Dissertation
IMPACT OF MICROWAVE-ASSISTED PASTEURIZATION SYSTEM AND HIGH PRESSURE PROCESSING ON MICROBIAL SAFETY AND QUALITY PARAMETERS OF GREEN BEANS
Doctor of Philosophy (PhD), Washington State University
01/2021
Handle:
https://hdl.handle.net/2376/119044
Abstract
Even though the RTE meal sector has seen significant growth in sales, most RTE meals are produced by conventional methods, which have a severe effect on the nutritional and sensorial quality of food. Therefore, to meet consumer expectations, food companies seek novel methods for manufacturing microbiologically safe RTE meals without compromising quality and with an adequate shelf life. Among novel methods, high pressure processing and microwave pasteurization have proven potential to produce RTE meals. Therefore, this research was conducted to evaluate the quality properties of green beans treated by high pressure processing (HPP) and microwave-assisted pasteurization system (MAPS) during storage. In the first and second part of this research, green beans were pasteurized in mild (600 MPa/10 min for HPP and 70°C/2 min for MAPS) and severe (600 MPa/20 min/45°C for HPP and 90°C/10 min for MAPS) intensity levels. The first study on mild pasteurization resulted in different efficacies of pasteurization methods against L. innocua ATCC 51742 in green beans. The degradation in color and chlorophyll after pasteurization treatments and during storage was not significantly different for HPP and MAPS. The mild conditions of HPP and MAPS had no significant effect on the firmness and pH of the green beans. The higher vitamin C content was observed in MAPS-treated beans compared to HPP-treated ones. Both pasteurization treatments at severe levels (HPP and MAPS) resulted in a decrease in greenness and hue angle of the green bean samples. Similar retention in chlorophyll a and b during the storage was observed for HPP- and MAPS-treated green beans. The firmness values of HPP-treated green beans were higher compared to that of the MAPS-treated beans. The green beans treated by HPP and MAPS started bulging after 3 and 5 weeks of storage at 7°C with a reduction in pH, respectively.
The results of this work demonstrate that both HPP and MAPS offer advantages as a pasteurization method for preserving the quality attributes of green beans. Pasteurization of HPP and MAPS at a mild level provides higher retention in quality attributes, while at a severe level is suitable to extend the shelf-life of RTE green beans.
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Details
- Title
- IMPACT OF MICROWAVE-ASSISTED PASTEURIZATION SYSTEM AND HIGH PRESSURE PROCESSING ON MICROBIAL SAFETY AND QUALITY PARAMETERS OF GREEN BEANS
- Creators
- SUMEYYE INANOGLU
- Contributors
- Juming J Tang (Advisor)Gustavo V Barbosa-Canovas (Committee Member)Shyam S. Sablani (Committee Member)Meijun Zhu (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 185
- Identifiers
- 99900591956101842
- Language
- English
- Resource Type
- Dissertation