Drying of Rough Rice in Oven: An Experimental Study

2015 ◽  
Vol 365 ◽  
pp. 77-81 ◽  
Author(s):  
J.V. Silva ◽  
E.M.A. Pereira ◽  
T.H.F. Andrade ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Experimental Study ◽  
Relative Humidity ◽  
Moisture Content ◽  
Product Quality ◽  
Air Temperature ◽  
Drying Rate ◽  
Rough Rice ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Mechanical Movement

This paper aims to present an experimental study of rough rice (BRSMG CONAI cultivar) drying by using a stationary method. The grain was dried in an oven with air mechanical movement under controlled conditions of velocity, temperature and relative humidity. In order to obtain balanced moisture content, the samples studied were kept at 40 and 70°C. Results of the drying and heating kinetics of the grain during the process are shown and analyzed. It was found that higher drying rate and lower time for drying as higher air temperature (70°C) is used. It can be concluded that the reduction of the moisture content of the grain, is considered very complex and, depending on the method and drying conditions, can substantially provokes breaking and cracks, which reduces final product quality.

A Proposed Method for Quantifying Thermal Exposure Incurred during Rough-Rice Drying

2021 ◽  
Vol 64 (2) ◽  
pp. 475-484
Author(s):  
Seth Graham-Acquaah ◽  
Terry J. Siebenmorgen
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Thermal Desorption ◽  
Thermal Exposure ◽  
Drying Process ◽  
Rough Rice ◽  
Thermal Sterilization ◽  
End Use ◽  
Rice Drying ◽  
Drying Conditions

HighlightsDrying conditions affect rice end-use functionality.Thermal exposure incurred by rough rice may differ depending on drying conditions.A framework is proposed for deriving an index that can show how much heat exposure rough rice incurs during drying.Abstract. Heated air is used to dry most rice in the U.S. Thus, commercial rice drying can be considered a thermal process that aims to remove moisture from rough rice until a desired moisture content is reached. Parallels can be drawn between rice drying and thermal sterilization that is targeted at reducing microbial load because moisture content reduction during drying follows similar decay rate kinetics as the reduction in microbial load during thermal sterilization. Given the different combinations of drying air conditions (air temperature and relative humidity), as well as drying and tempering durations, employed in various dryer designs for rice drying and the impact that these conditions have on rice end-use functionality, this study sought to derive a thermal treatment index (drying process values) that is similar to the F0 value concept used in thermal sterilization for quantifying and comparing the thermal exposure incurred by rice during drying under various scenarios. Using data collected from rough-rice drying experiments, a decimal desorption value (Dmv) that represents the duration required to cause a 90% reduction in moisture ratio during drying at a specified temperature was determined, from which a thermal desorption constant (Zmv) that represents the increase in temperature necessary to cause a 90% reduction in Dmv during drying was established. Subsequently, a thermal desorption value (Fmv) was derived to express the duration that a rice lot would have been heat treated at a reference temperature during drying to produce an equivalent effect on moisture content as that produced by the actual drying process. Keywords: End use, Moisture content, Peak viscosity, Postharvest, Relative humidity, Rice, Temperature.

scholarly journals Drying Rate and Product Quality Evaluation of Roselle (Hibiscus sabdariffa L.) Calyces Extract Dried with Foaming Agent under Different Temperatures

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mohamad Djaeni ◽  
Andri Cahyo Kumoro ◽  
Setia Budi Sasongko ◽  
Febiani Dwi Utari
Keyword(s):  
Antioxidant Activity ◽  
Relative Humidity ◽  
Product Quality ◽  
Drying Rate ◽  
Hibiscus Sabdariffa ◽  
Drying Time ◽  
Air Temperatures ◽  
Different Temperatures ◽  
Dried Extract ◽  
Drying Conditions

The utilisation of roselle (Hibiscus sabdariffa L.) calyx as a source of anthocyanins has been explored through intensive investigations. Due to its perishable property, the transformation of roselle calyces into dried extract without reducing their quality is highly challenging. The aim of this work was to study the effect of air temperatures and relative humidity on the kinetics and product quality during drying of roselle extract foamed with ovalbumin and glycerol monostearate (GMS). The results showed that foam mat drying increased the drying rate significantly and retained the antioxidant activity and colour of roselle calyces extract. Shorter drying time was achieved when higher air temperature and/or lower relative humidity was used. Foam mat drying produced dried brilliant red roselle calyces extract with better antioxidant activity and colour qualities when compared with nonfoam mat drying. The results showed the potential for retaining the roselle calyces extract quality under suggested drying conditions.

Fissuring Kinetics of Rough Rice during the Drying Process

2020 ◽  
Vol 36 (5) ◽  
pp. 639-645
Author(s):  
Zephania R. Odek ◽  
Terry J. Siebenmorgen ◽  
Ashok Saxena
Keyword(s):  
Relative Humidity ◽  
Time Interval ◽  
List Type ◽  
Drying Process ◽  
Milled Rice ◽  
X Ray ◽  
Rough Rice ◽  
Drying Conditions ◽  
Subsequent Storage ◽  
Kinetics Of

HighlightsDrying rough rice using harsh air conditions causes fissures to appear instantaneously during active drying.For mild drying air conditions, a time interval is required after the cessation of active drying before fissures appear.The majority of fissures due to active drying in rough rice kernels appear after drying has ceased.Abstract. Fissuring of rough rice kernels leads to breakage during milling, which results in head rice yield reductions. While other studies have addressed the fissuring kinetics of milled rice kernels, rice is normally dried and stored as rough rice. Thus, the objective of this research was to study the fissuring kinetics of rough rice kernels during the drying process and to characterize the configuration of the fissures. Rough rice kernels of cultivar CL XL745 with a bulk moisture content of 17% were dried using air at 40°C, 50°C, and 60°C each at relative humidity (RH) levels of 20%, 40%, and 60%. During the drying process (drying, tempering, and subsequent storage), X-ray images of rice kernels were recorded to enumerate fissures. As the drying air temperature was increased, the percentage of fissured kernels increased for all RHs evaluated. Conversely, as RH was increased, the percentage of fissured kernels decreased. Approximately 90% of fissures appeared after drying had ceased, increasing rapidly in the initial 6 h after drying. Kernels dried at high-temperature, low-RH drying air combinations had fissuring occur and appear instantaneously during active drying. In low-temperature drying conditions, fissures did not appear during active drying. Fissuring under such conditions required a time delay after active drying. This study shows the stages of the drying process when fissures appear in rough rice and the durations after active drying when fissures are expected to appear. Keywords: Glass transition, Post-drying, Relative humidity, Rice drying, Temperature, Tempering, X-ray imaging.

Heat and Mass Transfer and Volume Variations during Drying of Industrial Ceramic Bricks: An Experimental Investigation

2012 ◽  
Vol 326-328 ◽  
pp. 267-272 ◽  
Author(s):  
J. Barbosa da Silva ◽  
G. Silva Almeida ◽  
Gelmires Araújo Neves ◽  
W.C.P. Barbosa de Lima ◽  
Severino Rodrigues de Farias Neto ◽  
...  
Keyword(s):  
Experimental Study ◽  
Moisture Content ◽  
Air Temperature ◽  
Atmospheric Pressure ◽  
Drying Rate ◽  
Drying Process ◽  
Air Velocity ◽  
Brick Clay ◽  
Constant Weight ◽  
Rate Period

The purpose of this paper is to present an experimental study of brick drying. For the drying experiments, industrial brick (clay) was dried in an oven under controlled conditions of air velocity, air temperature and air relative humidity. The continuous drying experiments ended when the mass reached constant weight. In order, to obtain the balanced moisture content, each sample was kept under the same drying air temperature for 48 hours inside the oven. The tests were performed under atmospheric pressure. Results of the drying and heating kinetics and volume variations during the process are shown and analyzed. It was verified that air temperature has big influence in the drying rate during process. It was verified that the largest temperature, moisture content and stress gradients are located in the vertexes of the brick. The drying process happens in the falling drying rate period.

CATFISH DRYING (Clarias Batraclus) USING ‘TEKO BERSAYAP’ SOLAR DRYER

2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Time ◽  
Ambient Relative Humidity ◽  
Solar Dryer

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.

An Experimental Study of Heat and Mass Transfer During Drying of Packed Beds

1992 ◽  
Vol 114 (3) ◽  
pp. 727-734 ◽  
Author(s):  
W. C. Lee ◽  
O. A. Plumb ◽  
L. Gong
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Glass Beads ◽  
Drying Rate ◽  
Packed Beds ◽  
Transfer Coefficients ◽  
Model Predictions ◽  
Drying Models ◽  
Surface Saturation ◽  
Drying Conditions

An experimental study has been conducted to provide a data base for drying packed beds of granular, nonhygroscopic materials. Experimental results for drying rate, saturation distribution, temperature distribution, and surface saturation are reported for drying glass beads under carefully documented drying conditions. Capillary pressure for both imbibition and drainage was measured for the glass beads, whose size ranged from 65 μm to 450 μm. The drying results demonstrate that, contrary to available model predictions, porous materials do not necessarily exhibit saturation gradients that always increase with distance from the drying surface. Under certain conditions the capillary potential is sufficient to create an internal drying front. The measurements of surface saturation are the first to be reported. They are utilized to speculate on the reasons for the failure of drying models to compare well with experiment without adjusting the convective heat or mass transfer coefficients.

Effect of Pre-Treatment on the Drying Characteristics and Kinetics of Okra (Abelmoschus esculetus (L.) Moench) Slices

2009 ◽  
Vol 5 (2) ◽  
Author(s):  
Olajide Sobukola
Keyword(s):  
Air Temperature ◽  
Sample Thickness ◽  
Hot Water ◽  
Drying Rate ◽  
Diffusivity Coefficient ◽  
Drying Characteristics ◽  
Rate Period ◽  
Pretreatment Conditions ◽  
Air Dryer ◽  
Kinetics Of

The effects of air temperature (50, 60 and 70°C), sample thickness (2, 4 and 6mm) and pretreatment conditions (hot water blanching, 1 and 3% sodium metabisulphite solutions) on the drying characteristics and kinetics of okra were investigated using a convective hot air dryer at a flow rate of 1.5m/s. It was observed that pretreatment conditions, sample thickness and drying air temperature significantly (P<0.05) affected drying rate. Drying rate increases as temperature of drying air increases from 50 to 70°C. The drying curve for all experiments occurred in the falling rate period with no constant rate period. Three thin layer drying models (Page, modified Page I and Wang and Singh) were evaluated using coefficient of determination (R2), root mean square error (RMSE) and the reduced chi square (?2). The three models can appropriately describe the drying kinetics of okra slices considering the different experimental conditions. The effective diffusivity was determined using the Fick’s model and was observed to vary between 1.125x10-8 – 9.93x10-9m2/s and 1.165x10-8 – 7.131x10-9 m2/s for treated and untreated samples. The Arrhenius-type relationship describes the temperature dependence of diffusivity coefficient and was determined to be 16.749kJ/mol and 22.437kJ/mol for treated and untreated samples respectively.

Conversion of Alkoxide Solutions to Oxides: Evaporation of Products

1989 ◽  
Vol 155 ◽  
Author(s):  
R. A. Lipeles ◽  
D. J. Coleman
Keyword(s):  
High Flow ◽  
Drying Rate ◽  
Flow Rates ◽  
Long Time ◽  
Drying Rates ◽  
Drying Conditions ◽  
Kinetics Of ◽  
By Products ◽  
Evaporation Kinetics ◽  
Kinetics Monitoring

ABSTRACTThe evaporation of organic by-products released during drying of 1-mm thick silicon tetramethoxide gels was analyzed using gas chromatography. The evaporation kinetics of methanol depended on the drying rate achieved by flowing dry air over the gel. For drying at flow rates less than 50 cm 3/min, exponential kinetics were observed initially with a long time constant (about 100- to 400-min). For drying rates greater than 70 cm3/min, diffusional (t−1/2) kinetics were observed initially. Cracking of the gel during drying was used to indicate the degree of stress. At low drying rates, minor cracking was observed near the edges of the gel. At high flow rates, extensive cracking was observed in samples that exhibited early t−1/2 kinetics. Monitoring the kinetics of drying is essential to optimizing the drying conditions to minimize stress and cracking in gels.

Effect of Drying on Degradation kinetics of carotenoids and color of tomato pulp

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Indu Parmar ◽  
Gurpreet Kaur Chandi ◽  
Kalika Gupta ◽  
Balmeet Singh Gill
Keyword(s):  
Rate Constant ◽  
Color Change ◽  
Degradation Kinetics ◽  
Drying Rate ◽  
Drying Temperature ◽  
Hot Air ◽  
Visual Color ◽  
Tomato Pulp ◽  
Drying Conditions ◽  
Kinetics Of

Abstract Tomato pulp was dried under various drying conditions using hot air oven (65-950C), and cabinet drier (65-950C). The drying rate constant increased with increase in drying temperature. Among different combinations of Hunter L, a and b parameters, L*a could be used to describe the visual color change in tomato pulp during dehudration process.

Comparison of Drying Kinetics of Maize in Oven and in Pilot Silo Dryer: Influence on Moisture Content and Physical Characteristics

2016 ◽  
Vol 12 (6) ◽  
pp. 599-606 ◽  
Author(s):  
Flávia Daiana Montanuci ◽  
Raphaela Mulato Cavalcante ◽  
Camila Augusto Perussello ◽  
Luiz Mario de Matos Jorge
Keyword(s):  
Moisture Content ◽  
Temperature Increase ◽  
Drying Kinetics ◽  
Final Moisture Content ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Temperature ◽  
Design And Optimization ◽  
Process Kinetics ◽  
Kinetics Of

Abstract The study of process kinetics may aid the design and optimization of drying systems. This paper evaluated the influence of drying temperature (40, 60 and 80 °C) on the moisture content, drying rate, density, shrinkage and breakage of maize dried in two different dryers: oven and silo dryer. In both dryers, the temperature increase reduced drying time, final moisture content and shrinkage of the grains, however increased breakage. Drying rate was higher in the oven (6.4×10−4±2.3×10−4s−1 versus 5.4×10−4±1.2×10−4s−1), while shrinkage (15.2±4.7 % versus 24.4±5.6 %) and density increase (16.6±5.9 % versus 33.4±5.8 %) were more intense in the silo. There was a large release of husk in the silo dryer and the moisture content was slightly smaller in the lower layers respective to the upper ones.

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