The main objective of this study was to design gluten free rice cakes containing different gums and an emulsifier for baking in infrared (IR)-microwave
combination oven.
In the first part of the study, the effects of different gums (xanthan, guar,
xanthan-guar blend, & / #954 / -carrageenan, locust bean, hydroxypropyl methylcellulose
(HPMC) and xanthan-& / #954 / -carrageenan blend) and emulsifier blend (PurawaveTM) on
physical properties of cake batters were investigated. In the second part of the study,
weight loss, specific volume and texture of the cakes baked in different ovens were
determined. Macro and micro-structures of the cakes were investigated both
qualitatively and quantitatively by using image analysis and Scanning Electron
Microscopy (SEM). In the last part of the study, Response Surface Methodology (RSM) was used to optimize IR-microwave baking conditions and formulation of the
cakes.
Power law and Casson models were suitable to explain the rheological
properties. Xanthan and xanthan-guar gum blends resulted in higher apparent
viscosities as compared to other gums. Gum types affected the dielectric properties
and gelatinization enthalpies of cake batter.
Emulsifier addition increased the volume and porosity but decreased the
firmness of the cakes baked in IR-microwave combination oven. More porous cakes
were obtained when xanthan and xanthan-guar gum blend were used. Baking method
was found to be important in affecting porosity, pore size distribution and microstructure
of the cakes.
The highest quality gluten-free rice cakes were obtained when the formulation
contained xanthan gum and 5.38% emulsifier and baked using 40% microwave
power, 60% halogen lamp power for 7 min in IR-microwave combination oven. In
addition, baking time was reduced by 76.7% as compared to conventional baking.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/12611810/index.pdf |
| Date | 01 May 2010 |
| Creators | Turabi, Elif |
| Contributors | Sumnu, Gulum |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
Page generated in 0.0021 seconds