Source: UNIVERSITY OF ARKANSAS submitted to NRP
QUANTIFYING THE IMPACTS OF PRE- AND POST-HARVEST OPERATIONS ON RICE QUALITY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1003632
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2014
Project End Date
Sep 30, 2019
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF ARKANSAS
(N/A)
FAYETTEVILLE,AR 72703
Performing Department
Food Science
Non Technical Summary
Increasing competition in the global marketplace makes it imperative to improve post-harvest processing operations to maximize the economic value of the United States rice crop. Basic and applied research seeks to improve the efficiency and effectiveness of current processing operations and provide fundamental information for the development of new processes. Multidisciplinary research involving drying, storage, milling, end-use processing, and quality assessment seeks to enhance the quality and value of rice and rice products while quantifying and minimizing energy consumption.
Animal Health Component
70%
Research Effort Categories
Basic
20%
Applied
70%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5011530200010%
5011530202090%
Knowledge Area
501 - New and Improved Food Processing Technologies;

Subject Of Investigation
1530 - Rice;

Field Of Science
2020 - Engineering; 2000 - Chemistry;
Goals / Objectives
Quantify the effects of pre-harvest production practices, such as water and fertility management, as well as factors such as the moisture content (MC) at which rice is harvested, on rice physicochemical properties and resultant milling behavior to determine impacts on overall processing performance and product value.Quantify the impact of various drying strategies, formulated using a recently-developed hypothesis involving glass-transition principles, in relation to drying rates/capacities, milling yields, energy consumption, and end-use quality indices.Quantify the effects of post-harvest operations, particularly thickness grading, on rice physicochemical properties and resultant milling behavior as a means of improving overall processing performance and product value.
Project Methods
Samples of several long- and medium-grain rice cultivars at MCs ranging from high (24%) to low (13%) levels will be collected over multiple years from multiple locations throughout the Mid-South production region. For objective one, samples will be obtained from research trials at multiple University of Arkansas Research and Extension Centers. Bulk rice for objectives two and three will be obtained from multiple sources, comprising a mixture of University of Arkansas Research and Extension Centers and collaborator fields. Experimentation will be conducted at the University of Arkansas, Department of Food Science, Fayetteville, AR.For all objectives, harvested rough rice samples will be cleaned using a dockage machine, and ultimately, multiple analyses will be performed to measure physical and chemical, as well as bulk and individual kernel, properties. For objectives one and three, samples will be gently dried in thin layers to approximately 12.5% MC in a controlled temperature and RH chamber. Subsamples of the dried, rough rice will be analyzed for bulk density and 1000-kernel mass. Additional subsamples will be de-hulled, and the resultant brown rice evaluated for kernel dimensional distribution (SeedCount Rice Analyzer), chalkiness (Winseedle scanning system), total lipid content (Foss Soxtec extraction system), and protein content (Perten NIR spectrophotometer). Separate subsamples of the dried, rough rice will be hulled and then milled using a McGill No. 2 mill to determine milled rice yield and head rice yield. Using the resultant head rice, an extensive array of properties will be measured, including surface lipid content, protein content, color, chalkiness, and paste viscosity profile. For objective three only, samples will be thickness graded, and subjected to the same suite of analytical procedures. From all of these tests, it is desired to learn how milling and functional quality indices are affected by pre- and post-harvest impacts.For objective two, drying procedures will be developed based on a glass transition hypothesis and evaluated using an automated drying system. An extensive range of quality testing will be conducted to evaluate the effects of the various air condition/drying duration combinations incurred by the drying strategies. Trials will be conducted using a recently-developed and automated drying system capable of maintaining air conditions at set temperatures and RHs. Various drying air temperatures/RHs, rough rice MCs, drying durations, and tempering durations/conditions will be tested based upon this hypothesis. Also, drying trials will be conducted to determine drying rates over a range of temperatures and RHs. Strategies will be designed to dry rice both above and below the glass transition temperature line.After drying/tempering trials, samples will be gently dried to 12.5% MC, as needed, in a controlled temperature and RH chamber. Each dried rough rice sample will be subjected to the same analytical procedures as previously described for objectives one and two, this is to determine if the drying protocols affected milling quality and functionality. Also for objective two, the electrical and thermal energy consumption of various commercial drying, storage, and milling processes will be determined by using either existing energy usage records or using monitoring equipment to measure actual energy amounts used per unit of rice processed. On-going collaboration with drying/milling companies will allow energy measuring equipment and instrumentation to be installed at commercial facilities to collect this information over a range of operating conditions.

Progress 10/01/14 to 09/30/19

Outputs
Target Audience:Rice producers and processors Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate students were provided experiential learning opportunities on all of these projects. Additionally, the results of these projects have been reported at various venues to the rice industry. How have the results been disseminated to communities of interest?Besides presentations at professional society meetings and publishing in scientific journals, the results of our work have been presented annually at the University of Arkansas Rice Processing Program's Industry Alliance Meeting; this meeting convenes leaders of the major rice processing companies from the United States and several international companies as well. Presentations have also been made to the rice industry at individual companylocations. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? A study was conducted toquantify the effect of alternate wetting and drying (AWD), a water-saving technique for producing rice,on rice quality. Whilethe findingsassuaged concerns regarding milling yields, it showed that AWD could have some implications on chalkiness levels, albeit minor. This information is important for rice producers, especially those who produce rice in water-constrained environments. Since rice cultivars differ in how they behave under water stress, it may be necessary to evaluate the performance of other cultivars when produced using AWD. The thermal energy used to dry rice inan on-farm, cross-flow dryer ranged from 2,840 to 5,840 kJ/kg water removed for multiple tests conducted during two consecutive harvest seasons. Thermal energy efficiency ranged from 44 to 90%, indicating that in some instances, drying efficiency was quite good, but in others, improvement was needed. The cost to dry rice from the initial moisture contents, ranging from 16.6 to 21.7% to ~ 13% ranged from 7.7 to 12.0ยข/kg water removed. Based on the data collected from these tests, equations were developed to predict thermal energy use, based on ambient air temperature and the amount of water removed from the rice. These equations can be used to improve the logistical operation of driers to maximize energy efficiency.Information on thickness grading followed by milling of each fraction separately could improve overall milling performance of rice lots. This research has been provided to the rice industry. Rough rice of four currently-produced, long-grain cultivars was mechanically sieved, resulting in two thickness fractions, Thick (> 2 mm) and Thin (< 2 mm). Milled-rice yield (MRY), head-rice yield (HRY), lipid and protein content, bulk density, and milled-rice chalkiness were determined for each cultivar/thickness fraction. Thickness grading produced between 67% and 90% Thick kernels by mass. MRYs of Thick kernels were greater than Thin, and trended greater than unfractionated (UNF) kernels. Moreover, HRYs of Thick kernels were greater than both Thin and UNF. For the Thin fraction, greater total lipid and crude protein content, and lower bulk density, suggested many incompletely-filled kernels. Thick kernels had less chalkiness than Thin, and trended to have less chalkiness compared to UNF. Thickness-grading improved milling-yield parameters of thick kernels, and showed promise for reducing chalkiness. Although thickness-grading to remove thin kernels would create an extra process operation and flow stream, benefits to milling yield, and to improved visual perception through reduced chalkiness and greater kernel uniformity, could justify this procedure. 1. The impacts of water-saving approaches to rice production, specifically alternate wetting and drying (AWD), on rice quality indices were quantified. We found that milling quality was not impacted compared to conventionally irrigated rice, however AWD irrigation did show a tendency to increase chalkiness in rice compared to conventionally irrigated rice. 2. Our work in drying is addressing fissuring of rice kernels and its resultant reduction in head rice yield (HRY). The impact of our work will be to ultimately improve drying operations in the rice industry. 3. Studies were conducted in which rice kernel thickness grading was investigated to show how milling performance of the various thickness fractions compared to unfractionated rice.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Mukhopadhyay, S., T.J. Siebenmorgen, and A. Mauromoustakos. 2019. Effect of tempering approach following cross-flow drying on rice milling yields. Drying Technology DOI:10.1080/07373937.2018.1564760.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Prakash, B., T.J. Siebenmorgen, K.E. Gibson, and S. Kumari. 2019. Effect of storage moisture content on milling characteristics of rough rice Trans. of the ASABE 62(4): 1011-1019.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Shi, H., and T. J. Siebenmorgen, 2019. Effect of rice cultivar, type, form, and moisture content on the angle of repose. Applied Engineering in Agriculture 35(4): 361-368.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Shi, H., T.J. Siebenmorgen, H. Luo, and Z. Odek. 2019. Fissure detection and measurement in rough rice using X-ray imaging. Trans. of the ASABE 62(4): 859-866.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Odek, Z. R. and T.J. Siebenmorgen. 2019. Estimating Head Rice Yield of long-grain rice using a bending force instrument. Applied Engineering in Agriculture 35(3), 319-323.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Graham-Acquaah, S., T.J. Siebenmorgen, M.L. Reba, J.H. Massey, A. Mauromoustakos, A. Adviento-Borbe, R. January, R. Burgos and J. Baltz-Gray. 2019. Impact of alternative irrigation practices on rice quality. Cereal Chemistry. 96: 815-823.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Siebenmorgen, T.J. and H. Shi. 2019. Measuring the angle of repose of rice. 2018 Research Series 659; B.R. Wells Arkansas Rice Research Studies, R.J. Norman and K.A. K. Moldenhauer, editors. P. 404-411.
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Kumar, A., S. Yingling, C. Ruiz, Y. Dwiningsih, C. Gupta, J. Thomas, P. Counce, K.A.K. Moldenhauer, T.J. Siebenmorgen, and A. Pereira. 2019. Screening of Indica and Japonica rice subspecies for grain yield and quality under high nighttime temperature. 2018 Research Series 659; B.R. Wells Arkansas Rice Research Studies, R.J. Norman and K.A. K. Moldenhauer, editors. P. 61-66.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Odek, Z. and T.J. Siebenmorgen. 2019. Fissure formation kinetics of rough rice during drying. Oral presentation at the Annual International Meeting of the American Soc. of Agricultural and Biological Engineers. July 7-10. Boston, MA.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Graham-Acquaah, S. and T.J. Siebenmorgen, 2019. Effect of drying condition on pasting properties of rice. Oral presentation at the Annual Meeting of the Cereals & Grains Association. November 3-6. Denver, Colorado.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Graham-Acquaah, S., Siebenmorgen, T.J., and Reba, M.L. 2019. Impact of alternative irrigation practices on rice quality. Oral presentation at the Annual Meeting of the Cereals & Grains Association. November 3-6. Denver, Colorado.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Mukhopadhyay, S. and T.J. Siebenmorgen. 2019. Effect of different factors on the angle of repose of rice. Oral presentation at the annual Industry Alliance Meeting, University of Arkansas Rice Processing Program. May 21-22. Fayetteville, AR.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Prakash, B. and T.J. Siebenmorgen. 2019. Effect of turnflows in cross-flow dryers on head rice yield. Oral presentation at the annual Industry Alliance Meeting, University of Arkansas Rice Processing Program. May 21-22. Fayetteville, AR.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Odek,Z. and T.J. Siebenmorgen. 2019. Fissuring kinetics of rough rice during drying. Oral presentation at the annual Industry Alliance Meeting, University of Arkansas Rice Processing Program. May 21-22. Fayetteville, AR.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Graham-Acquaah, S., T.J. Siebenmorgen. 2019. Impact of alternative irrigation practices on rice quality. Oral presentation at the annual Industry Alliance Meeting, University of Arkansas Rice Processing Program. May 21-22. Fayetteville, AR.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Graham-Acquaah, S., T.J. Siebenmorgen. 2019. Effect of drying conditions on pasting properties of rice. Oral presentation at the annual Industry Alliance Meeting, University of Arkansas Rice Processing Program. May 21-22. Fayetteville, AR.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2019 Citation: Graham-Acquaah, S., T.J. Siebenmorgen, M. L. Reba, J.H. Massey, A. Mauromoustakos, and A. Adviento-Borbe. 2019. Impact of alternative irrigation practices on rice quality. Poster presentation at the annual Industry Alliance Meeting, University of Arkansas Rice Processing Program. May 21-22. Fayetteville, AR.


Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Rice producers and processors Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Co-organized, hosted and presented at the Rice Quality short course that was sponsored by the American Association of Cereal Chemists and the University of Arkansas Rice Processing Program. How have the results been disseminated to communities of interest?Publication of results as peer-reviewed journal articles. Publication of results as oral and poster presentations. Annual presentation of results to members of the Rice Processing Program Industry Alliance Meeting at the annual meeting that was held May 22-23, 2018. What do you plan to do during the next reporting period to accomplish the goals?For goal 1, samples have been collected and experimentsareunderwayto quantify the impact of storage moisture content and milling moisture content on milling characteristics of rice. These experiments are planned to be completed this year. For goal 2, a unique drying apparatus has been constructed to be used in conjunction with an X-ray system to observe fissure formation during drying. Experiments will be conducted this year using that system to learn more about fissure formation in rice kernels during drying.

Impacts
What was accomplished under these goals? 1. Projects have been completed that quantify the impact of rice kernel thickness and moisture content on fissuring behavior. See published journal article. 2. Experiments have been conducted that quantify the impact of airflow rate in cross-flow driers on moisture content and milling yield distributions. 3. The work related to this goal was completed earlier in the project's life.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mukhopadhyay, S. and T.J. Siebenmorgen. 2017. Effect of airflow rate on drying air and moisture content profiles inside a cross-flow drying column. Drying Technology, DOI:10.1080/07373937.2017.1402024. p.1-16
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Prakash, B. and T.J. Siebenmorgen. 2018. Single parameter thin layer drying equations for long-grain rice. Trans. of the ASABE 61(2): 733-742.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Prakash, B. and T.J. Siebenmorgen. 2018. Mathematical modeling of a cross-flow rice dryer with grain inverters. Trans. of the ASABE 61(5): 1757-1765.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Odek, Z., T.J. Siebenmorgen, and A. Mauromoustakos. 2018. Relative impact of kernel thickness and moisture content on rice fissuring during drying. Applied Engineering in Agriculture 34(1):239-246.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2018 Citation: Siebenmorgen, T.J. and Z. Odek. 2018. An update of University of Arkansas Rice Processing Program Research. Invited presentation to the Arkansas Driers and Warehousemans Assoc. Annual Meeting. Feb. 2, 2018. Tunica, MS.
  • Type: Book Chapters Status: Published Year Published: 2018 Citation: Siebenmorgen, T.J., B. Grigg, P. Counce, and J. Hardke. 2018. Chapter 15. Production factors impacting rice milling yield. Rice Production Handbook, MP192. J. Hardke ed. Cooperative Extension Service, University of Arkansas.
  • Type: Book Chapters Status: Published Year Published: 2018 Citation: Hardke, J. and T.J. Siebenmorgen. 2018. Chapter 13. Rice Grades. Rice Production Handbook, MP192. J. Hardke ed. Cooperative Extension Service, University of Arkansas.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2018 Citation: Bhagwati, P. and T.J. Siebenmorgen. 2018. Single-parameter thin-layer drying equations for long-grain rice. Oral presentation at the Annual International Meeting of the American Soc. of Agricultural and Biological Engineers. July 29, 2018. Detroit, MI.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2018 Citation: Odek, Z. and T.J. Siebenmorgen. 2018. Impact of fissures formed during drying on rice kernel breaking strength. Oral presentation at the Annual International Meeting of the American Soc. of Agricultural and Biological Engineers. July 29, 2018. Detroit, MI.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2018 Citation: Shi, H., Siebenmorgen, T., Luo H., & Zeph O. 2018. Automatic fissure detection and measurement in rough rice using x-ray imaging. Oral presentation at the Annual International Meeting of the American Soc. of Agricultural and Biological Engineers. July 29, 2018. Detroit, MI.
  • Type: Book Chapters Status: Published Year Published: 2018 Citation: Siebenmorgen, T.J. 2018. Chapter 14. Laboratory measurement of rice milling yield. Rice Production Handbook, MP192. J. Hardke ed. Cooperative Extension Service, University of Arkansas.


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

Outputs
Target Audience:Rice producers and processors. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The annual University of Arkansas Industry Alliance Meeting was again held in May, 2017. Rice processors and producers attended to hear reports of research being conducted by the Rice Processing Program. An additional feature of this year's meeting was a section dedicated to new technology in the rice and grain industry. How have the results been disseminated to communities of interest?Research results have been presented at the above-described Industry Alliance Meeting and society meetings including the American Assoc of Cereal Chemists International and the American Society of Biological and Agricultural Engineers. Research articles have also been published in various scientific journals. Reports to rice producers have been published in a rice research series. What do you plan to do during the next reporting period to accomplish the goals?1. Continue to collaborate on the large project to evaluate the impacts of a new irrigation technology for rice. We will conduct all rice quality measurements. 2. Validate the mathematical drying model that has been developed using both pilot plant drying means and possibly through measurements of commercial-scale driers. 3. Study the fissuring behavior of rough rice kernels using an x-ray system and a specially-designed drying apparatus.

Impacts
What was accomplished under these goals? 1. Field tests were again conducted to evaluate the effects of alternate wetting and drying irrigation practices on yield and quality of rice. We are drying and milling samplesfor a collaborator. 2. A mathematical model has been completed and is being validated with pilot plant drying data. A thin-layer drying equation for rough rice was developed. The impacts of airflow rate on rice MC profiles and milling yields were measured using a specially-designed drying apparatus that simulates cross-flow dryer operation. The impacts of various tempering approaches on milling yields of rice dried in a cross-flow drying column were quantified. 3. The rlative impacts of kernel thickness and moisture content on fissure formation during drying were quantified.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mukhopadhyay, S. and T.J. Siebenmorgen. 2017. Glass transition effects on milling yields in a cross-flow drying column. Drying Technology, DOI:10.1080/07373937.2017.1351453
  • Type: Journal Articles Status: Published Year Published: 2107 Citation: Odek, Z., B. Prakash, and T.J. Siebenmorgen. 2017. X-Ray Detection of Fissures in Rough Rice Kernels. Applied Engineering in Agriculture 33(5):721-728.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Haydon, K.N. and T.J. Siebenmorgen. 2017. Impacts of delayed drying on discoloration and functionality of rice. Cereal Chemistry 94(4):683-692.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Prakash, B., S. Mukhopadhyay, and T.J. Siebenmorgen. 2017. Mathematical modeling of a cross-flow rice dryer. Trans. of the ASABE 60(3):999-1009.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Odek, Z., T.J. Siebenmorgen, and A. Mauromoustakos. 2017. Relative impact of kernel thickness and moisture content on rice fissuring during drying. Applied Engineering in Agriculture (in press).
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Grigg, B.C. and T.J. Siebenmorgen. 2017. Predicting milling yields of long-grain rice using select physical parameters. Applied Engineering in Agriculture 33(2):279-285.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mukhopadhyay, S. and T.J. Siebenmorgen. 2017. Physical and functional characteristics of broken rice kernels caused by moisture-adsorption fissuring. Cereal Chemistry 94(3):539-545.


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

Outputs
Target Audience:Rice producers and processors. Changes/Problems:Goals 1 and 3 have in large part been met. Our future work will concentrate on drying. Thus, emphasis will be placed on Goal 2. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Publication of results as peer-reviewed journal articles, Presentation of research results as oral and poster presentations. Annual presentation of results to members of our Rice Processing Program Industry Alliance Group. What do you plan to do during the next reporting period to accomplish the goals?Significant emphasis will be placed on Goal 2 in terms of mathematical model refinement and validation.

Impacts
What was accomplished under these goals? 1. A multi-year, plot-level study was completed that evaluated N-fertilizer and harvest moisture content effects on rice milling yields and quality. Two articles have been published to report this work. 2. A laboratory apparatus for simulating cross-flow drying has been revamped and experiments conducted to evaluate the factors listed in the goals statement. Experimental runs have been completed and data plotted. Manuscripts are now being written. A mathematical model describing cross-flow drier operation has been formulated and is being validated with the data from the above experiment. 3. Several laboratory studies have been conducted to evaluate thickness grading of rough rice as a means of improving overall milling yields. Multiple articles have been published on this work.

Publications

  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Grigg, B.C., T.J. Siebenmorgen, and R.J. Norman. 2016. Effects of nitrogen rate and harvest moisture content on physicochemical properties and milling yields of rice. Cereal Chemistry 93(2):172-181.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Rogers, C.W., R.J. Norman, T.J. Siebenmorgen, B.C. Grigg, J.T. Hardke, K.B. Brye, and E. Gbur. 2016. Rough rice and milling yields as affected by nitrogen, harvest moisture content, and cultivar. Agron. J. 108(2):813-821.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Billiris, M.A., T. Thurow, and T.J. Siebenmorgen. 2016. Using thermogravimetric analysis to measure the drying rates of individual rice kernels. Applied Engineering in Agriculture 32(6):------.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2016 Citation: Grigg, B.C. and T.J. Siebenmorgen. 2016. Milling yields and physicochemical properties of long-grain rice thickness fractions. Applied Engineering in Agriculture 32(6):------.


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

Outputs
Target Audience:Rice producers and processors. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Publication of results as peer-reviewed journal articles, and research bulletins. Presentation of research results as oral and poster presentations. Annual presentation of results to members of our Industy Alliance. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? 1. The multi-year study of the impacts of N rate x harvest-moisture-content (HMC) was completed; research summaries detailing the impacts on milling yields and functionality of rice, and on optimal nitrogen(N) rate x HMC combinations to achieve optimal agronomic/milling yields of rice, have been accepted for publication. Increased head rice yields(HRYs) were observed in response to increased N rate. Decreased HRYs were observed in response to the 15% HMC level. Increased HRYs were generally associated with decreased fissuring and chalkiness of brown rice kernels. No significant interactions between N rate and HMC were observed. Results of the N rate x HMC study suggest stable HRYs with N rates of 90 kg/ha or greater; however, harvest at HMCs below the 19% level introduces significant risk of reduced HRYs, possibly countering economic gains from extended in-field drying.The second year of a study characterizing the impacts of N-fertilizer scheduling on milling yield and quality was conducted in 2015, and hand-harvested rice samples are being analized. 2. Laboratory-scale experiments simulating on-farm, cross-flow drying operations have been initiated, with the goal of quantifying the impacts of multiple combinations of drying airflow-rate, temperature, and relative humidity, and initial moisture content (MC) of rice on milling yields within a rice bed. Additionally, a post-doctoral scientist has joined the project, with the goal of continuing efforts to model milling yields, throughput, and energy efficiency various drying systems. 3. Investigations of post-harvest thickness grading of rough rice to isolate kernels of secondary quality continue. One manuscript detailing the relationships between milling yields and physical properties of thickness-graded rice has been published, and a second detailing the impacts of thickness grading on milling yields and physicochemical properties of a broad array of long-grain rice cultivars is in review.Results of this fractioning trial indicate that rough rice kernels thinner than 1.9 mm accounted for the bulk of less mature, chalky kernels. Reducing the screen width from 2.0 to 1.9 mm maintained significantly greater HRYs in the thick kernels, while increasing the mass fraction of the thicker, high-quality kernels from 7 to 23 percentage points dependent on cultivar. Rice samples have been collected, and processing begun, for the second year of a colaborative project; the project was designed to determine the interactive impacts of production location, cultivar, and HMC on the presence of kernel defects (chalkiness, fissured kernels, and immature kernels), and determining whether milling yields, quality, and functionality of rice can be improved through thickness fractioning.

Publications

  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Grigg, B.C., T.J. Siebenmorgen, and R.J. Norman. 2015. Effects of nitrogen rate and harvest moisture content on physicochemical properties and milling yields of rice. Cereal Chemistry
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Rodriguez-Arzuaga, M., S. Cho, M.A. Billiris, T.J. Siebenmorgen, and H.-S. Seo. 2015. Impacts of degree of milling on the appearance and aroma characteristics of raw rice. Jrn. of the Science of Food and Agriculture
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Counce, P.A., T.J. Siebenmorgen, and A.A. Ambardekar. 2015. Rice reproductive development stage thermal time and calendar day intervals for six US rice cultivars in the Grand Prairie, Arkansas, over 4 years. Annals of Applied Biology ISSN 0003-4746 (2015):1-15.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Basutkar, N., T.J. Siebenmorgen, Y.-J. Wang, and J.A. Patindol. 2015. Functional properties of co-mingled rice cultivar lots. Cereal Chemistry 92(1):114-119.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Patindol, J.A., T.J. Siebenmorgen, and Y.J. Wang. 2015. Impact of environmental factors on rice starch structure; A review. Starch 67:42-54.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Grigg, B.C. and T.J. Siebenmorgen. 2015. Impacts of kernel thickness and associated physical properties on milling yields of long-grain rice. Applied Engineering in Agriculture 31(3):505-511.
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Rogers, C., R. Norman, T.J. Siebenmorgen, B. Grigg, J. Hardke, K Brye, and E. Gbur. 2015. Rough rice and milling yields as affected by nitrogen, harvest moisture content, and cultivar. Agronomy Jrn. doi: 10.2134/agronj2015.0254