70μm and mean crystal area of ~2900μm2. Below these threshold levels, cheeses presented with negligible grittiness. Above these threshold levels, grittiness was highly correlated with crystal length and area (r=0.93 and 0.96, respectively; P<0.001). These results indicate surface crystals have a direct impact on the sensorial quality of soft washed rind cheeses.
3
Štouračová, Anna. "Vliv podmínek skladování na obsah aromaticky aktivních látek v tavených sýrech." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216433.
Анотація:
The aim of this diploma thesis was to monitor influence of storage conditions (temperature and time) on content of aroma substances in sterilized processed cheeses and also on their flavour. The part of cheeses was stored at 6°C, second part at room temperature 23 °C and third part at 40 °C. Processed cheeses were produced by Madeta, a. s., sterilized at 117 °C 20 min. The analysis was made at regular intervals, cheeses stored 16 and 23 months were analysed in this work. The aroma compounds were isolated by SPME and subsequently identified and quantified by gas chromatography. In total 37 aroma compounds were identified and quantified, 7 aldehydes, 7 ketones, 6 acids, 12 alcohols and 5 esters. Total content of aroma compounds increases with higher storage temperature. The time of storage has also influence on content of aroma compounds, we may say, that content is increasing, although sharp growth was registered only after 23 months, namely in the thermostat. Simultaneously sensory analysis of cheeses was made. Ranking test and evaluation using scale were used. Cheeses from a fridge were always evaluated as the best in all categories. Cheeses stored at room temperature were evaluated worse and cheeses from thermostat were the worst. So it is apparent, that high temperature supports undesirable chemical changes in cheeses and certainly is related to their flavour.
4
Quiñones, Patricia Maria. "Characterization of exocytosis in vertebrate sensory hair cells." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1581455091&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
5
Aldworth, Zane Nathan. "Characterization of the neural codebook in an invertebrate sensory system." Diss., Montana State University, 2007. http://etd.lib.montana.edu/etd/2007/aldworth/AldworthZ1207.pdf.
6
Dintner, Sebastian. "Characterization of a sensory complex involved in antimicrobial peptide resistance." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-176173.
Анотація:
In their habitats, microorganisms are often in competition for limited nutrients. In order to succeed,
many Gram-positive bacteria resort to production of peptide antibiotics. Therefore, resistance
mechanisms against these compounds are essential. The first step of ensuring survival is the
perception of the harmful drugs and mediation of resistance against it. In recent years, a group of
ABC-transporters have been recognized as important resistance determinate against antimicrobial
peptides. The expression of these transporters is generally regulated by a two-component system,
which in most cases is encoded next to the transporter. Together they are described as detoxification
modules. The permeases of the transporters are characterized by a large extracellular domain, while
the histidine kinases lack an obvious input domain. One of the best understood examples is the
BceRS-BceAB system of Bacillus subtilis, which mediates resistance against bacitracin, mersacidin
and actagardine. For this system it was shown that the histidine kinase is not able to detect the
substrate directly and instead has an absolute requirement for the transporter in stimulus perception.
This describes a novel mode of signal transduction in which the transporter is the actual sensor and
therefore regulates its own expression. To date, mechanistic details for this unique mode of signal
transduction remain unknown. Several other examples have been described for transport proteins that
have acquired additional sensing or regulatory functions beyond solute transport, and these have been
designated trigger transporters. For these bifunctional transporters a direct protein-protein interaction
with membrane-integrated or soluble components of signal transduction relays has been postulated.
However, for most sensor/co-sensor pairs, conclusive proof of such an interaction is lacking, and so
far little is known about the sites that might mediate contacts between the putative protein interfaces
and how communication is achieved.
Based on sequence and architectural similarities, we identified over 250 BceAB-like transporters
in the protein database, which occurred almost exclusively in Firmicutes bacteria. To whether the
regulatory interplay between the ABC transporter and the two-component system was a common
theme in these antimicrobial peptide resistance modules, we carried out a phylogenetic study of these
identified systems. We identified a clear coevolutionary relationship between transport permeases and
histidine kinases. Furthermore, we identified conserved putative response regulator binding sites in the
promoter regions of the transporter operons. Additionally, we were able to provide a tool to identify
TCSs for transporters lacking a regulatory system in their genomic neighbourhood, which was based
on the coclustering of histidine kinases and transporter permeases. These findings also suggested the
existence of a sensory complex between BceAB-like transporters and BceS-like histidine kinases.
To further investigate the signaling mechanism, we performed a random mutagenesis of the
transport permease BceB with the aim to identify regions or residues within the transporter that are
involved in signaling and/or resistance. With this approach we were able to identify mutations that affected either the ability for signaling or mediation of resistance. This showed a partial genetic
separation of the two qualities, which could be achieved by single amino acid replacements. These
results provide first insights into the signaling mechanism of the Bce system.
In order to analyse the proposed communication between two-component system and ABC
transporter, we further characterized their interactions by in vivo and in vitro approaches. We could
demonstrate that the transporter BceAB is indeed able to interact directly with the histidine kinase.
Because it was unknown how the signal perception by BceAB-type transporters occurs, we next
analyzed substrate binding by the transporter permease BceB and could show direct binding of
bacitracin by BceB. Finally, in vitro signal transduction assays indicated that complex formation with
the transporter influenced the activity of the histidine kinase.
In summary this thesis clearly shows the existence of a sensory complex comprised of BceRS-like
two-component systems and BceAB-like ABC transporters and provides first functional insights into
the mechanism of stimulus perception, signal transduction and antimicrobial resistance mechanism
employed by these wide spread detoxification systems against antimicrobial peptides.Um sich in solch hart umkämpften Habitaten wie dem Boden zu behaupten sind Bakterien dazu übergegangen Antibiotika zu produzieren, um das Wachstum der Konkurrenz einzudämmen. Eine Gruppe solcher Substanzen sind antimikrobielle Peptide, die von Gram-positiven Bakterien produziert werden. Zum Schutz vor Peptidantibiotika haben Gram-positive Bakterien eine Vielzahl verschiedener Resistenzmechanismen entwickelt. Den effizientesten Resistenzmechanismus gegen Peptidantibiotika stellt eine Gruppe ATP-abhängiger ABC-Transporter dar. Diese Transporter weisen einen besonderen Transmembranaufbau auf. Sie bestehen aus zehn Transmembranhelices und einer großen extrazellulären Domäne. Die Expression dieser Transportergruppe wird durch ein Zweikomponentensystem reguliert. Die Histidinkinase besitzt ebenfalls einen ungewöhnlichen Transmembranaufbau, da sie keine offensichtliche Bindedomäne besitzt. Zusammen bilden der Transporter und die Histidinkinase ein Resistenzmodul gegen Peptidantibiotika, das in Firmicutes weit verbreitet ist. Eines der am besten verstandenen Systeme ist das BceRS-BceAB System in Bacillus subtilis. Dieses System vermittelt Resistenz gegen Bacitracin, Actagardin und Mersacidin. Für dieses System konnte gezeigt werden, dass die Histidinkinase BceS alleine nicht in der Lage ist, auf Bacitracin zu reagieren, sondern stattdessen für die Reizwahrnehmung und die Vermittlung der Resistenz auf den Transporter BceAB angewiesen ist. Der Transporter reguliert somit eine eigene Produktion. Wie der Resistenzmechanismus in diesem System genau funktioniert konnte bisher aber noch nicht hinreichend geklärt werden. Dass Transporter neben ihrer Funktion Substrate über eine Zellmembran zu transportieren auch an der Reizwahrnehmung und der Antwortregulation beteiligt sein können, ist in unterschiedlichsten Beispielen beschrieben worden. Um die Signalweiterleitung an membranständige oder zytoplasmatische Komponenten des Signalwegs gewährleisten zu können, müssen diese miteinander interagieren, zum Beispiel durch direkte Protein-Protein Interaktionen. Bisher konnte jedoch für viele solcher Sensorkomplexe keine endgültige Erklärung für solch eine Interaktion dargestellt werden. Basierend auf einer Datenbankanalyse konnten über 250 BceAB-artige Transporter identifiziert und ein Großteil davon einer BceS-artigen Histidinkinase zugeordnet werden. Durch eine phylogenetische Studie konnte weiterhin gezeigte werden, dass BceRS-artige Zweikomponentensysteme und BceAB-artige Transporter in Firmicutes Bakterien weit verbreitet sind und sich über Ko-Evolution gemeinsam zu Resistenzmodulen gegen Peptidantibiotika entwickelt haben. Dazu konnte eine konservierte Antwortregulator-Bindestelle in den Promoter Regionen der Transporteroperons bestimmt werden. Zudem war es möglich aufgrund dieser Klassifizierung für diejenigen Permeasen ohne ein benachbartes Zweikomponentensystem anhand der Genomsequenz ein mögliches Regulationssystem zuzuordnen. Diese Erkenntnisse unterstützten die Vermutung über einen sensorischen Komplex zwischen BceS-ähnlichen Histidinkinasen und BceAB-ähnlichen ABC Transportern. In einer weiteren Studie konnten mittels zufälliger Mutagenese der Transporterpermease BceB Aminosäurereste identifizierte werden, die an der Signalweiterleitung und/oder Resistenzvermittlung beteiligt waren. Durch einige der eingefügten Mutationen wurde nur die Signalweiterleitung bzw. nur die Resistenz beeinträchtigt. Dies spricht dafür, dass eine partielle genetische Trennung der Aufgaben des Transporters möglich ist. Hierdurch konnten erste wichtige Einblicke in den Signalweiterleitungsmechanismus des Bce-Systems gewonnen werden. Um die vorgeschlagene Kommunikation zwischen Zweikomponentensystem und ABCTransporter weiterführend zu untersuchen, wurden Interaktionsstudien durchgeführt. Die auf in vitro und in vivo Studien basierenden Ergebnisse konnten eine direkte Interaktion zwischen BceS und BceAB darstellen. Darüber hinaus konnten wir in dieser Arbeit durch eine Oberflächenresonanz- Spektroskopie zum ersten Mal zeigen, dass die Transporterpermease Bacitracin direkt und spezifisch bindet. Außerdem konnte durch eine in vitro Rekonstruktion des Signalwegs im Bce-System gezeigt werden, dass die Aktivität der Histidinkinase durch die Anwesenheit des Transporters beeinflusst wird. Zusammenfassend zeigt die vorliegende Arbeit direkte Hinweise, dass BceRS-artige Zweikomponentensysteme und BceAB-artige ABC-Transporter zusammen einen sensorischen Komplex für Peptidantibiotika bilden. Dies wird unterstützt durch erste funktionelle Einblicke in die Mechanismen der Reizwahrnehmung und Signalweiterleitung in diesen in Firmicutes Bakterien weit verbreiteten Resistenzsystemen.
7
Piras, Simone. "Volatile and sensory characterization of white wines from minority grapes varieties." Master's thesis, ISA, 2019. http://hdl.handle.net/10400.5/19567.
8
Bord, Cécile. "Impact du traitement thermique sur les perceptions sensorielles et les préférences des consommateurs pour les fromages à pâte persillée : cas de la fourme d'Ambert." Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22567/document.
Анотація:
Les fromages d’«Appellation d’Origine Protégée» (AOP) présentant un cahier des charges précis sont garants d’un savoir-faire, d’une tradition et d’un lien avec le terroir et sont également reconnus pour leurs qualités organoleptiques. Malgré une bonne implantation au niveau du marché et une consommation non négligeable, certains fromages AOP voient leurs ventes baisser. Pour dynamiser certains de ces fromages, notamment les fromages à pâte persillée, leur utilisation comme « fromages ingrédients » s’avérerait pertinente. Ce nouveau segment, très porteur pour les fromagesindustriels, consiste à les utiliser dans des préparations culinaires aussi bien à chaud qu’à froid. L’objectif des travaux de cette thèse est de réaliser d’une part un focus sur les propriétés sensorielles des fromages à pâte persillée AOP du Massif central, induites par le chauffage et plus particulièrement de la Fourme d’Ambert, en étudiant les fractions solubles de ces fromages, d’un point de vue biochimique et sensoriel, et d’autre part de connaître les préférences des consommateurs vis-à-vis des fromages à chaud. Dans un premier temps, un screening sur le comportement à chaud de différentes catégories de fromages à pâte persillée a conduit à identifier des différences texturales et gustatives et de ce fait, à catégoriser les fromages selon leurs aptitudes culinaires. Ce positionnement sensoriel a ainsi permis de sélectionner un « fromage modèle » : la Fourme d’Ambert. Dans une seconde phase, l’étude des fractions solubles a confirmé sa contribution relative dans la perception gustative des fromages à pâte persillée. Toutefois, aucune différence sensorielle n’est observée sur les fractions suite au traitement thermique malgré quelques différences sur la teneur de certains composés sapides. Enfin, la dernière phase a consisté à identifier les préférences des consommateurs vis-à-vis de la Fourme d’Ambert à froid et à chaud. Quelle que soit la température, le fromage est bien apprécié par les consommateurs. La segmentation des consommateurs révèle des perceptions différentes selon trois groupes : un groupe avec des préférences pour des fromages très typés, à l’inverse, un groupe ayant une attirance pour les fromages ayant des flaveurs moins prononcées et un dernier, axé sur les préférences des fromages à chaud. Corrélées aux profils sensoriels, aux commentaires libres des consommateurs et à leurs attentes, certaines variables sensorielles ou comportementales ont pu expliquer ces différences de préférences. Ces résultats montrent l’intérêt de l’usage de certains fromages à pâte persillée AOP en tant que « fromages ingrédients » présentant de bonnes aptitudes culinaires, par leurs propriétés fonctionnelles et gustatives. L’acceptation des fromages à chaud par les consommateurs renforce le fait que les fromages AOP peuvent être utilisés aussi bien à froid qu’à chaud, permettant ainsi l’innovation dans la filièrePDO cheeses through their specifications are recognized for a quality in relation to a geographical origin, technical know-how, and a typical gustative quality. Despite a good consumption of PDO cheeses, the marketed volumes decreased for most of them. In order to make them more attractive, some cheeses as Blue cheeses could be used as “cheeses ingredient”. Cheeses are usually consumed at the end of a meal but a new trend is emerging: cheeses are more and more used in culinary preparations, both hot (pizza, gratin, sauce) and cold (sandwiches, salads). The main objective of this study was to firstly highlight the impact of heating on sensory properties of French PDO Blue cheeses and more particularly Fourme d’Ambert. The water-soluble fraction which plays an important role in the favour of cheeses was secondly studied in order to evaluate the impact of heating on this extract. The last objective consisted in measuring the consumers liking towards cold and heated cheeses. Therefore, sensory and biochemical methods were performed to describe crude cheeses and liking. The first study highlighted the impact of heating on both textural properties and flavour of four PDO blue-type cheeses. The main results showed that PDO cheeses present different culinary properties and thus are compatible with a use into hot preparations. The first step allowed to select a model cheese: Fourme d’Ambert. The second step consisted in studying the impact of heating on the crude cheeses and on the water-soluble fraction. In parallel, the gross composition was performed on soluble fractions and cheeses according to heating treatment. Although no treatment difference was observed on the water-soluble fraction gustatory profile, a slight difference was showed on certain chemical constituents between the water-soluble extracts. The last step was focused on the consumers liking towards cold and heated cheeses. The results showed that cheeses were much appreciated whatever heating treatments highlighting a slightly preference towards heated cheeses. Moreover, 3 groups of consumers were formed based on different preferences. One group preferred heated cheeses while two others groups preferred cold cheeses. Consumers’ group preferences were explained by means of sensory profiles and open-ended questions responses.Finally, this study shows the opportunities of new culinary uses for Blue cheeses. Sensory methods application had allowed to provide detailed information on heating properties of blue cheeses. In addition, consumers’ acceptance reinforce that PDO cheeses can be used in cold or heated preparations
9
Cheng, Albert Wu. "Characterization of irx-1 transcription factor in C. elegans male sensory ray development /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202007%20CHENG.
10
Chan, Wai Hung. "Characterization of mab-22 genetic pathway in male sensory ray assembly of caenorhabditis elegans /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202006%20CHAN.
11
Lam, Yiu-Man. "Characterization of cuticle collagens and their biosynthetic process in C. elegans sensory ray morphogenesis /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202007%20LAMY.
12
Pimpinella, Sofia [Verfasser]. "Characterization of neuronal circuits processing specific sensory modalities in the spinal cord / Sofia Pimpinella." Berlin : Freie Universität Berlin, 2020. http://d-nb.info/1216104980/34.
13
Lee, Seung-Joo. "Characterization of odor-active compounds in California Chardonnay wines using sensory and instrumental data /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
14
So, Ka Chai. "Characterization of mab-22 gene and its role in caenorhabditis elegans sensory ray formation /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202004%20SO.
Анотація:
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 116-123). Also available in electronic version. Access restricted to campus users.
15
Brondi-Mendes, Juliana Zara 1988. "Percepção do consumidor brasileiro em relação a queijo frescal com reduzido teor de gordura." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255803.
Анотація:
Orientadores: Walkíria Hanada Viotto, Jorge Hanada ViottoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Nos últimos anos, o mercado de produtos light vem se expandindo graças a um segmento de consumidores preocupados com a qualidade de vida e saúde. O mercado dos lácteos com reduzido teor de gordura está na liderança entre os produtos light mais procurados. Assim, este estudo teve por objetivo avaliar os motivos que influenciam na decisão de compra de queijos com reduzido teor de gordura tanto quanto compreender as razões em não consumi-los e avaliar a composição físico-química, perfil de textura, mobilidade de água por ressonância magnética nuclear de baixo campo e aceitação de diferentes amostras comerciais de queijo frescal light disponíveis no mercado a partir dos processos de fabricação tradicional, acidificação direta e ultrafiltração. Análise conjunta foi a ferramenta utilizada para tentar entender a estrutura de preferência dos consumidores de queijo frescal light, ou seja, compreender a complexidade do processo de escolha e decisão de compra do consumidor. Na primeira fase, caracterizada pelas análises laboratoriais, foi verificado a diferença na composição entre as diferentes fabricações de queijo frescal light, sendo os ultrafiltrados os queijos mais macios, de maior umidade e consequentemente menor de teor de gordura e proteína total. Os resultados de ressonância magnética nuclear revelaram o comportamento da água quanto ao seu estado (livre ou imobilizado) para todas as amostras. Na segunda fase, um questionário sócio demográfico e sobre hábitos de compra foi aplicado a 151 consumidores de queijos light revelando que os principais consumidores são pessoas acima dos 40 anos com alto poder aquisitivo, preocupados em manter hábitos mais saudáveis. Por outro lado, falta de hábito foi a principal razão alegada em não consumir queijos light. A análise conjunta revelou que os consumidores consideram mais importante a textura desses queijos, seguido do tamanho da porção e alegação nutricional. Dentre os níveis de cada fator, queijo fresco de consistência firme, porção individual, light com 40% menos gordura, foram os que tiveram maior preferência. De maneira geral, todos os processos de fabricação de queijo fresco light avaliados foram bem aceitos, com média em torno de 6-7 para aceitação global
Abstract: In recent years, the light products market is expanding due to a segment of consumers concerned about the quality of life and health. The reduced fat dairy market is in the lead among the most sought light products. This study aimed to evaluate the reasons that influence the buying decision of reduced fat content cheeses as well as to understand the reasons not to consume them and evaluate the physical and chemical composition, texture profile analysis, mobility of water by low-field nuclear magnetic resonance and acceptance of different commercial samples of light fresh chesse available in the market from traditional manufacture processes, direct acidification and ultrafiltration. Conjoint analysis was the tool used to understand the consumer preference structure of light fresh cheese, thus, understand the complexity of the process of choosing and consumer buying decision. In the first phase, characterized by laboratory analysis, it was found that the difference in composition between different light fresh cheese manufacturing processes, being the ultrafiltered cheeses the softer cheeses, of high moisture and consequently lower fat content and total protein. The results of nuclear magnetic resonance showed the water behavior regarding to its state (free or immobilized) for all samples. In the second phase, a demographic and shopping habits questionnaire was applied to 151 consumers of light cheeses showing that the main consumers are people over 40 years old with the higher income, concerned about maintaining healthier habits. On the other hand, the lack of habit was the main reason reported at not consume light cheeses. The conjoint analysis showed that consumers consider most important texture of these cheeses, followed by the portion size nutritional claim. Among the levels of each factor, fresh cheese of firm consistence, individual portion and light with 40% less fat, were the ones who had higher preference. In general, all manufacturing process of light fresh cheese evaluated were well accepted, averaging around 6-7 for global acceptance
Mestrado
Tecnologia de Alimentos
Mestra em Tecnologia de Alimentos
16
Hua, Pierce. "Characterization of a novel pre-pore loop antibody against rat TRPV1." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111948.
Анотація:
Splice variants of the transient receptor potential vanilloid type-1 (TRPV1) channel appear to be involved in the physiological detection of extracellular fluid (ECF) osmolality in the supraoptic nucleus (SON) and organum vasculosum lamina terminalis (OVLT). It remains to be determined whether these splice variants are directly involved as pore-forming proteins in the osmosensory transduction complex. Since these TRPV1 splice variants are not sensitive to capsaicin antagonists, such as capsazepine (Sharif Naeini et al., 2007), novel tools that specifically interfere with ion permeation through TRPV1 are required for functional studies on the involvement of this channel. In this study, we developed rabbit polyclonal antibodies targeting specifically the extracellular pre-pore loop region of rat TRPV1 (PH-4281). Histological results showed that PH-4281 is specific to rat TRPV1 and TRPV1 expression is found in regions that are known to be osmosensitive. PH-4281 could be used as a specific tool to study the osmosensory transduction complex.
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Vyas, Daivik B. "What a Handful! Electrophysiological Characterization of Sensory and Cognitive Biases on Spatial Attention and Visual Processing." Scholarship @ Claremont, 2016. http://scholarship.claremont.edu/cmc_theses/1321.
Анотація:
Attention uses sensory inputs and goals to select information from our environment. Monkey electrophysiological literature demonstrates that visuo-tactile bimodal neurons (respond to visual and tactile stimuli presented on/near the hand) facilitate multisensory integration. Human behavioral studies show that hand position/function bias visual attention. Event-related potentials (ERPs) reveal the cortical dynamics coordinating visual inputs, body position, and action goals. Early, sensory ERPs (N1) indicate multisensory integration. Later, cognitive ERPs (P3) reflect task-related processing. Study 1 investigates a discrepancy between monkey and human literatures. Monkey studies demonstrate bimodal neuron responses equidistantly around the whole hand, but human studies demonstrate attentional bias for grasping space. In a visual detection paradigm, participants positioned their hand so target and non-target stimuli appeared near the palm or back of the hand; ERPs were measured. N1 components indicated no amplitude differences between Palm vs. Back conditions, but P3 components revealed greater target vs. non-target differentiation for Palm conditions. Results suggest cortical timing underlies grasping vs. whole hand bias differences: early processing does not differentiate using hand function, but cognitive processing does when stimuli are discriminated for action. Study 2 investigates whether proprioceptive inputs facilitate visual processing. In a visual detection paradigm, participants viewed stimuli presented between occluders blocking view of a hand positioned either near or far from the stimuli. N1 amplitudes were similar for near and far conditions, but P3 amplitudes for target/non-target differences were accentuated for near conditions. Proprioceptive effects emerge later in processing. ERP reveals the cortical dynamics underlying hand position effects on vision.
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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/.
Анотація:
Peanuts are a valuable agricultural commodity and roasted peanut flavor is the driving force for consumer purchase and consumption. The development of off-flavors is a major concern to the peanut industry and physiological differences (i.e. oil and sugar content) among the different maturity classes can influence the presence and/or absence of specific flavors. Fruity fermented (FF) is a common off-flavor found in peanuts and is developed when peanuts are cured at excessive temperatures (>35ºC). Previous literature has characterized FF off-flavor using descriptive sensory analysis; however, there is little information on FF off-flavor using consumer evaluation. The peanut plant has an indeterminate flowering pattern meaning a range of maturities are present at harvest and the immature and mature peanuts differ in roasting and flavor quality. Immature peanuts tend to have more FF off-flavor than mature peanuts which results in a FF distribution within large peanut lots. The flowering pattern and heterogeneous distribution of immature and mature seed make it challenging to obtain an accurate determination of FF off-flavor in a bulk lot. Establishing links between flavor and volatile flavor compounds can be obtained by using sensory and instrumental analyses. Currently, there is little research published on the volatile components that contribute to naturally occurring FF off-flavor. The objectives of this research were to: i) characterize consumer?s perception of FF off-flavor, ii) measure the variability and determine the FF distribution in bulk lots, iii) and identify the volatile compounds responsible for naturally occurring FF off-flavor using sensory and instrumental analyses. Descriptive sensory analysis was conducted to determine the no FF and FF samples used for the consumer study. Two-hundred and eight consumers evaluated a control (no FF off-flavor), low (1.0 FF) intensity, and a high (3.0 FF) intensity using two different scaling techniques: category and line scales. Results indicated FF off-flavor negatively impacts consumer acceptance of peanuts and the line scales were more sensitive and showed more differences among the samples compared to the category scale. The second study investigated the distribution of FF off-flavor in peanut lots and the results indicated that FF intensity varied from lot to lot and within a single bulk lot. Solvent assisted flavor evaporation (SAFE), solidphase microextraction (SPME), gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS), and model systems were conducted to identify the compounds responsible for naturally occurring FF off-flavor. Volatile analysis indicated that ethanol and the esters previously reported as causing FF off-flavor were not detected in natural FF samples by solvent extractions; however, they were present in natural and artificially created Georgia Green and Flavor Runner 458 samples by headspace extractions. These findings emphasizes that the use of laboratory created samples should not be used to identify off-flavor sources in peanuts. Additionally, the use of analytical techniques to identify FF off-flavor in bulk lots cannot be achieved using ethanol or esters as indicators.
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Arendse, Garron Mark. "Selection and metabolic characterization of mesophylic starter cultures for optimizing the sensory attributes of fruit flavoured Maas." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51906.
Анотація:
Thesis (MSc Food Sc)--Stellenbosch University, 2000.ENGLISH ABSTRACT: Maas is a traditional fermented milk drink of the indigenous people of Southern Africa and can thus be used to uplift the nutritional status of the South African population, especially for the lower income groups. Furthermore, the problem of lactose intolerance among the Black population can also be addressed by the consumption of Maas. The objective of this study was to screen mesophylic lactic acid bacterial strains (25 in total) from the University of Stellenbosch Food Science Culture Collection for suitable metabolite production and then to produce traditional Maas with a starter culture combination that produces a distinctive acid and traditional flavour. The representative 25 single lactic acid starter strains were identified as Lactococcus lactis subsp. leetis biovar diacetylactis (12 strains), L. leetis subsp. leetis (four strains) and L. leetis subsp. cremoris (nine strains). These strains were inoculated into pasteurised full cream milk and activated for 8 h at 22°C. Pasteurised full cream milk was then inoculated with each of the activated starter strains, incubated at 22°C for 16 h and assessed for acid production abilities (pH = 4.6) under controlled time-temperature conditions. The results of this study showed that nine of the single strains, L. lactis subsp. leetis biovar diacetylactis (S1, S2, S3 and S5), L. teetis subsp. lactis (S13, S15 and S16) and two L. leetis subsp. cremoris strains (S17 and S22), produced sufficient acid, rendering them suitable for the use as starters in the production of traditional Maas. A pH range of 4.3 - 5.1 was reached by the nine single strains after 16 h at 22°C. Two-strain starter combinations were then formed by combining the most suitable single L. leetis subsp. leetis biovar diacetylactis, L. lactis subsp. lactis and L. lactis subsp. cremoris strains, respectively. From the data, it was concluded that acceptable Maas could be produced with four two-strain combinations (S3S 17, S3S22, S5S17 and S5S22). This selection was again based on suitable acid and metabolite production, as well as on sensory evaluation of the final product. These four two-strain combinations produced sufficient acid to reach a pH in the 4.6 - 4.8 range, and showed a high metabolite concentration for the most suitable compounds and formed a thick, smooth and creamy body texture after 16 h at 22°C. Three-strain combinations formed between the two-strain starter combinations and L. leetis subsp. teetis strains (813, 815 and 816), were also evaluated. With these combinations a lack of a pronounced Maas flavour was found. Thus, it was decided to add aroma producing strains of the species Leuconostoc mesenteroides subsp. dextranicum (strain L1) and L. mesenteroides subsp. citrovorum (strain L2) to the three-strain combinations. Four culture combinations (A, B, C and D) were then formed by combining the selected Leuconostoc strains (L1 and L2) with the most suitable Lactococcus strains (83,817,813 and 822). These combinations produced sufficient acid to reach the pH 4.5 - 4.6 range after 14 h at 22°C. Acetaldehyde was the major flavour metabolite formed in the Maas made with these four combinations, with concentrations ranging between 26.6 - 89.3 mg.l ̄ ¹, while other flavour metabolites (ethanol, acetone, diacetyl and 2-butanone) were present at lower concentrations. It was found that three of the four culture combinations (A, C and D) were characterised by a superior, but delicate flavour and a typical characteristic Maas body texture. Fruit flavoured Maas was subsequently prepared with the three most suitable culture combinations (A, C and D) using 11 flavours and a sensory evaluation performed. The statistically evaluated data showed that the appearance, smoothness, flavour intensity, sweetness and overall acceptability were influenced by the type of fruit flavour and the culture combination. Fruit flavour 4 (banana) was the most preferred flavour. The sensory panellists also indicated that the culture combination C gave the best overall acceptability over a three week study period. Data on the shelf-life study of natural unflavoured Maas, prepared with the three culture combinations (A, C and D), showed that the Maas still had an acceptable appearance, taste and good microbiological quality after 15 d at refrigerated temperatures.
AFRIKAANSE OPSOMMING: Maas is 'n tradisionele gefermenteerde melkdrankie onder die inheemse bevolking van Suid-Afrika en kan gebruik word om die voedingstatus van die Suid-Afrikaanse bevolking te verhoog, veral vir die laer inkomste groepe. Bowendien, kan die probleem van laktose intoleransie onder die Swart gemeenskap ook aangespreek word deur die verbruik van Maas. Die doel van hierdie studie was om enkelstam mesofiliese melksuur bakterieë (25 in totaal) van die Universiteit van Stellenbosch Voedselwetenskap Kultuur Versameling te ondersoek vir geskikte metaboliet produksie en tradisionele Maas met 'n kenmerkende suurheid en tradisionele geur met 'n geskikte kultuur kombinasie te produseer. Die toonaangewende 25 enkelstamme is Lactococcus lactis subsp. leetis biovar diacetylactis (12 stamme), L. lactis subsp. lactis (vier stamme) en L. lactis subsp. cremoris (nege stamme). Hierdie stamme was in gepasteuriseerde volroom melk geïnokuleer en geaktiveer vir 8 h teen 22°C. 'n Inokulum van die onderskeie geaktiveerde stamme is hierna in gepasteuriseerde volroom melk geplaas, vir 16 h teen 22°C geïnkubeer en hul vermoë om suur te produseer (pH = 4.6) onder beheerde tyd-temperatuur kondisies is bepaal. Die resultaat van die studie het aangedui dat nege enkelstamme, naamlik L. leetis subsp. lactis biovar diacetylactis (S1, S2, S3 en S5), L. lactis subsp. leetis (S13, S15 en S16) en twee L. leetis subsp. cremoris (S 17 en S22), geskikte suurheidsvlakke vir die produksie van Maas bereik het. 'n pH vlak van 4.3 - 5.1 is na 16 h teen 22°C deur hierdie nege enkelstamme bereik. Twee-stam kombinasies is onderskeidelik gevorm tussen die geskikte enkel L. lactis subsp lactis biovar diacetylactis, L. lactis subsp. lactis en L. lactis subsp. cremoris stamme. Die gevolgtrekking gemaak uit die data, is dat aanvaarbare Maas voorberei kan word met vier van die twee-stam kombinasies (S3S17, S3S22, S5S17 en S5S22) op grond van suurvorming, metaboliet produksie en sensoriese evaluasie. Hierdie vier kombinasies het genoegsame suur geproduseer om 'n pH vlak van 4.6 - 4.8 bereik, hoë metaboliet konsentrasies geproduseer en 'n dik, gladde en romerige tekstuur aangeneem na 16 h teen 22°C. Drie-stam kombinasies is gevorm tussen die onderskeie twee-stam kombinasies en L. lactis subsp. lactis stamme (813,815 en 816) en ook geëvalueer. Die tekort aan 'n skerp Maas geur in die drie-stam kombinasies het daartoe gelei dat Leuconostoc mesenteroides subsp. dextranicum (stam L1) en L. mesenteroides subsp. citrovorum (stam L2) bygevoeg is. Vier kultuur kombinasies (A, B, C en D) is gevorm deur die geselekteerde Leuconostoc stamme (L1 en L2) te kombineer met die mees gepaste Lactococcus stamme (83, 817, 813 en 822). Hierdie kombinasies het genoegsame suur geproduseer wat 'n pH vlak van 4.5 - 4.6 na 14 h teen 22°C bereik het. In die Maas wat met bovermelde kombinasies gemaak is, was die asetaldehied die mees geproduseerde geur metaboliet teen konsentrasies van 26.6 - 89.3 mg.l ̄ ¹. Ander geur metaboliete (etanol, asetoon, diasetiel, 2-butanoon) is in laer konsentrasies geproduseer. Daar is gevind dat drie uit die vier kultuur kombinasies (A, C en D) 'n superieur, delikate geur wat 'n tipies karakteristiek van die Maas gehad het. Vrugte gegeurde Maas geproduseer met die drie kultuur kombinasies (A, C en D) deur 11 geursels te gebruik, is sensories geëvalueer. Die statistiese geëvalueerde data het getoon dat die voorkoms, gladheid, geur intensiteit, soetheid en die algehele aanvaarbaarheid beïnvloed is deur die tipe vrugte geursels en die kultuur kombinasies. Die vrugte geursel 4 (piesang) het voorkeur geniet. Die sensoriese paneellede het ook aangedui dat kultuur kombinasie C die algehele mees aanvaarbare Maas geproduseer het oor die studie periode van drie weke. Data van die rakleeftyd van die natuurlike ongegeurde Maas wat geproduseer is met die drie kultuur kombinasies (A, C en D) het aangedui dat die Maas na 15 d by yskas temperatuur steeds 'n aanvaarbare voorkoms, smaak en goeie mikrobiologiese kwaliteit gehad het.
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Rodriguez, Carla Jeanette. "Product Development, Sensory Evaluation and Characterization of Bioactive Isothiocyanates from Broccoli Sprout Powder delivered in Tomato Juice." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1544800823179656.
21
Buck, Vinodini. "Rheological Properties of Peanut Paste and Characterization of Fat Bloom Formation in Peanut-Chocolate Confectionery." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/26881.
Анотація:
Fat bloom in chocolates is the gray-white discoloration and dullness that can occur
on the surface of the confectionery. Fat bloom is a common quality defect that can result
from temperature fluctuations during storage. Chocolates candies with peanuts or other nut
fillings are more prone to fat bloom compared to plain chocolates, due to a release of
incompatible nut oils into the chocolate matrix. The overall goal of this study was to
determine if differences in triacylglycerol (TAG) composition and rheological properties of
high, medium, and normal oleic peanuts influence fat bloom formation. All three peanut
varieties showed high concentrations of triolein. Normal oleic peanuts had a slightly
higher trilinolein than high and medium oleic peanuts, which contained trilinolein in trace
amounts. Peanut pastes from the three peanut varieties all had a minimum apparent yield
stress, and all pastes showed varying degrees of shear thinning. The apparent yield stress
of high and normal oleic pastes was higher than the apparent yield stress of medium oleic
paste. The absolute value of the flow index behavior was 1 for the high oleic peanut paste,
suggesting friction in the experimental apparatus, even with use of Teflon plates. The
peanut chocolate candies took around 45 days for significant dulling of the chocolates with
temperature cycling between 26-29 °C approximately every 26 hours. Optical microscopy
scans showed differences in glossiness and surface textural attributes of the unbloomed and
bloomed peanut chocolate confectionery. Consumer evaluation showed some differences
in the glossiness and significant differences in surface texture of unbloomed and bloomed
chocolates. A majority (62%) of the survey respondents had seen whitish discoloration in
chocolates and 40% of the respondents thought this is because the chocolate had grown old.Ph. D.
22
Miller, Krisha Lynn. "Chemical and sensory characterization of oat bran from experimental oat lines with varying amounts of total beta-glucan." [Ames, Iowa : Iowa State University], 2007.
23
Carvalho, Joelia Marques de. "Virgin cashew nut oil (VCNO) and extra virgin cashew nut oil (EVCNO): processing, characterization, sensory evaluation and bioactivity." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15334.
Анотація:
A amÃndoa de castanha de caju (ACC) à um dos principais produtos do agronegÃcio cearense, mas tambÃm à fonte de renda para pequenos produtores rurais, principalmente nos perÃodos de estiagem. A amÃndoa de castanha de caju de maior valor para comercializaÃÃo à que aquela se classifica como inteira de primeira qualidade. As amÃndoas de castanha de caju de qualidade inferior, por cor ou quebradas durante o processamento, chegam a perder 80% do seu valor comercial. Desta forma, este trabalho teve como objetivo o desenvolvimento de um Ãleo a partir da amÃndoa de castanha de caju de classes inferiores, avaliando os mÃtodos de extraÃÃo a frio (extra virgem - OEV) e com aquecimento prÃvio em micro-ondas (virgem - OV), sua composiÃÃo e caracterÃsticas quÃmicas e fÃsicas, sua estabilidade, caracterÃsticas sensoriais e bioatividade. Na seleÃÃo das amÃndoas para extraÃÃo, considerou-se as caracterÃsticas fÃsico-quÃmicas e de qualidade oxidativa, utilizaram-se seis classes inferiores: B1, S1, W4, SP1, SP2, P1 e uma classe de amÃndoa inteira de primeira qualidade (W240) como referÃncia. Considerando os parÃmetros avaliados, optou-se pelo uso das amÃndoas SP2, de menor preÃo de mercado, visto que todas as classes avaliadas apresentaram boa qualidade fÃsico-quÃmica e oxidativa, com potencial para extraÃÃo do Ãleo (lipÃdios totais superiores a 50%). Na avaliaÃÃo dos processos de extraÃÃo, observou-se maior rendimento da amostra com aquecimento prÃvio em micro-ondas. A amostra OV tambÃm apresentou maior estabilidade oxidativa com tempo de induÃÃo mÃdio de 46,25 horas, contra 39,03 horas da amostra OEV. Possivelmente a maior estabilidade se deu pela maior presenÃa de fenÃlicos totais na amostra OV (316,4 mg/100g) do que na amostra OEV (202,17 mg/100g). Ambos os Ãleos apresentaram aÃÃo antioxidante, possivelmente pela presenÃa de compostos como tocoferÃis, Ãcidos graxos mono e poli-insaturados, fitosterÃis e fenÃlicos identificados nas amostras. Na avaliaÃÃo antimicrobiana, o Ãleo OV possivelmente pelo maior teor de fenÃlicos, apresentou aÃÃo mais efetiva contra microrganismos patogÃnicos, em especial Listeria mocytogenes. Os Ãleos de amÃndoa de castanha de caju OV e OEV apresentaram aÃÃo antiproliferativa contra cÃlulas de cÃncer de mama (MCF7), pulmÃo (A549) e fÃgado (HepG2) somente em altas concentraÃÃes, superiores a 200 Âg/mL. Nos testes sensoriais com consumidores (grupos focais) e na AnÃlise Descritiva Quantitativa Otimizada percebeu-se interesse em consumir o produto caso estivesse disponÃvel no mercado, tanto por seus atributos sensoriais como pelo apelo regional do produto. Os principais atributos das amostras foram brilho, cor amarela, odor e sabor de castanha. Dentro dos aspectos avaliados, o aquecimento prÃvio com micro-ondas pode oferecer um maior rendimento de extraÃÃo, sem perdas significativas dos compostos bioativos ou diminuiÃÃo da aceitaÃÃo sensorial.The cashew nut (CN) is a major agribusiness product of CearÃ, but it is also an income source for small farmers, especially in drought periods. The cashew nut with greater value to market is standardized as whole-grade. The cashew nut inferior grades by color or broken during processing, lose 80% of their market value. This study aimed to develop an oil from the inferior grades cashew nut, evaluating the cold extraction methods (extra virgin - EVCNO) and preheating in microwave (virgin - VCNO), its composition and chemical and physical characteristics, stability, sensory characteristics and bioactivity. In the selection of kernels for extraction, considered the physical and chemical characteristics and oxidative quality, we used lower six grades and qualities: B1, S1, W4, SP1, SP2, P1 and a whole nut-grade grade (W240) as reference. Considering the evaluated parameters, we opted for the use of SP2 kernel, due to the lower market price, since all grades and qualities evaluated showed good physical and chemical quality and oxidative, with potential for oil extraction (total lipids of over 50%). In the assessment of extraction processes, there was a higher yield of the sample with pre-heating in a microwave. The OV sample also showed greater oxidative stability with average induction time of 46.25 hours, 39.03 hours against the OEV sample, possibly given by the greater presence of phenolic compounds in sample VCNO (316.4 mg / 100g) than the sample EVCNO (202.17 mg / 100g). Both oils showed antioxidant activity, possibly due to the presence of compounds such as tocopherols, fatty acids mono and polyunsaturated, phytosterols and phenolic identified in the samples. In antimicrobial evaluation, the VCNO oil possibly due to increased phenolic content, made more effective action against pathogenic microorganisms especially Listeria mocytogenes. VCNO and EVCNO showed antiproliferative action against breast cancer cells (MCF7), lung cancer cells (A549) and liver cancer cells (HepG2) only at high concentrations greater than 200 mg/mL. In sensory tests with consumers (focus groups) and Optimized Descriptive Profile perceived interest in consuming the product if it was available in the market, both for their sensory attributes as the regional appeal of the product. The main attributes of the samples: shining, yellow color, odor and taste of nuts. Considering the evaluated aspects, preheating with microwave can offer a higher yield of extraction, without significant loss of bioactive compounds or decreased sensory acceptance.
24
Paissoni, Maria Alessandra. "Characterization of anthocyanins and condensed tannins from grapes and their qualitative incidence on astringency and bitterness sensory properties." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0383/document.
Анотація:
Dans le vin rouge, les composés phénoliques sont souvent associés à la qualité du produit. Parmi eux, les anthocyanes sont responsables de la couleur du vin rouge et chaque cépage possède un génome spécifique déterminant le profil anthocyanique de chacun. Les pratiques culturales peuvent influencer l’accumulation de ces molécules dans la baie de raisin, tandis que les différentes techniques fermentaires peuvent modifier leur extraction. Les flavanols monomères, oligomères et polymères des pépins et des pellicules contribuent à l’amertume et l’astringence des vins. Pendant la vinification et l’élevage, ceux-ci réagissent avec les anthocyanes modifiant les propriétés du vin. De nombreuses publications concernant les caractéristiques sensorielles des flavanols ont été réalisées, alors que la contribution sensorielle des anthocyanes est encore mal connue. Cette thèse se décompose en deux parties. La première partie s’intéresse à l’étude de l’utilisation d’ozone gazeux comme technique pré-fermentaire sur les cépages rouges Nebbiolo et Barbera après récolte et pendant le passerillage. L’ozone est une technique innovante pour la réduction des contaminations microbiennes et la réduction du dioxyde de soufre. L’influence de cette technique sur les parois cellulaire des pellicules, sur l’extraction, la concentration en flavanols et en anthocyanes pendant la macération a été évaluée. L’étude montre que l’ozone possède un impact sur la macération des raisins, induisant une extraction plus importante des anthocyanes dans le Nebbiolo. En revanche, l’ozone n’influence ni les anthocyanes moléculaires, ni le profil variétal de chaque cépage. Pendant le passerillage, l’inverse a été étudié. L’extraction des anthocyanes dans le Nebbiolo est diminuée. A l’inverse, bien que moins d’anthocyanes soient retrouvées dans le raisin de Barbera, le traitement ne possède aucun impact sur l’extraction de celles-ci. Concernant les flavanols, l’extraction est moins influencée par le traitement à l’ozone. Des différences ont été retrouvées dans le cépage Nebbiolo. Les flavonols sont plus concentrés après le traitement avec l’ozone sur les raisins post-récolte, alors qu’ils diminuent pendant le passerillage. La modification causée sur la paroi cellulaire par l’ozone ainsi que la dureté des pellicules pourraient prédire l’extraction des anthocyanes et des flavanols, grâce à des analyses multi-variées. En conséquence, le traitement avec l’ozone doit être adapté en fonction du cépage et du produit final désiré. Dans la deuxième partie, les anthocyanes des raisins ont été extraites à partir des raisins et ces extraits ont été fractionnés en trois fractions, glucoside, acetyl-glucoside et cinnamoyl-glucoside, par Chromatographie de Partage Centrifuge (CPC) et CLHP (Chromatographie Liquide Haute Performance) préparative. L’évaluation de l’astringence a été réalisée par des analyses de précipitation protéique avec une protéine modèle BSA (Bovine Serum Albumin) et des protéines salivaires, les anthocyanes réagissant avec ces dernières. Les analyses sensorielles et l’évaluation de l’astringence ont été combinées. La concentration en anthocyane diminue après le traitement avec les protéines salivaires, dans l’extrait total et dans les fractions, en particulier les cinnamoyl-glucosides apparaissent comme les plus réactives avec les protéines salivaires. Les seuils de perception gustatifs ont été calculés avec la méthode “Best estimate threshold” dans le vin modèle. Les fractions acétyl-glucosides et cinnamoyl-glucosides, suivies de la fraction glucoside, possèdent des seuils de perception plus bas aux concentrations retrouvées dans les vins. Les descripteurs associés à ces fractions sont l’amertume et l’astringence. Ces résultats démontreraient que les anthocyanes apportent une contribution sensorielle dans la perception du vin en bouche, corrélée à l’acétylation des moléculesIn red wine, phenolic compounds are generally associated with the quality of products. Among them, anthocyanins extracted from skins are responsible for wine colour. The grapevine genomes determine the anthocyanins profiles, but several factors in the vineyard can influence their accumulation, as well as post-harvest techniques can modify their extraction during winemaking. Monomeric, oligomeric and polymeric flavanols from skins and seeds contribute to astringency and bitterness of wine and during winemaking and ageing complexes formation with anthocyanins modifies wine characteristics. Several publications are available to understand flavanols sensory characteristics, whereas anthocyanins role has not consensus in scientific literature. This PhD thesis is composed by two parts. The first part deal with the evaluation of the use of gaseous ozone as post-harvest technique in red wine grapes Nebbiolo and Barbera used on both fresh grape and during withering. Ozone treatment is an innovative technology proved to avoid mycobiota spoilage and preserving from the use of sulphur dioxide. Its influence on flavanol and anthocyanin contents and extractabilities during maceration was evaluated, considering skin cell wall modification. In fresh grape, ozone influenced skin maceration for both the varieties, leading to a higher anthocyanin extraction in Nebbiolo grapes and lower in Barbera. Ozone did not influence the final individual anthocyanin extractability, respecting the varietal anthocyanin fingerprint. During dehydration, opposite trend was found: in Nebbiolo reported no change in the content of total anthocyanins just after ozone-assisted dehydration, but their extraction yield was lower. On the contrary, although lower contents of anthocyanins were found in Barbera grapes no differences in final extractability was found. Regarding oligomeric and polymeric flavanols, their extractability was less affected by the ozone treatment. Only in Nebbiolo, both oligomeric and polymeric flavanol extraction was increased in fresh grape, whereas it is slightly decrease during dehydration. The ozone-induced modification of skin cell wall composition together with skin hardness parameters fitted well in multivariate models to predict anthocyanins, oligomeric flavanols and polymeric flavanols extraction. Therefore, the ozone treatment should be adapted depending on the variety and on the target wine. In the second part, grape anthocyanins were isolated depending on the acylation patterns, i.e. glucoside, acetyl-glucoside, and cinnamoyl-glucoside by a combination of centrifugal partition chromatography (CPC) and preparative-HPLC. Protein precipitation analyses to assess astringency and sensorial analysis were carried out. Anthocyanins reacted with both bovine serum albumine and salivary proteins, in different extent, since higher interaction between anthocyanins and salivary proteins was found with a significative reduction of total extract and fractions glucoside, acetyl-glucoside, and cinnamoyl-glucoside. The latter in particular is the more reactive to salivary proteins. Sensorial analysis was carried out as detection threshold test. Best estimated threshold (BET) of anthocyanins were resulted in wine-range scale, in particular acetyl-glucoside and cinnamoyl-glucoside BET are lower of glucoside threshold, and descriptors reported were astringency and bitterness. These results show that anthocyanins can be detected as in-mouth properties contributors, and the magnitude of their involvement is related to anthocyanins acylation
25
Mirlohi, Susan. "Characterization of Metallic Flavor in Drinking Water: An Interdisciplinary Exploration through Sensory Science, Medicine, Health, and the Environment." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/77313.
Анотація:
Scientific explorations can lead to life changing discoveries or light the path for new discoveries as scientists continue to carry or pass on the torch of knowledge to current and future generations. This torch of knowledge radiates in many directions, as the path of discovery often demands a multidimensional perspective. This research explored the many aspects of metallic flavor in drinking water through applications of sensory science, medicine, health, and the environment.
Humans interact with their environment through the five senses and are often exposed to contaminants through multiple routes; oral intake of trace metal contaminants through drinking water is a likely source. The biochemical mechanism by which humans are able to detect the flavor of strongly metallic agents such as iron has been previously elucidated, but little is known about population variability in the ability to sense metallic flavors. This research evaluated sensory thresholds and biochemical indicators of metallic flavor perception in healthy adults for ferrous iron in drinking water; 61 subjects aged 19 – 84 years, participated. The findings demonstrated an age-dependent sensitivity to iron indicating as people age they are less sensitive to metallic perception; impairment of olfactory functions is a contributing factor.
Unlike in healthy adults, where human senses are often protective of overexposure to contaminants, and supportive of sensations of everyday life's pleasures, cancer patients often suffer from chemosensory dysfunctions. Metallic phantom taste is a commonly experienced sensation, yet very little studied aspect of this debilitating disorder. Impact of cancer therapy on chemosensory functions of patients with malignant brain tumors undergoing combined modality treatment (CMT) was explored. The results indicated that chemosensory dysfunctions of the patients can range from minimal to moderate impairment with maximum impairment developing during the 6-week CMT. Study of salivary constituents may provide clues on to the causes of chemosensory dysfunctions.
On health aspects, implication of individual sensitivity to metallic flavor on beverage choices and overall water consumption was assessed in 33 healthy adults through self-reported beverage questionnaire. The results indicated that among the elderly reduced intake of drinking water coincided with reduced sensitivity to metallic flavor. The findings have important health implications in terms of hydration status and beverage choices.
Finally, with environmental exposure relevance, preliminary findings on sensory properties of zerovalent iron nanoparticles (nZVI) indicated that oral exposure to nZVI may induce sensory properties different from that of ferrous iron, likely predictive of a diminished detection of metallic flavor by humans. Further research is warranted in this area.Ph. D.
26
Choy, Siu Wah. "Characterization of a transcriptional repressor complex and mab-21 interacting genes in male sensory ray patterning of C. elegans /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?BIOL%202006%20CHOY.
27
Obst, Katja [Verfasser], Karl-Heinz [Akademischer Betreuer] Engel, and Thomas [Akademischer Betreuer] Hofmann. "Phytochemical Characterization and Sensory Evaluation of Macropiper excelsum / Katja Obst. Gutachter: Karl-Heinz Engel ; Thomas Hofmann. Betreuer: Karl-Heinz Engel." München : Universitätsbibliothek der TU München, 2014. http://d-nb.info/1068002247/34.
28
Weightman, Jayne. "Characterization of Chenin Blanc wines produced by natural fermentation and skin contact : focus on application of rapid sensory profiling methods." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96008.
Анотація:
Thesis (MSc)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Producers of South African (SA) dry and semi-dry Chenin blanc table wines are currently experimenting with winemaking techniques to modulate the flavours of the predominantly fruity styles of this genre. An important stage during wine style development is sensory profiling paired with consumer acceptance testing, before wine is produced on industrial scale. With those aforementioned goals in mind, this study was conducted in partnership with two commercial SA wine cellars. The main focus of the study was an investigation into the treatment effects of two winemaking techniques, respectively grape skin contact and natural fermentation, on the sensory profiles of experimentally produced Chenin blanc wines. Results obtained with descriptive sensory analysis (DA) of the wines were compared to those obtained by two rapid sensory profiling methods, namely projective mapping (PM) and frequency of attribute citation (FC). A consumer preference study was also done on the wines. In order to understand the treatment effects better, the dominant non-Saccharomyces yeasts that were present during the natural fermentations were identified using polymerase chain reaction (PCR), while the major volatile chemical compounds were identified with chromatography and mass spectrometry. The sensory and chemical profiles of the naturally fermented wines were significantly different from those of the inoculated wines. PCR analysis identified some of the yeasts present during alcoholic fermentation. In comparison to the inoculated fermented wines, the naturally fermented wines were generally perceived to have more intense and riper tropical fruity aromas, with enhanced sweetness and reduced intensities of sourness, bitterness and astringency. The wines fermented on the skins (FoS) had lower ester and volatile thiol concentrations than the control wines (with no skin contact) and limited skin contact wines. Sensory attributes linked to the FoS wines included aromas of dried fruit, dried grass and a vegetative character, with an increased sour and bitter taste and astringent mouthfeel. In contrast, the wines that were produced with limited skin contact (12 hours) retained their tropical fruity aromas better than the FoS wines. Limited skin contact seemed to have had a less harsh effect on the taste and mouthfeel than the FoS wines. A consumer study was done to establish a Generation Y consumer group’s (18-35 years) preference for the different treated wines. Overall, the naturally fermented wines, which were described as having a strong tropical fruit character, were preferred. The FoS wines were generally disliked by the consumers. Results obtained from the three sensory analysis methods, respectively DA, PM and FC, were similar, thereby confirming the suitability of the rapid methods PM and FC, to extract qualitative information from the sensory profiling of white wine. The results of this study made a significant contribution towards validation of rapid sensory methods for wine evaluation, which are particularly valuable in the context of sustainability and technology transfer to research and industry alike. The knowledge gained on the chemical profiles of SA Chenin blanc is novel and this is one of the first reports on the volatile thiol content of SA Chenin blanc wine.
AFRIKAANSE OPSOMMING: Produsente van Suid-Afrikaanse (SA) droë en semi-droë Chenin blanc tafelwyne eksperimenteer tans met wynmaaktegnieke om die oorwegend vrugtige style van hierdie genre te varieer. ‘n Belangrike fase van wynstylontwikkeling is sensoriese profilering van die produkte met gepaardgaande verbruikersaanvaardingstoetse, voordat die wyne op industriële skaal geproduseer word. Met dié bogenoemde doelwitte in gedagte, was hierdie studie in vennootskap met twee kommersiële SA wynkelders gedoen. Die hooffokus van die studie was om die invloed van twee wynmaaktegnieke, onderskeidelik druifdopkontak en natuurlike fermentasie, op die sensoriese profiele van eksperimenteel geproduseerde Chenin blanc wyne te ondersoek. Resultate wat met beskrywende sensoriese analise (DA) van die wyne verkry is, is vergelyk met dié wat deur twee vinniger sensoriese profileringsmetodes metodes, naamlik projektiewe kartering (PM) en frekwensie van kenmerkaanhaling (FC) verkry is. 'n Verbruikervoorkeurstudie is ook op die wyne gedoen. Ten einde die behandelingseffekte beter te verstaan, is die dominante nie-Saccharomyces giste wat teenwoordig was tydens die natuurlike fermentasie geïdentifiseer met behulp van die polimerasekettingreaksie (PCR), terwyl die vernaamste vlugtige chemiese verbindings geïdentifiseer is met chromatografie en massaspektrometrie. Die sensoriese en chemiese profiele van die natuurlike gefermenteerde wyne was beduidend anders as dié van die geiinokuleerde wyne. PCR analise het sommige giste wat teenwoordig was tydens alkoholies fermentasie geïdentifiseer. In vergelyking met die geiinokuleerde wyne, het die natuurlik gefermenteerde wyne intenser en ryper tropiese vrugtige aromas getoon, met ‘n verhoogde perspesie van soetheid en laer intensiteite van suurheid, bitterheid en vrankheid. Die wyne wat berei is deur fermentasie op die druifdoppe (FoS) het laer konsentrasies van esters en vlugtige swawelverbinding gehad, as die kontrole wyne (geen dopkontak) en beperkte dopkontak wyne. Sensoriese eienskappe gekoppel aan die FoS wyne was geasssosieer met gedroogde vrugte, gedroogde gras en 'n vegetatiewe aroma, met gepaardgaande verhoogde suur en bitter smaakpersepsies en ‘n frank mondgevoel. In teenstelling, het die wyne wat geproduseer is met 'n beperkte dopkontak (12 uur) hul tropiese vrugtige aroma beter behou as die FoS wyne. Beperkte dopkontak het ook ‘n minder negatiewe uitwerking op die smaakpersepies van bitterheid en vrankheid gehad. ‘n Verbruikerstudie is gedoen om 'n groep jong Generasie Y verbruikers (18-35 jaar) se voorkeure vir die verskillende behandelings te bepaal. Oor die algemeen is die natuurlike gefermenteerde wyne, wat beskryf is met 'n sterk tropiese vrugtekarakter verkies, terwyl die groep nie van die FoS wyne gehou het nie. Resultate wat verkry is met drie sensoriese analise metodes, onderskeidelik DA, PM en FC, was soortgelyk en die geskiktheid van die vinniger metodes, PM en FC, om kwalitatiewe inligting van witwyn se sensoriese eienskappe te verkry, is bevestig. Die resultate verkry met hierdie studie maak ‘n beduidende bydrae tot die validering van vinniger sensoriese metodes vir wynevaluering, wat veral waardevol is in die konteks van volhoubaarheid en tegnologieoordrag na navorsing en die industrie. Die nuwe kennis wat in hierdie studie gegenereer is met die chemiese profilering van SA Chenin blanc wyn is baie waardevol en hierdie is een van die eerste narvorsingsprojekte oor die inhoud van vlugtige swawelverbings in SA Chenin blanc wyn.
29
Degen, Rudolf [Verfasser], Marc [Akademischer Betreuer] Spehr, and Ivan [Akademischer Betreuer] Manzini. "Identification and physiological characterization of calcium-activated ion channels in vomeronasal sensory neurons of the mouse / Rudolf Degen ; Marc Spehr, Ivan Manzini." Aachen : Universitätsbibliothek der RWTH Aachen, 2021. http://d-nb.info/1238693865/34.
30
Pereira, Jorge Alberto dos Santos Guieiro. "Characterization of tradional cooked blood and rice sausage from Monchique and shelf life study with different packaging technologies." Doctoral thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/9268.
31
Silva, Paula Porrelli Moreira da. "Conservação de polpa de juçara (Euterpe edulis) submetida à radiação gama, pasteurização, liofilização e atomização." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/64/64134/tde-22042013-171346/.
Анотація:
No Brasil há espécies frutíferas pouco exploradas, que representam oportunidade aos produtores para acessarem mercados especiais, onde consumidores valorizam o caráter exótico e a presença de nutrientes capazes de prevenir doenças degenerativas. Nesse contexto, a palmeira juçara, originária da Mata Atlântica, por muito tempo explorada apenas para a retirada do palmito, atualmente, vem ganhando espaço pela polpa dos seus frutos. Sua cor roxa intensa se deve à presença das antocianinas, poderosos antioxidantes que atuam inibindo ou diminuindo os efeitos desencadeados pelos radicais livres. A polpa é altamente perecível sendo problemática sua conservação em temperatura ambiente, dificultando sua valorização no mercado. Diante disso, são necessárias tecnologias que minimizem perdas nutricionais e sensoriais a fim de produzir alimentos saudáveis, saborosos e duradouros. Este estudo consta de cinco experimentos com polpa de juçara, que objetivaram: avaliar a composição físicoquímica, mineral e lipídica; realizar a caracterização sensorial através da Análise Descritiva Quantitativa (ADQ); avaliar a conservação físico-química e sensorial quando submetida à radiação gama, acidificação e pasteurização em tacho aberto e desidratação por atomização e liofilização. Os frutos foram obtidos no Parque das Neblinas (Mogi das Cruzes/SP) e despolpados no Departamento Agroindústria, Alimentos e Nutrição (ESALQ/USP). Verificou-se que a polpa de juçara é ótima fonte energética e dos minerais K, Fe, Co, Mg, Cu, Zn, Mn e Mo; é rica em antocianinas e em ácidos graxos de boa qualidade (palmítico, oleico e linoleico). A irradiação da polpa foi realizada no Instituto de Pesquisas Energéticas e Nucleares (IPEN - São Paulo, SP) com as doses 0,0; 2,5; 5,0; 7,5 e 10,0 kGy e armazenada a 6°C durante 30 dias (avaliações quinzenais). O referido processo não se mostrou promissor para a conservação do produto a 6°C, pois a degradação das antocianinas e compostos fenólicos foi acelerada e a cor alterada de roxo para marrom, além de não ter sido bem aceita sensorialmente. Ainda, foram estudadas oito combinações entre acidificação (pH<4,0), pasteurização (85°C/5 min.) e armazenamento a 6°C e -18°C, durante 60 dias, com análises quinzenais. A polpa pasteurizada e acidificada foi a que melhor manteve as características físico-químicas e sensoriais, sendo a temperatura de congelamento a variável de melhor resultado. A avaliação da qualidade da polpa desidratada por atomização e liofilização, embalada em bolsas de polietileno (PE) e polietileno revestido com camada de alumínio (PA) durante 120 dias em temperatura ambiente e ao abrigo da luz, revelou que ambos os processos conferiram qualidade físico-química satisfatória e conservação durante o armazenamento, sendo a embalagem PA a mais adequada devido à menor absorção de umidade e prevenção da oxidação. Sensorialmente, como suco reconstituído e adicionado de banana nanica e açúcar, a polpa de juçara liofilizada foi a mais bem aceita. Para a ADQ, foi treinada equipe para a avaliação de amostras congeladas e pasteurizadas pós-embalagem (85°C/5 min.) armazenadas sob refrigeração e congelamento, visando-se obter o perfil sensorial de cada uma. A polpa pasteurizada congelada foi a que apresentou melhores características sensoriais, sendo descrita como aerada, pouco heterogênea, sabor pouco amargo e pouco adstringenteIn Brazil there are unexplored fruit species, which represent an opportunity for producers to access special markets, where consumers appreciate the exotic character and presence of nutrients capable of preventing degenerative diseases. In this context, juçara palm (Euterpe edulis), native of the Atlantic Forest, has long been explored only for the removal of the stem, but currently the pulp of its fruit is becoming more popular. The intense purple color is due to the presence of anthocyanins, powerful antioxidants that act by inhibiting or decreasing the effects unleashed by free radicals. The pulp is highly perishable and its preservation is impossible at room temperature, lowering its market value in sales. In face of this, we need technologies that minimize nutritional and sensorial losses in order to produce healthy, tasty and long lasting foods. This study consists of five experiments with juçara pulp, which aimed to: evaluate the physico-chemical, mineral and lipid composition; realize the sensory characterization by Quantitative Descriptive Analysis (QDA); evaluate the physico-chemical and sensory conservation when submitted to radiation gamma, acidification and pasteurization, and dehydration by spray and freeze drying. The fruits have been obtained at Parque das Neblinas (Mogi das Cruzes/SP) and depulped at Agribusiness, Food and Nutrition Department (ESALQ/USP). Was verified that juçara pulp is excellent source of energy and minerals K, Fe, Co, Mg, Cu, Zn, Mn and Mo; rich in anthocyanins and fatty oils of good quality (palmitic, oleic and linoleic). The irradiation of pulp was performed at the Institute of Energy and Nuclear Research (IPEN - São Paulo, SP) at doses 0,0, 2,5, 5,0, 7,5 and 10,0 kGy and stored at 6°C for 30 days (fortnightly assessments). That process was not promising for the conservation of the product at 6°C, because the degradation of anthocyanins and phenolic compounds was accelerated and the color changed from purple to brown, in addition to lacking been accepted sensorially. Further, eight combinations have been studied among acidification (pH<4.0), pasteurization (85°C/5 min.) and storage at 6°C and -18°C for 60 days with biweekly tests. The pasteurized and acidified pulp was that best maintained the physicochemical and sensory characteristics, and the freezing storage was the variable of the better result. The evaluation of quality pulp dehydrated by freeze and spray drying, packaged in bags of polyethylene (PE) and polyethylene-coated aluminum layer (PA) for 120 days at room temperature and protected from light, revealed that both processes conferred physicochemical quality satisfactory and conservation during storage, the packaging PA is the most suitable due to lower absorption of moisture and prevention of oxidation. Sensorially, as reconstituted juice and added to sugar and banana nanica, juçara pulp freeze dried was the more accepted. For the QDA have been trained team for the evaluation of frozen and postpackaging pasteurized samples (85°C/5 min.) stored under refrigeration and freezing, in order to obtain the sensory profile of each. The frozen pasteurized pulp presented the best sensory characteristics, being described as aerated, slightly heterogeneous, taste slightly bitter and slightly astringent
32
Krech, Joshua D. "Characterization of Inhbb, Heatr5a, & Cyp2s1 Expression in Dorsal Root Ganglia by In-Situ Hybridization." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1622497045566932.
33
Mahmoud, Mohamed [Verfasser], Andrea [Akademischer Betreuer] Buettner, and Michael [Gutachter] Rychlik. "Rainbow trout from aquacultural farming − characterization of aroma profiles as basis for future targeted optimization of sensory quality / Mohamed Mahmoud ; Gutachter: Michael Rychlik ; Betreuer: Andrea Buettner." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2019. http://d-nb.info/1190359405/34.
34
Dintner, Sebastian [Verfasser], and Susanne [Akademischer Betreuer] Gebhard. "Characterization of a sensory complex involved in antimicrobial peptide resistance : communication between a histidine kinase and an ABC transporter in Bacillus subtilis / Sebastian Dintner. Betreuer: Susanne Gebhard." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1062492692/34.
35
Pinto, Luan Ãcaro Freitas. "Acerola (Malpighia emarginata DC) and pineapple (Ananas comosus L. Merrill) as adjuncts in processing beer: characterization and acceptability." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14306.
Анотація:
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoBeer is the most consumed alcoholic beverage in the world. Its consumption is associated with festivities and celebrations, being recognized by its customers as a beverage with high caloric value. However, this beverage contains a variety of bioactive compounds, vitamins and minerals that promote benefits when its intake is made moderate manner. The market is every day looking for different and even unique products, thus arises the field of craft beers. The objective of this study was to develop a craft beer with acerola and pineapple and study their physicochemical and sensory characteristics, as it brings a new alternative in this niche market, besides the association with increased its functional characteristics. We used the rotational central composite design (CCRD) for the development of treatments where the variation of the percentage of addition of the acerola fruit juice and pineapple varied at levels of 5 to 25% of the total volume of beer. The CCRD included eleven trials: four factorial points, four axial and three repetitions at the central point. The results of the CCRD were analyzed using the Response Surface Methodology (RSM), with the response variable physico-quÃmcos and sensory parameters. For statistical analysis was applied to analysis of variance, Tukey test and regression analysis. Processing took place in laboratory scale. The pulps were characterized by physical-chemical analysis, and then made by the addition of juice during the process of maturation that occurred simultaneously with primming process amber glass bottles of 355 ml. The results of the sugar content, total acids and pH of fruit pulps showed satisfactory being considered suitable for the maturation process. The results of physicochemical tests showed similar results in all treatments, and the factor adding fruit juice was directly proportional to parameters such as acidity and pH, and inversely proportional to parameters such as alcohol, real extract, apparent extract and extract primitive. Microbiological testing resulted in a minimum count of coliforms, thermotolerant and molds and yeasts, adapting to the standards set by law for beer, showing the process control efficiency, ensuring product quality. The means of the sensory attributes of all samples showed up outside the stopband, especially for samples 5 and 8, which have higher pineapple juice content. The results of the response surface showed that addition of up to 16% of both pulps pineapple or additions of high concentrations (up to 28%) in groups with low concentrations of acerola (up to 6%) show a maximization of sensory attributes. It was concluded that the use of pineapple pulp and acerola as adjuncts in the beer processing proved to be a viable alternative due to satisfactory results in sensory evaluation, and physical and chemical characteristics that proved a craft beer with acidy/fruity characteristics.
A cerveja à a bebida alcoÃlica mais consumida no mundo. Seu consumo està associado a festividades e comemoraÃÃes, sendo reconhecida pelos seus consumidores como uma bebida com alto valor calÃrico. Entretanto, essa bebida contÃm uma variedade de compostos bioativos, vitaminas e minerais, capazes de promover benefÃcios quando a sua ingestÃo à feita de maneira moderada. O mercado està a cada dia buscando produtos diferenciados e atà exclusivos, surge assim o campo das cervejas artesanais. O objetivo deste trabalho foi desenvolver uma cerveja artesanal com acerola e abacaxi e estudar suas caracterÃsticas fÃsicoquÃmicas e sensoriais, pois traz uma nova alternativa neste nicho de mercado, alÃm da associaÃÃo ao aumento de suas caracterÃsticas funcionais. Foi utilizado o Delineamento Composto Central Rotacional (DCCR) para o desenvolvimento dos tratamentos, onde a variaÃÃo do percentual de adiÃÃo de suco de fruta de acerola e abacaxi variou em nÃveis de 5 a 25% do volume total da cerveja. O DCCR incluiu onze ensaios: quatro pontos fatoriais, quatro axiais e trÃs repetiÃÃes no ponto central. Os resultados do DCCR foram analisados atravÃs da Metodologia de SuperfÃcie de Resposta (MSR), tendo como variÃveis resposta os paramÃtros fÃsico-quÃmcos e sensorias. Para a avaliaÃÃo estatÃstica foi aplicada a anÃlise de variÃncia, teste de Tukey e anÃlise de regressÃo. O processamento ocorreu em escala laboratorial. As polpas foram caracterizadas atravÃs de anÃlises fÃsico-quÃmicas e em seguida fez-se a adiÃÃo do suco durante o processo de maturaÃÃo que ocorreu simultaneamente ao processo de primming em garrafas de vidro Ãmbar de 355 mL. Os resultados do teor de aÃucares, Ãcidos totais e pH das polpas de frutas apresentaram satisfatÃrios sendo considerados adequados para o processo de maturaÃÃo. Os resultados dos testes fÃsicoquÃmicos mostraram resultados semelhantes em todos os tratamentos, sendo que o fator adiÃÃo de suco de frutas foi diretamente proporcional a parÃmetros como acidez e pH, e inversamente proporcional a parÃmetros como teor alcoÃlico, extrato real, extrato aparente e extrato primitivo. Os testes microbiolÃgicos resultaram em uma contagem mÃnima para coliformes totais, termotolerantes e bolores e leveduras, adequando-se aos padrÃes estabelecidos pela legislaÃÃo para cerveja, mostrando assim a eficiÃncia do controle do processo, garantindo a qualidade do produto. As mÃdias dos atributos sensoriais de todas as amostras apresentaram-se fora da faixa de rejeiÃÃo, com destaque para as amostras 5 e 8, as quais possuem maiores teores de suco de abacaxi. Os resultados das superfÃcies de resposta mostraram que adiÃÃes de atà 16% de ambas as polpas ou adiÃÃes de elevadas concentraÃÃes de abacaxi (atà 28%) em conjuntos com baixas concentraÃÃes de acerola (atà 6%) mostram uma maximizaÃÃo dos atributos sensoriais. Concluiu-se que a utilizaÃÃo das polpas de abacaxi e acerola como adjuntos no processamento de cerveja mostrou-se uma alternativa viÃvel devido aos resultados satisfatÃrios na avaliaÃÃo sensorial, alÃm de caracterÃsticas fÃsicoquÃmicas que comprovaram uma cerveja artesanal com caracterÃsticas Ãcida/frutada.
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Koenig, Lea. "Démarche taxonomique appliquée à la structuration hiérarchique d’un lexique aromatique et application à la caractérisation sensorielle des vins par une méthode HRATA." Thesis, Nantes, Ecole nationale vétérinaire, 2020. http://www.theses.fr/2020ONIR144F.
Анотація:
La caractérisation aromatique des vins est une tâche complexe, même pour les évaluateurs expérimentés. Pour la faciliter, les termes aromatiques peuvent être regroupés par catégorie d’odeurs et présentés parfois sous forme de roues. Dans cette thèse, une nouvelle méthodologie, appelée Hierarchical-Rate-All-That-Apply (HRATA) est proposée. Celle-ci associe une structuration hiérarchique des attributs avec la méthodologie Rate-All-That-Apply (RATA) et est appliquée à la caractérisation aromatique de vins. Une première réflexion porte sur la structuration hiérarchique d’un lexique de termes aromatiques sur la base d’une expérimentation de tri libre. La représentation des proximités entre termes s'appuie sur la méthodologie des arbres additifs qui combinée à une stratégie de catégorisation permet de proposer une structuration taxonomique du lexique mis en œuvre. Une attention particulière est également portée sur l’influence de l’expertise dans la structuration d’un lexique aromatique du vin. La structuration hiérarchique est finalement intégrée lors de l’évaluation sensorielle au moyen d’une épreuve de notation de type RATA. Cette nouvelle méthode HRATA offre plus de liberté aux sujets car ils peuvent sélectionner les termes descriptifs à partir d'une grande variété d'attributs, généraux ou spécifiques selon leur sensibilité individuelle. Du point de vue statistique, les méthodes usuelles sont adaptées pour l’identification des attributs discriminants et la détermination d’une carte des produits. Du point de vue statistique, les méthodes usuelles sont adaptées pour l’identification des attributs discriminants et la détermination d’une carte des produitsThe aromatic characterization of wines turns out to be a complex task, even for well-trained assessors. To gain ease, a common way consists in grouping terms into odor categories and organizing them by wheels. In this thesis, a new methodology, called Hierarchical-Rate-All-That-Apply (HRATA), is proposed. It combines a hierarchical structuration of the set of attributes together with Rate-All-That-Apply (RATA) notation. The HRATA methodology is then applied for the aromatic characterization of wines. In the first part, the structuration of a lexicon of aromatic terms is defined on the basis of a free sorting experiment. The representation of the proximities between terms is carried out by means of additive trees. An original partitioning technique is proposed, on the basis of an additive tree, which makes it possible to set up the taxonomic structuration of the lexicon. Particular attention is also paid to the influence of expertise in the structuration of an aromatic lexicon of wine. The hierarchical structure, thus obtained, is finally integrated into a sensory evaluation by means of a RATA rating. This new methodology HRATA provides a user-friendly characterization for subjects since they can rate descriptive terms from a wide variety of attributes, general or specific, depending on their individual sensitivity. From a statistical point of view, an adaptation of the usual techniques is carried out for the identification of discriminating attributes and the determination of a product map
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Brard, Margot. "Méthodologies statistiques pour le recueil et l’analyse de données de caractérisation de grands ensembles de stimuli - Application à la caractérisation sensorielle de produits & à la caractérisation de gestes culinaires." Thesis, Rennes, Agrocampus Ouest, 2019. http://www.theses.fr/2019NSARG017/document.
Анотація:
Dans le secteur agroalimentaire, la caractérisation des gestes culinaires est considérée de plus en plus comme un levier d’innovation. En observant et en analysant la manière avec laquelle leurs produits sont appréhendés en cuisine par les usagers (consommateurs ou professionnels), les industriels peuvent en effet déceler des pistes d’amélioration ou des idées de nouveaux produits.Dans ce travail de recherche, nous proposons de nouvelles méthodes dédiées à la caractérisation des gestes culinaires. Leur caractère innovant repose sur le fait qu’elles relèvent d’une approche quantitative, et non d’une approche qualitative comme cela est usuellement le cas. Elles s’inspirent en partie de deux méthodes de caractérisation utilisées en analyse sensorielle : le tri libre et la Q-méthodologie binaireNous voyons comment des développements méthodologiques apportés à ces dernières permettent de caractériser des grands ensembles de stimuli. Ces développements sont liés à la fois à la procédure de recueil des données et à la procédure d’analyse statistique des données.En particulier, nous proposons plusieurs procédures statistiques permettant d’aborder des problématiques variées : l’analyse d’un ensemble de partitions contenant des données manquantes, la classification non supervisée de profils d’évaluations binaires basée sur la notion d’accord inter-évaluateurs, etc.Nous voyons ensuite que les deux méthodes de caractérisation quantitatives ‘améliorées’ sont applicables à des gestes culinairesIn the agri-food sector, the characterization of culinary techniques - through their observation and analysis - is increasingly seen as a lever for innovation. By analyzing how their products are used in the kitchen by the users (consumers or professionals), the manufacturers can detect improvement tracks or ideas for new products.In this research, we propose new methods dedicated to the characterization of culinary techniques. Their innovative nature is based on the fact that they are based on a quantitative approach, and not on a qualitative approach as is usually the case. They partially draw their inspiration in two methods of characterization used in sensory analysis: the free sorting and the binary Q-methodologyWe see how methodological developments brought to the latter make it possible to characterize large sets of stimuli. These developments are both related to the procedure of data collection and to the procedure of statistical analysis of the data. In particular, we propose several statistical procedures to address various issues: the statistical analysis of a set of partitions containing missing data, the unsupervised agreement-based clustering of a set of profiles of binary evaluations, etc.Then, we see that these two 'improved' quantitative methods of characterization can be successfully applicable to culinary techniques
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Bianchi, Elisa [Verfasser], Wolfgang [Akademischer Betreuer] Wurst, and Ruiz Ramón A. [Akademischer Betreuer] Torres. "Characterization of molecular mechanisms that govern the formation of neuronal circuits in the developing vertebrate spinal sensory-motor system / Elisa Bianchi. Gutachter: Wolfgang Wurst ; Ramón A. Torres Ruiz. Betreuer: Wolfgang Wurst." München : Universitätsbibliothek der TU München, 2010. http://d-nb.info/1056936819/34.
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Sanahuja, Solange Désirée Maximilienne [Verfasser], Heiko [Akademischer Betreuer] Briesen, Heiko [Gutachter] Briesen, and Andrea [Gutachter] Büttner. "Multimodal & Spectral Characterization of Complex Food Textures : Crispiness and Friction-Related Textures Explained by Mechanical, Acoustical, Tribological and Sensory Analyses / Solange Désirée Maximilienne Sanahuja ; Gutachter: Heiko Briesen, Andrea Büttner ; Betreuer: Heiko Briesen." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1230985220/34.
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Zhai, Xiaoting [Verfasser], Michael [Akademischer Betreuer] Granvogl, Karl-Heinz [Gutachter] Engel, and Michael [Gutachter] Granvogl. "Characterization of the Key Aroma Compounds in Raw Toona sinensis (A. Juss.) Roem. Buds and Their Products by Application of the Molecular Sensory Science Concept / Xiaoting Zhai ; Gutachter: Karl-Heinz Engel, Michael Granvogl ; Betreuer: Michael Granvogl." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1224047125/34.
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ALMEIDA, Renata Duarte. "Tecnologia para produção industrial de umbuzada de corte." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/928.
Анотація:
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RENATA DUARTE ALMEIDA – TESE (PPGEP) 2017.pdf: 2335363 bytes, checksum: 0dab812c856b00737582f4fa8aeb67f6 (MD5)Made available in DSpace on 2018-06-11T20:04:19Z (GMT). No. of bitstreams: 1 RENATA DUARTE ALMEIDA – TESE (PPGEP) 2017.pdf: 2335363 bytes, checksum: 0dab812c856b00737582f4fa8aeb67f6 (MD5) Previous issue date: 2016-12
O umbu apresenta um grande potencial a ser explorado e o desenvolvimento de novas tecnologias visa estabelecer condições que retardem o seu amadurecimento, mantendo a qualidade e prolongando a vida útil durante o armazenamento, possibilitando ainda minimizar as perdas pós-colheita e o surgimento de novos produtos no mercado, a exemplo dos doces de corte que podem estimular fortalecimento da agricultura familiar e o desenvolvimento de pequenas agroindústrias. Objetivou-se, com este trabalho, o desenvolvimento de uma tecnologia para produção de doce de umbu de corte com leite e sem leite preservando o sabor característico da fruta e de aceitação sensorial. Os frutos foram cozidos em água durante 5 minutos após fervura, em seguida foi feita a extração da polpa de forma manual, a massa obtida foi homogeneizada e acondicionadas em freezer horizontal à temperatura de -30ºC. Foram investigados, assim, as características, físicas, físico-quimicas, químicas, microbiológicas da polpa pré-cozida e dos doces de corte de umbu, o comportamento reológico das diferentes formulações para a elaboração dos doces a 5, 10, 15 e 25 ºC, as curvas de congelamento das formulações nas temperaturas de -20, -50 e -75ºC, além da avaliação instrumental de textura, teste TPA e da análise descritiva de ordenação dos doces de corte de umbu. Os doces que apresentaram maior porcentagem de leite/açúcar (I) 89,32% e açúcar (II) 85,21% em suas formulações resultaram em um maior rendimento e tempo de preparo dos doces. No estudo reológico para uma tensão de cisalhamento fixa a taxa de deformação diminui com o aumento da temperatura, confirmando o caráter não newtoniano e comportamento pseudoplástico, os modelos de Herschel-Bulkley e Mizrahi-Berk apresentaram ajustes semelhantes e também foram os melhores modelos para todas as formulações estudadas. As curvas de congelamento apresentaram as três fases bem definidas e um comportamento tendencioso, no qual a difusividade efetiva média aumenta à medida que diminui a quantidade de água e aumenta os sólidos presentes nas amostras. A avaliação do parâmetro de firmeza indica que o aumento da concentração de polpa de umbu aumenta o valor da adesividade, uma vez que o processo faz com que o tempo de cocção seja maior, tornando o produto mais firme e consequentemente, mais adesivo. Os valores de gomosidade e mastigabilidade apresentam o mesmo comportamento da firmeza, em que, quanto maior for a concentração da polpa de umbu nos doces elaborados, maior será a energia necessária para mastigar o produto. Percebe-se que o doce (II) sem adição de leite em sua formulação apresentou o maior valor médio (4,41) na análise de preferência, aparência (4,64), cor (5,05) e consistência (4,41), o que indica a maior preferência pelos julgadores. No entanto, mesmo os doces sem adição de leite possuindo coloração semelhante aos doces comerciais de goiaba a similaridade desses doces não influenciou nos resultados dessa pesquisa, conforme as médias de preferência foram verificadas também nos doces de umbu com adição de leite nas formulações, I (4,11), III (3,73) e V (4,12) o que resulta na boa aceitação pelos julgadores.
The umbu has great potential to be exploited and the development of new technologies aiming to establish conditions that delay ripening, maintain quality and prolong shelf life, will contribute to minimize postharvest losses and the emergence of new products on the market, such as fruit preserves that can stimulate the strengthening of family farming and the development of small agro-industries. The objective of this work was the development of a technology for the production of umbu sweet paste with milk and without milk preserving the characteristic fruit flavor and sensory acceptance. The fruits were boiled in after boiling water for 5 minutes, then the pulp was extracted manually, the mass obtained was homogenized and conditioned in a horizontal freezer at the temperature of -30 ° C. Several characterization techniques were employed namely: the physical, chemical, physicochemical, and microbiological characteristics of the precooked pulp and the umbu paste; the rheological behavior of the different formulations for the preparation of umbu pastes at 5, 10, 15 and 25 ºC; the freezing curves of those formulations at temperatures of -20, -50 and -75ºC; as well as the instrumental evaluation of texture, TPA test and the descriptive analysis of the order of the umbu paste. The sweets that presented the highest percentage of milk / sugar (I) 89.32% and sugar (II) 85.21% in their formulations resulted in a higher yield and higher preparation time of the umbu paste. In the rheological study, using a constant shear stress, the rate of deformation decreases with increasing temperature, confirming the non-Newtonian character and the pseudoplastic behavior, where the Herschel-Bulkley and Mizrahi-Berk models presented similar adjustments and were also the best models for all the formulations studied. The freezing curves presented the three well defined phases and a biased behavior, where the average effective diffusivity increases with decreasing water content and increasing solids content in samples. The evaluation of the firmness parameter indicates that the increase of the concentration of umbu pulp increases the value of the adhesiveness, due to the necessity of larger cooking times making the product firmer and consequently more adhesive. The guminess and chewiness values show the same firmness behavior, which is the higher the concentration of the umbu pulp in the umbu paste, the greater the energy required to chew the product. It was observed that the umbu paste (II) without added milk in its formulation had the highest mean value (4.41) in the analysis of preference, appearance (4.64), color (5.05) and consistency (4.41), which indicates the highest preference of the judges. However, eventhough the umbu paste without added milk had similar coloration to the commercial guava paste, the similarity of both pastes did not influence the results of the present research, as the averages of preference were also verified in the umbu paste with addition of milk in the formulations, I (4,11), III (3,73) and V (4,12) which results in a good acceptance by the judges.
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Rocha, Patrícia Andrea Bastião. "Characterization of bacteria isolated from Portuguese traditional cheeses." Master's thesis, 2019. http://hdl.handle.net/10451/40577.
Анотація:
Tese de mestrado, Microbiologia Aplicada, Universidade de Lisboa, Faculdade de Ciências, 2019A fermentação tradicional de queijos e realizada em muitos países do mundo, nomeadamente Portugal, sendo que consiste no aproveitamento dos microrganismos naturalmente presentes no leite cru. Estes microrganismos encontram-se no leite devido as diferentes etapas de colheita e manuseamento durante e apos esse processo. Sendo que, alteram as moléculas presentes no leite através da fermentação dando novas propriedades ao produto final que será posteriormente curado. As condições destas fases de fermentação e maturação diferem entre tipos de queijos e zonas de produção, determinando as propriedades organoleticas do produto final. Os queijos de Azeitão e Nisa fazem parte dos 10 queijos portugueses que possuem a categoria de denominação de origem protegida (DOP). As zonas de produção dos queijos de Azeitão são Palmela, Sesimbra e Setúbal e as de Nisa são Nisa, Crato, Castelo de Vide, Marvão, Portalegre, Monforte, Arronches e Alter do Chão. Ambos são produzidos com leite de ovelha cru. No caso de Nisa o leite provém de uma raça de ovelha chamada Merina Branca e no caso de Azeitão não se especifica uma raça. O coalho vegetal usado na produção de ambos queijos é obtido de Cynara cardunculus L. Devido às diferentes fases e condições de produção o queijo de Azeitão consiste numa pasta semi-mole e amanteigada, de cor branca ou ligeiramente amarelada com um sabor ácido e salgado. O queijo de Nisa consiste numa pasta semi-dura de cor branca amarelada com um sabor ligeiramente ácido e um cheiro intenso. As bactérias ácido lácticas (BAL) são um grupo de vários géneros que partilham características em comum como serem gram-positivas, catálase negativas, não formam esporos, anaeróbicas facultativas e terem um nível G+C baixo. Para além disto, o seu nome provém da sua capacidade para fermentar açúcares, transformando-os em ácido láctico através de homo- ou heterofermentacao. Este grupo e o predominante em leite cru e, portanto, em queijos produzidos de forma artesanal e essas bactérias vão desempenhar diversos papéis ao longo da fermentação e maturação deste tipo de queijo. Os géneros de BAL que predominam em comidas fermentadas como os queijos são Lactococcus, Streptococcus, Pediococcus, Leuconostoc, Lactobacillus e Enterococcus. Tendo em conta que estas bactérias formam parte tanto da cadeia alimentar como da microbiota de animais e seres humanos podem servir como veículo de transmissão de genes ao existir uma transferência genética entre espécies ou géneros, como descrito na literatura. A problemática desta possível transferência ocorre quando esses genes conferem resistência a antibióticos ou fatores de virulência que anteriormente essas bactérias não possuíam. Essa transferência pode ocorrer para algumas bactérias que formam parte da nossa microbiota e são responsáveis por infecções oportunistas ou para bactérias patogénicas presentes no nosso corpo devido a uma infecção. Resistências adquiridas a antibióticos tem sido estudadas e observadas em BAL, em concreto em Enterococcus spp. devido ao seu papel patogénico oportunista. Foram descritas resistências a antibióticos de diferentes classes como ϐ-lactâmicos, cefalosporinas, aminoglicosidos, lincosamidas e estreptograminas. Em concreto, resistências a tetraciclina e eritromicina são das mais preocupantes devido a importância destes antibióticos e porque esta resistência tem sido atribuída ao uso indevido de antibióticos em comida de animais. Este trabalho teve como objetivo continuar o estudo de queijos de Azeitão e Nisa DOP que começou numa dissertação anterior onde se caracterizaram estes queijos pela sua microbiota e propriedades físico-químicas. Seguido deste estudo foi também analisada a diversidade dos microbiomas destes produtos como parte de outra dissertação. Assim, o presente trabalho consistiu em comparar os resultados anteriores de diversidade e caracterização microbiológica assim como completar essa análise com a procura de resistências a antibióticos e fatores de virulência. Durante o ano de 2018 foram recolhidos queijos de seis queijarias de Azeitão e de duas queijarias de Nisa. A partir destes foram feitas contagens de unidades formadoras de colonias (UFC) e isoladas as bactérias de diferentes grupos, nomeadamente, BAL isoladas com meio MRS (maioritariamente Lactobacillus spp.), Lactococcus spp. com meio M17 e Enterococcus spp. isoladas com meio SBA. Depois foi extraído o ADN desses isolados para realizar a técnica de RAPD-PCR e análise de dendrogramas criados com os perfis de bandas obtidos. A partir estes dendrogramas foi analisada a semelhança entre os isolados dos distintos queijos e foram obtidos índices de diversidades dos diferentes grupos de bactérias e queijarias estudadas. Esta diversidade e as contagens de bactérias foram comparadas as obtidas noutras dissertações deste mesmo projeto nas quais se estudaram anos de produção anteriores. Partindo destes mesmos dendrogramas, foram escolhidos isolados representantes de cada queijaria e realizados testes de resistência a antibióticos assim como a presença de factores de virulência. Relativo aos diferentes anos de produção estudados não foi observada uma tendência clara de contagens de UFC quando comparados os anos ou queijarias, isto e, não houve queijos que tivessem consistentemente maior ou menor numero de bactérias sendo que este numero foi variável ao longo dos anos. Enquanto a diversidade, foram observadas poucas coincidências nas queijarias com maior ou menor índice de diversidade. No caso dos lactococos foi observado o menor índice correspondente aos anos 2018 e 2016 na mesma queijaria, A4. Nos enterococos foi também encontrada a menor diversidade na mesma queijaria, N9, nos queijos dos anos 2018 e 2016. Nas amostras de 2018 o grupo com maior diversidade foi o dos enterococos mas cabe destacar que os três grupos bacterianos tiveram índices muito parecidos. A identificação dos representantes deste grupo de bactérias dos queijos de 2017 foi realizada com uma multiplex PCR e a maioria de isolados foi identificado como E. faecium, seguido por E. faecalis y E. durans estando igualmente representados em número de isolados. Foram encontradas diferenças significativas no numero de resistências ao longo dos anos nos grupos Lactococcus spp e Enterococcus spp. No caso deste último género, ocorreram também diferenças significativas entre o número de isolados resistentes de diferentes queijarias durante os três anos estudados. As resistências a antibióticos encontradas no grupo de BAL foram a clindamicina e eritromicina, no caso dos lactococos as resistências que foram observadas neste trabalho são consideradas intrínsecas pelo que não haveria possibilidade de transferência dessas resistências para outras bactérias. As resistências extrínsecas encontradas nos enterococos foram a teicoplanina, ciprofloxacina, tetraciclina, cloranfenicol, eritromicina e vancomicina. Apesar de terem sido observados isolados resistentes a três antibióticos de três classes diferentes estes não cumpriam todos os requisitos de modo a serem considerados multirresistentes. No estudo de fatores de virulência foi detetada a capacidade de hemólise em 11% dos representantes de 2016, 6% nos de 2017 e 12% nos de 2018. No teste para identificar a produção de gelatinase so foram observados dois resultados positivos e esses pertenciam a isolados de queijos de 2017. Concluindo, a diversidade do microbioma e as contagens dos queijos de Azeitão e Nisa estudados não seguiram nenhum padrão nos anos que foram comparados. O número de Enterococcus spp. resistentes diminuiu desde 2016 ate ao ultimo ano estudado neste trabalho, 2018, mas as resistências encontradas nos isolados de 2018 foram a antibióticos mais relevantes para a saúde pública como são a vancomicina, eritromicina e tetraciclina. No mesmo sentido, também não foram encontrados isolados multirresistentes e os fenótipos dos fatores de virulência estudados não foram observados em grande quantidade. Contudo, deve ser referido que o estudo destes queijos continuara e serão feitos mais testes tanto no âmbito da diversidade como do potencial patogénico dos isolados das bactérias acido lácticas presentes.
Azeitão and Nisa cheeses are products with protected designation of origin (PDO) traditionally manufactured in Portugal with sheep’s raw milk. The predominant group of bacteria in cheeses is lactic acid bacteria (LAB) which includes genera like Lactococcus spp. and Enterococcus spp., these are the microorganisms our work will be focusing on. The fact that these bacteria have important roles both in foods and the gut of animals (including humans) makes them conductors for both positive impact, such as probiotic features, and negative impact, such as transference of virulence factors or antibiotic resistances. Our aim with this work was to analyse the diversity of LAB in Azeitão and Nisa cheeses from several origins and years of production and assess the negative traits these bacteria could have and transfer such as antibiotic resistances, hemolysis and production of gelatinase. Enumeration of previously mentioned bacteria was performed, and results were compared to other years of production. During the years studied no unit had consistently higher CFU counts. Lactococcus spp. was the group with highest bacteria counts in the majority of units during the three years studied and Enterococcus spp. was the one with the lowest CFU. For diversity analysis, RAPD-PCR were performed in order to create dendrograms for each cheesemaking unit and bacterial group. Just like for bacterial enumeration, no specific trends were observed in the diversity values for the units throughout the studied years. Concerning 2018 cheeses, the group with the highest diversity was Enterococcus spp. even though it was also the one with less CFU. This independence between CFU counts and diversity was noted all through our work in different years, units and groups of bacteria. Identification of 2017 enterococci representatives was performed using a multiplex PCR and showed a predominance of E. faecium, followed by E. faecalis and E. durans that were equally represented. Pathogenic potential of representative isolates was assessed through the search of antibiotic resistances and virulence factors. Antibiotic susceptibility was studied through disc diffusion assays. Significant differences were observed in the number of resistances found in studied years for lactococci and enterococci. Between units there was also significant differences in the total number of resistances during 2016, 2017 and 2018 in enterococci. In LAB isolates resistances considered non intrinsic were found, to clindamycin and erythromycin. Furthermore, enterococci isolates resistant to teicoplanin, ciprofloxacin, tetracycline, chloramphenicol, erythromycin and vancomycin were observed. Isolates resistant to three or more antimicrobial agents were observed but these didn’t comply with the characteristics necessary to be classified as multidrug-resistant (MDR) bacteria. Virulence factors were studied and hemolysis was detected in 11% of representative isolates from 2016, 6% from 2017 and 12% in isolates from 2018 cheeses. Furthermore, only two positive results for gelatinase were found in 2017 representative isolates. In conclusion, our results showed that no pattern of bacterial enumeration or microbiome diversity is present throughout different years of production in artisanal cheeses such as the ones studied. Moreover, although alarming resistances were found in enterococci no multi-drug resistance isolates were observed. Further work should be performed to continue the characterization of the pathogenic potential of isolates present in these cheeses.
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Sousa, André Filipe Santos. "Generation and characterization of functional sensory neurons from hESCs and hiPSCs." Master's thesis, 2016. http://hdl.handle.net/10316/33508.
Анотація:
SOUSA, André Filipe Santos - Generation and characterization of functional sensory neurons from hESCs and hiPSCs. Coimbra : [s.n.], 2016. Dissertação de Mestrado em Biologia Celular e Molecular.The lack of access to the neuronal tissue, limited our understanding about its development and physiology of pain in humans. Therefore, the generation of functional human sensory neurons for disease modelling, drug screening and clinical applications is an urgent and unmet need. Nociceptors are the sensory neurons related to sense the pain, characterized by the presence of transient receptor potential channels which have sensory functions linked to transduction of noxious stimuli as well as signalling within the pain system. In this thesis, we first characterized the nociceptors generated from induced pluripotent stem cell with a protocol developed on the laboratory, comparing it to a protocol described by Young et al., 2014. We used techniques as real-time reverse transcription-polymerase chain reaction and staining to check the neuronal phenotyping of the cells generated, as well as calcium imaging as a functional assay, to test about the functionality of transient receptor potential (TRP) channels, in order to characterize the neurons generated. We showed that only after 50 days of differentiation with both protocols we can have functional mature sensory neurons, with transient receptor potential cation channel sub family V, member 1 and transient receptor potential cation channel subfamily A, member 1 being activated. Moreover, the best results were achieved with the adapted protocol. Next, we focused on different approaches to improve the differentiation protocol. Changing cell line and replating dilution, did not enhance the protocol. Hence, we next hypothesized that current hurdles to speed up differentiation might be overcome by overexpression of key transcription factors involved in the sensory neurons differentiation: PR domain 12, brain-specific homeobox 3A, insulin gene enhancer and kruppel-link zinc finger transcription factor. A technique used on the laboratory, recombinase-mediated cassette exchange, was employed to generate two cell lines, one overexpressing PRDM12 and the other overexpressing ISL1-BRN3A-KLF7. We proved that in the new cell lines, the transcription factors were being correctly overexpressed, and collectively our results demonstrate that overexpressing PRDM12 improves the homogeneity of the cells generated. Further studies are required to evidence the impact of this new cell lines on the upgrading of the differentiation protocol. This work will open new opportunities for investigating in vitro disease modelling and evaluation of pharmacological responds to pain research.
A falta de acesso ao tecido neuronal limita o nosso conhecimento acerca do seu desenvolvimento e da fisiologia da dor nos humanos. Portanto, a geração de neurónios sensoriais humanos funcionais de forma à criação de modelos de doenças relacionadas com a dor, triagem de drogas e aplicações clinicas é uma necessidade urgente e não atendida. Os nociceptors são os neurónios sensoriais responsáveis por receber o estímulo da dor, caracterizados pela presença dos TRP channels que têm funções sensoriais na medida em que estão ligados à transdução de estímulos nocivos assim como à sinalização dentro do sistema da dor. Nesta tese, primeiramente caracterizamos os nociceptors gerados a partir de células estaminais recorrendo a um protocolo desenvolvido no nosso laboratório, comparando-o a um protocolo descrito por Young et al., 2014. Foram usadas técnicas como qRT-PCR e staining, de forma a conferirmos o fenótipo neuronal das células geradas, assim como calcium imaging como um teste funcional acerca da atividade dos TRP channels com o objetivo de caracterizarmos os neurónios gerados. Aqui, demonstramos que apenas após 50 dias de diferenciação com ambos protocolos conseguimos obter neurónios sensoriais maduros funcionais, com a ativação de TRPV1 e TRPA1. Ainda, o protocolo adaptado no laboratório teve melhores resultados. De seguida, focamo-nos nas várias formas de melhorarmos o protocolo de diferenciação. Mudar a linha celular usada e a diluição na fase de replating não aperfeiçoou o protocolo. Sendo assim, supomos que as barreiras em conseguir uma diferenciação mais rápida podiam ser ultrapassadas pelo aumento de expressão de fatores de transcrição envolvidas na diferenciação de neurónios sensoriais: PRDM12, BRN3A, ISL1 e KLF7. Uma técnica usada no laboratório, RMCE, foi usada de forma a gerar duas linhas celulares, uma com o aumento de expressão de PRDM12, e a outra com o aumento de expressão de ISL1, BRN3A e KLF7. Neste trabalho provamos que as novas linhas celulares estavam de facto com a expressão aumentada dos fatores de transcrição inseridos, e os nossos resultados demonstram que o aumento de expressão de PRDM12 contribuiu para o melhoramento da homogeneidade das células geradas. Futuros estudos têm de ser feitos de forma a evidenciar o impacto destas duas novas linhas celulares no aprimoramento do protocolo de diferenciação. Este trabalho vai abrir novas oportunidades para a investigação in vitro de modelos de doenças e a avaliação de respostas farmacológicas na investigação da dor.
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Pollen, Noel R. "Instrumental and sensory characterization for a texture profile analysis of fluid foods." 2002. http://www.lib.ncsu.edu/theses/available/etd-08262002-175913/unrestricted/etd.pdf.
45
Jiang, Sin-Ying, and 蔣欣穎. "Characterization of age-related changes in olfactory sensory neurons in C. elegans." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ea86d9.
Анотація:
碩士國立臺灣大學
分子醫學研究所
105
Sensory cilia, microtubule-based subcellular organelles, are involved in sensing chemical or mechanical stimuli. Dysfunction of the sensory system occurs during aging. Previously, we have described age-related morphological changes in amphid sensory cilia in C. elegans, such as reduced AFD ciliated endings and enlargement of periciliary membrane compartments of ASI and ASE neurons. To characterize the morphological changes of other amphid sensory neurons in C. elegans during aging, we studied the olfactory sensory neurons, AWB and AWC. We found focal enlargement of AWB cilia and curling of AWC cilia. Overexpression of TAX-2 cation channel, which activates the neurons, improves age-related AWC cilia defects, suggesting a role for neural activity in sensory cilia maintenance during aging. In summary, we found that olfactory sensory cilia showed morphological deterioration during aging, which may be one of the indicators of aging of the sensory neurons.
46
Choi, In-duck. "Development, physical, and sensory characterization of extruded, indirectly puffed peanut-based snack products." 2002. http://purl.galileo.usg.edu/uga%5Fetd/choi%5Fin-duck%5F200205%5Fphd.
Анотація:
Thesis (Ph. D.)--University of Georgia, 2002.Directed by Robert D. Phillips. Includes articles submitted to The journal of food sciene, The journal of agricultural and food chemistry, and The journal of texture studies. Includes bibliographical references.
47
Ettinger, Laurel. "Characterization and Consumer Liking of Commercial Pureed Foods." Thesis, 2012. http://hdl.handle.net/10214/3929.
Анотація:
Dysphagia, a condition commonly associated with older adults suffering from stroke or degenerative diseases, often requires a modified texture food diet. Although commercial pureed foods are available in Canada for treatment of dysphagia, little is known regarding their sensory, nutritional, and textural properties, and whether these foods are liked among consumers. The objectives of this research were to characterize the sensory, nutritional, and textural properties of commercial pureed carrot, turkey, and bread products and to determine their liking in two groups of older adults; non-dysphagic and pureed consumers. It was found that commercial pureed foods differed significantly across brands in these properties and liking differed between the two study populations. Future research should focus on creating standards for commercial companies to follow to ensure that all products are as safe as possible for swallowing.OMAFRA, CIHR
48
Baião, Luís Francisco Lima. "Characterization of the sensory profile of sea urchin aiming at the selection of premium gonads." Doctoral thesis, 2021. https://hdl.handle.net/10216/139159.
49
Kim, Young Jun [Verfasser]. "Characterization of the sensory rhodopsin II, transducer II complexes from Halobacterium salinarum / vorgelegt von Young Jun Kim." 2010. http://d-nb.info/1007018313/34.
50
Junior, Julio Cesar Machado. "Chemical, biological and sensory characterization of hops and dry-hopped beers: Perspectives for use of Portuguese genotypes." Tese, 2019. https://hdl.handle.net/10216/121941.