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1
Yang, Ni. "Flavour reformulation and flavour stability". Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12595/.
Testo completoAbstract (sommario):
ABSTRACT This project addressed two areas in the flavour industry – flavour reformulation required as a consequence of ingredient changes and flavour stability in solid food products. The aim of the flavour reformulation study was to evaluate both instrumental and modelling approaches to reformulate commercial flavourings for food products of different fat contents. A strawberry flavouring was chosen, which delivered an acceptable flavour in pectin jelly (0% fat) but did not perform so well in chewy candy (8% fat). Aroma release profiles in people eating these two sweets were measured by APCI-MS, the relative release differences for each flavour compound was determined and then used to reformulate the strawberry flavouring so its release in both sweets was similar. The sensory performance of candies confirmed a significant difference between the reformulated and original flavour (p < 0.05). The modelling approach was based on compound hydrophobicity (Log P) and the fat content of the food. This was used to estimate relative differences in flavour delivery for products with two varying fat contents. Flavourings were reformulated for yoghurt with reduce fat level, and the measured results showed good correlation with model’s prediction (r = 0.95). The aim of the flavour stability study was to explore the impact of product storage and flavour solvent in biscuits with vanilla flavouring. After eight weeks storage at 45 °C, up to 20% vanillin loss was measured, but sensory results suggested no difference in vanilla flavour perception. Texture analysis indicated that biscuits using triacetin (TA) as flavour solvent were more brittle than biscuits made with propylene glycol (PG). This was explained by X-ray CT analysis results which showed TA biscuits had larger pores than PG biscuits. Additionally, TA solvent provided higher vanillin stability during storage, so it should be a better choice than PG solvent used in flavourings for biscuits. IMPACT STATEMENT This research proved that it is feasible to apply laboratory-derived knowledge and adapt scientific techniques in a commercial context. It also demonstrated how the research findings can be transferred into the commercial field through two studies. The first study successfully illustrated two novel approaches to reformulate flavourings between food products of differing fat contents. Comparing with traditional trial and error process, this study demonstrated that instrumental and modelling approaches can be more effective ways for flavour reformulation in the flavour and food industry. The cost of flavour reformulation including the reformulation time and the cost in-use can therefore be reduced considerably. The results of this study have been presented to company’s major clients worldwide, and this has been applied commercially in a range of products including the successful reformulation of a £50 M (2010, brand value) soft drink into new formats (2011). The second study increased the understanding of the flavour stability within the stored food products. This ensured the flavour company to deliver high quality materials not only to their clients before food manufacturing, but also maintained its quality in the food products during storage for their end users. Comparing two flavour solvents – propylene glycol and triacetin, the results of this study suggested that triacetin is a better solvent as it offered better flavour stability in the stored biscuits. The findings can also be applied to reduce the cost in-use for vanilla flavouring in biscuit, which is especially beneficial for food and flavour company when high cost natural vanilla flavourings are required.
2
Senia, Fabrizio. "The flavour puzzle and flavour symmetries". Doctoral thesis, Scuola Normale Superiore, 2017. http://hdl.handle.net/11384/85900.
Testo completoAbstract (sommario):
The presence of approximate flavour symmetries is invoked to make New Physics models near the TeV scale compatible with the very demanding quark flavour violation tests. These tests pose a serious threat for any acceptable Standard Model extension at the TeV scale, motivated by naturalness issues. Suitable approximate flavour symmetries can provide an appropriate suppression to unwanted flavour effects, while leading to peculiar patterns of small, but potentially detectable in forthcoming experiments, deviations in flavour observables.
After reviewing the two most popular options in the literature for such symmetries (U(2)3 and U(3)3), we focus on lepton flavour violation (LFV) which also gives very severe experimental bounds. Making U(2)3
and U(3)3 compatible with SU(5) Grand Unified flavour group allows us to make quantitative predictions about LFV processes (...). Using an Effective Field Theory approach new effects in the quark sector are discussed as well and the explicit realization of this scenario in the specific case of Supersymmetry is analyzed in detail.
Finally, we try to explain the recent tensions in B physics, hinting toward New Physics deviations of lepton flavour universality in semileptonic decays, in the context of a U(2)5 flavour symmetry and a tree
level leptoquark (LQ) exchange. The current experimental deviations can be accommodated invoking a vector-electroweak singlet LQ with a relatively large value (below 1 TeV) of the ratio between its mass and its dominant coupling. A partial UV completion of this scenario based on
a SU(4) x SO(5) x U(1)X Composite Higgs model with a U(2)5 flavour symmetry is examined. Special attention is given to new effects in both indirect (flavour and electroweak) observables and collider signatures.
The original part of this thesis is contained in chapters 4, 5, 6 and it is
mainly based on the work published in the papers [1, 2, 3].
3
Davies, Sarah. "The role of context in flavour-flavour evaluative conditioning". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/the-role-of-context-in-flavourflavour-evaluative-conditioning(799fc71d-da53-4269-9eb7-3e59e659af06).html.
Testo completoAbstract (sommario):
In recent decades the role of context in food consumption behaviour has been the focus of some research. However little is known about whether context influences the way in which we learn to like foods. Most of our food likes and dislikes are acquired through experience. A number of different processes are thought to be involved. One such mechanism is flavour-flavour evaluative conditioning (EC). In flavour-flavour EC a novel flavour (Conditioned Stimuli; CS) is repeatedly paired with a flavour that already evokes an affective response (Unconditioned Stimuli; US). The outcome of these repeated pairings is a shift in liking towards the CS that is in line with the affective value of the US. There is reason to believe that certain contextual factors may influence this type of food preference learning. However few studies have investigated this. In this thesis the impact of several contextual factors on flavour-flavour EC is explored. We also explore the use of approach behaviour as an indirect measure of liking.Chapters 2 and 3 present evidence of the influence of two external contextual factors in flavour-flavour EC. In Chapter 2 the effect of information was investigated. Conditioning in unrestrained eaters was marginally enhanced when conditioning was presented in the context of positive information regarding the CS-US pairings. Results show that information may influence flavour-flavour EC, possibly through assimilation and contrast effects. In Chapter 3 the effect of physical context on flavour-flavour EC was explored. Results showed that conditioning was context specific. Conditioning effects were strongest when participants acquired conditioning and were tested in the same context compared to those who acquired conditioning in one context and moved to a second context for testing. Chapter 4 presents a methodological investigation of the efficacy of using approach behaviours as a way to indirectly measure liking for real drink stimuli. Approach behaviours were shown to differ according to drink valence with quicker approaches exhibited for pleasant drinks compared to aversive drinks. Approach behaviours were then used as an indirect measure of drink liking in Chapter 5. Chapters 5 and 6 explore two factors related to the internal context. Chapter 5 explores the role of cognitive resources in flavour-flavour EC. In two experiments conditioning was shown to be reduced under conditions of cognitive load suggesting a role for cognitive resources in flavour-flavour EC. Chapter 6 presents an exploration of the effect of mood on flavour-flavour EC. There was no effect of mood on conditioning per se, however results showed that sad participants rated CS flavours more positively than happy participants, a finding that is interpreted with reference to mood regulation. The work presented in this thesis provides evidence that many factors related to the context within which learning occurs can influence flavour-flavour EC. Flavour-flavour EC is shown to be context specific, dependent upon cognitive resources and open to influence from information and mood. These findings highlight the importance of context in food behaviour.
4
Newton, Angela. "Flavour formation in ghee". Thesis, University of Canterbury. Biology, 2014. http://hdl.handle.net/10092/9276.
Testo completoAbstract (sommario):
Consumers place a high level of importance on flavour when assessing the acceptability of
food. The flavour of dairy products can be affected by heating both during processing and
by consumers during food preparation. Of particular importance to the flavour of heated
dairy products is the highly complex network of Maillard reactions. Previously, emphasis has
been placed on undesirable flavours generated through the Maillard reaction in dairy
products and efforts have been made to minimise the formation of these flavours. However,
beneficial flavours are also formed by the Maillard reaction. Dairy products such as ghee are
formed by heating and are characterised by their unique flavours; these flavours are
generated by the Maillard reaction.
The objective of this thesis was to unravel the factors that influence the Maillard and
caramelisation reactions that occur during the cooking of ghee. Particular focus was placed
on the impact that the structure of the cream had on the reaction, and how manipulation of
these parameters could provide an avenue for the control of the Maillard reaction.
The development and validation of model reaction systems for the Maillard and
caramelisation reactions involved the variation of parameters including cooking time,
temperature, pH, phosphate buffers and salt. A group of eleven compounds including acetic
acid, furfural, 2-acetylfuran, butyrolactone, 2(5H)-furanone, furfuryl alcohol, maltol, 2-
acetylpyrrole, hydroxymaltol, hydroxymethylfurfural (HMF) and dihydro-4-hydroxy-2(3H)-
furanone (DHHF) were monitored to determine the impact of these parameter changes.
These results provided a starting point to assess the impact of food structure on these
reactions. To assess the impact of food structure a series of matrix structures were designed
starting from an aqueous matrix. The first component that was added to the aqueous matrix
was fat to generate a two phase structure. Emulsion structures were then formed from the
two phase structure using emulsifiers and high pressure homogenisation.
Analysis of the volatile compounds formed as the matrix structures were altered was carried
out using headspace solid phase microextraction/ gas chromatography mass spectrometry
(SPME/GCMS). Results indicated that fat is a key structural component in flavour generation
via the Maillard reaction. This could have implications for low fat foods where the flavour
developed during cooking is important. The addition of fat indicated a significant impact on
the Maillard reaction with a less significant impact seen on the caramelisation reaction.
The formation of two emulsions with inverted structures provided a means to alter the ratio
of volatile compounds in the cooked samples. The oil in water emulsion generated a volatile
compound profile similar to that of the fat containing matrix, whereas the water in oil
emulsion produced a different ratio of these same compounds.
The results reported in this thesis shed some light on the relationship between food
structure and flavour formation during the cooking of milk fat emulsions. These structures
will create future opportunities to manipulate the structure of food to control flavour
formation.
5
Ropkins, K. "Flavour generation in wheatflakes". Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310834.
Testo completo
6
Clawson, A. R. "Flavour formation in wheatflakes". Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284429.
Testo completo
7
Foster, John Julian. "Flavour violation and supersymmetry". Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422121.
Testo completo
8
MacNamara, Kevin. "Flavour components of whiskey". Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52849.
Testo completoAbstract (sommario):
Thesis (PhD)--Stellenbosch University, 2002.ENGLISH ABSTRACT: Aged distilled spirits such as whiskey are complex mixtures of flavour compounds in an ethanol-water matrix. The flavour compounds involved can have widely different volatility and relative amounts. Many of the organoleptic properties that make whiskey suitable for commercial sale have their origin in reactions occurring during the ageing process in oak wood barrels. To investigate the complex changes that take place during spirit ageing a preparative fractional vacuum distillation process was developed. Both high and low volatility compounds could be individually isolated as fractions and free from both the ethanol matrix and the fermentation fusel alcohols. This allowed a range of sensory and analytical procedures to be conducted on these fractions, in particular to investigate changes occurring during ageing. Gas chromatographic (GC) analysis of the low volatility fraction is complicated by the fact that both the compounds and their ethanol matrix have very similar chromatographic behaviour when separated simultaneously on standard chromatographic phases. Compound and matrix co-elution becomes a major problem and conditions for mass spectrometric (MS) investigation are disadvantageous. A two-dimensional GC configuration using dissimilar chromatographic phases was configured to overcome these limitations. Using this approach 27 compounds were separated and identified. Headspace injection was used to increase detection sensitivity. Changes with ageing for seven compounds present at very low levels were quantified. In addition changes in the most abundant compounds were quantified by standard split injection, and changes in trace level sulfur compounds by headspace injection with sulfur chemiluminescent detection (SCD). Increases of the concentrations of pleasant fruity ethyl esters and acetates were established. Volatile sulfides with generally objectionable aroma showed concomitant major decreases. Appropriate techniques could also be applied to the low volatility compounds recovered from the whiskey water fraction. High temperature GC-MS analysis of an extract of the water fraction allowed the identification of 30 compounds. Three phenolic esters were identified in whiskey for the first time. These compounds were synthesised and shown to be contributory to desirable ageing flavour. Increases in concentrations of 16 oak derived compounds during alO year ageing period were established. Several compounds increased significantly over this time period. Ratios of aromatic phenolic aldehydes, and changes in these ratios during ageing, were unique to the type of barrel used in these experiments. This suggests that the final sensory properties of aged whiskey may be more dependent on wood parameters than previously thought. Preparative reverse phase High Pressure Liquid Chromatography (HPLC) with an ethanol water gradient was used to further fractionate an extract of the low volatility compounds. Subsequent analysis and sensory testing allowed a group separation of compounds with each group contributing characteristic attributes to the total flavour. One group contained the three new phenolic esters together with a number of other unidentified compounds. This group was found to be important for desirable ageing flavour that seems to develop slowly with time. Further studies in this area to understand the individual and synergistic contributions of the many facets of ageing chemistry will have important commercial implications.
AFRIKAANSE OPSOMMING: Verouderde spiritus soos Whiskey is 'n komplekse mengsel van geurstowwe in 'n etanolwater oplossing. Die vlugtigheid van die geurstowwe asook die konsentrasies waarin hul aanwesig is, varieer aansienlik. Verskeie van die sintuiglike eienskappe wat kommersiële waarde aan whiskey verleen, het huloorsprong in reaksies wat tydens die verouderingsproses in eikehoutvate plaasvind. Ten einde die ingewikkelde veranderinge wat tydens die veroudering van spiritus plaasvind, te ondersoek, is 'n preparatiewe fraksionele vakuumdistillasieproses ontwikkel. Hoogs vlugtige en minder vlugtige verbindings kon geskei word in afsonderlike fraksies wat vry was van etanol en fuselalkohole. Dit het die sintuiglike en fisies-chemiese analises van die fraksies moontlik gemaak, veralom die veranderings wat tydens veroudering plaasvind, te ondersoek. Gaschromatografiese (GC) analise van die fraksie met 'n lae vlugtigheid word gekompliseer deur die feit dat hierdie komponente en die etanol waarin dit opgelos is soortgelyke chromatografiese eienskappe toon wanneer hul gelyktydig op standaard gaschromatografie fases geskei word. Die gelyktydige eluering van dié komponente en etanol waarin hul opgelos is, skep 'n probleem wat nadelig vir massaspektrometriese (MS) analise is. Die beperkings is oorkom deur die gebruik van tweedimensionele GC en stasionêre fases met uiteenlopende eienskappe. Op dié wyse is 27 verbindings geskei en geïdentifiseer. Die veranderinge in konsentrasies tydens veroudering is vir sewe verbindings gekwantifiseer. Veranderinge in die konsentrasies van die verbindings teenwoordig in die hoogste konsentrasies is gekwantifiseer deur split-inspuitings, terwyl veranderinge in die spoorkonsentrasies van vlugtige swawelverbindings mbv dampfase-inspuitings en met swawel chemolumisensie deteksie (SCD) bepaal is. Toenames in die konsentrasies van die aangename vrugtige esters en asetate is bepaal. Vlugtige sulfiede met meesalonaanvaarbare aromas toon gelyktydige groot afnames. Geskikte tegnieke is ook gebruik vir die herwinning van minder vlugtige verbindings met die waterfase van whiskey. Hoë temperatuur GC-MS analises van 'n ekstrak van die waterfase het die identifikasie van 30 komponente moontlik gemaak. Drie fenoliese esters is vir die eerste keer in whiskey gevind. Hierdie verbindings is gesintetiseer en hul bydrae tot die gewenste verouderingsgeur is sintuiglik bevestig. Toenames in die konsentrasies van 16 eikehoutverwante verbindings gedurende 'n verouderingsperiode van 10 jaar is bepaal. 'n Betekenisvolle toename het voorgekom in die konsentrasies van verskeie van hierdie whiskey verbindings. Die verhoudings van aromatiese fenoliese aldehiede en die verandering in die verhoudings tydens veroudering was kenmerkend van die tipe eikehoutvat wat gebruik is. Dié bevinding dui daarop dat die fenole sintuiglike eienskappe van verouderde whiskey meer afhanklik mag wees van eikehout parameters as wat voorheen algemeen aanvaarbaar is. Preparatiewe omgekeerde fase hoëdrukvloeistofchromatografie met etanol/water as 'n gradient elueermiddel is gebruik om 'n ekstrak van die minder vlugtige verbindings verder te fraksioneer. Verdere GC-, MS- en sintuiglike analise het die skeiding van groepe van verbindings waarvan elk kenmerkende bydraes tot die totale geur lewer, moontlik gemaak. Een groep het drie nuut geïdentifiseerde fenoliese esters, tesame met 'n aantal ongeïdentifiseerde verbindings, bevat. Daar is vasgestel dat hierdie groep 'n belangrike bydrae maak tot die gewenste geur wat klaarblyklik stadig tydens veroudering ontwikkel. Verdere ondersoeke in hierdie verband om die individuele en sinergistiese bydraes van verskeie fasette van die chemie van veroudering te verstaan, kan belangrike kommersiële implikasies hê.
9
Tietz, Melanie. "Starch-flavour interactions : impact on flavour retention and release in model food systems /". Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17517.
Testo completo
10
Bird, Thomas. "Flavour studies with LHCb : b-meson mixing, lepton-flavour violation and the velo upgrade". Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/flavour-studies-with-lhcb-bmeson-mixing-leptonflavour-violation-and-the-velo-upgrade(7a8a7cf6-4885-4bc3-80b7-8208d606cf9f).html.
Testo completoAbstract (sommario):
Semileptonic B decays of the type Bq⁰→Dq⁻μ⁺ν (where Dq⁻→K⁻K⁺pie⁻) are selected and their lifetimes are corrected using a statistical simulation-based correction called the k-factor. Using 1 fb⁻¹ of LHCb data the B⁰ and Bs⁰ mixing frequencies are measured to be Deltamd = ( 0.503 ± 0.011 (stat) ± 0.013 (syst) ) ps⁻¹ and Deltams = ( 17.93 ± 0.22 (stat) ± 0.15 (syst) ) ps⁻¹. We exclude the null hypothesis of no mixing for the B⁰ and Bs⁰ by 5.8 and 13.0 standard deviations respectively. This is the first observation of Bs Bsbar mixing using only semileptonic B decays. The lepton flavour violating decay D⁰→eμ is searched for, using tagged D⁰ decays from D*→D⁰pie, and the measurement is normalised using D⁰→K⁻pie⁺ decays. No evidence is seen of an excess over the expected background and so a limit is placed B(D⁰→eμ) < 1.3×10⁻⁸ at a 90% confidence level using 3 fb⁻¹ of LHCb data. This improves the previous measurement by a factor of 20 and is the world's best measurement. Possible upgrades to the LHCb VELO detector are simulated and aspects of the upgraded detector are optimised to ensure that all tracks within the angular acceptance can be detected with high precision. Finally the simulated performance of the current and upgraded VELO detectors are compared.
11
Wright, Jonathan P. "Tea flavour : delivery and perception". Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439985.
Testo completo
12
Beal, Andrew David. "Flavour development in malted barley". Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386977.
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13
Boddington, John. "The flavour chemistry of rhubarb". Thesis, University of Bath, 1993. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760646.
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14
Clark, Rebecca A. "Multimodal flavour perception : the impact of sweetness, bitterness, alcohol content and carbonation level on flavour perception". Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/13432/.
Testo completoAbstract (sommario):
Flavour perception of food and beverages is a complex multisensory experience involving the gustatory, olfactory, trigeminal, auditory and visual senses. Thus, investigations into multimodal flavour perception require a multidisciplinary design of experiments approach. This research has focussed on beer flavour perception and the fundamental interactions between the main flavour components - sweetness, bitterness (from hop acids), alcohol content and carbonation level. A model beer was developed using representative ingredients which could be manipulated to systematically vary the concentration of the main flavour components in beer and was used in the following experiments. Using a full factorial design, the physical effect of ethanol, C02 and hop acid addition was determined by headspace analysis and in-nose expired breath (in-vivo) measurements. Results from headspace and in-vivo methods differed and highlighted the importance of in-vivo measures when correlating to sensory experience. Ethanol and C02 significantly increased volatile partitioning during model beverage consumption. The effects of ethanol and C02 appeared to be independent and therefore additive, which could account for up to 86% increase in volatile partitioning. This would increase volatile delivery to the olfactory bulb and thus potentially enhance aroma and flavour perception. This was investigated using quantitative descriptive analysis. Results showed that C02 significantly impacted all discriminating attributes, either directly or as a result of complex interactions with other design factors. C02 suppressed the sweetness of dextrose and interacted with hop acids to modify bitterness and tingly perception. Ethanol was the main driver of complexity of flavour and enhanced sweet perception. In a first study of its kind, the impact of C02 on gustatory perception was further investigated using functional magnetic resonance imaging (fMRI) to understand cortical response. In addition, classification of subjects into PROP taster status groups and thermal taster status groups was carried out. Groups were tested for their sensitivity to oral stimuli using sensory techniques and for the first time, cortical response to taste and C02 was investigated between groups using fMRI techniques and behavioural data. There was no correlation between PROP taster status and thermal taster status. PROP taster status groups varied in their cortical response to stimuli with PROP super-tasters showing significantly higher cortical activation to samples than PROP non-tasters. The mechanism for thermal taster status is not currently known but thermal tasters were found to have higher cortical activation in response to the samples. The difference in cortical activation between thermal taster groups was supported by behavioural data as thermal tasters least preferred, but were more able to discriminate the high C02 sample than thermal non-tasters. This research has provided in-depth study into the importance of flavour components in beer. It advances the limited data available on the effects of C02 on sensory perception in a carbonated beverage, providing sound data for the successful development of products with reduced ethanol or C02 levels. The use of functional magnetic resonance imaging has revealed for the first time that oral C02 significantly increases activation in the somatosensory cortex. However, C02 seemed to have a limited impact on activation strength in 'taste' areas, such as the anterior insula. Research comparing data from PROP taster status groups and thermal taster status groups has given insight into the possible mechanisms accounting for differences in oral intensity of stimuli.
15
Perkins, Melinda Louise. "Stale flavour volatiles in UHT milk /". [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18113.pdf.
Testo completo
16
Edwards-Stuart, Rachel. "Creating innovative flavour and texture experiences". Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/27644/.
Testo completoAbstract (sommario):
The work presented in this thesis describes the use of scientific research in the development of novel texture and flavour experiences and their potential for use in fine gastronomy. In order to create an interesting textural experience, modified celluloses were investigated. Their unique property is that they have the ability to gel at high temperatures, but return to the solution state upon cooling. This phenomena was used to test the hypothesis that hot gels made from these materials could melt at temperatures greater than mouth temperature, providing a melt-in-the-mouth sensation on consumption in a fashion analogous to gelatine. Melting temperatures of these hot gels were calculated using the techniques of rheology and differential scanning calorimetry, as well as more empirical methods, and results showed that gels made from a number of different hydroxypropylmethylcelluloses (HPMCs) displayed melting temperatures above 37°C. In order to predict their flavour release properties, the mixing efficiency of the solutions were investigated and results showed that solutions made from the lower molecular weight HPMCs showed more desirable mixing behaviour, suggesting better flavour release than those made from high molecular weight HPMCs. Furthermore, these solutions also had more desirable mouth-feel attributes, as determined by sensory analysis, yet their inherent flavour attributes were less pleasant. Therefore, modified celluloses show potential use in producing hot gels that melt in the mouth. The second part of this thesis was focussed on developing novel flavour experiences, and this was done by creating drinks that changed their flavour as they were consumed. The development of a tomato flavoured drink, whose flavour changed due to the sequential heightening of its tastant profile, is described here, and it was found that the presence of each tastant at a volume needed to invoke swallowing was more important than the order in which the tastes were administered in terms of ensuring that each different flavour was perceived. In addition, a banana flavoured drink whose flavour changed on consumption to mimic a ripening banana was also created, and this work showed the importance of the matrix on flavour perception at both the physical and psychological level, which has important consequences in general in the development of flavoured products. The work described in this thesis therefore shows the potential use that scientific research can play in aiding the creation of novel concepts applicable to the world of fine gastronomy.
17
Hau, Miranda Y. M. "Dynamics of flavour binding to starch". Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339656.
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18
Symonds, Michelle. "Perceptual learning in flavour aversion conditioning". Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282301.
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19
Hill, Victor John. "Heavy flavour physics from lattice QCD". Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.252696.
Testo completo
20
Granger, Andrew. "The flavour of warped extra dimensions". Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/61606/.
Testo completoAbstract (sommario):
Models with warped extra dimensions offer a promising solution to the hierarchy problem. However, it is known that flavour changing neutral currents arise at tree level in models with warped extra dimensions, which can lead to fatally large corrections to rare processes in the standard model. Since the introduction of the warped mechanism in 1999 by Randall and Sundrum, modifications of the original AdS5 geometries have been considered, having different phenomenologies. In particular, it has been previously shown that CP-violation in the K-K mixing system can be suppressed in what is known as the soft-wall model, in which the extra dimension is effectively compactified via a background scalar dilation field. Prior to the work presented in this thesis, however, this study had been limited to a background geometry with a specific form. A detailed study of bosonic propagators in soft-wall models has been conducted as part of this research, yielding some novel results, which permit the study of particle interactions throughout an extended family of warped 5D backgrounds in a practicable way. This methodology has then been applied, via the development of numerical routines, to an investigation of K and B meson phenomenology in a range of geometries in this family. The relevant and necessary technical prerequisites are reviewed and discussed, including (but not limited to) some of the general properties of warped extra dimensions, the application of Kaluza-Klein theory in warped 5D, topics in flavour physics and quark mixing and the application of effective field theory methods in perturbative calculations of flavour observables. It is found that there is indeed a significant interplay between the structure of the extra dimension and flavour phenomenology at a scale of 1-10 TeV. Although it turns out that the previously studied construction was already quite well-optimised with regard to flavour constraints, it is demonstrated that one can do more to ameliorate these via deformations to the background geometry and modifications to the power law dependence of the fermion masses on the extra dimension.
21
White, Christopher David. "Heavy flavour production at small χ". Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.614367.
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22
Jones, David Andrew. "A fuller flavour treatment of leptogenesis". Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/347525/.
Testo completoAbstract (sommario):
The theoretical foundations of the seesaw mechanism and baryogenesis are developed, prior to a discussion of leptogenesis - the idea that the baryon asymmetry of the universe (BAU) originates in the physics of the seesaw mechanism. Particular emphasis is placed upon several novel lepton avour effects arising from decays of the next-to-lightest right-handed neutrino (RHN), N2. Two new effects are identified: the "flavour swap scenario" and "phantom leptogenesis", either of which can give local order-of-magnitude enhancements to a BAU generated via leptogenesis. Leptogenesis is next reformulated in terms of the density matrix, where decoherence and gauge boson themalisation are taken into account and flavour-basis-independent expressions for the BAU are derived and subsequently specialised to the two RHN model in a two-flavoured basis. This model is then studied extensively, for both standard model and supersymmetric realisations, with N2 decays fully taken into account. In both cases new N2-dominated regions are identified, corresponding to models with light sequential dominance. It is shown that these regions get enlarged upon consistent inclusion of the "phantom terms". Results are altered in the supersymmetric case where tan beta becomes large and it is shown that new allowed regions emerge, strikingly so for the case of an inverted hierarchy.
23
Hunt, Philip. "A study of B → DK and D0 production using D0 → K+π-π+π-decays at LHCb". Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:4b48ebc4-dd04-4741-8ab3-1ac8620f1cb0.
Testo completoAbstract (sommario):
A precision measurement of the CKM angle γ from tree-level processes is one of the principal goals of the LHCb experiment. The results from this study are compared to predictions from two different theoretical models and from the default LHCb tuning of the PYTHIA Monte Carlo event generator, and the results shown to be in good agreement. The cross-section results are also compared to an independent LHCb measurement. LHCb analyses rely on the ability to identify kaons and pions with a high efficiency and low mis-identification rate, achieved by two Ring Imaging Cherenkov (RICH) detectors. To ensure optimal performance of the RICH detectors, the time alignment of the Level-0 (L0) front-end electronics modules has been optimised using a combination of a pulsed laser system installed in the LHCb cavern and pp collision data. After the time-alignment procedure, the L0 modules have been time-aligned to within approximately ° 1ns across both detectors.
24
Grabalosa, Gándara Marc. "Flavour Tagging developments within the LHCb experiment". Doctoral thesis, Universitat de Barcelona, 2012. http://hdl.handle.net/10803/84088.
Testo completoAbstract (sommario):
Flavour Tagging at the LHCb experiment is a fundamental tool for the measurement of B oscillations and the study of CP violation. This document explains the development of different tagging techniques and the different strategies used to combine them to determine the flavour of the B meson as precisely as possible. The response of the tagging algorithms also needs to be optimized and calibrated. Both procedures are described using the available LHCb datasets corresponding to various integrated luminosities. First results on the tagging performances are shown for different control channels and physics measurements.
25
Singh, Simon L. "Heavy flavour physics at CERN pp collider". Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385498.
Testo completo
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Gkatzionis, Konstantinos. "Flavour production of Stilton blue cheese microflora". Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11395/.
Testo completoAbstract (sommario):
In the blue cheese Stilton the starter mould Penicillium roqueforti grows and sporulates during the ripening period and is considered to be responsible for the unique blue cheese aroma. However, the sporulation of the mould, which results in the formation of blue veins, takes place in a fraction of the Stilton matrix which overall is very heterogeneous. Most blue cheeses develop a secondary microflora of yeasts which may affect their aroma. The aim of this study was to investigate the yeast flora of Stilton, the aroma profile of the cheese and the role of the yeasts in the aroma production. The approach in this work was to study individually the different sections of Stilton (the blue veins, the white core and the outer crust) as previous studies have demonstrated each section has a differing bacterial flora. In addition to the classical microbiology, a series of molecular techniques (Denaturing Gradient Gel Electrophoresis, Restriction Fragment Length Polymorphism and Terminal RFLP) were compared and applied for the screening of the local fungal communities in the cheese. The results showed that the two approaches were complementary. It was concluded that the structure of the fungal community was different for each section of the cheese. The aroma profiles of the three different sections of Stilton were studied using solvent extraction Gas Chromatography-Mass Spectrometry (GC-MS), a headspace GC-MS technique (SPME GC-MS) and direct headspace analysis (Atmospheric Pressure Chemical Ionisation [APCI]-MS). The different sections of Stilton presented different aroma profiles. Overall, the blue and the outer crust had similar profiles. These two sections contained higher amount of ketones while the white contained higher amounts of alcohols and aldehydes. Yeast isolates and the starter Penicillium roqueforti were cultivated alone and in combination in a cheese model and the aroma production was studied with SPME GC-MS analysis. The co-culture of the starter Penicillium roqueforti and individual yeast isolates resulted in aroma profiles different from those that were produced by the mould or the yeasts individually. The model of Penicillium roqueforti with Yarrowia lipolytica resulted in an aroma more similar to blue cheese than produced by the mould alone. Sensory analysis (Flash profile technique) was used in order to compare the aroma of this model with the aroma of blue cheeses and the perception of the combined culture was found to be similar to Stilton cheese, whereas that of the mould alone was not. Yeasts are a significant part of the microflora of Stilton and they are able to affect the aroma production. Selected isolates of Yarrowia lipolytica could be used in combination with Penicillium roqueforti for the production of blue cheese aroma e.g. as a starter culture.
27
Burseg, Kerstin M. M. "Flavour perception of biscuits a psychophysical approach". Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503909.
Testo completoAbstract (sommario):
A psychophysical approach was applied to study cross-modality between texture, sweetness and aroma in a real food system (biscuits). A range of biscuits varying in fat, flour and sugar levels as well as sugar form and sugar pre-treatment were made according to a statistical D-optimal Mixture Design (main effects crossed with a categorical factor). This allowed control of the interactions between ingredients in the complex biscuit system but also expressed ingredient-texture relationships in mathematical terms. Studying biscuit texture (structure and mechanical properties) revealed that the biscuit system was dominated either by a glassy sucrose (dissolved sugar) or crystalline sucrose (granulated sugar) rich matrix embedding more or less native starch granules, irrespective of which sugar form was used, fat formed a continuous layer and acted as a "glue" to hold the biscuit matrix together. With the exception of gluten development, flour did not play a significant role in the formation of the biscuit structure.
28
Channell, Guy Andrew. "Oxidative flavour chemistry and biochemistry in parsley". Thesis, University of Nottingham, 1996. http://eprints.nottingham.ac.uk/13970/.
Testo completoAbstract (sommario):
Deterioration of flavour quality during processing and storage is often brought about by oxidative processes. These typically involve oxygen or an active form of oxygen in effecting transformation of a wide range of volatile and non-volatile compounds, including key quality chemicals, flavour precursors and antioxidants. To investigate the nature of the chemical and biochemical change within vegetables and herbs, unblanched frozen parsley was selected as a suitable tissue. The chemical status of parsley during technological processing was determined using novel analytical protocols (SNCV A/SNCNV A) implemented as part of a unified strategy for the quantitative analysis of volatile and non-volatile species. The analysis utilized a single stabilized solution produced from plant tissue, under a regime which minimized isolation stress and artifact formation. On frozen storage (-10OC) the principal volatiles of parsley, myrcene, beta-phellandrene and menthatriene were extensively degraded to non-volatile products at differential rates. p-Cymenene and the tentatively assigned menthatriene diepoxide were formed as minor volatile oxidation products. Myristicin remained largely unchanged. Under similar frozen storage, chlorophyll 'a' displayed significant degradation with only minor amounts of chlorophyllide 'a', pheophytin 'a' and 13[superscript]2 hydroxychlorophyll 'a' formed. Ascorbic acid was extensively degraded in timescales preceding monoterpene and chlorophyll loss. Thermal blanching of parsley extensively prevented the degradation of the monoterpenes, suggesting that endogenous enzymes were responsible for the changes. Elimination of oxygen, in the absence of blanching, prevented volatile loss, confirming the requirement for oxygen. The hypothesis that peroxidase can operate in a co oxidative couple with the flavonoid, apigenin-7-glucoside and hydrogen peroxide, as proposed by Yamauchi (1985), was investigated to establish its potential role in the degradation of terpenoids and chlorophyll. In model experiments, using horseradish peroxidase, menthatriene and chlorophyll showed extensive degradation only when all components of the couple were present. In addition the requirement for oxygen was also established. Naringenin and umbelliferone have been shown to behave similarly to apigenin, as co-substrates for peroxidase. Lycopene, with some structural similarity to menthatriene, was also susceptible to co-oxidation. Polyphenol oxidase, proposed to operate in a similar fashion to peroxidase with mono- and di-phenols as substrates (Montedoro et al. 1995), in model experiments did not cause the degradation of chlorophyll. The co-oxidative role of lipoxygenase in parsley is believed to be of minor significance, however, it is likely to be responsible for the production of low levels of hexanal observed during thawing of frozen parsley. From this thesis it is concluded that the aroma and colour quality loss in frozen unblanched parsley probably results from the oxidative degradation of the unsaturated monoterpenes and chlorophyll 'a' respectively via an oxidative cascade initiated by the action of peroxidase.
29
Langridge, James P. "Correlating instrumental and sensory analyses of flavour". Thesis, University of Nottingham, 2004. http://eprints.nottingham.ac.uk/11060/.
Testo completoAbstract (sommario):
The relationship between in vivo captured data from an atmospheric pressure chemical ionisation mass spectrometer (APCI-MS) and sensory/psychophysical analyses was investigated. The stimuli used were mainly single volatiles under gas phase control or calibration by development of different olfactometry methods. Gas phase concentration retronasal (via the mouth to the nasal cavity) and orthonasal (via the nostrils) thresholds were determined for a trained panel of 13 individuals. Four volatiles were used with different sensory/physico-chemical properties and an adapted staircase method was employed to measure the individual thresholds. The data showed good repeatability over short durations of one week and also longer ones of eight months. It was used to test the hypothesis that thresholds varied between people due to differences in their in-nose concentration as measured or estimated by the APCI-MS. The analysis did not support this theory but relationships between orthonasal and retronasal thresholds were shown, in which the latter were -50 times lower than the former. Threshold determination of a larger group of 20 individuals revealed clusters of individuals. Methods of producing square edged pulses of aroma compound in the gas phase were developed using a modified chromatograph autosampler with a gas flow of 5 mL. min 1 and pulse rate of 0.6 secs. A trained panel of 23 individuals performed two types of sensory test using pulsed and constant olfactometer outputs of isoamyl acetate. The original intention was to reveal whether pulsed odorants were perceived as the same as or different to constant concentration. Initial experiments yielded results that were difficult to interpret, although the nature of the results was clarified when simultaneous breath by breath analysis techniques were employed. Here it was shown that each individual in different repetitions disrupted the olfactometer output pattern in unpredictable ways. This pattern disruption was measured in two instrumental configurations, as either volatiles in an exhalation or volatiles as they were inhaled together with two types of sensory test. In both sensory tests the pattern of aromas in an inhalation revealed a relationship with perception. In particular, the sensory response in the time intensity study was related to differences in the inhalation profiles between people, which in turn was related to an individual's breathing. This shows that physiological differences such as breathing and the structure of the nasal cavity have an impact on perception.
30
Hollowood, Tracey Ann. "Taste-aroma-matrix interactions determine flavour perception". Thesis, University of Nottingham, 2002. http://eprints.nottingham.ac.uk/10262/.
Testo completoAbstract (sommario):
A newly recruited sensory panel was trained in magnitude estimation and time intensity sensory techniques. Sensory analysis was combined with instrumental analysis using MS Nose to investigate the relationship between stimulus and perception using simple model food systems. Volatile release data was collected after swallowing aqueous solutions containing a cocktail of aroma compounds. The compounds varied in their persistence during subsequent exhalations dependent on the degree of association with the mucous lining of the throat. The rate of breathing had no effect on the shape or intensity of the release profile. The data was successfully modelled using the basic principles of interfacial mass transfer. The mechanistic model included some estimated parameters for un-measurable anatomical and physiological variables, kinetic properties of the flavour compound and terms to represent the oscillatory breathing and airflow rate. Aside from the 1st exhalation, the model fitted the data very well. The panel rated the intensity of minty flavor in a 6% gelatine gel, containing varying concentrations of carvone. The flavor was assessed using Magnitude Estimation and Time Intensity Methods. In addition, the quantity of carvone released from the gel and reaching the assessors nose was measured, breath by breath during eating, using the MS Nose. The results showed that the quantity of volatile delivered to the nose was directly proportional to the concentration in the sample, however, the absolute quantity varied greatly between individuals. Further differences were observed in the temporal dimension of their release profiles, which related to differences in their anatomy, physiology and eating habits. In some cases, these differences were mirrored by the sensory data. The relationship between perceived intensity and sample concentration was linear for both types of sensory data. Neither the speed of eating nor the concentration of volatile reached in-nose, affected an individuals ability to judge intensity. There was evidence to suggest, however, that the speed of eating affected the level of adaptation to the carvone stimulus. The affinity of the aroma compound for water (hydrophobicity) was an important factor in influencing the temporal characteristics of the instrumental and sensory data. When aroma release was rapid (< Tmax) the sensory response occurred slightly later whereas when the aroma release was much slower (>Tmax), with intensity increasing more gradually, the sensory response preceded the instrumental data. These phenomena were explained in terms of a lag phase for neural processing when the stimulus was presented quickly and adaptation to the stimulus when it was delivered over a longer period of time. A trained sensory panel assessed flavour and sweetness intensity in solutions containing varying concentrations of Hydroxy Propyl Methylcellulose (HPMC), sugar and flavour volatile. The flavour and sweetness of the viscous solutions were rated using magnitude estimation with a controlled modulus. In addition, the concentration of volatile released on the breath was measured using MS Nose. For low concentrations of HPMC (<0.5g/100g), perceived flavour intensity remained the same, however, a steady decrease was noted at higher concentrations (>0.6g/100g). The change in perceived intensity occurred at the point of random coil overlap (c*) for this hydrocolloid. The perceived sweetness of the solution showed a similar pattern with increasing HPMC concentration, although the inflection at c* was not so obvious. Despite the change in perceived flavour intensity, the actual concentration of volatile measured on the breath was not affected by the change in HPMC concentration. Low order polynomial models were produced to describe perceived flavour intensity and sweetness in viscous solutions containing HPMC and potential explanations for the changes in perception were discussed.
31
Hayashida, Yasuo. "The furanones in Japanese barley miso flavour". Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/566.
Testo completo
32
Dimelow, Christopher P. "Flavour retention and release in crumb foods". Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415490.
Testo completo
33
Cook, David J. "The effects of viscosity on flavour perception". Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289066.
Testo completo
34
Brauss, Michael S. "Flavour release from fresh and processed foods". Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310836.
Testo completo
35
Harter, Margaret. "Microbial demethylation for flavour and fragrance compounds". Thesis, University of Kent, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293959.
Testo completo
36
Cowan, Greig Alan. "Single-colour and single-flavour colour superconductivity". Thesis, University of Glasgow, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412941.
Testo completo
37
Sehra, Gurmukh S. "Surface acoustic wave based flavour sensor system". Thesis, University of Warwick, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416148.
Testo completo
38
Marriott, Raymond. "The phytochemistry of blackcurrant flavour and aroma". Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.760553.
Testo completo
39
Turner, Jessica Margaret. "Leptonic flavour symmetries and their cosmological dynamics". Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12249/.
Testo completoAbstract (sommario):
Neutrino oscillations, and the implication of non-zero neutrino masses and mixing, is one of the most significant particle physics discoveries in recent times. Flavour symmetries provide a compelling explanation of the pattern of mixing we observe in the lepton sector. The discovery of neutrino oscillations provides indisputable evidence that neutrinos have non-zero masses and mixing. Measuring the fine structure of neutrino mixing is one of the foremost challenges in experimental neutrino physics and understanding the origin of the pattern of mixing is of great interest from a theoretical perspective. The observed pattern of mixing in the lepton sector could be explained by the presence of a non-Abelian discrete symmetry and in this doctoral thesis, we study the phenomenological implications of applying a Non-Abelian, discrete flavour symmetry, Gf = A₅, in combination with a generalised CP symmetry, to the lepton sector. We consider all possible Abelian residual symmetries in the charged lepton (Gℓ) and neutrino (Gν) sectors. In the more constrained scenario, the set of Abelian residual symmetries we study are Gℓ = {Z₃,Z₅,Z₂ x Z₂} and Gν = Z₂ x CP. We focus on the mixing patterns that are compatible with experimental bounds and discuss in detail the testability of these predictions at upcoming accelerator, reactor and neutrinoless double-beta decay experiments. We find the synergy between upcoming oscillation facilities allows for this flavour symmetric approach to be fully tested. In addition, we consider a less constraining set of residual symmetries, Gℓ = Z₂ and Gν = Z₂ x CP, and find there are many more predictions with more complicated correlations between neutrino parameters. In complement to the discussion of leptonic flavour symmetries, we present a new mechanism of leptogenesis which proceeds via lepto-bubble nucleation. This mechanism has direct connections with leptonic flavour models and low-energy neutrino parameters. We calculate the lepton asymmetry using the Closed-Time Path formalism and we find the phase transition temperature to be T ~ 10¹¹ GeV, similar to that of high-scale thermal leptogenesis.
40
Saporta, Albert. "Phenomenological analysis of charged lepton flavour changes". Thesis, Lyon, 2019. http://www.theses.fr/2019LYSE1110/document.
Testo completoAbstract (sommario):
Dans cette thèse de doctorat, nous étudions les processus de violation de la saveur des leptons chargés dans le cadre de la théorie des champs effective, dans laquelle les effets de nouvelle physique peuvent être paramétrés par des opérateurs invariants de jauge et de dimension plus élevées, construits avec les champs du modèle standard. La découverte de l'oscillation des neutrinos est une preuve claire que la violation de la saveur leptonique peut se produire et que les neutrinos ont une masse. Dans le modèle standard avec des neutrinos massifs, les processus de violation de la saveur des leptons chargés sont fortement supprimés, et la découverte de tels processus serait un signal clair de physique au-delà du modèle standard. Après une introduction générale sur le modèle standard de la physique des particules et au-delà, ce manuscrit contient deux chapitres d’introduction. Le premier chapitre présente le contexte théorique et expérimental pour les recherches de processus de violation de la saveur des leptons chargés, et leur potentiel pour contraindre les modèles de nouvelle physique. Nous faisons une revue de nombreux processus et des expériences actuelles, puis nous discutons des perspectives pour les expériences à venir. Le deuxième chapitre décrit le formalisme de l'approche de la théorie des champs effective. Nous discutons des principes de la renormalisation et du calcul des boucles avec la régularisation dimensionnelle. Nous discutons également des équations du groupe de renormalisation qui décrivent l’évolution et le mélange des coefficients avec l'échelle d'énergie. Enfin, nous abordons deux approches différentes dans la théorie des champs effective. Après avoir introduit le contexte expérimental et le formalisme de la théorie des champs effective, nous étudions la conversion d’un muon en électron dans les noyaux dans une approche top-down, et la violation de la saveur des leptons chargés dans les désintégrations à deux et trois corps de mésons pseudo-scalaires dans une approche bottom-up. Nous listons d'abord les opérateurs et les coefficients associés qui contribuent aux processus. Dans notre travail, nous nous concentrerons principalement sur les opérateurs de dimension six. Nous calculons les rapports de branchement pour chaque processus en fonction des coefficients des opérateurs à l 'échelle expérimentale et utilisons les bornes expérimentales pour contraindre les coefficients. Nous utilisons également les équations du groupe de renormalisation pour calculer l’évolution et le mélange des coefficients avec l'échelle d'énergie dans les approches top-down et bottom-up. Les résultats présentés dans cette thèse sont basés sur deux publications [1, 2]In this doctoral thesis, we investigate charged lepton flavour violating processes in effective field theory, in which possible new physics effects can be parametrized by higher dimensional gauge invariant operators built from Standard Model fields. The discovery of neutrino oscillations is a clear evidence that lepton flavour violation can occur and that neutrinos are massive. In the Standard Model extended with massive neutrinos, charged lepton flavour violating processes are strongly suppressed, and the discovery of such processes would be a clear signal of physics beyond the Standard Model. After a general introduction on the Standard Model of particle physics and beyond, this manuscript contains two introductory chapters. The first one introduce the theoretical and experimental context for the searches of charged lepton flavour violating processes, and their huge potential to constrain new physics model. We make a review of many processes and the current experiments, then we discuss the prospects for the upcoming experiments. The second chapter describe the formalism of the effective field theory approach. We discuss the principles of renormalization and loop integrals calculations with dimensional regularization. We also discuss the renormalization group equations that describe the running and the mixing of the coefficients with the energy scale. Finally, we discuss two different approaches in effective field theories. After introducing the experimental context and the effective field theory formalism, we study the μ → e conversion on nuclei in a top-down approach and charged lepton flavour violating two and three body decays of pseudoscalar mesons in a bottom-up approach. We first list all the operators and their associated coefficients that contribute to the processes. In our work, we mostly focus on dimension six operators. We compute the branching ratios for each processes as a function of the operator coefficients at the experimental scale, and use the experimental upper limit to constrain the coefficients. We also use the renormalization group equations to compute the running and the mixing of the coefficients with energy scale in both top-down and bottom-up approaches. The results discussed in this thesis are based on two publications [1, 2]
41
Lee, K. Y. Monica. "Nature and origins of sensory character in Scotch whisky". Thesis, University of Strathclyde, 2000. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=20360.
Testo completoAbstract (sommario):
Scotch whisky production is central to the local economy, with an interesting history, and dominates international markets for brown spirit products. Researchers have characterised whisky congener compositions, behaviour and the nature of wood maturation of whisky. However there remain difficulties in understanding the nature and origins of sensory character in Scotch whiskies, a central issue being development of a consistent flavour terminology. A key aim was revision of the Scotch whisky flavour wheel, to optimise sensory analysis and training of assessors in the distilling industries, and for consumer studies. The nature of flavour perception in Scotch whisky was then explored, investigating flavour terms currently in use among industrial sensory assessors. This language was revised using standard reference compounds in 23% abv grain whisky to anchor individual flavour attributes. The wheel incorporates only positive attributes to meet current needs for interaction between sen sory, marketing and technical professionals. Concepts of flavour sensation and perception were reviewed with a separation into the reductionist and consideration of the holistic nature of perception. Sensation and perception are from different levels of human reliance, microscopic and macroscopic. The former is important in sensory assessment and the latter, in understanding consumer choice. Flavour thresholds and 95% recognition for standard flavour reference compounds were established in 23% grain spirit. The relationships between attribute weighting and product category in blends was explored using 40 retailed blends of four categories - Deluxe, Standard, Retailer and West Highland. Relationships between product category and headspace concentration of important congeners from solid phase micro-extraction (SPME) were explored to clarify the basis of discrimination.
42
Stephens, Elke M. "Effect of fatty acid composition on the flavour of Korean and Australian beef". Title page, table of contents and abstract only, 2001. http://hdl.handle.net/2440/37938.
Testo completoAbstract (sommario):
A preliminary trial to determine the effect of repeated freezing and thawing on beef striploins, showed that the effect of thawing on frozen non-aged beef significantly improved tenderness, flavour and acceptability, indicating that thawing had a similar effect to aging. In the subsequent study, 207 beef striploins were collected from the Southern Crossbreeding Project (SXB: 70 heifers grainfed for 80 days, 70 steers grainfed for 180 days), Davies Gene Mapping Project (DGM: 30 steers grainfed for 180 days) and also 37 Hanwoo striploins imported into Australia from Korea. SXB animals consisted of Hereford cross calves sired by Belgian Blue, Limousin, South Devon, Hereford, Angus, Wagyu and Jersey bulls. DGM animals consisted of purebred Limousins and Jerseys and Limousin by Jersey crosses. Sensory analysis of beef striploins involved semi-trained taste panel assessments, using nine-point category scales for initial and sustained juiciness, beef flavour, beef fat flavour, oily flavour, buttery flavour, chicken-skin flavour, corn flavour, grassy flavour and overall acceptability. Flavour acceptability was positively enhanced by increased levels of intramuscular fat (IMF%). Significant differences in breed were apparent for juiciness, beef flavour, buttery flavour and flavour acceptability, after adjusting data to a constant level of intramuscular fat, suggesting that some variation in flavour may be genetic. The Korean Hanwoo displayed a numerically higher intensity of chicken score and lower intensity of beef flavour. Australian cattle breeds differed in fatty acid composition between each other and also to that of the Korean Hanwoo. The latter had 57% mono-unsaturated fatty acids, which was significantly higher (P<0.001) than the Australian breeds (47%). Since IMF% was confounded with breed, breed differences were not significant when adjusted for IMF%. Jersey animals most closely resembled the Hanwoo in fatty acid profile, whilst animals containing Limousin differed markedly from the Hanwoo. A chemical sensor was able to establish significant differences between Korean Hanwoo and Australian animals and predominantly mirrored differences in fatty acid composition and to some extent flavour. Development of prediction equations from individual fatty acids was disappointing (R2< 15%). However, when fatty acid data, IMF% and chemical sensor data were combined to form prediction equations, moderate R2 values were obtained of (24% to 43%).Thesis (M.Ag.Sc.)--School of Agriculture & Wine, 2001.
43
CHIARELLI, PERDOMO IGOR. "PRODUCTION OF NATURAL AROMA COMPOUNDS BY BIOCATALYSIS". Doctoral thesis, Università degli Studi di Milano, 2019. http://hdl.handle.net/2434/694810.
Testo completoAbstract (sommario):
Gli esteri svolgono un ruolo rilevante nell'industria alimentare, sono tra i composti più importanti e versatili di aromi e fragranze naturali in alimenti, bevande e cosmetici. La loro preparazione da substrati naturali e l'utilizzo di bioprocessi (eg. fermentazione o reazioni enzimatiche) è attrattivo, perché il prodotto finale può essere etichettato e commercializzato in UE e USA come naturale. Pertanto, nuovi approcci biotecnologici per ottenere aromi sono desiderati, una volta che siano efficienti e sostenibili. Molti esteri con proprietà aromatiche possono essere ottenuti enzimaticamente usando lipasi che catalizzano reazioni di esterificazione, transesterificazione o interesterificazione. In questa tesi di dottorato abbiamo sviluppato due sistemi per la produzione di esteri con proprietà aromatiche: 1) Un metodo biocatalitico per la preparazione enzimatica di diversi esteri con proprietà aromatiche da alcoli primari (isoamilico, n-esilico, geranilico, cinnamilico, 2-feniletilico e benzilico) ed esteri etilici naturalmente disponibili (formiato, acetato, propionato e butirrato). Le biotrasformazioni sono catalizzate da un'aciltransferasi di Mycobacterium smegmatis (MsAcT) e precedute da eccellenti rese (80- 97%) e brevi tempi di reazione (30-120 minuti), anche quando sono state utilizzate concentrazioni di substrato elevate (fino a 0,5 M). Questa strategia enzimatica rappresenta un'alternativa efficace all'applicazione delle lipasi nei solventi organici e un miglioramento significativo rispetto ai metodi già noti in termini di uso ridotto di solventi organici, aprendo la strada a una preparazione sostenibile ed efficiente degli agenti aromatizzanti naturali. 2) Un metodo biocatalitico con la lipasi legata al micelio liofilizzato di Aspergillus oryzae che catalizza l'esterificazione diretta di alcoli e acido acetico in solvente organico. Ha mostrato un'elevata stabilità verso substrati e prodotti. L'acqua prodotta durante l'esterificazione non ha influenzato in modo significativo l'equilibrio della reazione, consentendo conversioni elevate. Queste caratteristiche sono state sfruttate per preparare esteri con proprietà aromatiche dell'acetato (isoamil e cinnamil acetato) in sistemi in batch e continui. È stato sviluppato un continuous stirred tank membrane reactor (CST-MR) ovvero un reattore continuo a membrana sotto agitazione per garantire una buona produttività e un'elevata stabilità del biocatalizzatore. Entrambi i sistemi di produzione sono promettenti, rappresentano due diverse alternative e possono essere ulteriormente ottimizzati e scalati per gli interessi del settore.Esters play a significant role in the food industry, they are among the most important and versatile components of natural flavours and fragrances in food, drinks and cosmetics Their preparation starting from natural substrates and using bioprocesses (e.g., fermentation or enzymatic reactions) is appealing, since the final product can be labelled and commercialized in EU and USA as natural. Therefore, new biotechnological approaches for obtaining flavours are highly demanded as long as they are efficient and sustainable. Many flavour/fragrance esters can be enzymatically obtained using lipases that catalyse esterification, transesterification or interesterification reactions. In this PhD thesis we studied two systems for production of flavours esters: 1) A straightforward biocatalytic method for the enzymatic preparation of different flavour esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalysed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and preceded with excellent yields (80-97%) and short reaction times (30-120 minutes), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared to already known methods in terms of reduced use of organic solvents, paving the way to a sustainable and efficient preparation of natural flavouring agents. 2) Mycelium-bound lipase of dry mycelium of Aspergillus oryzae catalysed direct esterification of alcohols and acetic acid in organic solvent, showing high stability towards substrates and products. Water produced during the esterification did not significantly affect the equilibrium of the reaction, allowing for high conversions. These features were exploited for preparing flavour-active acetate esters (e.g., isoamyl and cinnamyl acetate) in batch and continuous systems. A continuous stirred tank membrane reactor (CST-MR) was developed securing good reactor productivity and high biocatalyst stability. Both production systems are promising, represent two different alternatives and can be further optimized and scaled up for the interests of the industry.
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Pettersson, Kristian. "Musik som "krydda" : En studie i hur musik kan användas på stjärnkrogar för att förhöja upplevelsen av mat och dryck". Thesis, Luleå tekniska universitet, Institutionen för konst, kommunikation och lärande, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-60005.
Testo completoAbstract (sommario):
När restaurangguiden Guide Michelin utdelar de prestigefyllda stjärnorna är det endast matenoch drycken som ska bedömas. Vid ett besök på en stjärnkrog möter vi emellertid en helhet iform av en atmosfär som vi upplever genom våra sinnen (syn, hörsel, känsel, lukt och smak).Upplevelsen av mat och dryck är en multisensorisk upplevelse som skapas via neurologiskaprocesser i hjärnan. Det innebär att allt runtomkring oss som vi registrerar med våra sinneninnan, samt medan vi äter och dricker kommer att påverka hur vi upplever maten ochdrycken. Därför kan det ifrågasättas om det möjligtvis kan finnas andra faktorer som påverkarGuide Michelins bedömning? Kan musik ha en inverkan?Denna studie har undersökt hur stjärnkrogar kan utveckla måltidsupplevelsen med inriktningpå hur musik kan förhöja upplevelsen av mat och dryck.Semistrukturerade intervjuer har genomförts med fyra stjärnkrogar i Stockholm. Dessutom görstudien en kartläggning av och ger en inblick i den forskning som försöker hitta sambandmellan musik, mat och dryck.Resultatet från studien visar att det är möjligt för stjärnkrogar att använda sig av musik iutformandet av måltidsupplevelsen för att förhöja upplevelsen av mat och dryck. Det har dockinte varit möjligt att utforma en konkret modell för hur det ska gå till, utan endastrekommendationer och förslag ges. Rekommendationerna och förslagen skulle även innebäraatt de undersökta stjärnkrogarna behöver ändra sina nuvarande arbetssätt.Ett behov av ytterligare forskning ses som nödvändig innan forskningen om hur musik kanpåverka upplevelsen av mat och dryck kan få ett större praktiskt tillämpningsområde.When the restaurant guide Michelin awards its prestigious stars, the review is to be based solelyon the quality of food and beverages. However, visiting a starred restaurant, the visitor enters awhole atmosphere experienced through all senses (sight, hearing, touch, smell and taste). Theexperience of food and beverages is multi-sensorial stemming from neurological processes inthe brain. Hence, everything our senses register before and during the meal will affect ourexperience of what we are eating and drinking. In light of this, questions can be raised aboutthe reviews of the Michelin Guide – are there perhaps other factors besides the quality of thefood and beverages influencing the assessment of the restaurants? Can music be such aninfluence?This study has examined in which ways Michelin starred restaurants can develop the mealexperience, specifically how music can enhance the experience of food and beverages.Semi-structured interviews have been conducted with four Michelin starred restaurants inStockholm. Moreover, the study aims to outline previous research connecting food, beveragesand music.The result of the study shows the possibility for Michelin starred restaurants to use music as anenhancement in the creation of the experience of food and beverages. A construction of anexplicit model for restaurants hasn't been possible. The study contains generalrecommendations and suggestions, which in turn would require changes in star restaurants’work methods.Additional research is seen as necessary before the study of the influence of music on the mealexperience can have a broader practical application.
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Huber, Patrick. "Three flavour effects in future neutrino oscillation experiments". [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969864272.
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Koliandris, Andreas. "Relationship between texture of gels and flavour release". Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/11689/.
Testo completoAbstract (sommario):
To provide further insight into the relationship between the structure of hydrocolloid solutions and gels and perception of taste and flavour, solutions of gelatin and locust bean gum, and gels prepared from mixtures of (a) high acyl and low acyl gellan (b) carrageenan and locust bean gum were studied. Both solutions contained sodium chloride and the gels were flavoured with ethyl butyrate. The gels were classified from rheological measurements into 3 categories: strong/brittle, intermediate and soft/elastic. Volatile release was measured by monitoring nose space volatile concentration during consumption using Atmospheric Pressure Chemical Ionisation-Mass Spectrometry (APCI-MS). In addition headspace measurements were performed with APCI-MS. The headspace concentrations did not exhibit significant differences between the gels systems but the release of ethyl butyrate in-nose was affected by the matrix, showing a higher intensity for the more brittle gels containing high levels of low acyl gellan. The release of Na' following a two bite compression was monitored by the use of an ion specific electrode. The more brittle gels containing high levels of low acyl gellan and high amount of K-carrageenan exhibited significantly higher release of Na'. Strain at break correlated inversely with salt release (r2=-0.87) and nose space volatile concentration (r2=-0.55). In a later stage gelatin was added (1-5%) in the previous mixtures of HA-Gellan and LA-Gellan (constant polysaccharide concentration of 0.6%). The rheological analysis of the gels yielded different behaviour of the gels. At low levels of LA-Gellan the rheological data can be explained by polymer blending laws. At higher levels of LA-Gellan, development of elastic behaviour from the previous brittle gels observed does not fit polymer blending law theory. Flavour release during diffusion experiment showed that at 37°C the gels containing gelatin exhibited higher salt release. Temperature sweeps have shown that a drop of G' is observed around 27-28° C indicating that the gelatin present in the mixture is melting. However the level of the drop of G' indicates that the continuous phase of the gel composite was the gellan system. Volatile release was measured by monitoring nose space volatile concentration during consumption using Atmospheric Pressure Chemical Ionisation-Mass Spectrometry (APCI-MS) but showed no significant differences between the different gels. Headspace experiments performed at different temperatures showed that the gels containing high amounts of gelatin when compared to control gels that contained 0% gelatin exhibited higher release of ethyl butyrate. To mimic the mixing of gelatin with saliva after melting, gelatin solutions at 50°C containing salt were mixed with water. Even at high concentrations (30%) of gelatin mixing efficiency and release was very efficient. In contrast when locust bean gum solutions containing salt were mixed with distilled water it was found that both salt release and mixing efficiency decreased at polysaccharide concentrations above c*. It is concluded that the intensity of flavour perception in hydrocolloid solutions and gels is dominated by the release of the tastant. In solutions this is favoured by good mixing behaviour between the hydrocolloid solution and saliva and in gels by a low strain at break. A gelatine replacement should not only show melt in the mouth behaviour but good mixing between the melted gelatin and saliva. It was shown that thermal processing at 121°C induced deacetylation of HA-gellan at much lower pH than would normally be needed in a typical deacetylation process. Therefore new textures can be achieved through deacetylation through heat processing. When gels which were prepared by deacetylation by heat processing were compared with blends that had an equivalent acyl content different textures were obtained even though the Young's modulus was very similar at the same total acyl content. The implications of this work for gelled petfood products is discussed.
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Plotkowiak, Margarethe. "Maximising nutritional and flavour qualities of pork sausages". Thesis, Queen's University Belfast, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.579775.
Testo completoAbstract (sommario):
Both lipid oxidation and the Maillard reaction have been researched extensively. There has been a multitude of books, reviews and publications dealing with the details and products of either reaction. Both are key contributors to the formation of flavour and aromas of cooked foods. However, while many compounds are formed that are desirable, some compounds have been found formed by both reactions which are possibly detrimental to human health. In 2002, it emerged that acrylamide has been found in foods. As acrylamide is a potent toxin, a lot of research has been done in the last years to determine its origin and also how much of it is present in different foods types. Since its discovery it has been determined that acrylamide indeed is formed during the cooking process at high temperatures as an undesired side product of the Maillard reaction. Similarly, a side product of both Maillard reaction and lipid oxidation, Nϵ-carboxymethyllysine (CML), can be formed during advanced lipid oxidation and advance glycation. This compound is a marker for a group of compounds that has been linked with diseases such as renal diseases and Alzheimer's. The aim of this project was to determine how changes in the originating reactions, i.e. Maillard reaction and lipid oxidation, would impact the formation of both desired and undesired products. However, the objective was not only to learn how both compounds could be successfully reduced in a food product but also how the changes to induce these reductions would impact sensory qualities. To help answer these questions, a system was selected which was as close as possible to an actual food product and where changes could be introduced easily. Pork sausages were chosen as a common and popular food which was easily produced and manipulated. This Thesis first describes experiments to evaluate the impact of the composition (meat, fat, rusk, water and seasoning) and cooking on analyses for acrylamide and CML as well as sensory properties and. volatile compounds. These sausages were also compared to commercial samples for all analyses. Secondly, the effect of two antioxidants, one water- and one lipid-soluble, at two concentrations, raw and cooked, on CML, volatiles compounds and sensory properties were compared. Both experiments, change in composition and impact of antioxidants, showed interesting results. In the first experiment, the sensory evaluation showed that preference of consumers lay with samples that were high in fat and rusk but low in meat. The preferred samples were closest to the commercially available ones. Conversely, it was those samples containing high rusk that also showed some acrylamide. However, even at the highest levels measured (25ug/kg), acrylamide from sausages poses no threat to human health. Composition has a tremendous effect on the formation of CML. It appears that low levels of rusk result in higher initial levels of CML but that high levels of . protein result in lower levels of CML following the cooking process. The measured levels of CML (l0mg/kg - 35mg/kg) compare to the reported quantities of CML found in bread, meat or sausages, However, there is not yet a consensus upon whether or not dietary intake of CML is detrimental so no recommendation can be made if the levels of CML found in the experimental and commercial sausages are safe to consume. In the second experiment, two different types of antioxidants at two concentrations were incorporated during the manufacturing process into the recipes of selected experimental groups of the first experiment. The incorporation of antioxidants successfully reduced the formation of CML with varying effectiveness as different groups (high meat/ low meat, high fat/Iow fat and high rusk/Iow rusk) responded differently. Samples containing more water responded best to the water- soluble antioxidant with the biggest reduction of CML, whereas samples containing more fat or rusk showed only very little or no reduction of CML. While more work needs to be performed to fully confirm and understand these effects, the initial results indicate that antioxidants can be used as an effective way of reducing CML in foods. The antioxidant activity in the sample was also tested using colorimetric assays and while samples of the first experiment showed only very little activity the activity of the samples containing antioxidants from the second experiment even at a low level surpassed the activity measured in the commercial samples. The sensory trials showed that samples with added rosemary extract or green tea extract at low levels showed no difference to the in the sensory acceptability whereas samples containing green tea at a higher level had the lowest acceptance. Overall, the main impact on flavour is the composition of the ingredients fat, rusk and meat with the preference towards high fat and high rusk samples. On the other hand, the formation of the undesired side product CML can be improved through the introduction of antioxidants whereas acrylamide, albeit predominantly formed in the preferred high rusk/ high fat samples does not pose a threat to human health in the first place so further reduction is not necessary.
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Jasionowicz, Piotr. "The chemical and genetic basis of tomato flavour". Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12792/.
Testo completoAbstract (sommario):
Tomatoes often lack the characteristic good taste that consumers expect. In recent years, the fruit and vegetable industry has focused on traits such as yield, colour, and fruit size; however, flavour has been largely forgotten, at least for varieties that are grown in bulk and are cheap to purchase. Tomato volatiles are one of the most important flavour contributors along with sugars and organic acids. Over 400 volatiles are present in tomato, but only about 30 are considered critical to tomato flavour. The purpose of this study was to identify volatile Quantitative Trait Loci (vQTL) using publicly available Solanum pennellii and Solanum habrochaites introgression lines (ILs). Detection of vQTL is an essential milestone for identification of candidate genes involved in tomato flavour. Identification of vQTL was undertaken by screening the ILs using Atmospheric Pressure Chemical Ionisation Mass Spectrometry (APCI-MS) and Gas Chromatography Mass Spectrometry (GC-MS). Additionally key volatiles and their interactions were evaluated in a series of sensory experiments using tomato juice and tomato purée. The study revealed that, the S. pennellii population had several major effects including those on IL1-4, which had a vQTL for C6 volatile E-2-hexenal. It was possible to identify a sub-IL, 1-4-1 that also harboured this vQTL. In this IL1-4-1 region of chromosome 1, 122 genes were present including a possible, candidate gene likely to be involved in lipoxygenase pathway. The sensory experiments showed strong impact of methyl salicylate on other volatiles; E-2-hexenal and citral showed positive effects in purée studies. Determined taste detection thresholds for volatiles in tomato juice and purée were established. Keywords: volatile, genes, tomato juice, tomato purée, flavour.
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Petit, CeÌline E. F. "Multimodal flavour perception : influence of colour and chemesthesis". Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438309.
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Bingham, Alison F. "Mechanisms by which maltol and talin potentiate flavour". Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293502.
Testo completo