Although radio-frequency (RF) methods have been used for decades in many heating and drying processes, there is still a need for more engineering design data related to the design of the applicators and the performance of these systems before costly prototypes are built. Energy, temperature, and the effect produced by the high frequency field parameters on biological materials need to be examined with regard to their effects on the resulting processing requirements. / Wheat-seed infection by a fungus such as Fusarium graminearum can considerably lower the seed germination and the quality of the harvest. A study was thus conducted to determine the combined effect of different levels of RF power, temperature, and moisture content on the quality of seed-grade wheat and fungus inactivation. Similar treatment combinations were studied with seed-grade soybean in view on improving germination. With higher power, higher temperature (90°C) and higher moisture content (14%), the fungus mortality significantly increased, with a fungal vigour of less than 0.1, and the germination quality of the seeds decreased to a germination vigour below 0.3. For soybean seeds, only treatments of low RF intensity (60°C) were successful in improving germination vigour especially at lowest moisture content typically found in stored seeds. / RF treated wheat was studied to identify the relationship between heating conditions and grain quality categorized in terms of kernel viability and structural damage. / The potential of an RF thermal treatment to improve and extend the storability of vacuum packaged carrot sticks was investigated. The results have shown that it is possible to treat carrot sticks to 60°C in less than 2 min to reduce the initial microbial load. The RF-treatments maintained colour, the vacuum of the packages, and the excellent taste of the carrot sticks. / RF heating was studied for the pasteurization of prepared samples of ham. The ham samples were brought to internal temperatures of 75 and 85°C, by RF heating with a 10 min residence time. The study indicates that radio-frequency heating can improve the storability of re-packed hams by reducing the bacterial load, reducing moisture loss during storage and maintaining an overall greater product quality. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36046 |
| Date | January 1999 |
| Creators | Orsat, Valérie. |
| Contributors | Raghavan, G. S. V. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Agricultural and Biosystems Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001686596, proquestno: NQ55367, Theses scanned by UMI/ProQuest. |
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