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Water and lipid-soluble meat flavour precursors are gradually formed post-mortem via biochemical reactions. Storage time and temperature can affect final flavour precursor concentrations which in turn will affect the sensory quality of cooked meat. Selected key flavour precursors were monitored in Bison bison longissimus dorsi muscles from six animals stored at 2, 4, 8, 15 and 21 days at 4°C, in order to evaluate the effect of post-mortem conditioning on the formation of flavour precursors. Results were correlated with sensory data obtained using quantitative descriptive analysis with 8 trained panelists. While lipid-soluble flavour precursors remained mostly unchanged, significant increases (P<0.05) in concentrations of water-soluble flavour precursors including reducing sugars (eg. ribose, xylose), free amino acids (eg. valine, leucine) and adenosine-5’-triphosphate (ATP) degradation products (eg. inosine and hypoxanthine) were obtained with chilled storage conditioning post-mortem. The overall balance and correlations of water-soluble flavour precursors with storage day 15 and 21 were reported and can potentially impact the eating quality of cooked bison meat.

Soybean production and consumption has increased in recent decades. However, trypsin inhibitor activity and “beany” flavour are two drawbacks limiting the utilization of soybean. In the present study, micronization, ethanol washing, and enzymatic hydrolysis (alone or in combination) were used to treat soybean. Micronization at 100 °C and 135 °C decreased the activity of both trypsin inhibitors (53% and 80% respectively), and lipoxygenase (51% and 99%, respectively). Ethanol increased the trypsin inhibitor activity while alcalase hydrolysis decreased its activity. Different treatment combinations affected trypsin inhibitor activity, with micronization having a major influence. “Beany” flavour related volatiles (hexanal, (E)- 2-hexenal, 1-hexanol, heptanal, (E)-2-octenal, (E)-2-nonenal, (E,E)-2,4-nonadienal, 2,4-decadienal, (E,E)-2,4-decadienal, 1-octen-3-ol, 2-pentylfuran and 3-octen-2-one) were significantly decreased with micronization. Ethanol effects varied with different volatiles. Soybean micronized at 135°C and washed with 65% ethanol was recommended for soybean processing due to its low trypsin inhibitor activity and low “beany” related volatile content.

It is astonishing both how little and how much we know about neutrinos. On one hand, the neutrino is the second most abundant particle in our Universe. Neutrinos may be created in the Sun, core collapse supernovae, cosmic rays, geological background radiation, supernova remnants and in the Big Bang. On the other hand, they have unimaginably small masses and are unwilling to react with their surroundings. Because of their abundance and their inclination to show us physics beyond the standard model of particle physics, neutrinos are hoped to carry yet unknown information of the Universe. However, it will take some effort and time to persuade the neutrinos to tell us what they know. Among the things we do not yet know of the neutrinos, is the -phase in the neutrino mixing matrix. If is in fact non-zero, neutrino flavour oscillations violate CP-symmetry. Also, if neutrino masses are introduced in the standard model through the See-Saw mechanism and if leptogenesis is a valid theory, CP-violation in neutrino oscillations could help explain why our Universe has no antimatter even though equal amounts of matter and antimatter should have been created at the Big Bang. In this thesis, we investigate the flavour evolution of supernova neutrinos. We present the full Hamiltonian in the flavour basis for our system and identify how the different contributions affect the evolution and in which environment. We also present a theoretical motivation from [1, 2] as to how a non-zero -phase affects the flavour evolution and the final energy spectra. The analytical conclusion is that it has no impact under the assumptions made in our analysis. Thus, the -phase may not be measurable from supernova neutrinos.

Water and lipid-soluble meat flavour precursors are gradually formed post-mortem via biochemical reactions. Storage time and temperature can affect final flavour precursor concentrations which in turn will affect the sensory quality of cooked meat. Selected key flavour precursors were monitored in Bison bison longissimus dorsi muscles from six animals stored at 2, 4, 8, 15 and 21 days at 4°C, in order to evaluate the effect of post-mortem conditioning on the formation of flavour precursors. Results were correlated with sensory data obtained using quantitative descriptive analysis with 8 trained panelists. While lipid-soluble flavour precursors remained mostly unchanged, significant increases (P<0.05) in concentrations of water-soluble flavour precursors including reducing sugars (eg. ribose, xylose), free amino acids (eg. valine, leucine) and adenosine-5’-triphosphate (ATP) degradation products (eg. inosine and hypoxanthine) were obtained with chilled storage conditioning post-mortem. The overall balance and correlations of water-soluble flavour precursors with storage day 15 and 21 were reported and can potentially impact the eating quality of cooked bison meat.

The traditional wood used to make barrels destined for use in the world wide wine industry is oak. However, oak chips and shavings can substitute for barrels to add flavour to wine and are very much more cost effective. As with the heat treatment of barrels, oak chips are toasted before use. This serves to pyrolyse lignin and hemicellulose, generating families of compounds that impart desirable flavours to wine. Other woods are very occasionally used in wine barrel construction, but no chips other than oak chips have been used to flavour wine. This is surprising given that all woods contain lignin and hemicellulose, the composition of which will vary perhaps usefully from species to species. The 12 woods used in this research, including American oak, were chosen on several criteria: botanical similarly to oak, exclusivity to New Zealand, and historical association with New Zealand. The woods were cut to chips measuring about 10 x 20 x 2.5 mm. The moisture content was measured after dry heating to 110°C. Fresh samples of chips were heated (toasting in the context of wine) to 200°C for 2 hours, 210°C for 3 hours, called light and heavy toasting respectively. Weight loss was determined. The colour of the untreated and toasted wood chips was measured in Hunter colour space, yielding data on lightness (L*), hue angle (the basic colour) and saturation (the intensity of colour). The moisture content of oak was the lowest of all the woods. The weight loss of oak chips at 200°C was much greater than that of other woods, but the colour change did not indicate losses due to severe charring. Overall, each wood behaved in a distinctive way to the toasting treatments, with some charring much more than others. Hue was the least affected, indicating that the basic colour of the woods was little changed by toasting. Light and saturation generally decreased strongly, particularly on heavy toasting. Colour was thus being lost and less light reflected. An unoaked chardonnay was infused with toasted chips at the rate of 5 g.L-1 for two weeks at room temperature, and later decanted. At all stages exposure to air was minimised. The 25 treatments (2 x 12 plus the unwooded control) were first assessed by a panel comprising eight experienced wine tasters and 29 AUT staff members who claimed some knowledge of wine flavour. This qualitative/semi-quantitative analysis required tasters to assess the wines in terms of 12 descriptors commonly associated with oaked wines (boxes were ticked for ‘sweet oak’, ‘smokey’, ‘vanilla’ etc.), and to choose the three most liked and the three least liked. 6 Confidential A principal component analysis of a correlation matrix of descriptors was used to summarise panelist’s opinion. The first two principal components explained 53 % of the variation and served to group descriptors into four quadrants, which were each associated with different woods and toasting levels. Most liked were totara light (toast), kahikatea heavy, manuka heavy and American oak light. Macrocarpa light toast was almost universally disliked. On the basis of liking and association with New Zealand, five woods and chosen toasting levels and the control were selected for hedonic trials (1 to 9 liking scale) with 180 consumers (age range and gender were identified) in six retail wine shops. The decreasing numerical of liking by treatment was totara (6.49), control, manuka, American oak, kahikatea, radiata pine (5.47), with an overall significant effect (P < 0.001) for treatment. Tukey’s test revealed that only totara and the control treatments were outstanding (P < 0.05). Retail wine shop as a factor was marginally significant. Older consumers liked the wines more (P < 0.05), as did females (P < 0.001). There were no significant interactions between any of the factors. Because of the difficulties in sourcing totara, manuka appears to be the most viable alternative to oak as a wine flavouring in the New Zealand context.

La vanillyl alcool oxydase est un biocatalyseur prometteur d’un point de vue réactionnel en raison de sa faible sélectivité sur les composés phénoliques substitués en position para. Elle catalyse l’oxydation d’une large gamme de dérivés 4-hydroxybenzylique, des réactions de déméthylation oxydative, de désamination, de déshydrogénation et d’hydroxylation ; notamment celle de l’eugénol. L’hydroxylation de ce dernier conduit à la formation d’alcool coniférylique. Dans le but d’utiliser l’eugénol comme substrat de biosytnhèse de dérivés vanilliques, nous avons développé, au cours de ce travail de thèse, deux souches exprimant le biocatalyseur d’intérêt : une souche de levure et une souche bactérienne.La première partie de la thèse a donc consisté à mettre au point un système d’expression pour la production de VAO dans la levure de boulanger et un procédé d’hydroxylation de l’eugénol en fermenteur. Le principal apport réside dans la construction de la souche 93645, qui contient la cassette d’expression VAO et une activité oxydase propre permettant la bioconversion de l’alcool coniférylique formé en acide férulique. En fonction des conditions de fermentation, 20 g/l d’alcool coniférylique ou 27 g/l d’acide férulique sont produits par les cultures de S. cereviaise- VAO 93645. La reproductibilité des procédés, ainsi que leur faisabilité à l’échelle pilote, ont été démontrés.Dans la seconde partie de cette étude, le même travail de clonage a été réalisé dans la souche Amycetales Streptomyces setonii ATCC 39116. La bactérie, reclassifiée en 2009 sous le nom d’Amycolatopsis sp 39116, est connue pour sa capacité à bioconvertir l’acide férulique en vanilline ; d’où l’intérêt d’exprimer l’enzyme VAO dans cette souche. Plusieurs stratégies de clonage ont été expérimentées et une souche recombinante, exprimant une activité VAO active a été obtenue. Les conditions optimales pour l'utilisation de cette dernière dans le cadre de la production de vanilline et d’alcool coniférylique ont été identifiées. Elles conduisent à la biosynthèse de 0,4 g/l vanilline et de 15 g/l d’alcool coniférylique. Les résultats mettent en évidence une activité insuffisante des oxydases de Streptomyces sur l’alcool coniférylique formé. Ce type de production n’a encore jamais été réalisé chez S. setonii et ces premiers résultats demandent encore des mises au point avec, sans doute, le clonage d’oxydases hétérologues permettant la bioconversion de l’alcool coniférylique formé en acide férulique. / Our aim was to develop a process for the biosynthesis of vanillin derivatives from eugenol.Vanillyl alcohol oxidase isolated from Peniciiiium simplissicimum, catalyzes the hydroxylation of eugenolinto coniferyl alcohol. In this study, two strains expressing the biocatalyst were constructed: a yeast,Saccharomyces cerevisiae, and a bacteria; Streptomyces setonii.It has been demonstrated that the wild strain Saccharomyces cerevisiae can bioconvert coniferyl alcohol, most probably due to its dehydrogenase activity. Strain 93645, genetically modified to expressvanillyl-alcohol oxidase, enabled us to optimize an industrial scale process for the production of natural ferulic acid.Streptomyces setonii strain ATCC 39116 was also genetically engineered to over-express VAO. Abioconversion process was developed leading to a coniferyl alcohol concentration of 15 g/1 coniferyl alcohol. The impact of several parameters; such as temperature, substrate addition mode and pH, werealso explored to improve the bioconversion reaction of coniferyl alcohol to vanillin. The amounts of product resulting from bacterial biosynthesis were however too low for implementation of an industrial process.

The hadronic decay D0 → KS pi+ pi- provides direct access to the measurement of the mixing parameters of the neutral charm meson system and allows to test for indirect CP violation. Mixing is a time-dependent phenomenon for which the time evolution of the transition amplitude of a D0 (anti-D0) decay to the final state KS pi+ pi- has to be considered. The parameters driving those time-dependent oscillations are x and y, depending on the masses and widths of the physical eigenstates. The CP violation parameters |q/p| and phi describe the superposition of the flavour eigenstates D0 and anti-D0 and of the physical eigenstates D1 and D2. By measuring the time- and phase-space dependent distribution of D0 → KS pi+ pi- decays, the mixing parameters can be extracted and a search for indirect CP violation can be performed. This thesis reports a measurement of the mixing parameters and the preparations of a measurement of the CP violation parameters on data collected with the LHCb experiment in 2011 and 2012, corresponding to an integrated luminosity of 3/fb. The D0 and anti-D0 mesons are required to originate from a semileptonic decay of a B meson. The parameters of interest are extracted from a fit in D0 decay time and the Dalitz variables. The phase-space distribution of D0 → KS pi+ pi- decays is modelled by expressing the three-body decay as a succession of two-body decays. The decay amplitude of a D0 or anti-D0 meson into KS pi+ pi- final state is a superposition of all possible intermediate resonances and the single resonances interfere with each other across the phase-space.

This diploma thesis deals with sensory evaluation of herbal non-alcoholic beverages, being a part of a new product development. The theoretical part provides information concerning chemical composition, health effects, food applications and aroma compounds of the herbs of interest (peppermint (Mentha piperita), sage (Salvia officinalis), St. John’s wort (Hypericum perforatum) and lemon balm (Melissa officinalis). Another topic is a description of sensory methods, requirements and arrangement of the analysis, statistical methods, and also technological processes leading to herbal syrups and beverages production. The practical part comprises sensory analysis of a few, newly designed, formulas of one-component and two-component alcohol free herbal beverages. The sensory panel consisted of 40 students of master's and also doctoral study programme at Faculty of chemistry, University of Technology Brno. Four subsequent experiments are introduced, each of them consisting of a few sensory tests and including corresponding sensory forms attached. The sensory tests arrangement was based on currently valid Czech Technical Standards, using a ranking, descriptive, paired comparison, sensory profile testing and scaling methods. For the purpose of statistical evaluation, Friedman, Kruskal-Wallis, PCA and Faktor analysis were used. Level of abilities and sensory experience of panelists were found comparable to consumer testing. The results include sensory characteristics of all of the beverages tested. In general, the one-component beverages were preferred to the two-component beverages and the additive colouring with aronia concentrate wasn´t found any benefitial, from the sensory point of view. The consumer questionnaire proved all of the samples to be very promising, but based on the sensory results, we would consider the mint and the sage-mint beverages being the most potentialy applicable samples.

This diploma thesis deals with the determination of aroma compounds in fruit yoghurts. These compounds are crucial for flavour of these dairy products. Two types of fruit yoghurts were analyzed, creamy (8 % of fat) and light (less than 0,1 % of fat), with various fruit ingredients, produced in dairy Mlékárna Valašské Meziříčí, spol. s r.o. Analysis was carried out by gas chromatography with extraction of analytes by SPME - solid phase microextraction. Six groups of different aromatic compounds such as ketones, aldehydes, organic acids and their salts, alcohols and sulfides in different amounts were determined. These compounds have mostly microbiological origin (Streptococcus salivarius subsp. thermophilus, Lactobacillus delbrueckii subsp. bulgaricus are dairy yoghurt cultures usually used for yoghurt production), less amounts are present in cow's milk or in dairy additives. Yoghurts were simultaneously sensory evaluated using ranking test, scale test and pair test for determination of acceptability and flavour. The assessors were students and staffs faculty of chemistry VUT.