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.

This work was undertaken to evaluate interactions between plant proteins and selected volatile flavour compounds on flavour delivery and heat-induced gelation properties for canola, pea and wheat proteins. An automated dynamic headspace GC/MS approach was adopted to monitor the change in flavour intensity in aqueous model systems. The extent of flavour binding was a function of protein source, protein isolation method and stereochemistry of the flavour compound. Using Differential Scanning Calorimetry and intrinsic fluorimetry, potential conformational changes due to partial denaturation of proteins were observed. Aldehyde flavours exhibited much higher “unfolding capacity” than ketones, which accounted for their remarkable binding affinities. Two volatile flavour by-products, 2-butyl-2-octenal and 2-pentyl-2-nonenal, were detected from the interactions between salt-extracted canola protein isolates (CPIs) with hexanal and heptanal, respectively, due to aldolisation reactions. Competitive bindings among homologous ketones and between heterologous aldehyde and ketone mixture were observed, while a synergistic effect was noted for aldehyde flavour mixtures. Environmental changes such as heating and addition of non-chaotropic salts increased binding for ketones; however, protein aggregation following continuous heating and denaturation of protein by chaotropic salt and at extreme pH values reduced ketone retention. Apart from molecular interactions, dramatic increases in flavour binding were monitored when physical adsorption of flavours on aggregated proteins was employed. By adding bonding disrupting agents, the molecular forces responsible for the interactions were probed with hydrophobic interactions, hydrogen bond and ionic interactions being prominent for benzaldehyde, 2-octanone and hexyl acetate, whereas covalent interactions were implicated for octanal and dibutyl disulfide. Selectively modifying proteins via chemical (acetylation and succinylation) and enzymatic (Alcalase) approaches significantly altered protein-flavour binding affinities and this was influenced by the type of flavours selected and associated type of binding. In general, addition of flavour compounds diminished protein heat-induced gel forming properties by disrupting protein inter- and intra-molecular hydrophobic interactions. However, gel strength was regained with increasing concentration and chain length of aldehydes possibly due to the additional unfolding effect on proteins due to aldehyde binding. This facilitated the gel formation process, consequently resulting in formation of stronger gels. / February 2016

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.

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In this thesis we use effective field theories of the strong interactions to improve our understanding of several quantities in the Standard Model of particle physics (SM). We also examine constraints on an extension of the SM scalar sector and study the implications for the Higgs mass. We first examine an approach to extracting the Cabibbo-Kobayashi-Maskawa matrix element |Vub| via the relationship between the B meson decays B -> Xu l nu and B -> Xs gamma, where Xi is any final state hadron containing a quark of flavour i. Model dependence is reduced in this approach since the non-perturbative shape function at leading order is universal and drops out; however the perturbative expansion at next-to-leading order is found to be poorly behaved. We carry out a renormalon analysis of the relationship between these spectra to examine higher order perturbative corrections and compare the fixed-order and log expansions. Our analysis can be used to estimate the perturbative uncertainty in the extraction of |Vub|, which we show to be relatively small. Next we take a step towards the broader goal of summing large phase space logarithms from a variety of jet algorithms using Soft Collinear Effective Theory (SCET). We develop a consistent approach to implementing arbitrary phase space constraints in SCET and demonstrate the connection between cutoffs in SCET and phase space limits. By considering several jet algorithms at next-to-leading order, we gain some insight into factorization of final state jets. In particular, we point out the connection between the ultraviolet regulator and factorization. Finally we consider a scalar sector that contains a colour-octet electroweak-doublet scalar, in addition to the SM Higgs. This extension contains the only scalar representations that Yukawa-couple to quarks and are consistent with minimal flavour violation. We examine constraints from electroweak precision data, direct production from LEPII and the Tevatron, and from flavour physics. We find both the Higgs and new scalars can be simultaneously light, with masses of O(100 GeV). The data also allows all the scalars to be heavy, with masses of O(1 TeV). The presence of the additional scalars removes the preference for a light Higgs, which normally emerges from fits to electroweak precision data.

No description available.

In this thesis we use effective field theories of the strong interactions to improve our understanding of several quantities in the Standard Model of particle physics (SM). We also examine constraints on an extension of the SM scalar sector and study the implications for the Higgs mass. We first examine an approach to extracting the Cabibbo-Kobayashi-Maskawa matrix element |Vub| via the relationship between the B meson decays B -> Xu l nu and B -> Xs gamma, where Xi is any final state hadron containing a quark of flavour i. Model dependence is reduced in this approach since the non-perturbative shape function at leading order is universal and drops out; however the perturbative expansion at next-to-leading order is found to be poorly behaved. We carry out a renormalon analysis of the relationship between these spectra to examine higher order perturbative corrections and compare the fixed-order and log expansions. Our analysis can be used to estimate the perturbative uncertainty in the extraction of |Vub|, which we show to be relatively small. Next we take a step towards the broader goal of summing large phase space logarithms from a variety of jet algorithms using Soft Collinear Effective Theory (SCET). We develop a consistent approach to implementing arbitrary phase space constraints in SCET and demonstrate the connection between cutoffs in SCET and phase space limits. By considering several jet algorithms at next-to-leading order, we gain some insight into factorization of final state jets. In particular, we point out the connection between the ultraviolet regulator and factorization. Finally we consider a scalar sector that contains a colour-octet electroweak-doublet scalar, in addition to the SM Higgs. This extension contains the only scalar representations that Yukawa-couple to quarks and are consistent with minimal flavour violation. We examine constraints from electroweak precision data, direct production from LEPII and the Tevatron, and from flavour physics. We find both the Higgs and new scalars can be simultaneously light, with masses of O(100 GeV). The data also allows all the scalars to be heavy, with masses of O(1 TeV). The presence of the additional scalars removes the preference for a light Higgs, which normally emerges from fits to electroweak precision data.