Behaviour of thermolabile materials in microwave vacuum dehydration

The objectives of this research were; 1) to design and develop a laboratory scale microwave vacuum dehydration testing rig for drying of thermolabile materials; 2) to study the drying mechanism of thermolabile material; 3) to determine the kinetics of microwave energy transfer in a vacuum testing ri...

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Main Author: Taib, Mohd. Rozainee
Format: Monograph
Language:English
Published: Faculty of Chemical and Natural Resource Engineering 2009
Subjects:
Online Access:http://eprints.utm.my/9752/
http://eprints.utm.my/9752/1/78223.pdf
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author Taib, Mohd. Rozainee
author_facet Taib, Mohd. Rozainee
author_sort Taib, Mohd. Rozainee
building UTeM Institutional Repository
collection Online Access
description The objectives of this research were; 1) to design and develop a laboratory scale microwave vacuum dehydration testing rig for drying of thermolabile materials; 2) to study the drying mechanism of thermolabile material; 3) to determine the kinetics of microwave energy transfer in a vacuum testing rig. A laboratory-scale microwave vacuum dehydration system was successfully developed for dehydration of thermolabile materials. Microwave is recognized as a fast heating process characterised by volumetric heating. Contrary to conventional dehydration method which heats from the surface of material, microwave heats material from inside out. Incorporation of vacuum enhances the microwave dehydration process by allowing water to vaporize at lower temperature. Thus, dehydration of thermolabile materials can be achieved at low temperature and shorter time thereby preventing degradation of nutritional values and texture. Behaviours of thermolabile materials such as jackfruit, guava and papaya in microwave vacuum dehydration were studied. Operating parameters such as microwave power and vacuum pressure were found to influence the dehydration process. Increment of microwave power resulted in higher drying rates but increased risks of charring. However, the charring could be reduced with combination of microwave power. Products dried by combination of microwave power has lesser shrinkage and softer texture due to porous (puffing) structure induced by vacuum condition. It also possessed better reconstitution ability. In addition, papaya dried using microwave vacuum was found to have high enzyme activity retained.
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spelling utm-97522010-06-22T04:25:52Z http://eprints.utm.my/9752/ Behaviour of thermolabile materials in microwave vacuum dehydration Taib, Mohd. Rozainee Q Science (General) The objectives of this research were; 1) to design and develop a laboratory scale microwave vacuum dehydration testing rig for drying of thermolabile materials; 2) to study the drying mechanism of thermolabile material; 3) to determine the kinetics of microwave energy transfer in a vacuum testing rig. A laboratory-scale microwave vacuum dehydration system was successfully developed for dehydration of thermolabile materials. Microwave is recognized as a fast heating process characterised by volumetric heating. Contrary to conventional dehydration method which heats from the surface of material, microwave heats material from inside out. Incorporation of vacuum enhances the microwave dehydration process by allowing water to vaporize at lower temperature. Thus, dehydration of thermolabile materials can be achieved at low temperature and shorter time thereby preventing degradation of nutritional values and texture. Behaviours of thermolabile materials such as jackfruit, guava and papaya in microwave vacuum dehydration were studied. Operating parameters such as microwave power and vacuum pressure were found to influence the dehydration process. Increment of microwave power resulted in higher drying rates but increased risks of charring. However, the charring could be reduced with combination of microwave power. Products dried by combination of microwave power has lesser shrinkage and softer texture due to porous (puffing) structure induced by vacuum condition. It also possessed better reconstitution ability. In addition, papaya dried using microwave vacuum was found to have high enzyme activity retained. Faculty of Chemical and Natural Resource Engineering 2009-08-31 Monograph NonPeerReviewed application/pdf en http://eprints.utm.my/9752/1/78223.pdf Taib, Mohd. Rozainee (2009) Behaviour of thermolabile materials in microwave vacuum dehydration. Project Report. Faculty of Chemical and Natural Resource Engineering, Skudai, Johor. (Unpublished)
spellingShingle Q Science (General)
Taib, Mohd. Rozainee
Behaviour of thermolabile materials in microwave vacuum dehydration
title Behaviour of thermolabile materials in microwave vacuum dehydration
title_full Behaviour of thermolabile materials in microwave vacuum dehydration
title_fullStr Behaviour of thermolabile materials in microwave vacuum dehydration
title_full_unstemmed Behaviour of thermolabile materials in microwave vacuum dehydration
title_short Behaviour of thermolabile materials in microwave vacuum dehydration
title_sort behaviour of thermolabile materials in microwave vacuum dehydration
topic Q Science (General)
url http://eprints.utm.my/9752/
http://eprints.utm.my/9752/1/78223.pdf