MANAGEMENT OF IN-BIN GRAIN DRYING AND STORAGE SYSTEMS FOR IMPROVED GRAIN QUALITY AND PREVENTION OF MYCOTOXINS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1002599
• Project No.: ARK02443
• Project Start Date: Mar 1, 2014
• Project End Date: Sep 30, 2018

Project Director
Atungulu, GR.

Recipient Organization
UNIVERSITY OF ARKANSAS
(N/A)
FAYETTEVILLE,AR 72703

Performing Department
Food Science

Non Technical Summary
Effective management of grain in the entire value chain, especially during post-harvest processing, is critical to mitigate current food safety/security concerns, particularly those related to mycotoxin contamination of grain and co-products. Mycotoxins, especially aflatoxin, are known carcinogens that pose a severe health hazard to human and animal consumers of grains and co-products.Freshly-harvested, high-moisture content grain must be dried to minimize (or prevent) excessive respiration and mold growth on grains. At present, most on-farm systems which use either natural air or slightly-heated air to dry grain are becoming very popular. With these systems, the grain could be dried more slowly which generally results in improved quality and also the drying practice reduces pressure on commercial driers. Although drying practice with on-farm systems can lead to very positive results, they are weather dependent and unfortunately could lead to over drying of grain, fissured kernels that reduce milling yields, result in loss of functional performance, nutritional and sensorial quality of the grain and even development of harmful molds in areas of the bin that incur delays prior to drying. In particular, the development of mycotoxin-producing mold leading to mycotoxin contamination of stored grain in the on-farm systems has become a great concern to the grain industry.Recently-introduced technology for use in on-farm drying systems offers a means to utilize the advantages of low-temperature, in-bin drying systems, yet prevent the disadvantages that are sometimes incurred. The new technology is governed by the principle of Equilibrium Moisture Content (EMC), which is the moisture content that a specific grain will attain if exposed to air with a given relative humidity and temperature for a long enough duration. Grain dried by continuous fan operation would be exposed to multiple drying/rewetting processes due to changing hourly/daily weather, resulting in inefficient and non-uniform drying. Natural air/low temperature (NA/LT) drying with fan operation in a given EMC window restricts the delivery of air that is too wet and/or too dry. The new NA/LT in-bin technology comprises cables to monitor not only air ambient conditions, but also grain moisture content and temperature throughout the entire grain bin mass and the data can also be accessed anytime via the internet. The systems have advanced fan and heater controls or self-adapting variable heat (SAVH) capability, which automatically adjusts the upper and lower EMC windows throughout the drying process, minimizing fan run-time hours and over drying costs, as well as moisture content non-uniformity.These new in-bin systems are becoming very popular and have great potential for wider adoption by many farmers. However, the duration required to achieve drying with the new systems is greatly affected by prevailing weather conditions (temperature and relative humidity). The real problem is that the weather may not allow drying of the grain, particularly the upper layers, in a timely manner. When this happens, there is a great possibility for mold growth in the grain mass, with potential mycotoxin development, and grain quality related problems such as loss of grades, functional performance, nutritional and sensory value may ensue as well. For instance, across the U.S. Mid-South, prevailing weather conditions will dictate the upper moisture content limit of grains that can be stored in these new in-bin drying/storage systems without significant "quality" deterioration and mold growth leading to mycotoxin development. The term "quality" could mean desirable characteristics for effective further processing and/or end-use. It is vital to know, for instance in the case of rice, how rapid grain "quality" attributes, such as grain yellowing, hardness, dry matter loss/respiration, milling, nutritional, functional (e.g. paste viscosity, stickiness, cohesiveness etc.) and sensory related characteristics change under prolonged high-MC conditions; and for the case of soybean destined for seed, how germination rate is impacted under different drying and storage conditions.The primary and practical questions the research will seek to answer for successful implementation of the new in-bin systems in Arkansas and the Mid-South are as follows: (1) what is the rate of grain "quality" reduction and mycotoxin development under various drying/storage scenarios; (2) with respect to stored product "quality", what is the upper moisture content limit for grain (rice, corn, sorghum, and soybean) placed into these systems at various locations; (3) what energy savings could be realized with these new in-bin drying/storage systems?

Animal Health Component

0%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
712	1599	2020	100%

Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
1599 - Grain crops, general/other;

Field Of Science
2020 - Engineering;

Keywords

mycotoxins

low temperature drying

natural air drying

grain drying and storage

grain quality

infrared heating

mycotoxin detection

Goals / Objectives
Determine the conditions under which natural air/low temperature (NA/LT) in-bin drying/storage results in reduced grain quality and production of harmful mold/mycotoxins.Establish mathematical (or simulation) models to predict the degradation rates of grain nutritional, functional and sensorial quality and mycotoxin development during NA/LT in-bin drying/storage.Evaluate the energy requirements for NA/LT in-bin grain drying/storage systems at different locations.Develop novel drying techniques which augment NA/LT in-bin grain drying/storage to achieve effective drying and decontamination of harmful fungi and mycotoxins.Develop rapid and nondestructive methods for detection of mycotoxin-producing grain fungi and their associated mycotoxins.

Project Methods
Laboratory studies will be set up to simulate conditions of temperature, relative humidity and air flow that are generally encountered in NA/LT in-bin drying/storage practices. Popularly grown grain cultivars of rice, corn, sorghum and soybean with varied moisture contents will be stored in the controlled temperature, relative humidity and airflow environment and the conditions under which drying/storage results in reduced grain quality and production of harmful mold/mycotoxins will be determined. The degradation rates of grain quality in terms of grades, nutrition, functional, and sensory values will be determined. The rates of mold development under typically encountered storage conditions will be determined and conditions which trigger mycotoxin development delineated.Accurate grain EMC information is crucial for accurate control of the newly-developed in-bin drying technology. New EMC determination techniques will be utilized to accurately determine EMCs for specific grains grown in Arkansas, including rice, corn, soybean, and grain sorghum. Also, in order to develop better prevention strategies for mycotoxin development in the bins, a database on microbial loads on these grains at harvest will be established. The information will be crucial to accurately quantify rates of grain dry matter loss due to respiration during drying and storage. A wide spectrum of intrinsic and extrogeneous factors that could impact grain EMC and microbial load, such as grain varieties, growing locations, and growth conditions at harvest, among other agronomical cultural practices will be considered in these studies. Some past studies have used a mathematical modeling tool called The Post-Harvest Aeration and Storage Simulation Tool - Finite Difference Method (PHAST - FDM) to predict in-bin drying and conditioning of grains. As a preliminary study, we modified the PHAST-FDM to simulate EMC-controlled and uncontrolled natural air drying of rice at four representative rice growing locations in Arkansas. Although the EMC-controlled drying strategy was found to be the best in terms of drying and fan operation costs, the findings from these simulations are yet to be validated experimentally. Such validations, which are crucial to improve predictions with the PHAST-FDM tool, will be performed in this study. More important and conspicuously missing in the preliminary modeling work and other similar studies on the use of the new NA/LT technology is consideration of grain "quality" aspects relevant to further processing and/or end-use application, as well as mycotoxin development. The study will determine "quality" and mold kinetics as functions of moisture and temperature and integrate the results in the PHAST-FDM. The information is vital to establish the critical moisture content and temperature limits that would help ensure desired grain "quality" and prevent mold development while using these new in-bin drying/storage systems. Such information will be useful for limiting the intake grain moisture content and/or operating the fan accordingly, especially for representative location and harvest date combinations in the U.S. Mid-South.This research will be conducted in collaboration with OPI-integris and IntelliAir, the leading manufacturers of cabling systems used in monitoring grain temperature, relative humidity and moisture content during in-bin drying/storage. These companies, as well as other stakeholders and equipment manufacturers, have expressed strong interest to partner in this research, and to support realization of the project objectives for multiple grains. In this study, simulation will be conducted using various fan control strategies to generate comparative results of the regimes of moisture content and fan run-times for various grains managed at different locations within Arkansas. Field studies will be done to validate models developed using laboratory studies to evaluate the implication of these new systems on the rates of grain "quality" reduction and mycotoxin development. The research partnership with the OPI-integris and IntelliAir is expected to lead to successful implementation of the recently introduced technology for in-bin grain drying/storage, especially in Arkansas and the Mid-South. The research team is also in consultation with farmers who have expressed great interest and have offered their bins equipped with the OPI-integris and/or IntelliAir cabling systems for sampling to validate simulation and laboratory research. A continuous IR drying system equipped with catalytic infrared (CIR) emitters for drying and decontamination of grain will be built for pre-drying grain. The system will be tested for drying and decontamination of microorganisms on grain, especially the mycotoxin-producing fungi. The effectiveness of using these systems for grain pre-drying followed by natural air or slightly heated in-bin drying/storage to reduce degradation in grain quality, functional, and sensory characteristics, and growth of harmful molds will be investigated. At the same time, the feasibility of the system to achieve improved performance when IR heating is combined with pulsed UV treatment will be evaluated; Mathematical models will be developed to describe drying characteristics, kinetics of grain "quality" change, and microbial inactivation with the above treatments for different grains.Multispectral imaging and spectroscopic techniques as well as analysis of volatile metabolites in headspace gases for detection and quantification of mycotoxin-producing fungi and associated mycotoxins will be investigated.The feasibility of using these techniques as alternative, rapid, real time and accurate methods for detection and quantification of mycotoxin-producing fungi in grain and co-products will be determined.

Progress 03/01/14 to 09/30/18

Outputs
Target Audience: Grain Growers Grain Processors Scientist/Engineers Extension Agents Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Invited talks: 1. Atungulu GG*. 2018. On-farm Drying and Storage of Grains. AgHeritage meeting, June 21, 201, Rice Research and Extension Center, Stuttgart AR. 2. Wilson S, Atungulu GG*. 2018. Kinetics of aflotoxigenic mold growth on rice. Poster Presentation, 22 - 23 May, 2018, 25th Industry Alliance Meeting Rice Processing Program, University of Arkansas System Division of Agriculture, AR. 3. Invited talk to Ghent University in Belgium and TU Graz in Austria Interdisciplinary/international collaborations: Prof Frank Devlieghere, Ghent University Belgium collaboration: Hosted visiting MS student from Ghent University Belgium in an interdisciplinary interdepartmental research collaboration Prof Hongrui Jiang, Guangxi University China collaboration: Hosted visiting graduate student, Zonghui Zhou (of the Institute of Light Industry and Food Engineering Guangxi University China). University of Arkansas Co-operate Extension: With extension Engineer, Dr. Sammy Sadaka to generate extension factsheets Arkansas State University: With Entomologist, Dr. Tanja McKay Member of the Rice Processing Program at the University of Arkansas Other faculty at the University of Arkansas: Drs. Frank Carbonero, Steve Ricke of the Food Science department and Jin-Woo Kin of Biological and Agricultural Engineering department, and Burt Bluhm of Plant Pathology in research causes that mutually benefit our programs; especially to access biosafety Level 2 requirements. Arkansas Association of Food Protection: Symposium organization to interface with industry, identify relevant research problems, and disseminate research finding. Equipment manufacturers, growers and grain processing allied companies: with AP Innovations Inc., Florenden Farms, FrigorTech Inc., and Valley View Inc .Grain School instruction and consultancy, Intellifarms University, Archie, MO (May 31, 2018) How have the results been disseminated to communities of interest?Grain School instruction and consultancy, Intellifarms University, Archie, MO (May 31, 2018): attended by 20 (growers, producers & new company employees and students); Instruction given on topics in grain storage management - 5 modules Invited talks given at international/local meetings and conferences (e.g. American Society of Agricultural and Biological Engineers meeting) Publications in peer reviewed journals What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Determined and documented in publications impacts of storage temperature and rice moisture content in conditions simulating in-bin drying scenarios: Shafiekhani S, Atungulu GG*. 2018. Impacts of storage temperature and rice moisture content on color characteristics of rice from fields with different disease management practices. Journal of Stored Product Research. 78 (1), 89-97. https://doi.org/10.1016/j.jspr.2018.07.001. Mohammadi Shad Z, Atungulu GG. 2018. Links Among Mold Growth And Rice Kernel Discoloration During Storage Of Long-Grain Hybrid, Long-Grain Pureline, and Medium-Grain Rice Cultivars. 2018 ASABE Annual International Meeting July 29 - August 1, 2018. Cobo Center Detroit, Michigan. An ASABE Meeting Presentation. Paper Number: 1800584.

Publications

• Type: Book Chapters Status: Published Year Published: 2018 Citation: i. Atungulu GG*, Kolb RE, Karcher J, Mohammadi-Shad Z. Postharvest Technology- Rice Storage and cooling conservation. Rice Chemistry and Technology, 4th Edition, (ed. Jinson Bao). Elsevier Publication, 525 B Street, San Diego CA 92101. Published by Elsevier Inc. in cooperation with AACC International. (pg. 517-555). https://doi.org/10.1016/B978-0-12-811508-4.00016-2.
• Type: Book Chapters Status: Published Year Published: 2018 Citation: ii. Atungulu GG*, and Sadaka S. Postharvest Technology- Rice Drying. Rice Chemistry and Technology, 4th Edition, (ed. Jinson Bao). Elsevier Publication, 525 B Street, San Diego CA 92101. Published by Elsevier Inc. in cooperation with AACC International. (Pg. 473-515). https://doi.org/10.1016/B978-0-12-811508-4.00015-0.
• Type: Book Chapters Status: Published Year Published: 2018 Citation: iii. Atungulu GG*, Olatunde G, Sadaka S. Rice Aeration: Fundamental and principles. In: Advances in Science and Engineering of Rice. (Eds. Zhongli Pan & Gabreil Ragab Khir). Destech Publications, 439 North Duke St., Lancaster, Pennsylvania 17602. (pg. 143-168).
• Type: Book Chapters Status: Published Year Published: 2018 Citation: iv. Atungulu GG*, Olatunde G, Sadaka S. Rice Safety. In: Advances in Science and Engineering of Rice. (Eds. Zhongli Pan & Gabreil Ragab Khir). Destech Publications, 439 North Duke St., Lancaster, Pennsylvania 17602. (pg. 169-190).
• Type: Book Chapters Status: Awaiting Publication Year Published: 2018 Citation: v. Atungulu GG*, Mohammadi Shad Z. Reference on Mycotoxins Occurrence, prevalence and Risk Assessment in Food Systems. In Handbook of Research on Technologies and Systems for Food Preservation. (Eds. Pedro Dinis Gaspar and Pedro Dinho da Silva.) IGI Global Book Publishers (In Press): https://www.igi-global.com/publish/call-for-papers/call-details/3192.
• Type: Book Chapters Status: Awaiting Publication Year Published: 2018 Citation: vi. Atungulu GG*, Shafiekhani S. Reference on Rice Quality and Safety. In Handbook of Research on Technologies and Systems for Food Preservation. (Eds. Pedro Dinis Gaspar and Pedro Dinho da Silva). IGI Global Book Publishers (In Press): https://www.igi-global.com/publish/call-for-papers/call-details/3192.
• Type: Book Chapters Status: Awaiting Publication Year Published: 2018 Citation: vii. Atungulu GG*, Shafiekhani S. Rice Drying Systems. In. Storage of Grains and Their Products 5th Edition (Eds. Rosentrater, Kurt A). Elsevier Publishers (In Press).

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Ag & Grain Process Engineers, Research Scientist, Graduate Student Engineers, Grain Growers, handlers & Processors, academicians Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Organized the first DEMO of rice Cooling in Arkansas (May 2017) followed by the first TRIAL of the technology for Rice in Arkansas (August - November 2017). Teamed with equipment manufacturers (FrigorTech Inc.), rice growers (Florenden Farms), bin systems Operations/Control managers (AP Innovations) and bin Constructions & ducting consultants (Valley View) to achieve the goal. The effort was a fruitful outreach to growers; we gathered insights into the practicality of the technology for rice drying and storage. Institute of Food Technologist (IFT) interview: The interview featured my research on IFT website and the IFT magazine [Inside Academia - section, pg. 22 August 2017 Issue]. How have the results been disseminated to communities of interest?Invited presentations such as a plenary or keynote address, seminars, or other; indicate if presentation was refereed/reviewed). NC-213: Marketing and Delivery of Quality Grains and BioProcess Coproducts (Multi-state Research Project): † Griffiths G. Atungulu*. 2017. On-farm, In-Bin Drying and Storage of Rough Rice. February 28th, 2017, Kansas City, MO Griffiths G. Atungulu*. 2017. One-pass Rice Drying with 915 MHz Industrial Microwave System. February 28th, 2017, Kansas City, MO International Conference on Food Security & Sustainability: †, ?, ? Griffiths G. Atungulu*. 2017. Rice Microbial Response to Drying by 915 MHz Industrial Microwave. 2nd International Conference on Food Security and Sustainability, San Diego CA, June 26-27, 2017. Griffiths G. Atungulu*. 2017. Rice Conditioning and Processing to Achieve Safe Storage and Shipping Conditions. 2nd International Conference on Food Security and Sustainability, San Diego CA, June 26-27, 2017. Arkansas Rice Expo: †† Griffiths G. Atungulu*. 2017. On-Farm, In-Bin Rice Quality Observations and Research. 2017 Arkansas Rice Expo. August 4th, 2017, Grand Prairie Center, Stuttgart, http://www.uaex.edu/rice-expo/. Gbenga Olatunde, Griffiths G. Atungulu*, Deandrae Smith. 2017. Potential of Using 915 MHz Industrial-Scale Microwave to Parboil Rice. 2017 Arkansas Rice Expo. August 4th, 2017, Grand Prairie Center, Stuttgart, http://www.uaex.edu/rice-expo/. Industry Alliance Meeting, Rice Processing Program: †† Griffiths G. Atungulu*. 2017. Impact of Storage Environment on Quality and Safety Metrics of Rice. Annual Industry Alliance Meeting, Rice Processing Program, University of Arkansas Division of Agriculture, Fayetteville Arkansas, May 23-24, 2016. Arkansas Association for Food Protection: ††,? Griffiths. G. Atungulu*. 2017. Chair and organizer: Pet Food and Animal Feed Safety Mini-symposium. Arkansas Association for Food Protection, Annual Educational Conference, September 19-21, 2017. Holiday Inn Hotel Springdale, Ark. Wendy Ortman, Griffiths G. Atungulu*. Workshop with Equipment Demo: Moisture in Foods vs. Accelerated Shelf Life Determination with the VSA (at the Pet Food and Animal Feed Safety Mini-symposium). Arkansas Association for Food Protection, Annual Educational Conference, September 19-21, 2017. Holiday Inn Convention Center, Springdale, Ark. Shantae Wilson, Griffiths G. Atungulu*. Selective Infrared Heating Techniques to Inactivate Mycotoxigenic Fungi on Food and Feed Ingredients. Pet Food and Animal Feed Safety Mini-symposium. Arkansas Association for Food Protection, Annual Educational Conference, September 19-21, 2017. Holiday Inn Convention Center, Springdale, Ark. Zeinab Mohammadi-Shad, Griffiths G. Atungulu*. Evaluation of Feed for Occurrence of Aflatoxin and Safety. Pet Food and Animal Feed Safety Mini-symposium. Arkansas Association for Food Protection, Annual Educational Conference, September 19-21, 2017. Holiday Inn Convention Center, Springdale, Ark. Riceland, Arkansas†† Atungulu* G. G. 2017 and Gbenga Olatunde, Stephen Rogers. One-pass microwave drying of rough rice. May, 23rd 2017. Presented at a meeting with Riceland, University of Arkansas Alumni Center in Fayetteville Ark. American Society of Agricultural & Biological Engineers (ASABE) - Kansas Section†† Atungulu* G.G. 2017. Research Program Update & Status of The Arkansas Section of American Society of Biological & Agricultural Engineers. March, 31st 2017, Manhattan Kansas Submitted several oral or poster presentations. What do you plan to do during the next reporting period to accomplish the goals?Investigation in the following areas: Chilling Aeration of Rough Rice to Secure Quality and Safety during On-farm, In-bin Drying and Storage

Impacts
What was accomplished under these goals? On-farm, in-bin drying and storage of grains using natural air, if not properly managed, is a process that is prone to grain mold contamination and associated mycotoxin contamination problems (e.g., aflatoxin), posing significant public health risks, and reducing overall grain quality. In collaboration with Arkansas grain producers and processors, our research continues to produce science-based knowledge to inform improved regional and national food security, chiefly in the rice, soybean, corn, and grain-sorghum industries, on issues of determining best drying and storage practices that maintain quality and mitigate contamination with toxigenic fungi and their associated mycotoxins, many of which are carcinogenic to humans.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: Atungulu G. G. & Olatunde G. A., Sammy Sadaka. 2017. Impact of Rewetting and Drying of Rough Rice on Prediction of Moisture Content Profiles during On-Farm In-Bin Drying and Storage. Drying Technology. Published online: http://dx.doi.org/10.1080/07373937.2017.1345933. Olatunde G. A & Atungulu G. G. 2017. Potential of Turbulence Interference in Rough Rice bin Drying and Storage System Fitted with Cabling Technology. Biosystems Engineering 163(2017), 1-14. http://dx.doi.org/10.1016/j.biosystemseng.2017.08.010. Atungulu*, G. G., and G. A. Olatunde. 2017. Assessment of New In-Bin Drying and Storage Technology for Soybean Seed. Drying Technology. Published online: http://dx.doi.org/10.1080/07373937.2017.1335751. Atungulu G., Thote S., and Wilson S. 2017. Dry Matter Loss for Hybrid Rough Rice Stored under Reduced Oxygen Conditions. Cereal Chemistry. 94 (3): 497-501.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:This project provides information pertinent to in-bin grain management. The target audience included grain producers, grain processors, research and development community including students, engineers and scientist in the grain process engineering field particularly dealing with rice, corn, and soybeans. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Supporting industry partners to determine equilibrium moisture content of their products. Milling rice samples for industry partners to determine levels of rice discoloration relative to storage environment Simulation models develop are helping us advice producers on best operating conditions for on-farm drying for local weather conditions Evaluating grain mycotoxin contamination and dockage levels during in-bin drying and storage How have the results been disseminated to communities of interest? Throughscientific publications and presentations in conferences. Presentation at Rice Expo in Arkansas What do you plan to do during the next reporting period to accomplish the goals?Rice related: Determine fungal microbiome profiles on rice and establish relationships to rice cultivar, rice growing location, pre-harvest fungicide treatments, and levels of aflatoxin contamination. Determine the growth kinetics of aflatoxin-producing fungi that commonly contaminate rice and associated aflatoxin formation on long-grain hybrid, long-grain pureline and medium grain rice for storage conditions encountered in on-farm, in-bin drying and storage systems. Identify fungi associated with variegated patterns and degrees of rice stain/discoloration as observed at storage conditions encountered in on-farm, in-bin drying systems. Corn related: Determine air recirculation rate in the infrared heating zone that provide the most effective corn drying rate and inactivation of aflatoxin-producing fungi. Determine infrared intensity and feeding rate that provide the most effective drying rate and inactivation of aflatoxin-producing fungi on corn for conveyor belts of different configurations. Assess that the effective treatment protocol discourages re-growth/germination of aflatoxin-producing fungal spores on stored grain post-treatment. Soybean related: Conduct experiments to determine soybean seed rehydration curves at conditions of natural air temperature and relative humidity encountered in Arkansas Determine mathematical models describing the relationships among rehydration duration/rate, microbial growth during rehydration, and seed germination potential Incorporate the developed models in mathematical simulations of natural air, in-bin rehydration to determine recommendable durations to condition sun dried soybean seeds to target market moisture content for Arkansas weather conditions, locations, and harvest-start date combinations while maintaining seed germination.

Impacts
What was accomplished under these goals? Rice Related: In the first year (2014) of this research, effort was made to determine the population and prevalence of microorganisms on freshly-harvested rice cultivars grown in different ecosystems within Arkansas. Medium-grain (Jupiter and Caffey), long-grain pureline (RoyJ and CL152), and long-grain hybrid (XL753 and XL723) rice cultivars were grown at four Arkansas locations (Stuttgart, Colt, Keiser and Rohwer) and a survey conducted, for the 2013 and 2014 rice crops, to determine microbial population and prevalence at harvest. The information obtained in 2014 provided baseline data regarding the initial population of molds on rice introduced into bins for drying and storage. In the same year, data describing the history of temperature and moisture content during on-farm drying and storage of rice at different locations within Arkansas was accessed using a grain management system by OPI Inc. The information was used to design lab-based experiments which were conducted using the 2014 rice crop and repeated in 2015, to determine kinetics of mold growth and aflatoxin development for hybrid rice. As milestones, we established the general kinetics of mold growth on two long-grain hybrid rice, XL753 and XL745 [i.e. for 2014 rice crop stored at moisture contents (MCs) ranging from 12.5% to 21.0% (wet basis) and temperatures ranging from 10°C to 40°C for a period of sixteen weeks] and repeated the experiments using the 2015 rice crop [i.e. two long-grain hybrid rice (XP760 and XL745)]. In addition to the above milestones, we also developed and validated mathematical models to simulate in-bin drying of rough rice with different drying strategies [i.e. considered rough rice initial MC, drying-start date, air flowrate, and fan control strategy (equilibrium MC controlled and uncontrolled drying modes of fan operation)]; consequently, established durations required to completely dry freshly-harvested rough rice to 13% MC for weather conditions in Arkansas rice growing locations. The results will be coupled with on-going studies on the kinetics of mold growth, specifically for rice inoculated with the aflatoxin-producing mold, A. flavus, to provide guidelines for suitable low temperature, natural-air drying strategies in Arkansas. It is expected that research results will promote the delivery of high-quality and mycotoxin-free rice thereby enabling farmers to receive high premiums from grain sales and also ensure safety of consumer health. Corn Related: Preventing proliferation of fungi on grain is the most desirable and effective known method for controlling contamination of the grain with mycotoxins. In the past 3 years, courtesy of CGS Board funding, fundamental and applied research have been undertaken to demonstrate the feasibility of infrared heating to improve drying rate of corn while simultaneously decontaminating aflatoxin-producing fungi that inhabit the grain. The study refined infrared processing parameters including heating intensity, heating duration and product-to-emitter (infrared energy source) gap size versus corn initial moisture content to diminish deterioration of the dried corn color and formation of stress-cracks post-treatment. Moreover, with support from start-up funds, courtesy of the University of Arkansas Division of Agriculture, a scaled up infrared heating unit with modular processing parameters was designed and built for scaled up grain drying and decontamination trials. Tests performed using the developed unit demonstrated potential of the new technology to significantly increase drying rates with the benefit of simultaneous inactivation of microorganisms inhabiting corn. Addition of tempering steps (holding grain post treatment at elevated temperatures of approximately 70°C for up to 4 h) significantly improved the process efficiency. At this point, it is envisioned however, that for better performance at field level, the technology's operating parameters need to be investigated further and optimized. The key parameters include air recirculation rate in the heating zone, conveyor belt configuration (solid or perforated), grain-bed thickness versus infrared intensity, and incoming grain moisture content versus feeding rate. These factors should be evaluated against drying rates, microbial inactivation, and aflatoxin contamination of stored corn post-treatment. In the absence of such knowledge, it may be a challenge to scale up the technology for field operations and treated products may remain susceptible to aflatoxin contamination. The goal of research, in the next phase, is to optimize a scaled-up infrared heating process to maximize drying rate and inactivation of mycotoxin producing fungi, especially those responsible for aflatoxin - a known carcinogen that pose health hazards to human and animal consumers of corn and co-products. Soybean Related: The goal of this research is to improve soybean seed quality, specifically the germination rate, in the recently-introduced natural air, in-bin drying/storage systems. The following are milestones attained to date: (1) Established constants to be used in models to predict equilibrium moisture content isotherms of soybean seeds grown in Arkansas. Emphasis was placed on verifying whether there exist disparities in the isotherms based on soybean growing locality and cultivar type. Results have revealed that growing locations do not have a significant effect on the isotherms characteristics, for the same soybean cultivars, but cultivar types do. Specially bred soybean cultivars such as the High-oil, High-sugar, and High-protein types displayed differences in isotherm characteristics. Accurate model-constants for predicting equilibrium moisture contents of soybeans are crucial to effective control of seed drying/storage systems that utilize the new technology with in-bin built cables and sensors. (2) Developed mathematical models and simulated in-bin drying/storage of soybean seed in several Arkansas conditions and locations: Stuttgart, Jonesboro, West Memphis, Monticello and the River Valley/Fort smith areas. Data generated report soybean seed drying durations, expected fan run times, and estimated drying costs per bushel for typically encountered drying air flowrates, drying-start dates, and soybean harvest moisture contents. The information will benefits soybean seed producers to determine the feasibility of using the new technology; is key in delineating critical drying/storage regimes that maintain seed germination. Overall, results and statistical analyses have showed that drying duration, final seed moisture content, percent over-drying, and drying cost were significantly affected by airflow rate and the fan operation strategy employed: continuous natural air; Equilibrium Moisture Content controlled natural air; air Equilibrium Moisture Content controlled but with supplemental heating option; natural air day only; and natural air night only fan operation strategies. A manuscript describing in details the simulations and results is currently in preparation with validations data to accompany the developed models. (3) Lab-based studies using three representative soybean seed types that were grown in Arkansas is on-going to determine the kinetics of the seed germination rate versus storage/drying duration and soybean initial moisture content. Part of this lab tests were conducted previously. However, a repeat of these studies is being carried out to verify the results obtained and also extend the data acquisition to cover wider range of storage temperature and moisture content conditions.

Publications

• Type: Journal Articles Status: Published Year Published: 2016 Citation: Atungulu G., and Hou Min Zhong. 2016. Assessment of strategies for natural air in-bin drying of rough rice in Arkansas locations. American Society of Biological and agricultural Engineers, Applied Engineering Journal, Vol. 32(4): 469-481. DOI 10.13031/aea.32.11361.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: G. G. Atungulu, H. Zhong, G. S. Osborn, A. Mauromoustakos, C. B. Singh. 2016. Simulation and Validation of On-Farm In-Bin Drying and Storage of Rough Rice. American Society of Biological and agricultural Engineers, Applied Engineering Journal, Vol. 32(6)
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Atungulu G., Thote S., Wilson S. 2016. Storage of Hybrid Rough Rice  Consideration of Microbial Growth Kinetics and Prediction Models. Journal of Stored Product Research, 69(2016), 235-244. http://dx.doi.org/10.1016/j.jspr.2016.09.003.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Olatunde G., Atungulu G., Sadaka S. 2016. CFD modeling of air flow distribution in rice bin storage system with different grain mass configurations. Biosystems Engineering 151(2016), 286-297. http://dx.doi.org/10.1016/j.biosystemseng.2016.09.007.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Thote S., and Atungulu G. 2016. Dry Matter Loss for Hybrid Rough Rice Stored under Reduced Oxygen Conditions. Cereal Chemistry. (in press).
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Wilson S.A., Atungulu, G.G., Olatunde Gbenga. 2016. Radiant heat treatments for corn drying and decontamination. Journal of Food Processing. (DOI:10.1002/jfpp.13193).
• Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Okeyo A., Olatunde G., Atungulu G., Sadaka S., McKay T. 2016. Infrared Drying Characteristics of Long-grain Hybrid, Long-grain Pureline, and Medium-grain Rice Cultivars. Cereal Chemistry. Posted online on 17 Aug 2016, First Look. http://dx.doi.org/10.1094/CCHEM-07-16-0181-R.
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Atungulu G.G., Smith D., Wilson S., Sadaka S., Rogers S. (2016). Assessment of one-pass drying of rough rice with an industrial microwave system on milling quality. American Society of Biological and agricultural Engineers, Applied Engineering Journal, Vol. 32(3): 417-429. DOI 10.13031/aea.32.11484.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:This project provides information pertinent to in-bin grain management. The target audience included grain producers, grain processors, research and development community including students, engineers and scientist in the grain process engineering field particularly dealing with rice, corn, and soybeans. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Telephoe call from some rice producers asking for help to monitor rice quality during in-bin drying and storage. They are especially concerned about possible yellowing or staining of rice and mycotoxin development. Some producers send us samples to measure the content of these quality indicators. We are also realizing that there are a few other things the farmers need to work on to improve their grain management situation. We are determining dockage levels in the grain and advising on the need to clean rice better before loading into the rice bins. We hold Industry Alliance Meeting where many stakeholder come togather to exchange ideas. How have the results been disseminated to communities of interest?Publications in peer reviewed journals such as the ones below: Sammy Sadaka, Scott Osborn, Griffiths Atungulu and Gagandeep Ubhi. 2015. On-Farm Grain Sorghum Drying and Storage. Arkansas Grain Sorghum Production Handbook, Chapter 10, pg1-12 Griffiths G. Atungulu, HouMin Zhong, Anne Okeyo, Supriya Thote. Prevalence of Molds on Freshly-harvested Long-grain Pureline, Hybrid and Medium-grain Rice Cultivars. American Society of Biological and agricultural Engineers, Applied Engineering Journal, 31(6), DOI 10.13031/aea.31.11216. Lawrence, J., Atungulu, G.G., Siebenmorgen, T.J. 2015. Modeling In-Bin Rice Drying using Natural-Air and Controlled-Air Drying Strategies. Transaction of American Society of Biological and Agricultural Engineering, 58(4), 1103-1111. DOI 10.13031/trans.58.10911. Wilson S. A., Atungulu, G.G., Couch, A., Sadaka, S. Radiant heating and tempering treatments for improving rate of moisture removal during drying of shelled corn. American Society of Biological and agricultural Engineers, Applied Engineering Journal, 31(5), 799-808. DOI 10.13031/aea.31.11243. Industry Alliace Meeting Held at the University of Arkansas in May 20-21, 2015 Casual Telephone and email communications What do you plan to do during the next reporting period to accomplish the goals?Rice: Research in year 3 has the following primary objectives: Conduct lab-based studies to determine the conditions under which natural air/low temperature (NA/LT) drying/storage result in production of harmful mold, specifically A. flavus and aflatoxins thereby reducing rice quality. Establish models to predict the rates of the mold and mycotoxin development during NA/LT in-bin drying/storage. Corn: The objectives in the third year of research will therefore focus on optimizing conditions for corn drying and microbial inactivation. Also, further testing of the recently-built continuous flow IR drying equipment will be conducted. More attention will be directed to increasing feeding rates to improve system throughput and assessing the effects thereof. The specific objectives are the following:- Determine the IR heating duration required to achieve complete inactivation of the aflatoxin-producing mold spores, A. flavus, on corn kernels. Determine suitable combination of IR heating time and intensity, and tempering time and temperature to maximize inactivation of aflatoxin-producing mold spores, A. flavus, on corn kernels. Conduct experiments using a newly built, pilot-scale, continuous flow IR drying equipment, to assess effects of varying feeding rates on drying of corn while achieving inactivation of harmful molds. Soybean: The project has the following primary objectives in year 3: Conduct lab-based studies to determine how drying/storage of currently-produced soybean of different varieties at given moisture content and air temperature impacts rates of germination. Consideration will be given to additional moisture content ranges and soybean cultivars. Perform natural air, in-bin drying simulations for soybean seed for various Arkansas locations to determine the implications of the recently-introduced in-bin drying/storage systems, on rates of seed germination. These simulation will be validated with future field-based studies. Conducts additional studies to determine isotherms of soybeans grown in Arkansas.

Impacts
What was accomplished under these goals? Rice Research: In the first year (2014) of this research, effort was made to determine the population and prevalence of microorganisms on freshly-harvested rice cultivars grown in different ecosystems within Arkansas. Medium-grain (Jupiter and Caffey), long-grain pureline (RoyJ and CL152), and long-grain hybrid (XL753 and XL723) rice cultivars were grown at four Arkansas locations (Stuttgart, Colt, Keiser and Rohwer) and a survey conducted, for the 2013 and 2014 rice crops, to determine microbial population and prevalence at harvest. The information obtained in 2014 provided baseline data regarding the initial population of molds on rice introduced into bins for drying and storage. In the same year, data describing the history of temperature and moisture content during on-farm drying and storage of rice at different locations within Arkansas was accessed using a grain management system by OPI Inc. The information was used to design lab-based experiments which were conducted using the 2014 rice crop and repeated in 2015, to determine kinetics of mold growth and aflatoxin development during in-bin drying and storage of hybrid rice. Investigations of the role of mold growth on rice discoloration was also incorporated in the experiment design. As milestones, we have established the general kinetics of mold growth on two long-grain hybrid rice, XL753 and XL745 [i.e. for 2014 rice crop stored at moisture contents ranging from 12.5% to 21.0% (wet basis) and temperatures ranging from 10°C to 40°C for a period of sixteen weeks] and are presently repeating the experiments using the 2015 rice crop [i.e. two long-grain hybrid rice (XP760 and XL745)]. In addition to the above milestones, we have also developed mathematical models to simulated in-bin drying of rough rice with different drying strategies [rough rice initial MC, drying-start date, air flowrate, and fan control strategy (i.e. equilibrium moisture content controlled and uncontrolled drying modes of fan operation)]; consequently, durations required to completely dry freshly-harvested rough rice to 14% moisture content using weather conditions in Arkansas rice growing locations of Jonesboro, West Memphis, Dermott, and Stuttgart have been established. The results will be coupled with on-going studies on the kinetics of mold growth, specifically for the aflatoxin producing A. flavus mold, to provide guidelines for suitable natural, low temperature air drying strategies for rice in Arkansas. Corn Research: In the first year (2014) of research, laboratory scale batch experiments were conducted to assess the effects of IR heating on drying rates of freshly-harvested corn at initial MCs of 20%, 24% and 28% (w.b.). Corn surface temperature rise with the IR heating, moisture removal, stress-crack formation, and color characteristics were studied. Also, auxiliary research to design and build a non-batch (continuous flow) IR drying and microbial inactivation system was performed. In the second year (2015), research focused on optimizing conditions for corn drying and microbial inactivation which targeted the aflatoxin-producing mold spores. Testing of the built continuous flow IR drying equipment was also performed. As milestones, from the batch experiments (2014), the surface temperature profiles, percentage points of moisture removed and the levels of microbial load reduction for corn [i.e. at initial MCs 20%, 24% and 28% (w.b.)] when subjected to single- and double-pass IR heating [i.e. at intensities 2.2 kW m-2 (7,336.1 Btu. hr-1. m-2) to 10.8 kW m-2 (36,851 Btu. hr-1. m-2)] were established. The experiments also assessed impacts of introducing tempering steps to improve effectiveness of sequential treatments. For instance, corn with MC 28% (w.b.) was heated in a single-pass, with IR intensity of 2.2 kW/m2 (PEG of 43 cm) to 90°C (IR heating duration 140 s ), followed by tempering for 6 h at 90°C, the percentage point moisture removed was 5.1, but 8.6 in a double-pass treatment; the microbial log reduction after the sample was further dried using natural air to safe storage MC of 13% were 3.9 and 4.5 for single- and double-pass, respectively. The construction of a single zone continuous flow IR heating system which utilizes CIR emitter powered by either natural or propane gas and with modular design for process parameter adjustments was successfully completed. In year two of research (2015), we commenced inoculation of corn samples with A. flavus molds to assess the treatment duration and intensity of IR which ensure complete inactivation of the molds. These treatments and data analyses are still ongoing. In the fall of 2015, we successfully tested the newly built continuous flow IR system to dry corn and inactivate mold with very promising results. However, the experiments need to be repeated in fall 2016 for duplication and result verification. At that time we also hope to assess the implications of corn feeding rate (to increase throughput) on system performance and energy requirements. Soybean research: In the first year (2014) of this research, effort were made to determine accurate EMC isotherms of soybeans currently produced and promoted in Arkansas; consideration was given to different soybean cultivars and growing location. Soybean grown in 2013 and 2014 crop seasons at the University of Arkansas Division of Agriculture Research Experiment stations were harvested and samples transported to the laboratory for isotherm data determination. The EMC isotherms were generated for temperature and equilibrium relative humidity (water activity) ranges typically encountered in Arkansas in-bin dying scenarios (i.e. from 15oC to 35oC and 0.1 to 0.9, respectively). In the second year (2015) of the research, studies to determine how drying and storage of currently-produced soybean cultivars of various moisture contents at various air temperatures impact rates of germination were performed; simulations to determine effects of fan control strategies on field drying and storage of the soybeans for different Arkansas locations was conducted. The following are Milestones attained to date: (1) we have established constants of EMC isotherms for soybean seeds grown in Arkansas. Growing locations do not have a significant effect on the isotherms, for the same soybean cultivars, but rather the cultivars do. Determination of EMC isotherms of more cultivars will proceed into the third year of the project. (2) We have performed lab-based studies using three soybeans grown in Arkansas and determined the kinetics of germination rate versus storage and drying duration and moisture content. The data acquired so far illustrate kinetics of soybean seeds of moisture contents 16% and 13% (wet basis) in temperature ranges of 15°C to 40°C. (3) In-bin drying of soybean has been simulated for Arkansas conditions and locations. The soybean drying durations, fan run times, and drying costs per bushel have been determined for simulations covering typically encountered drying air flowrates, drying-start dates, and soybean harvest moisture contents.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Griffiths G. Atungulu, HouMin Zhong, Anne Okeyo, Supriya Thote. Prevalence of Molds on Freshly-harvested Long-grain Pureline, Hybrid and Medium-grain Rice Cultivars. American Society of Biological and agricultural Engineers, Applied Engineering Journal, 31(6),DOI 10.13031/aea.31.11216.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Lawrence, J., Atungulu, G.G., Siebenmorgen, T.J. 2015. Modeling In-Bin Rice Drying using Natural-Air and Controlled-Air Drying Strategies. Transaction of American Society of Biological and Agricultural Engineering, 58(4), 1103-1111. DOI 10.13031/trans.58.10911.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Wilson S. A., Atungulu, G.G., Couch, A., Sadaka, S. Radiant heating and tempering treatments for improving rate of moisture removal during drying of shelled corn. American Society of Biological and agricultural Engineers, Applied Engineering Journal, 31(5), 799-808. DOI 10.13031/aea.31.11243.
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Shantae Wilson and Griffiths G. Atungulu. Application of radiant heat and tempering treatments to dry and decontaminate corn. 2015 Annual International Meeting, Jul 26-29, 2015, New Orleans, Louisiana. Control ID: 2188236
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Griffiths Atungulu and Zachary Young. Determination of Accurate Sorption Kinetics of Soybeans for Effective In-Bin Drying and Storage. 2015 Annual International Meeting, Jul 26-29, 2015, New Orleans, Louisiana. Control ID: 2189392
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Zachary Young and Griffiths Atungulu. Effects of Periodic Dehydration and Rehydration on Soybean Germination Rates and Vigor. 2015 Annual International Meeting, Jul 26-29, 2015, New Orleans, Louisiana. Control ID: 2189410
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Griffiths G. Atungulu, Supriya Thote, HouMin Zhong, Anne Okeyo. Prevalence of Molds on Freshly-harvested Long-grain Pureline, Hybrid and Medium-grain Rice Cultivars. 2015 Annual International Meeting, Jul 26-29,2015, New Orleans, Louisiana. Control ID: 2190198
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Supriya Thote and Griffiths G. Atungulu. Kinetics of mold growth and aflatoxin development on hybrid rice cultivars. 2015 Annual International Meeting, Jul 26-29, 2015, New Orleans, Louisiana. Control ID: 2190210
• Type: Other Status: Published Year Published: 2015 Citation: Griffiths Atungulu. 2015. New Engineering in Grain Drying and Storage - Maintaining quality and preventing mycotoxins. Resource Magazine. Published by the American Society of Agricultural and Biological Engineers. July/August 2015. Page 12-14
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Anne Okeyo, Griffiths G. Atungulu, Shantae Wilson,Arnelia Couch. Impact of radiant drying and decontamination of corn on sensory and functional quality indices. 2015 Annual International Meeting, Jul 26-29, 2015, New Orleans, Louisiana. Control ID:2188850
• Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: HouMing Zhong, Griffiths Atungulu. Simulation and effectiveness of In-Bin Rice Drying in United States Locations. 2015 Annual International Meeting, Jul 26-29, 2015, New Orleans, Louisiana. Control ID: 2189295
• Type: Book Chapters Status: Published Year Published: 2015 Citation: Sammy Sadaka, Scott Osborn, Griffiths Atungulu and Gagandeep Ubhi. 2015. On-Farm Grain Sorghum Drying and Storage. Arkansas Grain Sorghum Production Handbook, Chapter 10, pg1-12

Progress 03/01/14 to 09/30/14

Outputs
Target Audience: This project provides information pertinent to in-bin grain management. The target audience included grain producers, grain processors, research and development community including students, engineers and scientist in the grain process engineering field particularly dealing with rice, corn, and soybeans. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Some rice producers have started communication with us to help monitor rice quality during in-bin drying and storage. They are especially concerned about possible yellowing or staining of rice and mycotoxin development. Some producers send us samples to measure the content of these quality indicators. We are also realising that there are a few other things the farmers need to work on to improve their grain management situation. We are determining dockage levels in the grain and advising on the need to clean rice better before loading into the rice bins. How have the results been disseminated to communities of interest? Yes through some scientific publications and presentations in conferences. What do you plan to do during the next reporting period to accomplish the goals? Rice research: 1.Conduct field- and lab-based studies to determine the conditions under which natural air/low temperature (NA/LT) drying/storage results in production of harmful mold/mycotoxins thereby reducing rice quality. 2.Establish models to predict the rates of mold and mycotoxin development during NA/LT in-bin drying/storage. Corn research: 1. Determine effectiveness of sequential IR heating and tempering at varied temperature and time to achieve simultaneous drying and microbial decontamination of corn. 2. Determine the impact of the above treatments on corn nutritional and sensory quality; Soybean research: 1. Conduct lab-based studies to determine how drying/storage of currently-produced soybean of different varieties at given moisture content and air temperature impacts rates of germination. 2. Perform field-based studies to determine the implications of using the recently-introduced in-bin drying/storage systems on rates of seed germination.

Impacts
What was accomplished under these goals? Rice Research: Year 1 task was to determine the population and prevalence of microorganisms on freshly-harvested rice cultivars grown in different ecosystems within Arkansas. In 2013, medium-grain (Jupiter and Caffey), long-grain pureline (RoyJ and CL152), and long-grain hybrid (XL753 and XL723) rice cultivars were grown at four Arkansas locations (Stuttgart, Colt, Keiser and Rohwer). Samples of these rice cultivars were collected to determine microbial population and prevalence at harvest. The experiments were repeated in 2014, but extending the analyses to include identification of molds prevailing on the rice. Data for rice samples collected from the Stuttgart station during the 2013 and 2014 rice seasons showed that the hybrid rice cultivars contained the lowest mold population compared to long-grain pureline and medium-grain rice. The consistency of these findings with respect to other stations will be verified after all the analyses are completed. Laboratory experiments have been initiated whereby representative hybrid and long-grain pureline rice cultivars at harvest moisture contents ranging from 22% to 12.5% were placed in various temperature environments to determine kinetics of mold growth, mycotoxin development, and quality changes during storage. The quality indices studied include yellowing, head rice yield, and pasting characteristics. In addition, field studies are ongoing to determine kinetics of mold growth, mycotoxin development, and quality changes in actual field drying and storage conditions. At present, rice samples from on-farm, in-bin drying operations situated in three Arkansas locations (Mississippi, Jackson and Chicotcounties) are being periodically collected and brought to the laboratory for mold growth, mycotoxin development, and quality analyses. Corn Research: Year 1 task was to determine the effect of infrared (IR) heating on drying rate of freshly-harvested corn and evaluate dried-product characteristics. IR treatments of the 2013 corn crop at initial moisture contents of 20, 24 and 28% (w.b.) were subjected to IR treatments to establish surface temperature profiles of corn during IR heating. The information was used to determine percentage points of moisture removed upon IR heating to corn-surface temperatures of 50, 70, and 90°C at three levels of IR heating intensities (regulated by product-to-emitter-gap sizes of 11, 24 and 43 cm). Effects of IR heating followed by tempering corn for 0 to 6 h at 50, 70, and 90°C on moisture removal were established. However, experiments are underway to determine suitability of the tempering times to achieve acceptable microbial inactivation. Single- and multiple-passes of IR treatments to dry samples of freshly-harvested, high MC corn, of the 2014 crop, with IR heating only and IR heating combined with tempering and ambient air drying, to safe storage MC of 13.5% are ongoing; the impacts of these treatments on quality, for instance, stress-crack formation, inactivation of molds, and changes in corn pasting characteristics are being studied using batch-type and a recently built continuous IR heating equipment. Evaluation of the effect of IR heating on mold inactivation is ongoing and will be reported. Future experiments are designed to treat corn infected with aflatoxin-producing mold (Aspergillus flavus) and to determine kinetics of inactivation with IR heating and tempering. Soybean research: Accurate control of soybean drying and storage with new systems in-bin drying system using moisture and temperature cables hinges on accurate prediction of the grain EMC. Therefore, the key task in year 1 of the project was to determine the accurate EMC isotherms of soybeans currently produced and promoted in Arkansas. Representative soybean seeds (Armor 53-R88, Asgrow AG5332, Pioneer 95Y10, Progeny P5111RY, Terral REV 51R53, UA 5213C and UA 5612) grown in 2013 crop season at the University of Arkansas Division of Agriculture Research Experiment stations (Keiser and Pine Tree) were harvested and samples from three random plots transported to the laboratory for isotherm data determination. To generate the isotherms, the AquaLab Vapor Sorption Analyzer (VSA) was used. The VSA is an automatic isotherm generator capable of generating isotherms using both the Dynamic Vapor Sorption (DVS) method and the Dynamic Dew Point Isotherm (DDI) method. The DVS mode was used to generate the isotherm data for temperature and equilibrium relative humidity (water activity) ranging from 15oC to 35 oC and 0.1 to 0.9, respectively. These experiments are being repeated using the 2014 soybean crop. The same cultivars as the 2013 crop were grown in 2014 at the same locations to determine how EMC may vary from one season to another. Also, in order to develop a more robust EMC prediction model, additional cultivars of the 2014 soybean crop have been collected from several other University of Arkansas Division of Agriculture experimental stations including Mariana.

Publications

• Type: Book Chapters Status: Published Year Published: 2014 Citation: Zhongli Pan, Griffiths G. Atungulu, Xuan Li. 2014. Infrared Heating. In: Emerging Technologies for Food Processing. 2nd Edition. Da-Wen Sun (ed.). Academic Press-an Imprint of Elsevier, San Diego CA. Pg. 461-474
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Griffiths G. Atungulu, Hou Min Zhong, Koide Shoji. Simulation of Fixed-Bed Batch Drying of Rice Using the Sphere Drying Model. 2014 ASABE and CSBE | SCGAB Annual International Meeting, July 13  16, 2014, Montreal, Quebec Canada
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Griffiths G. Atungulu, Hou Min Zhong, Terry Siebenmorgen. Survey of factors affecting Microorganisms on Freshly-harvested Rice. 2014 ASABE and CSBE | SCGAB Annual International Meeting, July 13  16, 2014, Montreal, Quebec Canada
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Griffiths G. Atungulu and Zhongli Pan. 2014. Rice industrial processing worldwide and impact on macro- and micronutrient content, stability, and retention. ANNALS OF THE NEW YORK ACADEMY OF SCIENCES, 1324 (2014) 1528, doi: 10.1111/nyas.12492.
• Type: Other Status: Published Year Published: 2014 Citation: T. Siebenmorgen, G. Atungulu, R. Norman, T. Roberts, P. Counce. Impacts of Nitrogen-Fertilizer Management and On-Farm Drying Practices on Milling Yield and Quality of Rice. Ecosystems Interim report 01-2014 for BR Wells
• Type: Websites Status: Published Year Published: 2014 Citation: Rice Quarterly: Methods for stabilizing rice bran. June 2014/www. World-Grain.com
• Type: Websites Status: Published Year Published: 2014 Citation: Delta Farm Press: How to properly dry grains on-farm: http://deltafarmpress.com/rice/how-properly dry grain on-farm. (http://deltafarmpress.com/print/rice/how-properly-dry-grain-farm?page=1).