scholarly journals Kinetics of Gelatinized White Yam (Dioscorea Rotundata, Poir) During Convective Drying

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Adesola A Satimehin
Keyword(s):  
Relative Humidity ◽  
Goodness Of Fit ◽  
Convective Drying ◽  
Effect Of Temperature ◽  
Constant Rate ◽  
Thin Layer Drying ◽  
White Yam ◽  
Rate Period ◽  
Drying Models ◽  
Binomial Approximation

Gelatinized white yam cubes, having a moisture content of 196% dry basis were dried in a convective dryer under different conditions of air temperature (40, 50, 60 and 70°C) and relative humidity (20 - 50%). There was no constant rate period throughout the entire drying period as drying took place entirely during a falling rate period. The effect of temperature was more pronounced than that of relative humidity. The drying data were fitted to five thin-layer drying models. The goodness of fit of the models were evaluated by comparing the percent mean relative deviation modulus (E%), RMSE, χ2 and R2 between their observed and predicted moisture ratio. The Binomial approximation of Fick's diffusion equation gave the best fit to the drying data as the highest values of R2 and the lowest values of χ2 and RMSE were consistently obtained with the Binomial model equation.

scholarly journals Drying of green bean and okra under solar energy

2011 ◽  
Vol 17 (2) ◽  
pp. 199-205 ◽  
Author(s):  
İbrahim Doymaz
Keyword(s):  
Green Bean ◽  
Chi Square ◽  
Sun Drying ◽  
Constant Rate ◽  
Thin Layer Drying ◽  
Rate Period ◽  
Drying Models ◽  
Drying Curves ◽  
The Times

In this study, sun drying behaviours of green bean and okra were investigated. Drying experiments were conducted in Iskenderun-Hatay, Turkey. The drying study showed that the times taken for drying of green bean and okra from the initial moisture contents of 89.5% and 88.7% (w.b.) to final moisture content of around 15?0.5% (w.b.) were 60 and 100 h in open sun drying, respectively. The constant rate period is absent in drying curves. The drying process took place in the falling rate period. The drying data were fitted to thirteen thin-layer drying models. The performance of these models was investigated by comparing the determination of coefficient (R2), reduced chi-square (c2) and root mean square error (RMSE) between the observed and predicted moisture ratios. Estimations by Approximation of diffusion (for green bean) and Midilli et al. models (for okra) were in good agreement with the experimental data obtained.

scholarly journals Dehydration kinetics of onion slices in osmotic and air convective drying process

2014 ◽  
Vol 60 (No. 3) ◽  
pp. 92-99 ◽  
Author(s):  
V.A. REVASKAR ◽  
P.S. PISALKAR ◽  
P.B. PATHARE ◽  
G.P. SHARMA
Keyword(s):  
Osmotic Dehydration ◽  
Moisture Diffusivity ◽  
Convective Drying ◽  
Laboratory Model ◽  
Ratio Data ◽  
Thin Layer Drying ◽  
Rate Period ◽  
Drying Models ◽  
Drying Behaviour ◽  
Kinetics Of

The effect of different pre-treatments (i.e. osmotic dehydration in 10, 15 and 20°Brix NaCl solution and drying air temperature of 50, 60 and 70°C) on drying behaviour of onion slices were investigated. The onion slices were dried in a laboratory model tray dryer. Drying of onion slices occurred in falling rate period. Five thin-layer drying models (Exponential, Page, Henderson and Pabis, Logarithmic and Power law) were fitted to the moisture ratio data. Among the drying models investigated, the Page model satisfactorily described the drying behaviour of onion slices. The effective moisture diffusivity of pre-treated samples was higher than that of non-treated samples

Thin Layer Drying Process of Some Leafy Vegetables under Open Sun

2007 ◽  
Vol 13 (1) ◽  
pp. 35-40 ◽  
Author(s):  
O. P. Sobukola ◽  
O. U. Dairo ◽  
L. O. Sanni ◽  
A. V. Odunewu ◽  
B. O. Fafiolu
Keyword(s):  
Thin Layer ◽  
Effective Diffusivity ◽  
Thin Layers ◽  
Leafy Vegetables ◽  
Drying Process ◽  
Chi Square ◽  
Thin Layer Drying ◽  
Rate Period ◽  
Drying Models ◽  
Drying Curves

Open sun drying experiments in thin layers of crain-crain (CC), fever (FV) and bitter (BT) leaves grown in Abeokuta, Nigeria were conducted. The drying process took place in the falling rate period and no constant rate period was observed from the drying curves. Eight thin layer mathematical drying models were compared using the multiple determination coefficients (R2), reduced chi-square (χ2) and root mean square error (RMSE) between the observed and predicted moisture ratios. Accordingly, Midilli et al. model satisfactorily described the drying curves of the three leaves with R2 of 0.9980, χ2 of 2.0×10-4 and RMSE of 1.09×10-2 for CC leaves; R2 of 0.9999, χ2 of 2×10-6 and RMSE of 1.11×10-3 for FV leaves; and R2 of 0.9998, χ2 of 1.9×10-5 and RMSE of 3.3×10-3 for BT leaves. The effective diffusivity was found to be 52.91×10-10, 48.72×10-10 and 43.42×10-10 m2/s for CC, BT and FV leaves, respectively.

scholarly journals Effect of Temperature and Slice Size on Avocado Pulp Drying Rate and Oil Yield

2013 ◽  
Vol 34 (2) ◽  
pp. 116-124
Author(s):  
Abraham T. Temu
Keyword(s):  
Moisture Content ◽  
Chemical Properties ◽  
Oil Yield ◽  
Effect Of Temperature ◽  
Drying Rate ◽  
Seed Oils ◽  
Slice Thickness ◽  
Physico Chemical ◽  
Thin Layer Drying ◽  
Drying Models

The effect of temperature and slice thickness on avocado pulp drying rate and oil yield was determined at 50 o C, 60 o C and 70 o C. Pulp slices of 2mm and 5 mm thick were used. The avocado pulp was found to contain 74-75% (wet basis) water, which makes extraction of oil by both chemical and mechanical means difficult. Experimental results showed that oil yield increased with decreasing moisture content reaching a yield of 61% at 10% moisture content. The rate of drying increased with temperature, but decreased with slice thickness. The drying data obtained agreed well with several thin-layer drying models. The models showed that the characteristic drying constant increased linearly with drying temperature and decreased with slice thickness. The Physico-chemical properties of the obtained oil compared favorably with those obtained from other conventional seed oils.

Experimental study on convective drying of quince slices and evaluation of thin-layer drying models

2015 ◽  
Vol 8 (3) ◽  
pp. 169-177 ◽  
Author(s):  
Dimitrios A. Tzempelikos ◽  
Alexandros P. Vouros ◽  
Achilleas V. Bardakas ◽  
Andronikos E. Filios ◽  
Dionissios P. Margaris
Keyword(s):  
Experimental Study ◽  
Thin Layer ◽  
Convective Drying ◽  
Thin Layer Drying ◽  
Drying Models ◽  
Thin Layer Drying Models

scholarly journals Modelling and characteristics of thin layer convective air-drying of thyme (Thymus vulgaris) leaves

2019 ◽  
Vol 37 (No. 2) ◽  
pp. 128-134
Author(s):  
Osman Yağız Turan ◽  
Ebru Fıratlıgil
Keyword(s):  
Thin Layer ◽  
Goodness Of Fit ◽  
Food Preservation ◽  
Moisture Ratio ◽  
Coefficient Of Determination ◽  
Thymus Vulgaris ◽  
Drying Process ◽  
Thin Layer Drying ◽  
Drying Models ◽  
Kinetics Of

Fruit and vegetable dehydration has been extensively studied for the improvement of food preservation. Effects of drying temperature on the drying kinetics of thyme were investigated and a suitable drying model was obtained to describe the drying process. Drying behaviour of thyme leaves at temperatures of 50, 60, 70 and 80°C was determined by using a conventional drying oven, and moisture ratio and drying rates were calculated. Four different thin layer drying models, namely Lewis, Henderson and Pabis, Page, and logarithmic models, were used to fit the experimental moisture ratio data. Three statistical parameters: coefficient of determination (R<sup>2</sup>), chi-square (χ<sup>2</sup>) and root mean square error (RMSE) were used to compare the goodness of fit of the drying models. Logarithmic model and Page model give the best description of the drying process kinetics of thyme leaves by comparing the experimental values and predicted values.

scholarly journals Effect of Temperature and Relative Humidity on the Survival of Foodborne Viruses during Food Storage

2015 ◽  
Vol 81 (6) ◽  
pp. 2075-2081 ◽  
Author(s):  
Su Jin Lee ◽  
Jiyeon Si ◽  
Hyun Sun Yun ◽  
GwangPyo Ko
Keyword(s):  
Relative Humidity ◽  
Survival Data ◽  
Goodness Of Fit ◽  
Hepatitis A Virus ◽  
Plaque Assay ◽  
Food Storage ◽  
Effect Of Temperature ◽  
Murine Norovirus ◽  
Foodborne Viruses ◽  
Biphasic Model

ABSTRACTMillions of people suffer from foodborne diseases throughout the world every year, and the importance of food safety has grown worldwide in recent years. The aim of this study was to investigate the survival of hepatitis A virus (HAV) and viral surrogates of human norovirus (HuNoV) (bacteriophage MS2 and murine norovirus [MNV]) in food over time. HAV, MNV, and MS2 were inoculated onto either the digestive gland of oysters or the surface of fresh peppers, and their survival on these food matrices was measured under various temperature (4°C, 15°C, 25°C, and 40°C) and relative humidity (RH) (50% and 70%) conditions. Inoculated viruses were recovered from food samples and quantified by a plaque assay at predetermined time points over 2 weeks (0, 1, 3, 7, 10, and 14 days). Virus survival was influenced primarily by temperature. On peppers at 40°C and at 50% RH, >4- and 6-log reductions of MNV and HAV, respectively, occurred within 1 day. All three viruses survived better on oysters. In addition, HAV survived better at 70% RH than at 50% RH. The survival data for HAV, MS2, and MNV were fit to three different mathematical models (linear, Weibull, and biphasic models). Among them, the biphasic model was optimum in terms of goodness of fit. The results of this study suggest that major foodborne viruses such as HAV and HuNoV can survive over prolonged periods of time with a limited reduction in numbers. Because a persistence of foodborne virus on contaminated foods was observed, precautionary preventive measures should be performed.

Kinetic Models of Evaporation and Total Phenolics Degradation during Pomegranate Juice Concentration

2014 ◽  
Vol 10 (3) ◽  
pp. 383-392 ◽  
Author(s):  
Athanasia M. Goula ◽  
A. Tzika ◽  
K.G. Adamopoulos
Keyword(s):  
Thermal Degradation ◽  
Total Phenolics ◽  
Pomegranate Juice ◽  
Conventional Heating ◽  
Effect Of Temperature ◽  
First Order ◽  
Joint Influence ◽  
Thin Layer Drying ◽  
Different Temperatures ◽  
Drying Models

Abstract Pomegranate juice was concentrated by conventional heating at different temperatures (45, 50, 55, 60, and 65°C), and the effect of temperature on evaporation rate and on thermal degradation of total phenolics was investigated. Concentration kinetics modeling was developed based on thin-layer drying models. The logarithmic model was found to give better predictions than the others. The temperature dependence of the model constants was expressed by polynomial relationships. In addition, a first-order decay model, with an Arrhenius and a polynomial dependency on temperature and water content, respectively, was used to describe the joint influence of temperature and moisture content on the thermal degradation of total phenolics in a concentration process of pomegranate juice.

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