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.

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.

X-Ray Detection of Fissures in Rough Rice Kernels

2017 ◽  
Vol 33 (5) ◽  
pp. 721-728 ◽  
Author(s):  
Zephania R. Odek ◽  
Bhagwati Prakash ◽  
Terry J. Siebenmorgen
Keyword(s):  
Rice Yield ◽  
X Rays ◽  
Milled Rice ◽  
Substantial Impact ◽  
X Ray ◽  
X Ray Imaging ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Rice Drying

Abstract. X-ray imaging is a viable method of fissure detection in rough rice kernels owing to the ability of X-rays to penetrate hulls, thus allowing visualization of internal rice kernel structure. Traditional methods of fissure detection are only applicable for brown and milled rice, and therefore cannot be used to study fissures developed during rough rice drying. In this study, the fissure detection capability of an X-ray system was evaluated and the relationship between head rice yield (HRY), as measured through laboratory milling, and the percentage of fissured rough rice kernels was determined. Long-grain rice lots of various cultivars were dried using heated air at 60°C, 10% relative humidity (RH) for five drying durations to produce different degrees of fissuring, and then milled to determine HRY. A strong linear correlation (R2 = 0.95) between HRY and the percentage of fissured rough rice kernels after drying was determined. This correlation confirms the substantial impact that kernel fissures have on milling yields. Overall, these findings show the effectiveness of X-ray imaging in rough rice fissure detection, which could allow for drying research that may provide a better understanding of kernel fissuring kinetics. Keywords: Fissures, Grainscope, Head rice yield, Rice drying, X-ray imaging.

scholarly journals The Effect of Drying Parameters on the Quality of Pork and Poultry-Pork Kabanosy Produced according to the Traditional Specialties Guaranteed Recipe

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Marta Chmiel ◽  
Lech Adamczak ◽  
Katarzyna Wrońska ◽  
Dorota Pietrzak ◽  
Tomasz Florowski
Keyword(s):  
Relative Humidity ◽  
Salt Content ◽  
Raw Material ◽  
Chemical Components ◽  
Drying Process ◽  
Final Yield ◽  
Drying Conditions ◽  
Drying Chamber ◽  
Selection Of

The aim of this study was to determine the effect of differentiated air relative humidity during the drying process on selected quality features of TSG (traditional specialties guaranteed) pork and poultry-pork kabanosy. After heat treatment and 24-hour cooling at 4–6°C, the products were placed in three chambers at 15°C with differentiated air relative humidity: 60, 70, and 80%, respectively. The drying process was carried out until all variants of kabanosy achieved the required final yield of the product (<68%). Color components, water activity and shear force, water, protein, fat, and salt content, and the TBARS indicator values were determined. The drying process might be shortened (~50%) by a reduction of humidity in the drying chamber from 80 to 60%. The changes in the content of chemical components in pork kabanosy compared to poultry-pork ones demonstrated the different dynamics of the drying of the two types of kabanosy and the need for the selection of optimum drying conditions relative to raw material composition.

scholarly journals NIR Spectroscopy Detects Chlorpyrifos-Methyl Pesticide Residue in Rough, Brown, and Milled Rice

2020 ◽  
Vol 36 (6) ◽  
pp. 983-993
Author(s):  
Fatima S Rodriguez ◽  
Paul R Armstrong ◽  
Elizabeth B Maghirang ◽  
Kevin F Yaptenco ◽  
Erin D Scully ◽  
...  
Keyword(s):  
Pesticide Residue ◽  
Brown Rice ◽  
Nir Spectroscopy ◽  
List Type ◽  
Pesticide Level ◽  
Milled Rice ◽  
Near Infrared Reflectance ◽  
Independent Validation ◽  
Rough Rice ◽  
Rice Samples

HighlightsNIR spectroscopy detects quantitative and qualitative levels of chlorpyrifos-methyl residues in bulk rice.Levels of chlorpyrifos-methyl residues in bulk rice can be differentiated at 78% to 100% correct classification.Important NIR wavelengths for chlorpyrifos-methyl residue detection were identified.NIR spectroscopy can be used to detect maximum residue levels of chlorpyrifos-methyl pesticide in rice.Abstract. A rapid technique that uses near-infrared reflectance (NIR) spectroscopy for simultaneous qualitative and quantitative determination of the presence of varying concentrations of chlorpyrifos-methyl in bulk samples of rough, brown, and milled rice was established. Five rice varieties, free of pesticides, obtained from RiceTec Inc. and USDA-ARS Arkansas experimental field were used as rough rice samples and also processed to obtain corresponding brown and milled rice. Rice samples were treated with StorcideTM II containing varying levels of the active ingredient, chlorpyrifos-methyl: 0, 1.5, 3, 6, 9, and 12 ppm for rough rice, 0, 0.75, 1.5, 3, 4.5, and 6 ppm for brown rice, and 0, 0.1, 0.2, 0.4, 0.6, and 0.8 ppm for milled rice. Concentrations of chlorpyrifos-methyl were verified using gas chromatography-mass spectrometry analyses. A commercial NIR spectrometer (950-1650 nm wavelength range) was used to obtain spectra of bulk samples. Using partial least squares analysis for quantitative analysis, independent validation showed that chlorpyrifos-methyl residues in rough, brown, and milled rice are predictable with R2 ranging from 0.702 to 0.839 and standard error of prediction (SEP) of 1.763 to 2.374 for rough rice, R2 ranging from 0.722 to 0.800 and SEP of 0.953 to 1.168 for brown rice, and R2 ranging from 0.693 to 0.789 and SEP of 0.131 to 0.164 for milled rice. For qualitative analysis obtained using discriminant analysis, rough rice samples with concentrations of 0, 1.5, and 3 ppm pooled as low pesticide level (LPL) is distinguishable to 6, 9, and 12 ppm which were pooled as high pesticide level (HPL). Similarly, for brown and milled rice, the lower three concentrations pooled as LPL is distinguishable from the higher three concentrations pooled as HPL. Independent validation showed overall correct classifications ranging from 77.8% to 92.6% for rough rice, 79.6% to 88.9% for brown rice, and 94.4% to 100% for milled rice. Keywords: Food safety, Grain quality, NIR spectroscopy, Pesticide residue, Rice.

Adsorption Drying Characteristics of Angelica dahurica and Mathematical Modeling on Large Scale

2013 ◽  
Vol 807-809 ◽  
pp. 1960-1963
Author(s):  
Xin Ye Dai ◽  
Xiang Ji ◽  
Lei Tang ◽  
Hai Yan Wang ◽  
Qun Cui
Keyword(s):  
Relative Humidity ◽  
Wind Velocity ◽  
Large Scale ◽  
Angelica Dahurica ◽  
Drying Process ◽  
Medium Temperature ◽  
Drying Characteristics ◽  
Page Model ◽  
Nonlinear Regression Method ◽  
Drying Conditions

The low-temperature adsorption drying characteristics of thin-layer Angelica Dahurica were evaluated in a large scale dryer. The effects of drying medium temperature, relative humidity of drying medium and wind velocity on the drying characteristics were investigated. Page model using nonlinear regression method can preferably fit the drying characteristic of Angelica Dahurica under different drying conditions The work revealed the correlation between moisture content and drying process parameters. The drying coefficient and exponent in the page model can be expressed as a function of temperature, relative humidity and wind velocity of the drying air.

Effect of Rice Chilling on Drying, Milling, and Quality Characteristics

2020 ◽  
Vol 36 (5) ◽  
pp. 767-776
Author(s):  
Soraya Shafiekhani ◽  
Griffiths G Atungulu
Keyword(s):  
High Temperature ◽  
Cold Storage ◽  
Storage Temperature ◽  
Rice Yield ◽  
Quality Characteristics ◽  
List Type ◽  
Milled Rice ◽  
Heated Air ◽  
Rough Rice

HighlightsThis study experimentally simulated drying of rough rice subjected to various cold storage/chilling conditions.The rice was dried using slightly-heated air and high temperature air with procedures set to mimic those practiced by commercial systems.The moisture removal, drying rate constant, material state transition, milling and quality characteristics of rice upon drying conditions was investigated.The study provides important reference information for growers and rice processors using the relatively new rice cooling technology.Abstract. High temperature (field heat) and moisture content of freshly harvested rough rice promote excessive respiration and microbial growth. Therefore, the rice risks significant deterioration of quality due to delayed drying at peak harvest time when drying capacity becomes limited. The U.S. rice industry has identified that cooling/chilling the rice prior to drying to remove the excess heat, immediately after harvest, significantly preserves the quality of milled rice. This study experimentally simulated drying of rough rice after cold storage/chilling. The rice was dried using slightly-heated air and high temperature air with procedures set to mimic those practiced by commercial systems. Rough rice at moisture contents (MCs) of 16%, 19%, and 21% (wet basis) were stored at storage temperature (Ts) of 10°C, 15°C, and 20°C for up to 4 months. Following retrieval, the samples were dried at drying temperature (Td) of 35°C, 45°C, and 60°C and relative humidity (RH) of 20%. Each drying run comprised of two 20-min drying passes with the rice tempered at the drying Td for a duration of 4 h following every drying pass. Following the drying, the rice was conditioned in an equilibrium MC chamber (T=26°C, RH=56%) to 12.5% MC and then milled to evaluate milled rice yield and quality characteristics. The highest percentage points of MC removal (6.77% points) occurred following drying at air temperature of 60°C for samples with initial MC at 21% and stored at 20°C. Drying with air at 60°C decreased head rice yield (HRY) especially for samples with initial MC at 21% and stored at 10°C (HRY=51.4% versus those at 45°C and 35°C, HRY=55.95% and HRY=58.8%, respectively). Drying air temperatures studied (35°C, 45°C, 60°C) had no significant effect of causing discoloration of samples within the range of the studied initial MCs and storage temperatures. Peak and final viscosities of samples with different initial MCs (16%, 19%, and 21%) stored at 20°C followed by high temperature air drying (60°C) were significantly different from those of samples stored at 10°C and 15°C. The results provided insight into the drying, milling, and quality characteristics of rice after cold storage/chilling. The information provide foundation for development of new recommendations to improve quality of milled rice. Keywords: Conventional drying, Cooling/chilling, Milling quality, Rough rice, Storage.

Swelling Properties and Kinetics of Starch-g-Poly(acrylic acid) Hydrogels

2012 ◽  
Vol 550-553 ◽  
pp. 1316-1320
Author(s):  
Ji Yan Shi ◽  
Li Ren Fan ◽  
Ji Qing Song ◽  
Wen Bo Bai
Keyword(s):  
Relative Humidity ◽  
Acrylic Acid ◽  
Moisture Absorption ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Swelling Properties ◽  
X Ray ◽  
Hygroscopic Swelling ◽  
Kinetics Of ◽  
Poly Acrylic Acid

Starch-g-poly(acrylic acid) (CSt-g-PAA) hydrogels were prepared from cassava starch and acrylic acid by graft polymerization. The hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric-differential scanning calorimetry (TG-DSC). Additionally, the water absorbency and hygroscopic swelling properties of the hydrogels were investigated respectively. The two processes were simulated using mathematical modes. The results revealed that the crystal structure of starch was destroyed. At 40°C and relative humidity 90% (90% RH), the samples (starch mass15%, 50%) have a better performance of the moisture absorption. Hygroscopic rate declined with the increase of relative humidity.

Mathematical Modeling of Thin-Layer Solar Drying for Yarrow, Coriander and Hollyhock

2015 ◽  
Vol 11 (5) ◽  
pp. 691-700 ◽  
Author(s):  
Yasaman Amanlou ◽  
Teymour Tavakoli Hashjin ◽  
Barat Ghobadian ◽  
Gholamhassan Najafi
Keyword(s):  
Theoretical Models ◽  
Drying Kinetics ◽  
Medicinal Products ◽  
Drying Process ◽  
Chi Square ◽  
Air Temperatures ◽  
C 50 ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Best Fit

Abstract The objective of this study is to investigate the drying kinetics of Yarrow, Coriander and Hollyhock flowers. These three medicinal products were dried using a solar hybrid photovoltaic-thermal dryer. The drying process was examined at the air temperatures of 40°C, 50°C and 60°C and air velocities of 0.5, 1 and 1.5 m/s. The experimental drying data were fitted to different theoretical models to predict the drying kinetics. Nonlinear regression analysis was performed to relate the parameters of the model with the drying conditions. The performance of these models was evaluated by comparing the correlation coefficient ($${R^2}$$), root mean square error (RMSE) and the chi-square ($${\chi ^2}$$) between the observed and the predicted moisture ratios. Among all the models, the exponential two-term was found to have the best fit in this study. Also the influence of plant type, air temperature and velocity was investigated.

Validating the Glass Transition Hypothesis in Explaining Fissure Formation in Rough Rice Kernels During the Drying Process

2021 ◽  
Vol 64 (6) ◽  
pp. 1763-1770
Author(s):  
Zephania Odek ◽  
Terry J. Siebenmorgen ◽  
Griffiths G. Atungulu
Keyword(s):  
Glass Transition ◽  
Air Temperature ◽  
State Diagram ◽  
List Type ◽  
Drying Process ◽  
X Ray ◽  
Air Temperatures ◽  
X Ray Imaging ◽  
Material State ◽  
Fissure Formation

HighlightsX-ray imaging allows visualization of the fissuring that occurs at various drying air conditions.Drying air conditions that create severe intra-kernel material state gradients during drying result in kernel fissuring.The glass transition hypothesis was validated for explaining the fissuring of rice kernels during drying.Abstract. Fissured rice kernels tend to break during milling, leading to milling yield reductions. A hypothesis involving changes in material state properties has been proposed to predict kernel fissuring during the drying process. The hypothesis, referred to as the glass transition hypothesis, has been used to explain kernel fissuring during the drying process and has been supported by various milling studies. However, this hypothesis has not been validated from a fundamental fissuring standpoint. In this study, experiments were performed using drying air temperatures of 45°C, 50°C, 55°C, 60°C, and 65°C with relative humidity values that produced equilibrium moisture contents (EMCs) of 6%, 8%, 10%, 12%, and 14%. These EMCs would position the kernel surface at select regions on a rice material state diagram during drying. At the end of active drying, the kernels were tempered for 2 h at the drying air temperature. Fissures were viewed and detected in these kernels using X-ray imaging. Drying air temperature and EMC combinations that caused sufficient portions of the kernel surface to transition to the glassy region while the core remained in the rubbery region caused severe intra-kernel material state gradients. Such intra-kernel material state gradients caused severe fissuring, thus supporting the glass transition hypothesis in explaining fissure formation. At drying air temperature and EMC combinations that did not cause severe intra-kernel material state gradients, severe fissuring was averted, thus further supporting the glass transition hypothesis. Keywords: Glass transition hypothesis, Material state, Rice quality, State diagram, Tempering, X-ray imaging.

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