Diallel Analysis of Head Rice Percentage, Total Milled Rice Percentage, and Rough Rice Yield

Crop Science ◽  
1994 ◽  
Vol 34 (1) ◽  
pp. 42-45 ◽  
Author(s):  
Kenneth A. Gravois
Keyword(s):  
Rice Yield ◽  
Diallel Analysis ◽  
Milled Rice ◽  
Head Rice ◽  
Rough Rice

X-Ray Detection of Fissures in Rough Rice Kernels

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

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

Effect of Storage Moisture Content on Milling Characteristics of Rough Rice

2019 ◽  
Vol 62 (4) ◽  
pp. 1011-1019
Author(s):  
Bhagwati Prakash ◽  
Terry J. Siebenmorgen ◽  
Kristen E. Gibson ◽  
Shweta Kumari
Keyword(s):  
Moisture Content ◽  
Rice Yield ◽  
Surface Lipid ◽  
Milled Rice ◽  
Financial Return ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Milling Characteristics ◽  
The Mean

Abstract. Rough rice in the Mid-South U.S. is typically stored and milled at a moisture content (MC) between 12% and 13% on a wet basis. Drying harvested rice to lesser MCs requires increasingly greater energy and reduces the overall mass of rice, both of which translate into lesser financial return for the crop. Considering these disadvantages of drying and storing rice at lesser MCs, farmers and grain handlers have been interested in exploring storing rice at slightly greater MCs. The current study was undertaken to evaluate the effect of storing rice at five MCs (11%, 12%, 13%, 14%, and 15%) on milling characteristics, particularly surface lipid content (SLC), milled rice yield (MRY), and head rice yield (HRY); additionally, the effects of storing rice at two storage temperatures (25°C and 35°C) and several storage durations (up to one year) on milling characteristics were investigated. Five long-grain rice lots were harvested in 2016 and 2017 from several locations in Arkansas; rice from each lot was gently dried to the target MCs and then stored in sealed glass jars at selected temperatures. With an increase in storage MC, shorter milling durations were needed to achieve a given SLC, which could potentially reduce the cost of the milling operation. However, rice samples stored at greater MCs were observed to have lesser HRYs, which could reduce the economic value of rice. The mean HRYs of the 15% MC samples were 4.8 to 9.1 percentage points less than the mean HRYs of the 12% MC samples. This study quantifies the milling characteristics of rice when stored for various durations at different MCs and temperatures. Overall, these data will allow the rice industry to make informed decisions related to storage conditions of rice, specifically storage MC. Keywords: Head rice yield, Milling, Moisture content, Rice, Storage.

Prediction of Rice Milling Yield and Quality Attributes during Storage Using Regression Analyses

2019 ◽  
Vol 62 (5) ◽  
pp. 1259-1268
Author(s):  
Soraya Shafiekhani ◽  
Jung Ae Lee ◽  
Griffiths G. Atungulu
Keyword(s):  
Hybrid Rice ◽  
Storage Temperature ◽  
Rice Yield ◽  
Storage Conditions ◽  
Milled Rice ◽  
Yield And Quality ◽  
Head Rice ◽  
Rough Rice ◽  
Milling Yield

Abstract. Regression analyses were performed to determine the storage conditions that exhibited the best outcomes for long-grain, hybrid milled rice yield and quality. This study evaluated mold population on rough rice, milled rice discoloration, and head rice yield (HRY) after storage of rough rice in airtight conditions at moisture contents (MCs) of 12.5%, 16%, 19%, and 21% wet basis and temperatures of 10°C, 15°C, 20°C, 27°C, and 40°C at two-week intervals for 12 weeks. The experiment used a popular long-grain hybrid rice cultivar (XL745). Rice lots were procured from fields with and without conventional treatment of the field with fungicide for plant disease management. Field treatment and no field treatment were considered as a block, and a Mann-Whitney test was conducted to determine effect. The response surface method, an extension of second-order polynomial regression, was used to examine optimal treatment conditions. Mold population and milled rice discoloration from a combination of storage conditions were predicted using regression models. The first-order and second-order terms of temperature indicated a nonlinear relationship between temperature and ln(discoloration). The MC was positively associated with ln(discoloration), but the degree of impact may change with temperature because the interaction term was significant. From the model evaluation (R2 and lack-of-fit test), the discoloration level is expected to be 57% (49% to 66% confidence interval) under conditions of 20% MC, 40°C, and nine weeks of storage for samples procured from fungicide-treated rice fields. This discoloration change is substantial compared to the initial discoloration of 9%. At high temperature (40°C) and MC (21%), discoloration started immediately after two weeks of storage. Anaerobic storage conditions impeded mold growth, especially at high storage temperature (40°C). Low mold populations were observed in rice stored at low MC (16%). According to the regression model, the critical storage temperature that may lead to discoloration is between 27°C and 40°C. Pre-harvest fungicide treatment of rice in the field for disease control significantly improved the HRY but had no significant influence on mold population or discoloration. This study suggests a range of storage conditions to prevent losses in milling yield and quality of rice. In addition, the studied storage conditions mimicked the typical conditions for on-farm, in-bin drying and storage in the U.S. Mid-South, especially for the top layers of rice inside the bin, and therefore provide an important reference for growers and rice processors using in-bin structures to manage the quality of long-grain hybrid rice. Keywords: Discoloration, Head rice yield, Mold population, Regression analysis, Rice quality, Rice storage.

Milled Rice Quality Assessment

2010 ◽  
Vol 6 (2) ◽  
Author(s):  
Reza Farahmandfar ◽  
Esfandiyar Farahmandfar ◽  
Mahdi Ghasemi Varnamkhasti ◽  
Mahdi Zarei
Keyword(s):  
Rice Yield ◽  
Milling Process ◽  
Milled Rice ◽  
Rice Varieties ◽  
Breeding Lines ◽  
Head Rice ◽  
Rough Rice ◽  
Degree Of Milling ◽  
Head Rice Yield ◽  
Important Processing

Milling, an important processing step of rough rice, is usually done to produce white, polished grains. In this paper the quality of 22 milled rice varieties, common in Mazandaran, Iran, are investigated. These rice varieties included local varieties and breeding lines. Parameters assessed were head rice yield, degree of milling, husk removed percent, and total milling recovery. Results obtained revealed that the Tarom Mahali and Champa varieties have the highest head rice yield as 60.58 and 66.39 % and total milling recovery as 69.96 and 71.38 %, respectively. The greatest degree of milling value was found for the Haraz variety with a mean of 16.06 %. Also, it was found that the husk removed percent values were not statistically different among the varieties studied. Finally, considering all results obtained, the varieties of Tarom Mahali, Champa, and Neda showed to be more economical in the milling process.

Effects of Rotational Crop Herbicides on Rice (Oryza sativa)

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 648-654 ◽  
Author(s):  
David H. Johnson ◽  
J. Dwayne Beaty ◽  
Diana K. Horton ◽  
Ronald E. Talbert ◽  
Charles B. Guy ◽  
...  
Keyword(s):  
Dry Matter ◽  
Rice Yield ◽  
Growth And Yield ◽  
Clay Soils ◽  
Silt Loam ◽  
Previous Crop ◽  
Head Rice ◽  
Rough Rice ◽  
Rotational Crop ◽  
One Year

Experiments were conducted from 1989 to 1991 on two silt loam and two clay soils to determine the effect of herbicides applied to the previous crop on growth and yield of rice. All herbicides were applied preplant-incorporated at recommended rates adjusted as needed for soil texture. Rice was planted the following year. Imazaquin, imazethapyr, alachlor, metolachlor, clomazone, trifluralin, and atrazine did not injure rice the year following application. Norflurazon was the only herbicide to injure rice on silt loam soils, with injury at one silt loam location in one of two years. Norflurazon and fluometuron residues caused rice injury on clay soils, and chlorimuron residues caused injury in one year on a day soil. This chlorimuron carryover injury was from August-planted soybean but did not occur from June-planted soybean. Norflurazon, fluometuron, and chlorimuron temporarily reduced rice dry matter early in the season. No herbicide reduced either rough rice or percent head rice yield on any of the soils.

Broadleaf Signalgrass (Brachiaria platyphylla) Duration of Interference in Rice (Oryza sativa)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 747-750 ◽  
Author(s):  
John T. McGregor ◽  
Roy J. Smith ◽  
Ronald E. Talbert
Keyword(s):  
Rice Yield ◽  
Dry Weight ◽  
Kernel Weight ◽  
Rough Kernel ◽  
Weed Interference ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Rice Yields ◽  
Brachiaria Platyphylla

Interference from broadleaf signalgrass at a density of 180 plants/m2reduced rough rice yields of ‘Bond’ a maximum of 48% at 95 days after rice emergence and reduced yields of ‘Mars' a maximum of 21% from season-long interference. Interference durations of 40 days or longer reduced the panicles/m2, culms/m2, and plant height of rice. Straw dry weight of Bond and Mars was reduced 41 and 26%, respectively, from season-long interference. Increased durations of weed interference did not affect the number of spikelets/panicle, percent filled spikelets, rough kernel weight, or head rice yield of either cultivar. Broadleaf signalgrass produced less dry weight and fewer panicles/m2when grown with Mars than with Bond.

Impacts of Specific Power of Microwave at 915 MHz Frequency on Drying and Milling Characteristics of Parboiled Rough Rice

2021 ◽  
Vol 37 (2) ◽  
pp. 359-366
Author(s):  
Deandrae Lynette Smith ◽  
Griffiths G. Atungulu
Keyword(s):  
Rice Yield ◽  
Least Square ◽  
Specific Power ◽  
Drying Rate ◽  
Milled Rice ◽  
Volumetric Heating ◽  
Parboiled Rice ◽  
Rough Rice ◽  
Milling Characteristics ◽  
Drying Rates

HighlightsThis research investigated the feasibility of using a microwave (MW) set at 915 MHz frequency to dry high moisture content (MC) parboiled rough rice at 44.3% MC dry basis (d.b.).The research evaluated the impacts of specific power delivered during the drying of parboiled rough rice using a MW on post-drying milling characteristics.The volumetric heating phenomenon provided by MW offered a method to quickly remove 23.1% points of moisture from parboiled rough rice in one-pass to a MC of 21.2% d.b., with minimal impacts on the kernel quality.The findings suggest that increased MW specific powers have a positive effect on rice MC reduction but negatively affects the rice milling characteristics, especially the head rice yield.The study recommended that MW specific powers exceeding 2.92 kW.[kg-DM]-1 should not be exceeded during drying of parboiled rough rice to preserve the rice milling yields.ABSTRACT. The objectives of this research were to study the impacts of specific power of MW generated at 915 MHz frequency to dry high MC parboiled rough rice on moisture removal and milling characteristics of the parboiled rough rice. Long-grain rough rice of the cultivar (cv.) Mermentau at harvest MC of 31.6% dry basis (d.b.) was parboiled by soaking at 73°C for 3 h and then steamed at 67 kPa for 10 minutes. Following the parboiling process the sample was subjected to the MW drying. The drying was accomplished at MW specific powers that ranged from 1.10 to 8.77 kW. [kg-DM] -1 and 0.37 to 2.92 kW. [kg-DM] -1 (power per unit dry matter mass of the grain). These treatment levels of MW specific power were varied by heating parboiled rough rice for 2 and 6 minutes (min) at MW powers that ranged from 1 to 24 kW. The process of parboiling increased the rough rice MC to 44.3% dry basis (d.b.). During the MW drying, as the specific power increased, the general tendency was for rough rice final moisture content (FMC), milled rice yield (MRY) and head rice yield (HRY) to decrease while the drying rate increased. Parboiled rough rice samples treated with a specific power of 8.77 kW.[kg-DM] -1 while maintaining specific energy input at 0.29 kWh.[kg-DM] -1 had least-square means FMC, drying rate, MRY and HRY of 19.7% d.b. (S.D ± 1.1%), 12.3% d.b. [min-1] (S.D ± 0.8%) (2 min drying duration), 68.18% (S.D ± 1.70%) and 67.51% (S.D ± 0.73%) respectively. However, treatment at a lower specific power of 2.92 kW.[kg-DM] -1 while maintaining the same specific energy input of 0.29 kWh.[kg-DM]-1) resulted in least-square means FMC, drying rate, MRY and HRY of 21.2% d.b. (S.D ± 0.5%), 3.9% d.b. [min-1] (S.D ± 0.1%) (2 min drying duration), 73.22% (S.D ± 0.84%) and 73.21% (S.D ± 0.21%) respectively. The increased drying rates for treatments with higher specific power was associated with higher treatment powers and shorter treatment durations. Higher specific powers negatively impacted the observed MRY and HRY. The findings suggest that increased MW specific powers have a positive effect on rice MC reduction but above a certain threshold of specific power (2.92 kW.[kg-DM]-1) may negatively affect the milling characteristics of the parboiled rice. When used to dry high MC parboiled rough rice, rice processors should know that there exists an optimum drying rate that if exceeded the milled rice quality is negatively affected thus generating an economic loss to the parboiled rice industry. The volumetric heating phenomenon provided by microwave (MW) offers a means to quickly dry high MC parboiled rough rice. This can translate to considerable economic savings for the rice processor who often experiences low drying rates because of limited drying capacity, especially at peak rice harvest times. When drying rates are optimized, rice processors can expect minimal impacts on the kernel quality which can also be translated to considerable economic savings for the rice processor. Keywords: 915 MHz microwave, Microwave drying, Milling Quality, Parboiled rice, Specific power.

Effect of Post-Drying Tempering of Rice on Minimizing Kernel Fissuring and Maximizing Moisture Removal

2021 ◽  
Vol 65 (1) ◽  
pp. 1-9
Author(s):  
Zephania Odek ◽  
Terry J. Siebenmorgen ◽  
Andronikos Mauromoustakos ◽  
Griffiths G. Atungulu
Keyword(s):  
Rice Yield ◽  
Yield Reduction ◽  
List Type ◽  
Humidity Ratio ◽  
Percentage Points ◽  
X Ray Imaging ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Rice Drying

HighlightsMore moisture can be removed in a single drying pass without severely fissuring kernels when samples are tempered than when immediately cooled without tempering.Tempering rice kernels immediately after drying can reduce the percentage of fissured kernels by up to half of that when kernels are immediately cooled without tempering.Abstract. Improper rice drying results in kernel fissuring, leading to head rice yield reduction due to breakage during milling. The objective of this study was to determine the percentage points (pp) of moisture content (MC) reduction that can be achieved in a single drying pass without significantly fissuring kernels. Long-grain rough rice of cultivars CL XL745 and Diamond at initial MCs of 18%, 17%, 16%, 15%, and 14% were dried using air at 45°C/20% relative humidity (RH), 50°C/15% RH, 55°C/12% RH, 60°C/10% RH, and 65°C/8% RH to MCs of 17%, 16%, 15%, 14%, 13%, or 12% with and without post-drying tempering. All temperature/RH combinations resulted in a humidity ratio of 0.012 kg water kg-1 dry air. Tempering was conducted at the drying air temperature for 4 h. The resulting samples achieved between 1 and 7 pp of MC reduction in a single drying pass. The pp of MC reduction that can be attained in a single drying pass without causing significant fissuring varied across the cultivars tested. Generally, ~2 pp of MC reduction was achieved in a single drying pass for CL XL745 and ~4 pp for Diamond without causing adverse fissuring when samples were not tempered after drying. However, with tempering, ~3.5 pp of MC reduction was achieved in a single drying pass for CL XL745 and ~5.5 pp for Diamond without causing significant fissuring. However, these amounts varied depending on the drying air conditions and initial MC. For both cultivars, tempering immediately after drying reduced the fissured kernel percentage by up to half of that when the kernels were not tempered. These findings quantify the importance of rice tempering and provide information on how much moisture can be safely removed in a single drying pass. Such findings may be applied to different dryer types to reduce fissuring due to drying, thereby minimizing head rice yield reductions. Keywords: Drying, Glass transition, Rice quality, Single-pass drying, X-ray imaging.

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