scholarly journals Drying Modelling, Moisture Diffusivity and Sensory quality of Thin Layer dried Beef

2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.

Author(s):  
Toyosi Y Tunde-Akintunde

In this paper, the effect of sun and solar drying and pretreatment conditions (soaking in water; soaking in water and then blanching; blanching and then soaking) on the drying characteristics and kinetics of cassava chips were investigated. The drying time was shorter for samples pretreated by soaking only (SK) compared to the others. It was observed that pretreatment conditions and drying method significantly (P < 0.05) affected the drying rate. The drying for all experiments occurred in the falling rate period with no constant rate period. Four mathematical models were studied for the description thin layer drying characteristics of pretreated cassava chips. The models considered were the Henderson and Pabis, Newton, Logarithmic and the Page model. Comparing the correlation coefficients (R2), chi-square (c2) and root mean square error (RMSE) values of four models, it was observed that the highest values of R2 and lowest ?2 and RMSE were obtained using Page model. This shows that the Page model represents drying characteristics better than other models. The effective moisture diffusivity values were estimated from Fick’s diffusional model. These values obtained for solar dried samples were generally higher than those obtained for sun dried samples.


The study is aimed experimentally and compared with the theoretical results of drying kinetics of Nagpur orange fruit dried in a hot air electrical dryer. Orange fruit is highly perishable and needs to be consumed or processed immediately after harvest. Drying or dehydration is one of the most practical methods of preserving food products. Therefore, thin layer drying characteristics of falling rate of Nagpur orange are determined experimentally under different conditions of drying air temperatures, relative humidity and air velocities for different moisture contents. Thin layer models like Wang and Singh, Page and Henderson have been compared with Experimental results. The knowledge of drying kinetics helps for identification of exact drying time and air flow velocity for different moisture content. Here drying operation is carried out at a velocity of 1m/sec and 1.25 m/sec for different temperature of 55°C, 65°C and 75°C. This analysis reveals that drying temperature has a more significant effect on moisture removal while velocity has the least effect. Drying rate is found to increase with the increase in drying temperature and reduce with drying time. Experimental data is statistically correlated by plotting the drying characteristics curve. The analysis reveals that Wang and Singh's model is a better model to explain the drying behavior of Nagpur Orange fruit (R2=0.9888).


2020 ◽  
Vol 12 (2) ◽  
pp. 165-176
Author(s):  
Sunday Samuel Sobowale ◽  
Oluwole Benjamin Omotoso ◽  
Yusuf Olamide Kewuyemi ◽  
Olawale Paul Olatidoye

Nonlinear regression analysis was conducted for thin layer drying characteristics of two onion varieties (white and red) and some quality characteristics were also examined. The experimental data obtained at drying temperatures of 40, 50, and 60 oC and thicknesses of 2, 4 and 6 mm, was subsequently fitted into four commonly used models (Henderson and Pabis, Lewis, Page, and logarithmic). Moisture diffusivity and activation energy ranged from 8.9 × 10-10 to 8.4 × 10-9 m2/s and 55.98 to 65.68 KJ/mol, respectively. Significant differences (p&lt;0.05) were observed in the colour profile and rehydration ratio. The optimum desirable colour was obtained at 50 oC with 2 mm thick onion slices and the observed higher rehydration ratio indicates good quality of dried onions. Among the four selected drying models, the Page model predicted optimally (R2&gt; 0.9) and was found to be better in describing dried onion varieties, while the Lewis model provided the least fit.


Food Research ◽  
2021 ◽  
Vol 5 (6) ◽  
pp. 197-203
Author(s):  
N.M. Thuy ◽  
V.Q. Minh ◽  
T.C. Ben ◽  
H.T.N. Ha ◽  
N.V. Tai

With attractive flower colours ranging from dark green to purple, Butterfly pea (Clitoria ternatea L.) is grown year-round in Vietnam. The purpose of this study is to determine the effect of air temperature on drying time and antioxidant compounds of Butterfly pea flowers, fitting the drying curves and testing the goodness of fit. In this study, air drying characteristics of the Butterfly pea flowers were determined using drying air temperature from 55oC to 70oC at a constant air velocity of 1 m/s. The data of experimental moisture loss were fitted to selected seven thin-layer drying models. The effect of drying conditions on the anthocyanin and total phenolic compound changes of Butterfly pea flower were compared. The effect of temperature on the diffusivity was described using the Arrhenius equation with an activation energy of 71.63 kJ.mol- ¹. At increasing temperature, the effective moisture diffusivity values ranged from 2.39×10-12 and 7.76×10-12 m²s - ¹. The mathematical models were compared according to the three statistical parameters such as the coefficient of determination (R2 ), reduced chi-square (χ 2 ) and root mean square error (RMSE) between the observed and predicted moisture ratios. The highest value of R2 (99.8%) and the lowest values of χ 2 (0.0004) and RMSE (0.0178) were observed for drying air temperature of 70oC. Among the seven mathematical models tested with experimental data, the Page model could sufficiently be described the drying characteristics of the Butterfly pea flower.


Author(s):  
Ambe Desmond ◽  
Lobe Elias ◽  
Divine B. Nde

Potatoes (S. tuberosum L) is one of the most important tuber crops in the world. However, its high moisture content and inadequate storage and processing techniques have a negative influence on its quality and availability throughout the year. This work was carried out to optimize the blanching behavior and drying kinetics of potato slices. Fresh potato slices (5, 10 and 15 mm) were blanched at 70, 80 and 90°C for 1, 3 and 5 min following a 3k level full factorial design. The loss in Vitamin C was used as a quality marker for the optimization process. The influence of blanching on the drying behavior of potato slices was carried out at 50, 60 and 70°C. Results showed that blanching parameters had a significant (P < 0.05) effect on vitamin C loss. Optimum blanching conditions were blanching temperature of 80oC, blanching time of 3 min and a slice thickness of 10 mm which gave an average loss in Vitamin C of about 2.6%. Drying data were successfully fitted to three different thin layer drying models. The use of blanching as a pretreatment before the drying of potato is recommended because it reduces the drying time by 30%.


2021 ◽  
Vol 8 (2) ◽  
pp. 53-62
Author(s):  
Hendri Syah ◽  
Armansyah Halomoan Tambunan ◽  
Edy Hartulistiyoso ◽  
Lamhot Parulian Manalu

The objectives of this study were to determine a suitable thin layer drying model to describe the drying kinetics of Guazuma ulmifolia leaves and determine the mass transfer parameters of Guazuma ulmifolia leaves. The drying of Guazuma ulmifolia leaves was conducted in a laboratory scale dryer with various temperature (40oC, 50oC, and 60oC) and relative humidity (30%, 40%, 50% and 60%). Five drying models, namely, Newton, Henderson and Pabis, Page, Midilli-Kucuk, and Verma et al. were fitted to the drying data. The drying curve of guazuma leaves did not show a constant drying period during the drying period. The models suitability were compared base on coefficient of determination (R2), root square mean errors (RSME), and reduced mean square of deviation (X2). It was found that, among the models evaluated, the Midilli and Kucuk model is the best to describe the drying kinetics of Guazuma ulmifolia leaves. The effective moisture diffusivity was found to be in the range of 10-13 – 10-12 m2/s and the convective mass transfer coefficient was in the range of 10-9 – 10-10 m/s. The activation energy value was found to be 89.21 kJ/mol.


2021 ◽  
Vol 13 (1) ◽  
pp. 59-72
Author(s):  
Javid Ghasemi ◽  
Mehdi Moradi ◽  
Sayed Hossein Karparvarfard ◽  
Mohammad Taghi Golmakani ◽  
Amin Mousavi Khaneghah

The thin-layer drying kinetics of lemon verbena leaves were studied by using a solar cabinet dryer at air tempera-ture (at three levels of 30, 40, and 50°C), air velocity (at three levels of 2, 2.5, and 3 m/s), and mesh tray size (3, 6, and 10 mm). A completely randomized factorial design was used to analyze the effect of independent factors on drying time and essential oil yield. Results showed that all experiments have shorter drying time and higher essen-tial oil content than the shade-drying method. Also, the best drying conditions that led to an optimal essential oil yield (1.73 mL/g DM) involved a lower temperature (30°C) and velocity (2 m/s) and a mesh size of 10 mm. A good adaptation between the experimental and the predicted moisture content was observed, whereby the statistical criteria of R2, root mean square error, and k2 were calculated as 0.99, 0.08, and 0.01, respectively. Practical applicationsIn the current study, the effect of different drying states such as air velocity and drying temperature was studied on the drying behaviors and essential oil contents of lemon verbena leaves. The obtained results can lead us to a suitable drying condition that can be used in the subsequent designation of systems. Also, a mathematical model for the pre-diction of the leaves’ drying kinetics was constructed and evaluated, which could be approached in the drying systems.


2018 ◽  
Vol 192 ◽  
pp. 03041
Author(s):  
Setthawat Thanimkarn ◽  
Ekkapong Cheevitsopon ◽  
Jiraporn Sripinyowanich Jongyingcharoen

This study aimed to investigate the effect of drying temperature (40, 60, 80, and 100°C) on drying characteristics of Cissus quadrangularis Linn. (CQ) undergoing convective drying. Physical properties and phytochemicals of the dried CQ were also evaluated. CQ with the thickness of 5 mm was dried from about 10 to 0.1 g water/g dry matter. The results showed that increasing drying temperature increased drying rate (DR) and effective moisture diffusivity (Deff) and consequently decreased drying time. The drying time, maximum DR, and Deff were in the ranges of 85-1920 min, 0.0059-0.0248 g water/g dry matter·min, and 0.7302-9.1281×10-9 m2/s, respectively. Lower drying temperature could preserve quality of the dried CQ. Decreasing drying temperature resulted in greener and lower bulk density and shrinkage. The greatest total phenolic content (TPC) and quercetin content were obtained by drying the CQ at 60°C.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lahcen Hssaini ◽  
Rachida Ouaabou ◽  
Hafida Hanine ◽  
Rachid Razouk ◽  
Ali Idlimam

AbstractFirst convectional thin layer drying of two fig (Ficus carica L.) varieties growing in Moroccan, using partially indirect convective dryer, was performed. The experimental design combined three air temperatures levels (60, 70 and 80 °C) and two air-flow rates (150 and 300 m3/h). Fig drying curve was defined as a third-order polynomial equation linking the sample moisture content to the effective moisture diffusivity. The average activation energy was ranged between 4699.41 and 7502.37 kJ/kg. It raised proportionally with the air flow velocity, and the same pattern were observed for effective moisture diffusivity regarding drying time and velocity. High levels of temperature (80 °C) and velocity (300 m3/h) lead to shorten drying time (200 min) and improve the slices physical quality. Among the nine tested models, Modified Handerson and Pabis exhibited the highest correlation coefficient value with the lowest chi-square for both varieties, and then give the best prediction performance. Energetic investigation of the dryer prototype showed that the total use of energy alongside with the specific energy utilization (13.12 and 44.55 MWh/kg) were inversely proportional to the velocity and drying temperature. Likewise, the energy efficiency was greater (3.98%) higher in drying conditions.


2021 ◽  
Vol 37 (4) ◽  
pp. 713-724
Author(s):  
Fuji Jian ◽  
Mehul Patil ◽  
Digvir S. Jayas ◽  
Jitendra Paliwal

Highlights Thin-layer drying of fresh and sun-dried buckwheat hay was studied at 30°C to 180°C and 12.5% to 60% relative humidities. Buckwheat hay drying occurred in the falling-rate period. Partial sun-drying of the hay could reduce drying time by 50%. The D eff values of fresh flowers, leaves, and stems ranged from 1.4×10 -10 to 60×10 -10 m 2 /s. Abstract. Thin-layer drying characteristics of fresh and sun-dried buckwheat hay were studied at 30°C to 180°C, 12.5 to 60% relative humidities, and 0.2 m/s constant air velocity. The hay was harvested on three different times with a 10 to 12 d interval between the harvesting times. Half of the harvested hay was sun-dried on the field for 4 d (referred to as sun-dried hay). The drying behavior of flowers, leaves, and stems of the fresh and sun-dried hay was characterized. Moisture content of the fresh buckwheat flower was 0.777 to 1.633 (decimal dry basis), and fresh stems had a maximum moisture content of 5.64. Moisture content of the fresh hay decreased with the increase of growth time. Sun-drying on field could decrease more than half of the moisture content of the harvested fresh hay. Flowers, leaves, and stems needed varying drying times to reach their equilibrium moisture contents. The order of the drying time from the fastest to the slowest was flowers, leaves, then stems. Sun-dried and later harvested hay needed less drying time. The logarithmic model was the best fit for all drying processes of the flowers, leaves, and stems at different harvesting times and drying conditions. The effective moisture diffusivity of both fresh and sun-dried hay ranged from 1.4×10-10 to 60× 10-10 m2/s depending on different experimental conditions. The activation energy of the hay was from 21.08 to 33.85 kJ/mol. A power equation was the best equation to describe the drying constant of hay with their drying temperature. Keywords: Activation energy, Combination drying, Hay drying, Thin-layer drying, Water diffusivity.


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