Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Rheological characterization of tahin/pekmez (sesame paste/concentrated grape juice) blends
Download
index.pdf
Date
2003
Author
Arslan, Elif
Metadata
Show full item record
Item Usage Stats
348
views
0
downloads
Cite This
The aim of this study was to determine the rheological properties of tahin/pekmez blends at different tahin concentrations (20-32%) and temperatures (35-65 C) by using a concentric cylinder rotational viscometer. Samples were sheared with seven different rotational speeds at an increasing order. The shear rates (0.75-63.9 s-1) were calculated by the Power-law Approximation method. Tahin/pekmez blends were found to exhibit non-Newtonian, shear thinning behavior at all temperatures and tahin concentrations. The experimental data of apparent viscosity versus shear rate were successfully described by the Power-law model. The model parameters; flow behavior index, n varied in the range of 0.7-0.85, whereas the values for the consistency coefficient, K, were in the range of 282-2547 mPa.sn. Apparent viscosity and consistency coefficient of blends increased with increasing tahin concentration and decreasing temperature. Temperature dependency of K was described by an Arrhenius-type equation. Activation energies (Ea) of the blends appeared in the range of 13376-28592 J/mol as the tahin concentration was increased from 20% to 32%. The effect of temperature on n was found to be significant but did not follow any descriptive trend. The relationship between K and tahin concentration was explained by exponential and power functions while tahin concentration had no significant effect on flow behavior index. Power function was found to be superior in explaining the variation of Ea with tahin concentration. A mathematical model was formulated to determine the combined effect of temperature, tahin concentration and shear rate on apparent viscosity.
Subject Keywords
Rheology
,
Food
URI
http://etd.lib.metu.edu.tr/upload/1098581/index.pdf
https://hdl.handle.net/11511/13858
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Rheological characterization of tahin/pekmez (sesame paste/concentrated grape juice) blends
Arslan, E; Yener, Meryem Esra; Esin, A (2005-07-01)
Rheological properties of tahin/pekmez blends were determined at different tahin concentrations (20-32%) and temperatures (35-65 degrees C) by using a concentric cylinder rotational viscometer. Tahin/pekmez blends were found to exhibit non-Newtonian, shear thinning behavior at all temperatures and tahin concentrations. Apparent viscosity versus shear rate data was successfully fitted to the power-law model. The flow behavior index, n varied in the range of 0.7-0.85. The consistency coefficient, K, was in th...
KINETIC COMPENSATION DURING HOMOGENEOUS AND HETEROGENEOUS NUCLEATION OF ICE IN AQUEOUS SYSTEMS
OZILGEN, S; OZILGEN, M; REID, DS (Elsevier BV, 1994-01-01)
Homogeneous and heterogeneous nucleation rates of ice in aqueous systems are described in the literature with the equation J = A exp (B tau). There are a very large number of published data available for variation of the constants A and B with experimental conditions. Results of this study show that the parameters obtained in the experiments with differential scanning calorimeter and the microscopic technique may be described separately with an empirical compensation equation of the form In A = aB + b. The ...
Scalar mesons in radiative phi-meson decays into charged k-meson states
Öztürk, Fahri; Gökalp, Ahmet; Department of Physics (2008)
The role of $f_{0}(980)$ and $a_{0}(980)$ scalar meson intermediate states in the mechanism of radiative $\phi (1020)$ meson decay into two charged $K (494)$ mesons and a photon $\phi\rightarrow K^{+} + K^{-} + \gamma$ is investigated. For the contribution of scalar meson intermediate state two models are considered. In the kaon-loop model, the scalar meson intermediate state couples the final state to the initial $\phi$ meson through a charged kaon-loop. The second model, called no-structure model, consist...
DRYING BEHAVIOR OF HONEY-STARCH MIXTURES
Yener, Meryem Esra; OZILGEN, M (Wiley, 1987-07-01)
Drying behavior of honey‐starch mixtures at constant external conditions were studied. Mixtures with 0, 10, 20, 30, and 40% starch and the balance in honey were coated on aluminum plates at 0.25 mm thickness and dried in a laboratory oven at 60°, 70°, and 80°C. A mass transfer model with two falling rate periods was developed. In the first falling rate period, mass transfer coefficient was a linear function of moisture content. It was a constant in the second falling rate period. Mass transfer coefficients ...
Rheological properties of extruded dispersions of flaxseed-maize blend
WU, Min; Lİ, Dong; WANG, Li-Jun; Özkan, Necati; Mao, Zhi-Huai (2010-06-01)
Rheological properties of the extruded pastes of various extrusion conditions were investigated by dynamic oscillation and creep-recovery tests. Temperature sweep test showed that the starch gelatinization of non-extruded pastes took place at about 67 degrees C and no gelatinization was observed for the extruded sample. Frequency sweep tests could be represented by a Power law model and the samples showed gel-like behavior since storage modulus was much larger than loss modulus. The creep-recovery data were...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
E. Arslan, “Rheological characterization of tahin/pekmez (sesame paste/concentrated grape juice) blends,” M.S. - Master of Science, Middle East Technical University, 2003.