Griffiths Atungulu | University of Arkansas Division of Agriculture (original) (raw)

Uploads

Papers by Griffiths Atungulu

Nihon Shokuhin Hozō Kagakkaishi, 2012

2015 ASABE International Meeting, 2015

Cereal chemistry, Jul 1, 2017

Cereal Chemistry

Background and ObjectivesRice aging is an intrinsic phenomenon that leads to physicochemical chan... more Background and ObjectivesRice aging is an intrinsic phenomenon that leads to physicochemical changes in rice kernels. The goal of this study is to determine the physicochemical properties of rice dried using a 915 MHz microwave and then aged. Two rice cultivars, a medium grain cultivar Titan and long grain hybrid cultivar XL753, with a harvest moisture content of 20% ± 1% (wet basis) were used for the study. The rice samples were treated with two different drying methods, natural air drying as control and microwave heating at 915 MHz frequency followed by tempering and natural air cooling at 25°C and 56% relative humidity (RH). Microwave‐dried samples were treated at specific energies ranging from 360 to 630 kJ/kg of initial wet grain mass (kJ/kg‐grain). Head rice samples were stored for 6 months at 4°C and 25°C representing nonaged and aged samples, respectively. Physicochemical properties of the samples were determined.FindingsAged microwave‐dried rice had significantly higher set...

Cereal Chemistry

Background and ObjectivesUncooked rice is not classified as produce under the Food Safety Moderni... more Background and ObjectivesUncooked rice is not classified as produce under the Food Safety Modernization Act (FSMA) of the United States Food and Drug Administration produce safety rule because it is considered a food grain that is typically processed before consumption. However, uncooked rice is eaten by members of the raw food movement, pregnant pica patients, refugees in war zones, and young women as a perceived beauty treatment.FindingsThe consumption of raw rice may pose serious health risks such as foodborne illness, gastrointestinal issues, exposure to lectin and heavy metals, dental problems, and poor nutrition in consumers, especially those with low immunity including children and pregnant women. This review identifies the various circumstances under which raw rice is eaten or may be eaten, the possible health risks associated with raw rice consumption, and interventions that can be made to prevent the consumption of raw rice.ConclusionsMany interventions are available to cu...

Optimization of process parameters in rough rice drying using industrial microwave., 2016

2021 ASABE Annual International Virtual Meeting, July 12-16, 2021, 2021

Applied Engineering in Agriculture, 2022

HighlightsThis study determined adsorption and desorption isotherms of long-grain hybrid rough ri... more HighlightsThis study determined adsorption and desorption isotherms of long-grain hybrid rough rice in chilled environments.Parameters of the sorption models were evaluated by fitting experimental data in a thin layer drying equation.The moisture diffusivity and activation energy values of rough rice subjected to chilled environments were determined.The finite element method was used to simulate the heat and mass transfer of long-grain hybrid rice at low temperatures. . While chilling aeration technology for grains has found use in other countries, application in the U.S. for rice has not yet been widely adapted by the industry. The aim of this study was to determine the moisture sorption behavior of rough rice in chilled environments. Such data is vital for automated grain conditioning monitoring and control of aeration systems at cool ambient conditions. Adsorption and desorption isotherms of hybrid long-grain rough rice (XL745) subjected to temperature environments which are typi...

Journal of the ASABE, 2021

HighlightsMore moisture can be removed in a single drying pass without severely fissuring kernels... more HighlightsMore moisture can be removed in a single drying pass without severely fissuring kernels when samples are tempered than when immediately cooled without tempering.Tempering rice kernels immediately after drying can reduce the percentage of fissured kernels by up to half of that when kernels are immediately cooled without tempering.. Improper rice drying results in kernel fissuring, leading to head rice yield reduction due to breakage during milling. The objective of this study was to determine the percentage points (pp) of moisture content (MC) reduction that can be achieved in a single drying pass without significantly fissuring kernels. Long-grain rough rice of cultivars CL XL745 and Diamond at initial MCs of 18%, 17%, 16%, 15%, and 14% were dried using air at 45°C/20% relative humidity (RH), 50°C/15% RH, 55°C/12% RH, 60°C/10% RH, and 65°C/8% RH to MCs of 17%, 16%, 15%, 14%, 13%, or 12% with and without post-drying tempering. All temperature/RH combinations resulted in a h...

Applied Engineering in Agriculture, 2020

HighlightsThis study experimentally simulated drying of rough rice subjected to various cold stor... more 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.. 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 qual...

Applied Engineering in Agriculture, 2018

2018 Detroit, Michigan July 29 - August 1, 2018, 2018

2018 Detroit, Michigan July 29 - August 1, 2018, 2018

Applied Engineering in Agriculture, 2018

. Drying of small size samples usually represents a challenge to rice researchers. Using natural ... more . Drying of small size samples usually represents a challenge to rice researchers. Using natural air drying to dry these samples exposes them to the fluctuations of ambient air conditions. Therefore, the goal of this research was to evaluate the suitability of drying small size rough rice samples using heated husk as a heat transfer and moisture adsorbent medium. The proposed drying technique could be an attainable process, particularly because it represents conduction heat and moisture transfer rather than natural air drying. The required amounts of rice husk were placed in aluminum containers and kept in an oven overnight to reach the desired temperature. Heated husk samples were mixed with rough rice and maintained for the desired drying duration; following which, the husk and rough rice mixtures were separated pneumatically. The separated rough rice samples were collected to determine moisture content, drying rate, and rice quality. The highest mixture temperature of 34.0°C was achieved at the highest husk to rough rice ratio of 1:2 and the highest husk temperature of 110°C after 4 minutes. A maximum of 6.4% moisture reduction points was achieved by mixing the rice husk to rough rice by 1:2 on a weight basis and employing heated rice husk at 100°C. The highest drying rate of 5.99%/h was achieved during the first hour of drying with the husk-to-rough rice ratio of 1:2 and the husk temperature of 100°C. Milled rice yield ranged between 63.4% and 72.0% while the head rice yield ranged between 39.9% and 67.9%. An empirical correlation was developed to calculate the normalized moisture content as a function of the husk to rough rice ratio, the husk temperature and drying duration with a coefficient of determination of 0.775 under the studied conditions. Keywords: Conduction drying, Heat transfer medium, Moisture absorbent, Rice husk, Rough rice.

2019 Boston, Massachusetts July 7- July 10, 2019, 2019

Nihon Shokuhin Hozō Kagakkaishi, 2012

2015 ASABE International Meeting, 2015

Cereal chemistry, Jul 1, 2017

Cereal Chemistry

Background and ObjectivesRice aging is an intrinsic phenomenon that leads to physicochemical chan... more Background and ObjectivesRice aging is an intrinsic phenomenon that leads to physicochemical changes in rice kernels. The goal of this study is to determine the physicochemical properties of rice dried using a 915 MHz microwave and then aged. Two rice cultivars, a medium grain cultivar Titan and long grain hybrid cultivar XL753, with a harvest moisture content of 20% ± 1% (wet basis) were used for the study. The rice samples were treated with two different drying methods, natural air drying as control and microwave heating at 915 MHz frequency followed by tempering and natural air cooling at 25°C and 56% relative humidity (RH). Microwave‐dried samples were treated at specific energies ranging from 360 to 630 kJ/kg of initial wet grain mass (kJ/kg‐grain). Head rice samples were stored for 6 months at 4°C and 25°C representing nonaged and aged samples, respectively. Physicochemical properties of the samples were determined.FindingsAged microwave‐dried rice had significantly higher set...

Cereal Chemistry

Background and ObjectivesUncooked rice is not classified as produce under the Food Safety Moderni... more Background and ObjectivesUncooked rice is not classified as produce under the Food Safety Modernization Act (FSMA) of the United States Food and Drug Administration produce safety rule because it is considered a food grain that is typically processed before consumption. However, uncooked rice is eaten by members of the raw food movement, pregnant pica patients, refugees in war zones, and young women as a perceived beauty treatment.FindingsThe consumption of raw rice may pose serious health risks such as foodborne illness, gastrointestinal issues, exposure to lectin and heavy metals, dental problems, and poor nutrition in consumers, especially those with low immunity including children and pregnant women. This review identifies the various circumstances under which raw rice is eaten or may be eaten, the possible health risks associated with raw rice consumption, and interventions that can be made to prevent the consumption of raw rice.ConclusionsMany interventions are available to cu...

Optimization of process parameters in rough rice drying using industrial microwave., 2016

2021 ASABE Annual International Virtual Meeting, July 12-16, 2021, 2021

Applied Engineering in Agriculture, 2022

HighlightsThis study determined adsorption and desorption isotherms of long-grain hybrid rough ri... more HighlightsThis study determined adsorption and desorption isotherms of long-grain hybrid rough rice in chilled environments.Parameters of the sorption models were evaluated by fitting experimental data in a thin layer drying equation.The moisture diffusivity and activation energy values of rough rice subjected to chilled environments were determined.The finite element method was used to simulate the heat and mass transfer of long-grain hybrid rice at low temperatures. . While chilling aeration technology for grains has found use in other countries, application in the U.S. for rice has not yet been widely adapted by the industry. The aim of this study was to determine the moisture sorption behavior of rough rice in chilled environments. Such data is vital for automated grain conditioning monitoring and control of aeration systems at cool ambient conditions. Adsorption and desorption isotherms of hybrid long-grain rough rice (XL745) subjected to temperature environments which are typi...

Journal of the ASABE, 2021

HighlightsMore moisture can be removed in a single drying pass without severely fissuring kernels... more HighlightsMore moisture can be removed in a single drying pass without severely fissuring kernels when samples are tempered than when immediately cooled without tempering.Tempering rice kernels immediately after drying can reduce the percentage of fissured kernels by up to half of that when kernels are immediately cooled without tempering.. Improper rice drying results in kernel fissuring, leading to head rice yield reduction due to breakage during milling. The objective of this study was to determine the percentage points (pp) of moisture content (MC) reduction that can be achieved in a single drying pass without significantly fissuring kernels. Long-grain rough rice of cultivars CL XL745 and Diamond at initial MCs of 18%, 17%, 16%, 15%, and 14% were dried using air at 45°C/20% relative humidity (RH), 50°C/15% RH, 55°C/12% RH, 60°C/10% RH, and 65°C/8% RH to MCs of 17%, 16%, 15%, 14%, 13%, or 12% with and without post-drying tempering. All temperature/RH combinations resulted in a h...

Applied Engineering in Agriculture, 2020

HighlightsThis study experimentally simulated drying of rough rice subjected to various cold stor... more 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.. 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 qual...

Applied Engineering in Agriculture, 2018

2018 Detroit, Michigan July 29 - August 1, 2018, 2018

2018 Detroit, Michigan July 29 - August 1, 2018, 2018

Applied Engineering in Agriculture, 2018

. Drying of small size samples usually represents a challenge to rice researchers. Using natural ... more . Drying of small size samples usually represents a challenge to rice researchers. Using natural air drying to dry these samples exposes them to the fluctuations of ambient air conditions. Therefore, the goal of this research was to evaluate the suitability of drying small size rough rice samples using heated husk as a heat transfer and moisture adsorbent medium. The proposed drying technique could be an attainable process, particularly because it represents conduction heat and moisture transfer rather than natural air drying. The required amounts of rice husk were placed in aluminum containers and kept in an oven overnight to reach the desired temperature. Heated husk samples were mixed with rough rice and maintained for the desired drying duration; following which, the husk and rough rice mixtures were separated pneumatically. The separated rough rice samples were collected to determine moisture content, drying rate, and rice quality. The highest mixture temperature of 34.0°C was achieved at the highest husk to rough rice ratio of 1:2 and the highest husk temperature of 110°C after 4 minutes. A maximum of 6.4% moisture reduction points was achieved by mixing the rice husk to rough rice by 1:2 on a weight basis and employing heated rice husk at 100°C. The highest drying rate of 5.99%/h was achieved during the first hour of drying with the husk-to-rough rice ratio of 1:2 and the husk temperature of 100°C. Milled rice yield ranged between 63.4% and 72.0% while the head rice yield ranged between 39.9% and 67.9%. An empirical correlation was developed to calculate the normalized moisture content as a function of the husk to rough rice ratio, the husk temperature and drying duration with a coefficient of determination of 0.775 under the studied conditions. Keywords: Conduction drying, Heat transfer medium, Moisture absorbent, Rice husk, Rough rice.

2019 Boston, Massachusetts July 7- July 10, 2019, 2019