The influence of different drying temperatures and slice thicknesses on the
drying kinetics of turmeric slices was studied to show how moisture is
removed. The best model for predicting the drying kinetics was also
determined. Turmeric slices (3 mm, 5 mm, and 7 mm) were dried at 40, 50,
and 60 °C in a laboratory oven dryer. Four thin layer drying models (Newton,
Henderson and Pabis, Logarithmic, and Page) were fitted to the experimental
data and the selection was done based on the model with the highest correlation coefficient (R2), and lowest reduced chi-square (χ2), the sum of square error
(SSE), and root mean square error (RMSE). Drying time varied between 420
min and 1140 min as the air temperature increased from 40 °C to 60 °C. The
effective moisture diffusivity coefficient increased with increasing drying
temperature and was found to be between 1.35×10-10 m2/s, and 5.00×10-10 m2/s,
3.00×10-10 m2/s and 10.91×10-10 m2/s, and 4.56×10-10 m2/s and 13.00×10-10 m2/s at 40 °C, 50 °C, and 60 °C, respectively. The values obtained for the activation
energy for moisture diffusion were found to be 56.809, 56.060, and 45.561
kJ/mol for 3, 5, and 7 mm, respectively. The page model was found to best
describe the oven drying of turmeric slices.
In this investigation, the mechanism of mass (moisture and fat) transfer during deep-fat frying of robo (fried melon cake) was carried out. The plots of dimensionless concentration ratios against time were used to determine moisture transfer parameters including moisture diffusivity, moisture transfer coefficient, moisture transfer Fourier number, moisture transfer Biot number and activation energy and fat transfer kinetic parameters such rate constants and activation energy at different frying temperatures of 140, 155 and 170 0C. All moisture parameters increased linearly with frying oil temperatures except moisture transfer Biot number which deceased linearly with increase in temperature with correlation coefficient (R2) ≥ 0.99. There was also positive linear relationship between fat transfer rate constant and frying temperatures (R2 ≥ 0.99). An Arrhenius type of relationship was found between temperature and the effective moisture diffusivity and fat transfer rate constant (R2≥0.99) with activation energies values calculated as 25.66 and 42.18 kJ/mol, respectively. Both moisture loss and fat desorption after initial adsorption of 60 seconds were adequately modeled by the first-order kinetics adopted with high correlation coefficient (R2) value and were time and temperature dependent as revealed by Arrhenius analysis performed on the experimental data.
Maize (TZSR-W-1 NARZO-20) and soybean (TGX1448) flours were used for the development of extruded products. The flour formulations were
maize (46-52%), soybean (21-32%), and moisture content (16-26%). Central Composite Design (CCD) in Response Surface Methodology consisting
five factors (maize to soybean-water weight ratio -X1, soybean to water weight ratio -X2, barrel temperature (120, 160 and 200oC) -X3, die diameter
(6, 8 and 10mm) -X4 and screw speed (120, 160 and 200rpm) -X5 at three levels was used to determine the optimum process condition for the
proximate properties of the extruded products. The process parameters significantly influenced the dependent variables at p<0.05. The coefficients
of regression (R2) for the response equations ranged between 0.967 and 0.999 which is an indication that the variables were adequately fitted to
the regression equation and could predict the proximate values of the extrudates. The optimum process condition at desirability index of 1 were X1
(0.99), X2 (1.10), X3 (190oC), X4 (124rpm) and X5 (10mm).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.