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.

Overconsumption of foods is thought to be one of the main causes of the rising number of global obesity. This thesis aims to investigate the role of food flavour in human appetite and eating behaviour through three studies. The first study investigated whether the sweetness intensity of a milkshake affected ad libitum intake of the milkshake and sensory-specific satiety (SSS). In a crossover single-blinded design, 24 participants consumed ad libitum high, ideal and low sweetness (HS, IS or LS) milkshakes over three visits. After milkshake intake, participants consumed ad libitum one, or both of a sweet and a savoury snack. All milkshake consumption was similar, suggesting that the sweetness intensity did not affect the ad libitum intake of the milkshake. After intake of all sweet milkshakes, ratings of desire for something sweet decreased, and subsequent savoury snacks were consumed more than subsequent sweet snacks. The sweetness intensity of milkshakes did not affect the change in the desire for something sweet or the subsequent snack intake. Ratings of desire for something savoury increased after the intake of HS milkshake and were higher than the ratings collected following the intake of IS milkshake. Therefore, this study suggested that a sweeter milkshake did not affect the magnitude of SSS for sweet foods, but increased a stronger sensory-specific appetite (SSA) for savoury foods. The second study examined the effects of aroma, taste and their interaction on subjective appetite sensation and subsequent lunch intake. In a crossover design, 26 females consumed 1 of the 4 test drinks as a preload: 1) water; 2) strawberry aroma in water; 3) sucrose and citric acid in water; 4) strawberry aroma, sucrose and citric acid in water. The subsequent lunch intake did not differ after all drink preloads. The drink with only aroma or only taste were not different from water in affecting appetite sensation. A drink with both aroma and taste reduced hunger ratings greater than water or a drink with only taste or aroma, during 15 min drinking and up to 30 min post drinking. Meanwhile, the drink with both taste and aroma was the highest in perceived flavour intensity. This suggests enhancing flavour perception of a drink through aroma-taste cross-modal interaction can increase the satiating effect of a drink. The third study investigated effects of sweetness, thickness and caramel flavour perception of custards on expected satiation and expected satiety of the custards. 90 participants (65 females, 25 males) tasted 18 custard samples over two sessions. Ingredients of custards were different only in the concentrations of caramel aroma, Truvia sweetener and carboxymethyl cellulose (CMC), based on an experimental design. Thickness enhanced both expected satiation and expected satiety. Sweetness enhanced expected satiation but not expected satiety. Caramel flavour did not affect expected satiation or expected satiety. The cognitive expectation on satiation and satiety has previously been shown to determine self-selected portion size. Therefore, the current study suggests that manipulating sweetness and thickness perception of a food without changing its energy content might help portion size control, via manipulating consumers’ cognitive expectation of the food. In conclusion, manipulating food flavour is a promising area to explore with the respect to hunger suppression and fullness enhancing, limiting the intake of eaten foods while promoting intake of other foods via SSS or SSA, and contributing to the cognitive control of portion size. Therefore, manipulation food flavour might be helpful for appetite control and supporting an energy-restrict diet; however, it seems challenging to reduce actual food energy intake through manipulating only the flavour properties of foods.

This thesis is concerned with the uses of Ubiquitous Computing (UbiComp) in everyday domestic environments. The concept of UbiComp promises to shift computing away from the desktop into everyday objects and settings. It has the twin goals of providing ‘transparent’ technologies where the information has been thoroughly embedded into everyday activities and objects (thus making the computer invisible to the user) and also (and more importantly) of seamless integration of these technologies into the activities of their users. However, this raises the challenge of how best to support interaction with a ‘transparent’ or ‘invisible’ technology; if the technology is made visible, it will attract the user's attention to it and away from the task at hand, but if it is hidden, then how can the user cope with malfunctions or other problems in the technology? We approach the design of Human-Computer Interaction in the ubiquitous environment through the use of ambient displays, i.e. the use of subtle cueing, embedded in the environment which is intended to guide human activity. This thesis draws on the concept of stimulus-response compatibility and applies this to the design ambient display. This thesis emphasizes the need to understand the users’ perspectives and responses in any particular approach that has been proposed. Therefore, the main contributions of this thesis focus on approaches to improve human performance in the ubiquitous environment through ambient display.

This aim of this study was to explore the various influences on the food choices and behaviours of Maltese primary schoolchildren. Using an ecological framework and following sociological theory of consumption it sought to uncover any group differences in food perceptions, beliefs, preferences and intake, as well as identify any culture-cuisine orientations of foods consumed in different settings. A multi-method grounded approach was adopted, where results from each stage of the research informed the focus of subsequent stages. A culture-sensitive research tool was developed for exploring children’s food consumption and preferences in ten different home-based and non-home-based settings. Data was collected via a large-scale survey with a stratified sample of 7-8-year-old children (N=1088) and their parents (N=932). Follow-up focus group interviews with children (N=16 groups) and telephone interviews with parents (N=30) were also conducted in order to obtain more detail on influences on food intake. Analysis based on gender, household level of schooling, school type, region and access to cable TV showed that Maltese children’s overall food intake was fairly similar across groups, though some specific patterns did emerge. Girls seemed to prefer and consume ‘lighter’ more ‘feminine’ foods and boys ‘heavier’ more ‘masculine’ foods. Children attending independent (fee-paying) schools tended to exhibit more ‘modern’ food practices based on novel and processed foods. They also tended to eat weekday supper with their family less frequently than other groups. Children attending state schools tended to consume more meat-based meals, milk and traditional Maltese foods. Children from the rural island of Gozo seemed to place greater value on balance, quality and freshness of food and ate their weekday supper with their family more frequently. A pronounced Westernisation of Maltese children’s diet was evident. Traditional Maltese foods were only predominant in home-based snacks. Grandparents emerged as having an important role in exposing children to traditional cuisine. Mothers’ provision of food for children was based primarily on hedonic and health motives. Strategies used to promote consumption of healthy food included controlling availability, information-giving and being prescriptive rather than restrictive. In general, both children and parents acknowledged the value of school food rules, although attitudes differed with regard to extent of imposition. Parents also felt that TV food portrayal was a strong influence on their children’s food requests, as was to a lesser extent modelling of food behaviours by peers. Children’s knowledge of the health value of food was good, though a few misperceptions existed and certain food associations were barriers to intake. Taste, texture, convenience and healthfulness were key attributes which attracted children to food. Local health promotion initiatives and nutrition education interventions need to target the different influences on Maltese children’s food intake functioning at the different ecological levels. These include the children’s own food perceptions, beliefs and valuations, as well as the different routes of influence of the mother, grandparents, the school and television.

In global terms, Saudi Arabia is a rapidly developing country. As such, its food industries have yet to fully implement the food safety management systems common in the EU. In the hospitals sector, the Ministry of Health intends to implement Hazard Analysis Critical Control Points (HACCP) system to provide safe meals for patients, staff and hospital visitors. The aim of this study was to evaluate the readiness of the Saudi Arabian hospitals to implement HACCP by assessing the pre-requisites programmes in their foodservices departments. An audit form was used in four hospitals in Riyadh. Questionnaires were also used to assess self-reported behaviour, knowledge and attitudes of 300 foodservices staff. Lack of training was known to be a major omission in the pre-requisite programs (PRP’s) of all hospitals. Therefore a bespoke food safety training program was developed and delivered to food handlers in the participating hospitals. An assessment was then made to determine whether this intervention had any effect on their knowledge, attitude to food safety and self-reported behaviour. The results show that, the prerequisite programs were not implemented properly in the participating hospitals. Also, foodservices staff had a poor knowledge with regard to food safety. However, staff knowledge was significantly improved following the training (p. value < 0.05) and their level of knowledge remained stable after six months. Participants’ behaviours and attitudes also improved after the training. This indicates that, training has a positive impact on food handlers knowledge, practices and attitude.

The career pathways and aspirations of the next generation of hotel managers have not been previously documented or studied thoroughly, primarily because the majority of available studies have focused on the success stories of current hotel general managers. Many career-related studies have highlighted the importance of career development, and the purpose of this study was to address this gap in the research in the hotel industry by exploring the career pathways of middle managers through the understanding of their educational and training background, career experiences, factors that contribute and opportunities available for them. A qualitative study, using interviews and narrative analysis, was conducted in Kuala Lumpur, Malaysia, with 14 current hotel middle managers (the heads of hotel departments), 11 former middle managers and three hotel general managers. Participants were contacted via the professional social media platform, LinkedIn. Using Career Construction Theory (Savickas (2005)) and its three components of vocational personality, life theme and career adaptability as the meta-theory, this research examined the career experiences of participants to understand middle managers’ career pathways and aspirations from their own career stories or narratives. Each interview was recorded and transcribed and the responses were then coded by using the Atlas.tiTM software. The findings were used to discuss and address the research questions set for this research. The results were also linked to the managers’ career development opportunity structures, which may have influenced their decision to stay, progress or leave the industry. Several contributions were highlighted which include the importance of education and training, the personal narratives of each manager on their work experiences, the varied extent of the available opportunities, and the skills development of the middle managers in this research. Overall, it can be concluded that the middle managers’ career aspirations were individually constructed, contextualised by the opportunities available to them, continuous learning experiences, skills development, changes in their life stages, support that they received and the extent to which they were successful in adapting the challenges involved in their career transitions.

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.

There is demand from the food industry for novel savoury seasonings based on low-cost food ingredients, sourced from within the EU. A nucleotide and protein rich spray dried powder which was derived from a Fusarium venenatum fermenter waste stream and food-grade Alphitobius diaperinus with potential as a savoury flavour enhancer was evaluated. Enzymatic digestion of these two raw materials as a source of flavour precursors was evaluated. Serial enzyme combinations, enzyme dosages, sequence of enzyme application, pH, temperature and length of digestion for the liberation of amino acids and nucleotides were optimised for the liberation of taste active compounds. For amino acids, free glutamine (GLN) and glutamic acid (GLU) could be enhanced using a combination of peptidases on both raw materials. Digesting a spray dried powder derived from the fermenter waste stream of Fusarium venenatum with exopeptidase (1% Flavourzyme TM), resulted in an improved yield of GLN (from 0.1 mg/g to 28.9 mg/g powder) and GLU (from 1.71 mg/g to 5.98 mg/g powder). For milled Alphitobius diaperinus, mixed use of exopeptidase (1% Flavourzyme TM) and endopeptidase (2% Alcalase 1.4-fold increased yield of GLU (17.5 mg/g powder) and 1.7-fold increased yield of GLN (1.2 mg/g) as best production was obtained. For nucleotides, digestions of the waste stream with a yeast lytic enzyme (YL-TLTM) followed by a nuclease (RP-1GTM) resulted in the highest 5’-guanosine monophosphate (GMP) and 5’-adenosine monophosphate (AMP) production. Specifically, a 2% and 0.05% treatment by YL-TLTM and RP-1GTM respectively was shown to be optimal, followed by a 0.05% DeamizymeTM treatment for the conversion of AMP to 5’-Inosinic acid (IMP) of 38 mg/g. For the solid digestion of Alphitobius diaperinus, being treated with a nuclease tretment (2% RP-1GTM) followed by a 0.2% DeamizymeTM treatment for the conversion of AMP to IMP, resulted in the highest GMP yield, a 3.5-fold increased (2.6mg/g), and 7.8-fold increased IMP (4.7mg/g) production.

This study focuses on persuasive design concerning the household users&rsquo / energy saving behavior while using electrical household appliances for the housework. Household users form a balance at home determined by the household resources they have, and they do not want to change this fragile balance because it is established as a result of household users&rsquo / habitual behavior. It is crucial to persuade household users to save energy at home without disturbing the balance among resources. Persuasion becomes an effective tool at this stage. The study provides an efficient reallocation of the resources for energy saving behavior, which is supported by household resource reallocation and persuasion literature, and an empirical study.