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"Superfruits” is the terminology used in the media to refer to fruits with high neutraceutical value. Sea Buckthorn (Hippophae rhamnoides) is an example of a superfruit due to its high levels of vitamins, antioxidants and carotenoids. Indeed, the consumption of the phytochemicals found in sea buckthorn may reduce the risk of developing chronic diseases. Currently, the consumption of sea buckthorn is low due to sensory properties that have failed to gain the acceptance of consumers. Over the past decades, there has been an increasing awareness that plants are providers of high value phytochemicals and this initiated the investigation towards the phytochemicals content of sea buckthorn. Despite over twenty years of research on sea buckthorn, there is currently no general processing model to fractionate the plant into multiple products as a source for certain phytochemicals. This thesis examines the use of environmentally benign extraction methods to fractionate multiple products from sea buckthorn berries and the high volumes of by-products created during fruit processing and harvesting. Juice oil, juice concentrate and aroma fraction were fractionated from sea buckthorn berries using a combination of enzymatic, thermal and physical separation processes. By-products such as leaves accumulated during harvesting and pomace retained during fruit processing were processed using supercritical CO2 to create a source of leaf wax, pulp and seed oil. Each of these products generated were chemically characterised for their high value phytochemicals using a series of different analytical techniques. A diverse array of high value phytochemicals was identified in each product generated of which all have a broad application in cosmetic, neutraceutical, food and beverage formulations. This study has added value to sea buckthorn which is currently underutilised but is becoming increasingly important in many parts of the world.

Non-destructive ultrasonic pitch and catch ultrasound measurement of sound velocity was used to assess ripeness in ‘Envy’ apples during storage and to detect brown heart in swede. Ultrasonic group velocity was measured (path length over the transit time) through intact apples along the axial and radial directions of the mature and more mature fruit every two weeks for eight weeks at 4C and 20C. The velocity measurement was also conducted on the defective and non-defective Brown Heart (BH) swedes in an axial direction. Compression, puncture, and sugar level tests were also carried on the two maturity fruit groups, together with a puncture test on the vegetables. The differences between the ultrasonic velocity measured in the axial and radial directions in apples was significantly correlated with the firmness (as assessed by the compression and puncture tests) of the fruit and this is possibly due to increased homogeneity of the fruit during senescence. The correlations between ripeness and ultrasonic velocity in apples, and BH and ultrasonic velocity in swede were supported by the hypothesis of changes of volume fraction of air-water in the parenchyma. The parenchyma of the ripening apple was suggested to have undergone changes of cell compositions of the starch-sugar conversion, cell walls disassembly, and middle lamella disintegration during storage. These changes caused the accumulation of air-water mixtures in the cells, indicating the ripening process in apples. The PCA clearly discriminated the ripening apples based on the weeks of storage (weeks 2 to 8), the maturity levels (mature and more mature fruit), and the orientations of ultrasonic velocity measurements (the axial and radial directions). Meanwhile, the defective BH was suggested to cause the increasing ‘water-core’ of the internal volume in swede parenchyma. This finding was supported by the dissimilar TPA curves between the BH and the healthy swedes. The ultrasonic technique offers an alternative online, fast, economical, non-destructive assessment of firmness for the apples at different ripening stages, storage durations, and storage temperatures. It may assess the fruit ripeness along the postharvest chain and can evaluate the presence and levels of BH of an individual swede. Therefore, this technique signifies cost savings and high standard quality in fruit and vegetables.

Wheat distillers dried grains with soluble (wDDGS) are a by-product from bioenergy production and available in increasing quantities. Three experiments were carried out to evaluate the effects of feeding wDDGS in the presence or absence of enzymes on the productive performance, carcass characteristics, digestibility, and behaviour of broiler chickens. Experiment 1 evaluated the effect of wDDGS inclusion on the acceptability of different inclusion levels (0, 10, 20, & 40%) of wDDGS when substituting for wheat and soybean meal in four isonitrogenous diets differing in slightly amino acid but mainly NDF and energy contents. Results showed significantly lower feed intake in broilers consuming the 40% wDDGS diet that might have been due to the high percentage of fibre and perhaps poor palatability of the diet. The best FCR was recorded from birds fed the 0 or 10% wDDGS diet compared to 20 and 40% wDDGS. Birds fed 40% wDDGS diet had poorer (P < 0.05) crude protein digestibility, possibly due to the poor lysine digestibility of wDDGS as affected by the drying of insoluble residues after the fermentation of wheat. This effect was reflected in the linear decrease in the digestibility of diets with increasing wDDGS level. Total LWG of birds was lower with the 40% wDDGS diet which resulted in lower carcass weight. However, birds fed 10% wDDGS had a higher LWG and cold carcass weight, with similar edible carcass components comprising breast with bone, thighs, drumsticks neck and back to the 0% wDDGS diet. Experiment 2 tested the addition of an enzyme into the diets containing intermediate levels of the previously tested wDDGS to improve nutrient utilization. The study involved 168 broiler chicks in a completely randomized design with 3 X 2 factorial arrangement (3 wDDGS levels of 0, 15, 30% and 2 enzyme levels; No enzyme (NE) and with enzyme (E)). Six isonitrogenous diets were formulated and manufactured with and without enzyme inclusion (endo-1, 4-beta-xylanase 9200 U/g, alpha-amylase 1600 U/g and subtilisin as protease 16000 U/g). There were significant (P < 0.05) decreases in digestibility of nutrients with increasing levels of wDDGS inclusion in broiler diets. A reduction in performance was also observed with increasing inclusion level of wDDGS up to 30%. This experiment provided an indication that 15% wDDGS could be used in practical broiler diets. At 30% wDDGS both feed intake and weight gain were lower in v the presence and absence of enzyme which resulted in similar FCR than other treatments. The same trend for wDDGS and enzyme inclusion was seen at starter, finisher and overall periods of this experiment. Enzyme addition had no effect on dry matter and protein digestibility, or on growth and feed intake. Enzyme addition increased only the digestibility of calcium but reduced the digestibility of protein. Inclusion of 15% wDDGS with enzyme did not affect (P > 0.05) the carcass composition of broiler chickens, but 30% inclusion gave a poorer carcass and impaired performance. 30% wDDGS caused gizzard weight to increase, possibly due to accumulation of fibres which resulted in a slower passage rate of fibre fractions. The breast meat is considered to be the best meat, being the largest area of muscle concentration in broiler chickens, and was higher at 0 and 15% wDDGS level. Higher protein percentage of breast muscle at 0 and 15% wDDGS apparently revealed higher quality meat than in birds given the 30% wDDGS level. Enzyme supplementation showed a positive effect on some chemical components of broiler muscles where it increased the protein concentration in breast meat. Enzyme supplementation gave no performance benefits when added at manufacturer’s recommended level of 0.25kg/tonne in wDDGS-based diets, so increased inclusion rates for this enzyme and another enzyme mixture added to diets with moderate levels of wDDGS were investigated in experiment 3. Finally, experiment 3 compared the effects of the increased levels of two enzymes (A & B) on broiler performance, carcass characteristics, digestibility, fatty acids, and the gut microbial population. A total of 180 broiler chicks were used in a completely randomized design with 2 X 3 factorial arrangement by using 2 wDDGS levels (0, 15% in isonitrogenous diets) and 3 enzyme levels (no enzyme, NE and enzyme A= EA or B= EB). Here enzyme A contained 9200 U/g endo-1, 4-beta-xylanase, 1600 U/g alpha-amylase and 16000 U/g subtilisin as protease) & enzyme B contained 12200 U/g endo-1, 4-beta-xylanase, 1520 U/g endo-1,3(4)-beta-glucanase. The results demonstrated that neither the starter nor the finisher phase of the broilers showed any noteworthy differences in growth performance (daily feed intake, live weight gain and FCR) when fed 0 or 15% levels of wDDGS with or without the inclusion of enzymes. An increased digestibility of calcium was observed in the previous study as well as calcium and phosphorus in the present study. Improved digestibility of fibre fractions with addition of enzyme was not observed in this experiment. Some digestive organs such as the empty crop, total gut, empty gizzard and liver have had a higher weight due to the 15% vi wDDGS’s higher fibre content but this has no economic benefits. This study has concluded that the heightened quantities of enzyme A and the use of the improved enzyme B did not produce the desired effect on digestibility. The inconsistent results caused by these enzymes remain a great concern in this area of broiler production. In summary, these results indicated that feeding wDDGS-based diets with up to 10% inclusion in broiler production resulted in no negative impacts to broiler performance or carcass characteristics. 15% wDDGS inclusion resulted in increased protein content and reduced the ether extract content in broiler meat. Future studies should continue to investigate this technology of enhancing the nutritive availability to broiler chicken through the development and use of specific enzymes for wDDGS especially at high levels of their dietary inclusion. This should also investigate the optimum levels of enzyme to be applied as well as to develop a specific enzyme that would break the various structures of cell walls of NSP in wDDGS. There are currently no commercially prepared exogenous enzymes which target wDDGS NSP and these are needed to enhance the feeding values of wDDGS in terms of improved nutrient digestibility and performance of broiler chickens. Moreover, special emphasis should also be given to the economic aspect, broiler welfare and environmental impact concerning the use of enzymes together with wDDGS to replace wheat and soybean meal in broiler diets.

A quantitative measure of the amounts of nitrosatable compounds present in various foods was obtained by reacting whole foods with a large excess of sodium nitrite and studying the amount of N-nitroso compounds formed. This treatment produced several volatile N-nitrosamines, identified by combined gas chromatography - mass spectrometry, although the major products were non-volatile nitrosamines of unknown identity. To obtain a measure of the probable nitrosation that may occur in the human stomach, after a nitrite-containing meal is consumed, the same foods were exposed to low concentrations of sodium nitrite (10 and 100 ppm.) in a medium simulating the human stomach. Under these conditions nitrosation of foods did occur, the products being mainly non-volatile N-nitroso compounds. 'In vivo' studies were performed, where nitrite-containing meals were fed to humans. No nitrosation could be detected and it was observed that the ingested nitrite disappeared rapidly from the stomach contents. Studies, in which dogs were fed large amounts of nitrite and amine, resulted in the formation of the corresponding N-nitrosamine in the stomach. The catalysis of nitrosations by various biological anions was examined. None of the anions tested produced a marked catalytic effect and thiocyanate remains the most effective catalyst. Concentrations of thiocyanate, comparable to levels found in human saliva, were incorporated into incubations of food with nitrite in the simulated stomach medium, but there was no great enhancement in the amount of nitrosation that occurred. The possible nitrosation of peptide bonds was studied, using glycyl glycine. It was demonstrated that an N-nitroso derivative could be produced, although its yield was low. It was shown that other peptide bonds could also be nitrosated, but the nature of the constituent amino acids did not markedly affect the nitrosation. Several amines present in foods, were examined for their potential for nitrosation.

The development of the characteristic flavour of toffee has been investigated by a number of different methods. Macroscopic changes in the constituents of toffee due to the cooking process have been measured by standard methods and related to the chemical processes taking place in the system. The importance of reaction intermediates (Strecker aldehydes and 5-hydroxymethylfurfural) in the development of toffee flavour has been determined by the use of trained taste panels and chemical analysis involving extensive use of gas-liquid chromatography. The role played by butter in the development of toffee flavour has been investigated, with particular reference to aldehydes and carboxylic acids, by the use of trained taste panels and chemical analysis involving vacuum steam distillation techniques, followed by gas chromatography.

In this study of professional development in hotel, catering and institutional services, the need for research to revitalise professional education and services was established and the execution and consequences of that research considered. The origins of professionalism in hotel and catering, and institutional management were analysed to reveal the common importance of education to professional development in these fields. The educational role of professional bodies was examined and the problems of course content and development. Past and current developments in hotel and catering education were considered in the light bf critical evidence and the need for research to identify the Corpus of Professional Knowledge was established. Surveys of employers, professional managers, educationists and other sources produced substantial data from which to classify management jobs and analyse professional employment. In particular, the responsibilities of managers in the initial years of professional employment were analysed and the knowledge and skills currently required in all major sectors of the industry. Future requirements were separately examined. The framework of the Corpus was established in relation to important areas of management activity. The content was compiled on the basis of vocational relevance, to include common requirements for competent practitioners in all sectors and special requirements more important in some sectors. Documentation needs and updating requirements were also identified. The establishment of the Corpus of Knowledge in this field has had important consequences. First, it has provided the basis for the systematic development of a new professional qualification. Secondly, it provides the Hotel, Catering and Institutional Management Association with a firm basis from which to develop a comprehensive range of professional information services to members. Thirdly, it provides a source of long-term influence on educational developments, both in the progress towards a unified system of technical education and in maintaining such influence in the absence of direct involvement as a national examining body. It is suggested that this approach could provide similar benefits if applied to other developing fields of professional employment.

The metabolism of sodium nitrite by porcine skeletal muscle has been investigated in vitro under conditions relevant to the meat curing process leading to bacon and pasteurised ham, i,e. at pH 6.0 under reducing (anaerobic) conditions with nitrite at 3mM, (200 ppm). Other concentrations of nitrite were used to include the range relevant to curing ana beyond. The rate of loss of nitrite from model cures has been studied. In order to produce a 'balance sheet' of the nitrite added to model curing systems, the only stable isotope of nitrogen, [15]N, was used as a tracer. Nitrite, labelled to 96.1% with [15]N was found to be incorporated into both the non-water soluble fraction and the non-nitrite water soluble fraction of minced muscle cures. Analysis of the fractions revealed that enrichment was for the most part due to the formation of S-nitrosothiol derivatives and nitrosyImyogiobin. Analysis of the fractions also revealed the formation of nitrate, and non-volatile N-nitrosamines, the latter in concentrationsup to 2 ppm. Total recovery of the [15]N label was between 52 - 100%. Two methods of analysis of the [15]N were employed, mass spectrometry and emission spectroscopy. Analysis of the headspace gases of the model cures by high resolution mass spectroscopy confirmed the formation of nitric oxide V Volatile N-nitrosamines have been unequivocally identified by the development of two methods, both involving the use of high resolution mass spectroscopy and gas chromatography, in samples of foodstuffs preserved with nitrite prepared both commercially and in the laboratory.

The effect of sodium nitrite on the respiratory chain of porcine skeletal muscle mitochondria was investigated in vitro under conditions relevant to the meat curing process, that is, at pH 6.0 under reducing (anaerobic) conditions with sodium nitrite (3 mM, ~200 ppm). Other concentrations of nitrite were used to include the range relevant to curing and beyond. Improvements were made to the extraction of mitochondria by alterations to the homogenisation procedure and the extraction medium. Observations of respiratory chain cytochromes were made using differential spectrophotometry. For observations at -160&deg;C, where the cytochrome absorption bands are sharpened and intensified, low temperature cells were designed and constructed. The redox potential for the reduction of nitrite to nitric oxide is close to that for the reduction of oxygen to hydroxyl ions and attention was therefore focussed upon the terminal portion of the respiratory chain. At low concentrations, nitrite exerted a cyanide-sensitive oxidation of the respiratory chain cytochromes which was gradually inhibited by increasing concentrations of nitrite. At concentrations above 3 mM, nitrite produced a direct, non-enzymic oxidation of the cytochromes which superseded the inhibitory effect. Model systems studies, which used physiologically active ferrocytochrome c produced by reduction of the Terri (oxidised) form with H2/Pd, confirmed and extended the in vitro experiments and demonstrated the "inhibitory zone" of nitrite under aerobic conditions. Nitrite also inhibited the oxygen uptake of a mitochondrial suspension (measured polarographically). This effect corresponded to the inhibitory action of nitrite on cytochrome oxidation and is probably the result of inhibition of cytochrome oxidase by formation of a complex between reduced cytochrome a3 and the nitrosyl radical. The chronic or acute administration of nitrite in vivo did not affect the drug metabolising enzymes of rat liver. In addition, skeletal muscle mitochondria did not appear to influence either the synthesis or breakdown of nitrosamines in vitro.

Cereals such as wheat serve as staples for a large proportion of the world’s population. However, they contain relatively low concentrations of essential micronutrients such as zinc (Zn) in their edible tissues. This is a major issue for human nutrition and food security. The process of Zn uptake and partitioning in plants is highly controlled, with systems present for sensing and responding to Zn status. In the model plant, Arabidopsis thaliana, two transcription factors, bZIP19 and bZIP23, are thought to act as Zn sensors mediating the increased expression of Zn membrane transporters, ZIPs (Zrt/Irt-like proteins), in response to low Zn status. In this thesis the identification and characterisation of homologous bZIP transcription factors and ZIP transporters in wheat are described. TabZIP sequence analysis confirmed the presence of motifs characteristic to the F-group of bZIP transcription factors. Expression of these wheat bZIPs in an Atbzip19 bzip23 line showed a conservation of function between the Arabidopsis and wheat group F bZIPs. A key question is whether the wheat bZIP transcription factors and ZIP transporters are regulated by Zn. Gene-expression analysis indicated that the wheat transcription factors TabZIP1, 3a, 3b, 4 & 5, and the wheat ZIP transporters, TaZIP1, 4, 5, 6 & 7 are induced by Zn-deficient conditions. The Zn-transport capability of TaZIP1, 5, 6, 7 & 8 was confirmed using heterologous yeast expression. Additionally, the binding ability of TabZIPs to regulatory-elements in the promoters of TaZIPs was demonstrated. This links TabZIPs and TaZIPs in the Zn-regulatory mechanism of wheat. This research has identified key genes involved in the regulation, uptake and distribution of Zn in wheat. The molecular mechanisms elucidated will be important in the development of Zn biofortified wheat varieties as well as cultivars which maintain high yield in Zn-deficient conditions. These may prove vital in achieving global food security.