195 research outputs found

    Methods of rapid bruise assessment and the formulation of robust bruise indices for potatoes

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    When potato tubers are subjected to impacts, the sub-surface tissue may become discoloured as damaged cells produce the blue-black pigment melanin. Bruising caused during harvesting and handling can lead to downgrading of potatoes for the processing industry and quality retail trade. The two aims of this thesis were to reduce the time to detect bruising, and to develop a non-subjective method for the quantification of bruising.Reflectance spectrophotometry was investigated as a rapid, non-subjective and non- invasive way of detecting bruising. Wavelengths from ultraviolet to near infrared were selected by discriminant analysis to separate unbruised and bruised tubers. Neural nets were trained with these wavelengths to identify bruised tubers in a sample of unbruised and bruised tubers. The detection of bruising gave inconsistent results in unpeeled tubers, but proved to be reliable in peeled tubers.The rate of bruise development at air pressures up to 10 bar was measured by reflectance spectrophotometry and by a visual rating. The production of dopachrome, an orange pre-cursor pigment of melanin, was used as an early indication of bruising. Dopachrome is visible to the human eye and the time for bruise detection can be reduced to approximately 3 hours when compressed air is used.Infrared and microwave thermography were used to measure possible rises in bruised tissue temperature. Thermography was used in conjunction with scanning laser Doppler imaging to detect changes in the biological zero of bruised tissue. No significant differences could be detected between unbruised and bruised tubers using these techniques.Reflectance spectrophotometry was also used in combination with a colour digital camera to automatically measure bruise area in peeled tubers. While the camera alone could measure bruise area with precision, constant adjustments were needed. Reflectance spectrophotometry was faster but less precise than the camera for measuring bruise area.A new bruise index was formulated by taking measurements of the volume of a tuber removed per peeler stroke for the variety Record, and using the data to model the percentage volume lost for any variety. By counting the number of peeler strokes to remove a bruise an estimate of the tuber volume lost could be derived. This method can accommodate any type and size of bruise and results in an index that can be easily interpreted

    Potato sprout suppressants with particular reference to tecnazene

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    Abstract available p. ii-i

    Response in growth performance, blood metabolites, nutrient digestibility, digesta characteristics and carcass characteristics of Windsnyer pigs fed increasing levels of potato hash silage.

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    Doctor of Philosophy in Animal and Poultry Science. University of KwaZulu-Natal, Pietermaritzburg, 2017.Abstract available in PDF file

    Mattrygghet i Europa: en kartlegging av kritiske matpraksiser og kulturelle forskjeller i Frankrike, Norge, Portugal, Romania og Storbritannia

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    How is food handled in safe and unsafe ways from retail to fork in European households? This is the overall research question raised in this report. The aim of this report is to contribute to an in-depth, detailed, empirical and nuanced analysis of how food is handled in everyday life in five European countries: France, Norway, Portugal, Romania and the UK. The first chapters (Part 1) describe the food cultural difference and food safety variation between the five countries, theories of practices that underpin the study and the transdisciplinary methods employed for studying shopping, transportation, storage and cooking a meal with chicken and raw vegetables in 75 European households. The first empirical chapters (Part 2) introduce the households in this study (chapter 2.1), discuss the everyday food life the households (chapter 2.2) and describe food anxieties and experiences with foodborne illnesses (chapter 2.3). Part 3 concentrates on food procuring and organising practices in the households and includes three empirical discussions of shopping (chapter 3.1), transportation (chapter 3.2) and storage (chapter 3.3). Part 4 discusses food preparation and comprises five chapters discussing the order of cooking (chapter 4.1), chicken preparation (chapter 4.2), vegetable preparation (chapter 4.3), determining doneness (chapter 4.4) and washing hands (chapter 4.5). Finally, Part 5 discusses the main findings in the report and suggests further research steps.info:eu-repo/semantics/publishedVersio

    Social science perspectives on managing agricultural technology

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    TechnologyAgricultural researchResource managementFarmer participationEvaluation

    Social science perspectives on managing agricultural technology

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    Experiences of 15 social science research fellows who recount their roles in particular research projects at the International Agricultural Research Centers they were appointed. In addition to highlighting the contributions social scientists can make in the field of agricultural research, their papers offer a candid look at the kinds of work in which the Centers currently are engaged.Technology, Agricultural research, Resource management, Farmer participation, Evaluation, Farm Management, Research Methods/ Statistical Methods,
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