Dissertation
Electromagnetic and thermal analysis of microwave heating in 915 MHz single mode cavity systems: Microwave assisted thermal sterilization and pasteurization
Doctor of Philosophy (PhD), Washington State University
01/2017
Handle:
https://hdl.handle.net/2376/111976
Abstract
Microwave assisted thermal sterilization and pasteurization (MATS and MAPS) systems have great potential for the food industry to manufacture high quality and nutritious packaged foods with clean labels. This dissertation aimed to develop tools which will aid in the commercialization of the MATS and MAPS systems, and future development of food formulations and processing schedules for efficient microwave processing. Chapter 1 provides an introduction, history and fundamentals of food processing. Chapter 2 presents previous computer models and knowledge gaps in microwave assisted thermal processing.
Chapter 3 describes faster browning of fructose under alkaline conditions as a time-temperature indicator in microwave pasteurization processes. Reaction kinetics of browning showed a log linear relationship in the temperature range of 60-90°C. This non-enzymatic browning of fructose in mashed potato model food provided an efficient, convenient and cost effective tool to determine the heating patterns in MAPS system.
MAPS is a food processing technology which employs a novel way to transport food packages inside the microwave cavity. Carriers made up of stainless steel and polyetherimide are used to modify the electric field distribution and obtain uniform heating patterns. Chapter 4 presents, a computer simulation model and validation to analyze the effect of carriers on the electric field inside the cavity. The effect of frequency fluctuations on heating pattern was also investigated using computer simulations. The conclusion was reached that presence of metal food carriers provided uniform, stable and predictable heating patterns.
In MAPS and MATS, 915 MHz microwaves are launched from top and bottom of the food packages forming standing wave patterns within the foods. Chapter 5 discussed the development of a 1-D analytical model to compare the heating rates of different foods processed in multi-compartment and single compartment food packages. A novel dimensionless number (Jain-Tang) is proposed and was validated to estimate the influence of food dielectric properties and food thickness on microwave power dissipation. It was shown that this number can serve as general criteria to evaluate the effectiveness of microwave heating in packaged foods with pre-determined dielectric properties and package thickness.
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Details
- Title
- Electromagnetic and thermal analysis of microwave heating in 915 MHz single mode cavity systems: Microwave assisted thermal sterilization and pasteurization
- Creators
- Deepali Jain
- Contributors
- Juming Tang (Advisor)Shyam Sablani (Committee Member)Patrick D Pedrow (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Biological Systems Engineering
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 179
- Identifiers
- 99900581426901842
- Language
- English
- Resource Type
- Dissertation