College of Arts, Celtic Studies and Social Sciences - Doctoral Theses

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    Quantification of volatile compounds (oxidative and olfactory) in meat products and impact of seaweed addition on the sensory and volatile profiles of processed meat products
    (University College Cork, 2022-10) Garicano Vilar, Elena; Kerry, Joseph; O'Sullivan, Maurice; Kilcawley, Kieran; Teagasc
    Now more than ever consumers demand healthier food options, including meat products, with ‘clean-label’, sustainable and natural ingredients without compromising their sensory experience; hence a greater need for innovative concepts and approaches towards new product development is required. In this regard, seaweeds compose a credible source of functional ingredients with bioactive properties. There is a positive association between processed meat consumption and the risk of chronic diseases, such as cardiovascular disease, certain cancers or type II diabetes, due to their high levels of saturated fats and sodium. Processed meat refers to meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavour or improve preservation (i.e., frankfurters, ham, and canned meat). The optimization of processed meat products through the reduction of fat and the partial replacement of salt could potentially offset the risk. However, the influence of matrix changes on the character aroma compounds and sensory perception of the developed products could adversely affect consumer acceptability. Therefore, this research aims to characterize the volatile organic compounds (VOC) and aroma profiles of processed meat products and seaweed, and to study seaweed-based processed meat products in terms of shelf life and consumer perception. This thesis has demonstrated the feasibility of generating valuable VOC and aroma profiles of processed meat products and seaweed using sophisticated extraction, separation, and identification gas chromatography mass spectrometry techniques (GC-MS); and of developing a novel method using headspace high capacity sorptive (HiSorb) extraction for quantification of target lipid oxidation compounds. This in-depth approach provides information on the sensory characteristics and shelf life of the processed meat products (frankfurters and beef patties), following reformulation and/or storage. The work in this thesis primarily employed HiSorb and thermal desorption (TD) GC-MS (HiSorb TD GC-MS) with polydimethylsiloxane (PDMS) probes and headspace solid phase microextraction GC-MS (HS-SPME GC-MS) for VOC profiling, but also the use of gas-chromatography olfactrometry (GC-O) applications. Chapter 1 provides an updated insight into the main extraction/concentration techniques that are available for the determination of the main odour-active volatiles in beef and pork. Aroma compounds are challenging to extract, concentrate, separate, identify and quantify due to the complexity of meat. The review highlights the potential pros and cons of the main approaches used to date but also, how advances in extraction, chromatography and olfactometry helps elucidate more key aroma compounds. However, many VOC have been identified in beef and pork to date. It is the use of GC-MS and olfactometry methodologies that enable us to increase our knowledge of the importance of the key volatiles impacting on consumer perception, either positively or negatively. The review in chapter 2 provided insights into the volatile analyses of six commercially important brown and red seaweed species used in the food industry and highlighted the need for more information regarding VOC in edible macroalgae and to identify those most likely to impact sensory perception. This is as important for those VOC that positively or negatively contribute to sensory perception. Such information could be used to aid new product development or widen applications of these seaweeds in the food sector, one of which is in meat product formulation. In that regard, chapter 3 investigated the volatile profiles of dried brown (Himanthalia elongata, Undaria pinnatifida, Alaria esculenta) and red (Porphyra umbilicalis, Palmaria palmata) seaweeds, and a brown seaweed extract (fucoxanthin) from Laminaria japonica, some of which had not previously been described. A chemometric approach was used to collate data from GC-MS, direct sensory aroma evaluation, and GC-O to obtain a better understanding of their volatile profile and sensory perception. Once the volatile profiles of the seaweed were characterized, chapter 4 investigated the impact of the inclusion of four selected seaweeds (1 % w/w) in reformulated frankfurters in which salt addition was reduced by 50 % compared to a control. The overall acceptability of reformulated frankfurters containing seaweed was greatly influenced by the type of added seaweed (also linked to dosage), but overall, the addition of seaweed enabled salt reduction and thus improved the nutritional quality. Further processing of seaweed prior to addition, optimization of dose rates, combinations of seaweeds and/or highlighting potential nutritional benefits will be necessary before such products are accepted by consumers unfamiliar with seaweeds in their diet. Lipids may cause both desirable and undesirable flavours and aromas in meat. However, progressive lipid oxidation adversely affects meat quality. Sophisticated techniques such as GC-MS can be used to identify and quantify individual VOC associated with lipid oxidation. Hence, the aim in chapter 5 was to develop a GC-MS method using HiSorb extraction for untargeted volatile profiling and to quantify targeted LOC in raw beef patties over refrigerated storage. Using this approach to determine the concentrations of VOC associated with lipid oxidation that adversely impact sensory perception provided insights into the production parameters that could maximise the oxidative shelf life stability and quality of meat products. It is essential to expand the knowledge on how to protect foods against lipid oxidation. Synthetic antioxidants have been used for many years to retard lipid oxidation in foods. However, there is growing interest in replacing synthetic antioxidants with natural ingredients. Seaweeds are not only a valuable source of bioactive compounds and a good salt content replacer, but also exhibit extraordinary antioxidant potential which can be harnessed for a broad variety of food applications. Therefore, the validated HiSorb GC-MS method outlined in chapter 5 was applied to profile the aroma of raw beef patties reformulated with seaweed, packed in MAP, and stored under refrigeration conditions in chapter 6. The method was combined with GC-O to detect VOC changes that could cause off-flavours in the product over time, along with changes in colour and TBARS values indicative of lipid oxidation. The antioxidant activity of the seaweed was also examined in an attempt to evaluate their effect against product deterioration. The antioxidant activity present in seaweed, attributable to polyphenols, flavonoids and other antioxidants, opens new possibilities of application of these in fresh meat products. Their use could potentially increase shelf life of food products due to their antioxidant capacity, and replace artificial food additives.
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    Resistencia y solidaridad a través de la producción cultural de mujeres zapatistas y mayas: muralismo, teatro y video/web (1994-presente)
    (University College Cork, 2023-05-03) Cabrejas Regadera, Eva; Finnegan, Nuala; Serra Porteiro, Elisa Maria; SPLAS
    Abstracto El Ejército Zapatista de Liberación Nacional (EZLN), que apareció por primera vez en público en Chiapas, la noche de año nuevo de 1994, surgió de una profunda necesidad de cambio en la situación de los pueblos indígenas del país. Los zapatistas demandaron modificaciones estructurales en el sistema político mexicano que afectaron a la situación de los indígenas en cuestiones de tierra y organización política ante todo. Las mujeres participaron de manera muy activa como insurgentes, incluso antes de la revolución, y habían elaborado sus ideas como el rol de la mujer dentro de sus comunidades en la Ley Revolucionaria (1993). Por tanto, desde el principio del movimiento, la mujer ha sido eje central y ha formado parte clave del movimiento y sus visiones. Esta tesis se concentra en cómo ha evolucionado el rol de la mujer, su visión del futuro y su lucha epistémica por reivindicar sus derechos a través de la producción sociocultural y colectiva. Examina esta producción desde una posición teórica informada por las ideas sobre el feminismo des colonial e interseccional de Julieta Paredes (2010) y Francesca Gargallo (2013) entre otras. El primer capítulo se basa en el arte visual muralista comunitario del caracol Oventic como forma de manifestación colectiva y militante de protesta de la comunidad zapatista y que se deriva de mi trabajo de campo en la región en 2018. El segundo capítulo abarca los primeros vídeos de la mujeres zapatistas en internet y tres ejemplos de proyectos web, uno por mujeres mayas en la región y otros por mujeres zapatistas dentro de la Organización Comunitaria ProMedios: Las compañeras tiene grado, Oventic: Construyendo dignidad y EZLN Zapatistas Xulum’Chon Tejedoras de los Altos en Resistencia. El capítulo plantea también una discusión sobre los primeros proyectos web (Zap Women, ¡Ya Basta!, La Neta, Creatividad feminista, plataforma de solidaridad con Chiapas en Madrid y Retos Nodos Chiapas). El tercer capítulo avanza la discusión sobre la evolución de la mujer fuera de las comunidades zapatistas, explorando los trabajos teatrales de Petrona de la Cruz, escritora maya no perteneciente a la comunidad zapatista, pero que demuestra la transformación social de la mujer indígena de Chiapas y la forma de su resistencia colectiva por su derecho desigualdad. La tesis tiene como propósito principal demostrar como la lucha epistémica de las mujeres mayas y zapatistas se filtra y se canaliza a través de esta producción cultural.
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    Normative expectations and subjective beliefs: an incentivised experimental study
    (University College Cork, 2022-12-12) Wang, Cuizhu; Ross, Don; Harrison, Glenn; Georgia State University; University of Cape Town
    This thesis is an experimental study to investigate the operationalisability of the theory of social norms provided by Cristina Bicchieri. In Chapter 1 I critically summarise a main theme from recent literature and distinguish the accounts of norms based on social preferences from accounts based on social structure. I also summarise different theorists’ accounts of social norms as a social construct, in addition to surveying some issues scholars have raised empirically. Chapter 2 reviews the conceptual analysis of social norms by Bicchieri as a social structure based account. Bicchieri’s conceptual analysis introduces three kinds of condition for norm identification. I review these in detail, and suggest hypothesis testing corresponding to each kind of condition. Chapter 2 briefly analyses a critical problem for Bicchieri’s theory. Chapter 3 provides philosophical background that supports the intentional concepts applied in Bicchieri’s analysis of social norms. I suggest that the Dennettian account of Intentional Stance is the best philosophical framework for Bicchieri’s account of social norms. I also argue that Revealed Preference Theory from economics is an application of the Intentional Stance. I conjecture that adopting the Intentional Stance and applying Revealed Preference Theory to empirical data can allow for improved operationalisation of Bicchieri’s conceptual analysis. In Chapter 4 I provide critical review of some key experimental work by Bicchieri and co-authors applying her conceptual analysis of social norms. I then provide a critical review of a widely used toolbox from the current economic literature for norm elicitation. Then I introduce a more rigorous experimental protocol for investigating social norms understood following Bicchieri’s analysis. The toolbox suggested in my thesis addresses limitations identified in Bicchieri’s empirical work. Chapter 5 presents design of the experiment administered as the core element of the thesis. Chapter 6 shows and analyses the results from the experiments described in Chapter 5. It also introduces the statistical models used in my thesis to assess the extent to which Bicchieri’s analyses successfully guides experimental identification of social norms. Chapter 7 offers concluding theoretical reflections, and discusses possible extensions of the research presented in this thesis.
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    The fragile and imaginative world of learning to teach: experience, identity, pedagogy
    (University College Cork, 2022-10-07) Hinchion, Carmel; Hall, Kathy
    This PhD thesis is by Published Works. Its focus is on learning to teach in Initial Teacher Education. The key concepts explored include the experience of learning to teach, the identity-making process involved and the importance of pedagogy to the process. Student teacher texts of practice make up the data set and the methodology is interpretative in approach.
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    Early modern masters of suspicion
    (University College Cork, 2022) Di Carlo, Andrea; Dockstader, Jason; Leask, Ian
    This thesis interprets Niccolò Machiavelli, Michel de Montaigne, Francis Bacon, and John Milton, casting them as Masters of Suspicion. The category of ‘Master of Suspicion’ was introduced by Ricœur (1970) to describe how Marx, Nietzsche and Freud approached their respective economic, epistemological and medical contexts. After a recap on the thinking of Ricœur’s own Masters of Suspicion, I will move on to analyse the thinking of Machiavelli, Montaigne, Bacon, and Milton, whom I define as “early modern Masters of Suspicion”, Machiavelli, Montaigne, Bacon, and Milton. In the same way Ricœur analysed the context of Marx, Nietzsche and Freud, I will do the same with Niccolò Machiavelli, Michel de Montaigne, Francis Bacon, and John Milton. Machiavelli claimed that politics should not be driven by moral constraints; politics, as such, is a realm independent of morality. Montaigne created a new philosophical and literary genre, the essay, to examine a world that needed to reconsider its foundations. Unlike Machiavelli, he believed that different moral ideas could come together. Bacon claimed that scientific inquiries should not constrained by dogmatic interpretations of Aristotle. As a consequence, he set out to outline a novel method of scientific investigation. I argue in this thesis that Milton, like Machiavelli, Montaigne and Bacon, acted in a similar manner. He reassessed long-standing ideas of sovereignty by showing that even medieval political practices should be reconsidered in the midst of the English Civil War. He emphasised the necessity, like Montaigne, of a more personal “realm” where he could study himself and the changes of his time. Like Bacon, Milton believed that the epistemological obstacles of dogmatic Aristotelianism had to be overcome to allow science to freely flow. By framing Machiavelli, Montaigne, Bacon, Milton as Master of Suspicion, this thesis reconsiders their reception by exploring new possible avenues of research on their political, moral and scientific ideas.