scholarly journals Effects of Vacuum Drying on Structural Changes of Banana Slices

2013 ◽  
Vol 13 (1) ◽  
pp. 1 ◽  
Author(s):  
Wannapit Junlakan ◽  
Ram Yamsaengsung ◽  
Supawan Tirawanichakul
Keyword(s):  
Optimum Condition ◽  
Thin Layer ◽  
Chamber Pressure ◽  
Vacuum Drying ◽  
Drying Time ◽  
Drying Temperature ◽  
Overall Acceptability ◽  
Thin Layer Drying ◽  
Drying Kinetic ◽  
Drying Condition

The objective of this research was to study the optimum condition for the vacuum drying of banana slices using a vacuum dryer and to find out the appropriate thin layer equation for predicting the drying kinetic of bananas. The experiments were carried out at the drying temperatures of 60, 70, 80 and 90oC and absolute chamber pressure of 30 mmHg. The drying experiments were performed until the samples moisture content was lower than 3.4% (w.b.). Next, the dried products were analyzed for physical quality (in terms of color, shrinkage, and texture) and sensory quality (in terms of color, texture, flavor, crispness and overall acceptability). These data were used in choosing the optimum condition for the vacuum drying of banana slices. From experimental results, the drying time at the highest drying temperature was the shortest. At this condition, the dried banana slices showed the highest degree of yellowness, lower shrinkage, and more crispness compared to lower drying temperatures. From sensory analysis, each drying condition showed significant effect on consumer acceptability with the drying temperature of 70, 80 and 90oC showing the levels of the overall acceptability sensory qualities of dried banana is not significantly different. Consequently, the drying temperature of 90oC was suggested as the best drying condition for sliced bananas. Moreover, three mathematical models (Newton, Logarithmic and Page) describing thin layer drying were investigated. It was found that the thin layer equation providing the highest coefficient of determination (R2) and the lowest chi-square (X2) and root mean square error (RMSE) was the Logarithmic equation.

scholarly journals The Experimental Research of Drying Kinetics of Nagpur Orange Fruit (Citrus Sinesis- L) by Hot Air Electrical Dryer

2019 ◽  
Vol 8 (6S4) ◽  
pp. 1131-1134
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Orange Fruit ◽  
Kinetics Of

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).

scholarly journals The effect of ohmic heating pretreatment on drying of apple

2018 ◽  
Author(s):  
Aslı Isci ◽  
Naciye Kutlu ◽  
Merve Silanur Yilmaz ◽  
Hicran Arslan ◽  
Ozge Sakiyan
Keyword(s):  
Thin Layer ◽  
Ohmic Heating ◽  
Order Kinetic ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Kinetic ◽  
Apple Slices ◽  
Order Kinetic Model ◽  
Drying Rates ◽  
Kinetics Of

In this study, effects of ohmic pretreatment on the drying rates and color kinetics of apple were investigated. Apple slices were treated at different electric field strengths (20-30 and 40 V/cm) at 60°C for 1 min. Drying process was applied at 60˚C-2 m/s by using a tray-dryer. ΔE and moisture content were calculated. These values were fitted to the semi-theoretical thin-layer drying and the zero and first-order kinetic model. The shortest drying time was found samples treated with 30 V/cm. Wang&Singh model gave the superior fit to the experimental data. ΔE fitted well to the zero-order kinetic model.Keywords: Ohmic heating, drying, kinetic models, thin-layer models, apple.  

scholarly journals Application of sonication and freezing as initial treatments before microwave-vacuum drying of cranberries

2019 ◽  
Vol 2 (22) ◽  
pp. 151-167 ◽  
Author(s):  
Izabela Staniszewska ◽  
Szymon Staszyński ◽  
Magdalena Zielińska
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Physical Properties ◽  
Color Change ◽  
Vacuum Drying ◽  
Drying Time ◽  
Dried Fruits ◽  
Microwave Vacuum Drying ◽  
Drying Kinetic

The aim of study was to determine the influence of sonication and freezing on the kinetic of the microwave-vacuum drying, energy consumption and physical properties of whole cranberries as well as evaluate the applicability of sonication instead of freezing in order to change their physical properties and the drying kinetic of whole cranberries. Microwave-vacuum drying of whole cranberries with/without initial treatments took from 12 ± 1 to 14.5 ± 0.5 minutes. All of treatments did not significantly shorten the drying time of cranberries. However, they increased SMER values even by 31%. Despite of cryogenic freezing, all of treatments significantly increased the values of Dew. Sonication combined with drying allowed to obtain dried berries characterized by the lowest cohesiveness (0.19±0.02), springiness (0.62±0.02) and chewiness (3.4±0.8 N), while cryogenic freezing combined with drying allowed to obtain dried fruits characterized by highest springiness (0.75±0.03) and low chewiness (3.3±0.5 N). The highest lightness (32.2±0.7), redness (32.6±0.8), and yellowness (11.1±0.7) were found for fruits subjected to initial convective freezing before drying. The efficiency of sonication in color change was comparable to cryogenic freezing and much lower than convective freezing. All of initial treatments increased such thermal properties of dried cranberries as thermal conductivity and thermal diffusivity.

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
Keyword(s):  
Thin Layer ◽  
Sensory Quality ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Slice Thickness ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying

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.

scholarly journals Thin-layer mathematical modeling of apple slices drying, using open sun and cabinet solar drying methods

2021 ◽  
Vol 4 (2) ◽  
pp. 43-52
Author(s):  
Abdul Wasim Noori ◽  
Mohammad Jafar Royen ◽  
Juma Haydary
Keyword(s):  
Thin Layer ◽  
Mathematical Models ◽  
Water Activity ◽  
Model Fitting ◽  
Coefficient Of Determination ◽  
Drying Methods ◽  
Solar Drying ◽  
Drying Time ◽  
Climate Conditions ◽  
Thin Layer Drying

This paper aims to investigate the effect of climate conditions such as ambient temperature, humidity, pressure, sun radiation and pollution on sliced apples quality and drying time which are dried in an indirect forced cabinet solar drying (IFCSD) and open sun drying (OSD) systems. Both experiments were implemented at same place (Kabul, Afghanistan) and time. The IFCSD yield for saving time is 42.8 % which is more effective than drying in the OSD system. Simultaneously with the decreasing of sliced apple weight from 512.9 g down to 73.9 g, the water activity decreased from 0.955 down to 0.355 in the IFCSD system. For OSD system, the sample weight decreased from 512.6 g down to 78.4 g and its water activity from 0.955 down to 0.411. On the experiment day the average sun radiation was 571 w/m2 . The pressure drop between inlet and outlet of the dryer was 0.1 kPa. Different thin-layer mathematical models were investigated to identify the best model fitting the experimental data. The mathematical models’ performances were investigated by comparing the coefficient of determination (R 2 ), reduced chi-square (X2 ) and root mean square error (RMSE) coefficients. From all 11 applied thin-layer drying models the Page, Approximation diffusion, Verma et al and Midilli and Kacuk models are more fitted to our data.

Dry Characteristics and Kinetics of Explosion Puffing Dried Crispy Winter Jujube at Different Vacuum Drying Temperature

2011 ◽  
Vol 236-238 ◽  
pp. 2505-2509
Author(s):  
Xin Yi He ◽  
Jin Fu Liu ◽  
Li Li Cheng ◽  
Bu Jiang Wang
Keyword(s):  
Moisture Diffusivity ◽  
Percentage Error ◽  
Vacuum Drying ◽  
Drying Temperature ◽  
Thin Layer Drying ◽  
Relative Percentage Error ◽  
Drying Rates ◽  
Predicted Values ◽  
Drying Curves

Drying characteristics of crispy winter jujube dried by explosion puffing drying at different vacuum drying temperature were investigated. Selection of the best model was examined by comparing the determination of coefficient (R2), root means square error (RMSE), and mean relative percentage error (P) between the experimental and predicted values. As expected, higher drying rates were obtained with higher vacuum drying temperature. The results showed that the Modified Henderson and Pabis model provided better simulation of drying curves for crispy winter jujube according to thin-layer drying theory. The effective moisture diffusivity of crispy winter jujube dried by explosion puffing drying with higher vacuum drying temperature was higher than the others.

A Mathematical Model for Thin-Layer Drying of Litchi Pulp

2012 ◽  
Vol 192 ◽  
pp. 51-56
Author(s):  
Zhi Qiang Guan ◽  
Xiu Zhi Wang ◽  
Min Li ◽  
Xiao Qiang Jiang
Keyword(s):  
Experimental Data ◽  
Thin Layer ◽  
Heat Pump ◽  
Moisture Ratio ◽  
Drying Time ◽  
Page Model ◽  
Thin Layer Drying ◽  
Drying Models ◽  
Heat Pump Drying ◽  
Predicted Values

A drying experiment of litchi pulp was done with a self-built heat-pump drying system. A few commonly-used thin-layer drying models for foods were linearized and fitted with the drying experimental data to select a relatively optimal model of depicting the relationship between moisture ratio and drying time of the heat-pump drying of litchi pulp. It was found that the Page model is relatively optimal. The multivariate linear regression approach was employed to solve for the parameters of the Page model based on experimental data and an experimental verification was conducted; the verification results show that the predicted values of the Page model have a good fitness with the measured values and thus the Page model can predict more accurately the moisture ratio and drying rate of litchi pulp in a heat-pump drying process.

Mathematical Modelling of Thin Layer Sun and Solar Drying of Cassava Chips

2010 ◽  
Vol 6 (6) ◽  
Author(s):  
Toyosi Y Tunde-Akintunde
Keyword(s):  
Thin Layer ◽  
Correlation Coefficients ◽  
Moisture Diffusivity ◽  
Solar Drying ◽  
Drying Time ◽  
Drying Characteristics ◽  
Page Model ◽  
Thin Layer Drying ◽  
Rate Period ◽  
Pretreatment Conditions

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.

Influence of Drying Conditions and Mathematical Models on the Thin-Layer Drying of Mushrooms

2014 ◽  
Author(s):  
A. Stegou-Sagia ◽  
D. V. Fragkou
Keyword(s):  
Mass Transfer ◽  
Thin Layer ◽  
Mathematical Models ◽  
Drying Methods ◽  
Suitable Model ◽  
Drying Time ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Drying Models ◽  
Drying Rates

In the present research, experimental data from several studies about drying behavior of mushrooms have been selected and used to compare different drying methods and different mathematical thin layer drying models to simulate mushroom drying rates. The white button (Agaricus Bisporus), the oyster (Pleurotus Ostreatus) and the milky mushroom slices have been considered for drying in different dryers such as hot air cabinet dryer and fluidized bed dryer with different slice thicknesses, drying air temperatures (45 °C to 90 °C) and drying air velocities (0.2 m/s to 5 m/s). The entire drying process has taken place in the falling rate period, assuming that internal mass transfer occurred by diffusion in mushroom slices. The study shows that the drying air temperature and the drying air velocity have an effect on the moisture removal from mushrooms and also on the drying time. Mathematical models have been proved to be useful for design and analysis of heat and mass transfer during drying processes. All the drying models considered in this study could adequately represent the thin layer drying behavior of mushrooms. Furthermore, as it is obvious, any type of mushrooms has its own most suitable model.

DRYING KINETICS AND CROSS-LINKING OF SULFUR PREVULCANIZED THICK NATURAL RUBBER LATEX FILM

2013 ◽  
Vol 86 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Chen Jing ◽  
Yang Lei ◽  
Zhong Jieping ◽  
Li Sidong ◽  
Chen Yongjun ◽  
...  
Keyword(s):  
Film Formation ◽  
Natural Rubber Latex ◽  
Type Equation ◽  
Drying Kinetics ◽  
Latex Film ◽  
Cross Linking ◽  
Drying Time ◽  
Drying Temperature ◽  
Drying Kinetic ◽  
Link Density

ABSTRACT In order to investigate drying kinetics of thick natural latex (NR) samples after film formation and the effect on cross-linking of NR latex during the drying process, we employed drying experiment methods, swelling methods, and Fourier transform infrared spectroscopy (FTIR) methods to study the drying and vulcanizing characteristics of NR latex. The results show that the drying temperature and thickness of film have obviously affected drying characteristics. The drying kinetic equation is achieved by mathematic fitting, and the Henderson and Pabis model MR = a exp(−kt) was the best fitted model for the thick NR latex film. The effect of the drying temperature on the drying constant was assessed employing an Arrhenius type equation, which can be expressed as k = 6746 exp[−39.9 × 103/(RT)] (R = 8.314 J mol−1 K−1). The drying constant exponentially decreased with the increasing film thickness. At the beginning of drying, the cross-link density increases rapidly, and up to the maximum value, it would slightly decrease with the prolonged drying time, which the results of FTIR also agree with.

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