Macroalgae and commercial macroalgal polysaccharides as potential functional ingredients in muscle foods

Ulva rigida (UR) and Palmaria palmata (PP) were included in farmed Atlantic salmon diets at levels of 0-15% for 19 and 16 weeks, respectively. Quality and shelf-life parameters of salmon fillets stored in modified atmosphere packs (MAP) (60% N2 : 40% CO2) at 4ºC were compared to controls fed astaxanthin. Salmon fillets were enhanced with a yellow/orange colour. Proximate composition, pH and lipid oxidation were unaffected by dietary UR and PP. Salmon fed 5% UR and 5-15% PP did not influence sensory descriptors (texture, odour, oxidation flavour and overall acceptability) of cooked salmon fillets. Pig diets were supplemented with commercial wet- and spray-dried macroalgal (Laminaria digitata) polysaccharide extracts containing laminarin (L, 500 mg/kg feed) and fucoidan (F, 420 mg/kg feed) (L/F-WS, L/F-SD) for 3 weeks and quality and shelf-life parameters of fresh pork steaks (longissimus thoracis et lumborum) stored in MAP (80% O2 : 20% CO2) were examined. Level (450 or 900 mg L and F/kg feed) and duration (3 or 6 weeks) of dietary L/F-WS and mechanisms of antioxidant activities in pork were investigated. L/F-WS reduced (p < 0.05) lipid oxidation and lowered levels of saturated fatty acids in fresh pork after 3 weeks feeding. L/F-SD was added directly to mince pork (0.01 - 0.5%) and quality and shelf-life parameters of fresh pork patties stored in MAP (80% O2 : 20% CO2) were assessed. Direct addition of the L/F-SD increased levels of lipid oxidation and decreased surface redness (a* values) of fresh pork patties. Lipid oxidation was reduced in cooked patties due to the formation of Maillard reaction products. Cooked pork patties containing L/F-SD were subjected to an in vitro digestion and a cellular transwell model to confirm bioaccessibility and uptake of antioxidant compounds. In mechanistic studies, fucoidan demonstrated antiand pro-oxidant activities on muscle lipids and oxymyoglobin, respectively.

Issues in the prescribing of psychotropic and psychoactive medication for persons with learning disability: quantitative and qualitative perspectives

The administration of psychotropic and psychoactive medication for persons with learning disability and accompanying mental illness and/or challenging behaviour has undergone much critical review over the past two decades. Assessment and diagnosis of mental illness in this population continues to be psychopharmacological treatment include polypharmacy, irrational prescription procedures and frequent over-prescription. It is clear that all forms of treatment including non-pharmacological interventions need to be driven by accurate and appropriate diagnoses. Where a psychiatric diagnosis has been identified, it greatly aides the selection of appropriate medication, although a specific medication for each diagnosis, as was once hoped, is simply no longer a reality in practice. Part one of the present thesis seeks to address many of the current issues in mental health problems and pharmacological treatment to date. The author undertook a drug prevalence study within both residential and community facilities for persons with learning disability within the Mid-West region of Ireland in order to ascertain the current level of prescribing of psychotropic and psychoactive medications for this population. While many attempts have been made to account for the variation in prescribing, little systematic and empirical research has been undertaken to investigate the factors thought to influence such prescribing. While studies investigating the prescribing behaviours of General Practitioners (GP's) have illustrated the complex nature of the decision making process in the context of general practice, no similar efforts have yet been directed at examining the prescribing behaviours of Consultant Psychiatrists. Using The Critical Incident Technique, the author interviewed Consultant Psychiatrists in the Republic of Ireland to gather information relating not only to their patterns of prescribing for learning disabled populations, but also to examine reasons influencing their prescribing in addition to several related factors. Part two of this thesis presents the findings from this study and a number of issues are raised, not only in relation to attempting to account for the findings from part one of the thesis, but also with respect to implications for improved management and clinical practice.

Profiling phytochemical and nutritional components of potato

Potatoes (Solanum Tuberosum L.) contain secondary metabolites that may have an impact on human health. The aim of this study was to assess the levels of some of these compounds in a wide range of varieties, including rare, heritage and commercial cultivars. Vitamin C, total carotenoids, phenolics, flavonoids, antioxidant activity and glycoalkaloids were determined, using spectroscopy and chromatography, in the skin and flesh of tubers grown in field trials. Transcript levels of key synthetic enzymes were assessed by qPCR. Accumulation of selected metabolites was higher in the skin than in the flesh of tubers, except ascorbate, which was undetected in the skin. Differences were on average 2.5 to 3-fold for carotenoids, 6-fold for phenolics, 15 to 16-fold for flavonoids, 21-fold for glycoalkaloids and 9 to 10-fold for antioxidant activity. Higher contents of carotenoids were associated with yellow skin or flesh, and higher values of phenolics, flavonoids and antioxidant activity with blue flesh. Variety ‘Burren’ had maxima values of carotenoids in skin and flesh, variety ‘Nicola’ of ascorbate, variety ‘Congo’ of phenolics, flavonoids and antioxidant activity in both tissues, except antioxidant activity in the skin, which was higher in ‘Edzell Blue’. Varieties ‘May Queen’ and ‘International Kidney’ had highest glycoalkaloid content in skin and flesh respectively. The effect of the environment was diverse: year of cultivation was significant for all metabolites, but site of cultivation was not for carotenoids and glycoalkaloids. Levels of expression of phenylalanine ammonia-lyase and chalcone synthase were higher in varieties accumulating high contents of phenolic compounds. However, levels of expression of phytoene synthase and L-galactono-1,4-lactone dehydrogenase were not different between varieties showing contrasting levels of carotenoids and ascorbate respectively. This work will help identify varieties that could be marketed as healthier and the most suitable varieties for extraction of high-value metabolites such as glycoalkaloids.

Optimised crystal morphologies for active pharmaceutical ingredients and related studies

The majority of active pharmaceutical ingredients (APIs) are crystalline solids in their pure forms. Crystalline solids have definable morphologies, i.e. shape and size. Crystal morphology is determined by both the internal structure of the crystals and external factors during growth from solution. The morphology of a crystal batch can affect key processes during manufacturing. Companies generally accept whatever morphology the manufacturing process provides and deal with any subsequent problems by costly trouble‒shooting. Rational design of optimised morphologies for crystalline pharmaceutical solids would be a very significant technical and commercial advance. Chapter one introduces the concept of crystal nucleation and growth. The phenomenon of polymorphism alongside the causes and impact is discussed. A summary of the scope of instrumentation used in the investigation of crystal polymorphism and morphology, including crystal size distribution (CSD), is also included. Chapter two examines the research carried out during an exploration of the optimum crystallisation parameters of phenacetin. Following a morphological study, the impact this induces on particle density and flow properties is examined. The impact of impurities on the crystallisation properties of phenacetin is investigated. Significantly, the location of impurities within individual crystals is also studied. The third chapter describes an industrial collaboration looking at the resolution and polymorphic study of trometamol and lysine salts of ketoprofen and 2‒phenylpropionic acid (2‒PPA). Chapter four incorporates a solid state study on three separate compounds: 2‒chloro‒4‒nitroaniline, 4‒hydroxy‒N‒phenylbenzenesulfonamide and N‒acetyl‒D‒glucosamine‒6‒O‒sulfate. 2‒Chloro‒4‒nitroaniline and 4‒hydroxy‒N‒phenylbenzenesulfonamide both produced interesting, extreme morphologies which warranted further investigation as part of a collaborative study. Following a summarisation of results in chapter five, chapter six contains the full experimental details, incorporating spectral and other analytical data for all compounds synthesised during the course of the research.

Toxicity of manufactured nano-ZnO to Lemna minor

The rapid development of nanotechnology has led to a rise in the large-scale production and commercial use of engineered nano-ZnO. Engineered/manufactured nano-ZnO are applied in a broad range of products such as drugs, paints, cosmetics, abrasive agents and insulators. This can result in the unintended exposure of human beings to nano-ZnO and will inevitably result in the release of nano-ZnO in to the environment. Thus, it is necessary to assess the risk of nano-ZnO to the environment. In this thesis the toxicity of nano-ZnO was analysed using the aquatic, primary producer lesser duckweed (Lemna minor), and the mechanism of toxicity was analysed. Both short-term (one week) and long-term (six weeks) toxicity of nano-ZnO (uncoated) were determined. Results show that the toxicity of nano-ZnO added to the aquatic growth medium increases with increasing concentration and that toxicity accumulates with exposure time. A study of nano-ZnO dissolution reveals that the main reason for nano-ZnO toxicity on Lemna minor is the release of Zn ions. Nano-ZnO dissolution is pH dependent, and toxicity matches the release of Zn2+. Functional coating materials are commonly added to nano-ZnO particles to improve specific industrial applications. To test if coating materials contribute to nano-ZnO toxicity on lesser duckweed, the effect of silane coupling agent (KH550) coated nano-ZnO on Lemma minor was investigated. Results show that coating can decrease the release of Zn ions, which reduces toxicity to Lemna minor, in contrast to uncoated particles. Another commonly hypothesized reason for nano-ZnO toxicity is the formation of Reactive Oxygen Species (ROS) on the particles surface. As part of this thesis, the ROS formation induced by nano-ZnO was studied. Results show that nano-ZnO catalyse ROS formation and this can negatively affect duckweed growth. In conclusion, this work has detailed potentially toxic effects of nano-ZnO on Lemna minor. This study has also provides references for future research, and informs regulatory testing for nanoparticle toxicity. Specifically, the outcomes of this study emphasize the importance of exposure time, environmental parameters and coating material when analysing NPs toxicity. Firstly, impacts of longer exposure time should be studied. Secondly, environmental parameters such as pH and medium-composition need to be considered when investigating NPs toxicity. Lastly, coating of NPs should always be considered in the context of NPs toxicity, and similar NPs with different coatings require separate toxicity tests.