Air Drying Characteristics of Aerial Yam ( Dioscorea bulbifera ) (original) (raw)
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Air drying characteristics of Aerial yam (Dioscorea bubifera)
The study investigated the air drying characteristics of aerial yam in a fabricated air dryer within a temperature range of 50 to 70°C. Prior to drying, the sample was divided into two portions; one part was boiled at 100°C for 20min and the other part left fresh. The drying data was fitted to twelve well-known thin layer drying models. Among the models used, the Midilli et al., Verma et al., Diffusion Approach, Wang and Singh, Parabolic and Simplified Fick’s Diffusion models were found to be the best models to predict the moisture ratio values during the drying process with high capability. The effective moisture diffusivity was found to vary between the range of 1.401 ×10-10 m2/s to 6.720 x 10-10 m2/s for the fresh yam slabs and 7.223 x 10-11 m2/s and 2.306 x 10-10 m2/s for the boiled yam slabs over the temperature range of 50 to 70°C. The values for activation energy were 28.42kJ/mol, 30.33kJ/mol for fresh yam samples of thicknesses of 0.5cm and 1cm respectively, whereas the values for boiled yam were 6.77kJ/mol and 15.37kJ/mol for slabs of 1cm and 0.5cm thicknesses respectively. Pre-treating the aerial yam by boiling will be beneficial in the optimisation of processing method for the D.bulbifera.
Sanful et al 2015 Air Drying Characteristics of Aerial Yam (Dioscorea bulbifera).pdf
The study investigated the air drying characteristics of aerial yam in a fabricated air dryer within a temperature range of 50 to 70°C. Prior to drying, the sample was divided into two portions; one part was boiled at 100°C for 20min and the other part left fresh. The drying data was fitted to twelve well-known thin layer drying models. Among the models used, the Midilli et al.,Verma et al., Diffusion Approach, Wang and Singh, Parabolic and Simplified Fick’s Diffusion models were found to be the best models to predict the moisture ratio values during the drying process with high capability. The effective moisture diffusivity was found to vary between the range of 1.401 ×10-10 m2/s to 6.720 x 10-10 m2/s for the fresh yam slabs and 7.223 x 10-11 m2/s and 2.306 x 10-10 m2/s for the boiled yam slabs over the temperature range of 50 to 70°C. The values for activation energy were 28.42kJ/mol, 30.33kJ/mol for fresh yam samples of thicknesses of 0.5cm and 1cm respectively, whereas the values for boiled yam were 6.77kJ/mol and 15.37kJ/mol for slabs of 1cm and 0.5cm thicknesses respectively. Pre-treating the aerial yam by boiling will be beneficial in the optimisation of processing method for the Dioscorea bulbifera. Keywords: Drying rate, thin-layer drying models, activation energy, diffusion mechanism, drying curve.
The study investigated the air drying characteristics of aerial yam in a fabricated air dryer within a temperature range of 50 to 70°C. Prior to drying, the sample was divided into two portions; one part was boiled at 100°C for 20min and the other part left fresh. The drying data was fitted to twelve well-known thin layer drying models. Among the models used, the Midilli et al.,Verma et al., Diffusion Approach, Wang and Singh, Parabolic and Simplified Fick's Diffusion models were found to be the best models to predict the moisture ratio values during the drying process with high capability. The effective moisture diffusivity was found to vary between the range of 1.401 ×10 -10 m 2 /s to 6.720 x 10 -10 m 2 /s for the fresh yam slabs and 7.223 x 10 -11 m 2 /s and 2.306 x 10 -10 m 2 /s for the boiled yam slabs over the temperature range of 50 to 70°C. The values for activation energy were 28.42kJ/mol, 30.33kJ/mol for fresh yam samples of thicknesses of 0.5cm and 1cm respectively, whereas the values for boiled yam were 6.77kJ/mol and 15.37kJ/mol for slabs of 1cm and 0.5cm thicknesses respectively. Pre-treating the aerial yam by boiling will be beneficial in the optimisation of processing method for the Dioscorea bulbifera.
Effect of boiling, thickness (0.5 and 1cm) and temperature on drying time of Dioscorea bulbifera was investigated in a fabricated hot air drier at a temperature range of 50 -70°C. . The drying process was conducted in triplicates and average values recorded. The average moisture ratio was used to plot the drying characteristics curves for the temperature range studied with dimensionless moisture ratio against drying time. Drying took place mainly in the falling rate period whiles increased slab thickness influenced drying time for both the boiled and fresh yam slabs at all temperatures. Boiling was shown to have led to a decrease in the rate of moisture movement which led to increase in drying time of the yam slice at both thickness (0.5, 1cm). Drying time subsequently reduced with increase in hot air temperature. 70°C is therefore recommended for drying aerial yam. These results will provide food processors with information to determine the best processing conditions for the dioscorea bulbifera which will finally lead to elimination of waste.
Effect of boiling, thickness (0.5 and 1cm) and temperature on drying time of Dioscorea bulbifera was investigated in a fabricated hot air drier at a temperature range of 50 -70°C. The drying process was conducted in triplicates and average values recorded. The average moisture ratio was used to plot the drying characteristics curves for the temperature range studied with dimensionless moisture ratio against drying time. Drying took place mainly in the falling rate period whiles increased slab thickness influenced drying time for both the boiled and fresh yam slabs at all temperatures. Boiling was shown to have led to a decrease in the rate of moisture movement which led to increase in drying time of the yam slice at both thicknesses (0.5, 1cm). Drying time subsequently reduced with increase in hot air temperature. 70°C is therefore recommended for drying aerial yam. These results will provide food processors with information to determine the best processing conditions for the dioscorea bulbifera which will finally lead to elimination of waste. Keywords: Drying rate, drying curve, pre-treatment, case hardening, and moisture ratio.
Heliyon, 2020
This study applied Adaptive Neuro-Fuzzy Inference System (ANFIS) to predict the moisture ratio (MR) during the drying process of yam slices (Dioscorea rotundata) in a hot air convective dryer. Also the effective diffusivity, activation energy, and rehydration ratio were calculated. The experiments were carried out at three (3) drying air temperatures (50, 60, and 70 C), air velocities (0.5, 1, and 1.5 m/s), and slice thickness (3, 6, and 9 mm), and the obtained experimental data were used to check the usefulness of ANFIS in the yam drying process. The result showed efficient applicability of ANFIS in predicting the MR at any time of the drying process with a correlation value (R 2) of 0.98226 and root mean square error value (RMSE) of 0.01702 for the testing stage. The effective diffusivity increased with an increase in air velocity, air temperature, and thickness and the values (6.382E-09 to 1.641E-07 m 2 /s). The activation energy increased with an increase in air velocity, but fluctuate within the air temperatures and thickness used (10.59-54.93 KJ/mol). Rehydration ratio was highest at air velocityÂair tem-peratureÂthickness (1.5 m/sÂ70 C  3 mm), and lowest at air velocity  air temperatureÂthickness (0.5 m/ sÂ70 C  3 mm). The result showed that the drying kinetics of Dioscorea rotundata existed in the falling rate period. The drying time decreased with increased temperature, air velocity, and decreased slice thickness. These established results are applicable in process and equipment design, analysis and prediction of hot air convective drying of yam (Dioscorea rotundata) slices.
In current work, the drying kinetics and evolution of sample's core temperature and moisture distribution of yam slices during convective hot air drying were investigated. In the terms of drying kinetics, the effect of drying temperature (50, 55, 60, 65, 70 o C), relative humidity (20%, 30%, 40%, 50%) and sample thickness (5, 7, 9 mm) on drying characteristics of yam slices were studied. Results indicated that all the three factors had significant influence on the drying kinetics, whereas drying temperature gave the most significant effect, followed by relative humidity and sample thickness. Moisture effective diffusivity and activation energy were calculated and it was found that the diffusivity was in the range of 5.5454×10 -10 to 1.0804×10 -9 m 2 /s and the activation energy was 29.528 kJ/mol. Heat and mass transfer models were developed based on the finite element method to calculate the core temperature and moisture distribution of yam slices during drying.
IOP Conference Series: Materials Science and Engineering, 2021
Drying is one of the major unit operation in food industry and it kinetics data is required for optimization. The aim of this study was to evaluate the effect of air temperature (50, 60, and 70°C), air velocity (0.5, 1, and 1.5 m/s), and slice thickness (3, 6, and 9 mm) on the moisture ratio of yam slice during drying. Ten (10) different empirical models were used in fitting the experimental moisture ratio data, the prediction performance was evaluated with sum of square error (SSE), coefficient of determination (R2) and root mean square error (RMSE). The model fitting shows that the Two term model was most performed based on R2, SSE, and RMSE value. This result can be use to control the drying systems for yam slice.
FUOYE Journal of Engineering and Technology, 2019
The objective of this study was to estimate the moisture diffusivity of different sizes of white yam slices at different temperatures using a Refractance WindowTM dryer. To achieve this objective, dehydration of 1.5, 3.0 and 4.5 mm thick yam slices was performed with water temperatures of 65, 75, 85 and 95 oC in the flume of a Refractance WindowTM dryer. Variation of moisture content with dehydration time data were obtained during the dehydration operations. The activation energies of dehydration for different sizes of yam slices were estimated for the temperatures considered. For the process conditions studied, the effective moisture diffusivities varied from 5.35 x 10-08 to 1.45 x 10-07 m2/s. The effective moisture diffusivity, Deff, at a specified temperature was observed to increase with increasing yam slice size. The effective moisture diffusivity, Deff, at a specified yam slice size is observed to increase with increasing dehydrating temperature. The activation energy, Ea, for...
Single-Layer Drying of Purple Yam (Dioscoreaalata L.) Slices
Bulgarian Journal of Agricultural Science, 2018
Muhidong, J., S. Salengke and A. Surestyana, 2018. Single-layer drying of purple yam (Dioscoreaalata L.) slices. Bulg. J. Agric. Sci., 24 (1): 145–150 This research was intended to fi nd the best fi tted model to represent the drying behaviors of purple yam slices during singlelayer drying process. The research was conducted at Food Processing Laboratory of Agricultural Engineering Department, Hasanuddin University – Indonesia. Two levels of drying temperature (40 and 50°C) under two different air velocities (1.0 and 2.0 m.s-1) were applied. A tray dryer (Model EH-TD-300 Eunha Fluid Science) was utilized as the main equipment. The moisture ratios resulted from each drying treatment combination was determined and nine different thin-layer models were fi tted to these moisture ratios. The results indicated that all models performed well as shown by their high R2 values (> 0.9) with small χ2 and RMSE values. However, among all models, the Midili-Kucuk model consistently showed the b...