Role of Moisture Content in Affecting Head Rice Yield

1993 ◽  
pp. 357-396
Keyword(s):  
Moisture Content ◽  
Rice Yield ◽  
Head Rice ◽  
Head Rice Yield

scholarly journals Method of producing parboiled rice without steam by fluidized bed dryer

2020 ◽  
Vol 187 ◽  
pp. 01002
Author(s):  
Asadayuth Mitsiri ◽  
Somkiat Prachayawarakorn ◽  
Sakamon Devahastin ◽  
Wathanyoo Rordprapat ◽  
Somchart Soponronnarit
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Rice Yield ◽  
Experimental Result ◽  
Rice Starch ◽  
Parboiled Rice ◽  
Starch Gelatinization ◽  
Fluidized Bed Dryer ◽  
Head Rice ◽  
Head Rice Yield

A more simple methodology of producing parboiled rice is subject to be investigated in this work with proposed the method, the gelatinization of rice starch, commonly taking place at the steaming step in the traditional process, and drying are combined and replaced by a hot air fluidized bed dryer. A pilot-scale continuous fluidized bed, with a maximum capacity of 140-150 kg/h, has been designed, constructed and tested. Suphanburi 90 paddy variety with high amylose content was dipped into hot water at temperatures of 70, 80, 83°C for 4.0, 3.3, 3.2 h, respectively, to get the moisture content around 47-55% db and dried at 150-170°C using air speed of 3.5 m/s. The paddy bed depth within the dryer was 3 and 5 cm. In the dryer operation, the exhaust air was fully recycled and reheated again by 30 kW electrical heaters to the desired temperature. The experimental result has shown that parboiled rice with a different degree of starch gelatinization could be produced by this technique. The degree ranged between 80-100% as examined by differential scanning calorimeter. The exit moisture content was given in a range of 14-21% db, relying on the drying temperature and soaking time. The aforementioned exit moisture contents were not a detrimental effect on head rice yield although the tempering was not included. The head rice yield was given in the range of 59-66%, depending on the degree of starch gelatinization. The starch granules lost their original shape as revealed by scanning electron microscope.

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.

scholarly journals Effect of Varying Parboiling Conditions on Head Rice Yield for Common Paddy Varieties in Iran

2018 ◽  
Vol 21 (1) ◽  
pp. 1-7
Author(s):  
Fatemeh Rahimi-Ajdadi ◽  
Ezzatollah Askari Asli-Ardeh ◽  
Adel Ahmadi-Ara
Keyword(s):  
Moisture Content ◽  
Rice Yield ◽  
Drying Temperature ◽  
Milling Quality ◽  
Parboiled Rice ◽  
Head Rice ◽  
Rubber Roller ◽  
Head Rice Yield ◽  
Higher Temperature ◽  
Main Effects

AbstractVarious conditions of a parboiling process affect the qualitative parameters of paddy milling. In this study, the effects of drying temperature (45 and 60 °C), moisture content (8, 10 and 12% w.b.), steaming time (10, 20 and 30 min) and paddy varieties (Hashemi and Alikazemi) were investigated on head rice yield (HRY). The samples were husked using a rubber roller husker and whitened by a laboratory abrasive whitener. Results showed that the main effects of all parameters were significant onHRY(P<0.01). The utilization of higher temperature (60 °C), in comparison with non-parboiled rice, without reducing the milling quality was found as one of the advantages of parboiling. Among all experiments, the highestHRY(68.647%) was achieved in the combination of Alikazemi/45 °C/10 min/8%. In the majority of cases, the combinations including Alikazemi variety had higherHRYthan Hashemi. For Hashemi variety, the highestHRY(67.297%) was achieved in combination 45 °C/10 min/8%. In terms ofHRY, parboiling causes an increase of 25.8% and 43.3% respectively for Hashemi and Alikazemi. Therefore, it is highly recommended in processing of Alikazemi variety.

Establishment of Rice Quality Prediction Model for Intermittent Drying

2021 ◽  
Vol 64 (4) ◽  
pp. 1355-1363
Author(s):  
Qi Song ◽  
Xinhua Wei
Keyword(s):  
Moisture Content ◽  
Prediction Model ◽  
Intelligent Control ◽  
Evaluation Method ◽  
Rice Yield ◽  
Drying Process ◽  
Rice Quality ◽  
Head Rice ◽  
Head Rice Yield ◽  
Rice Drying

HighlightsThis study explored the feasibility of developing an evaluation method for rice quality.A unified quality scale for different drying cycles facilitates evaluation of rice quality after drying.A head rice yield (HRY) prediction model was established that fit well with the actual HRY.The established HRY prediction model can be used as a performance index for optimization of rice drying.Abstract. Intelligent control of the drying process is important to achieve better rice quality. An effective quality evaluation method is the basis for intelligent control of rice drying. To study the effects of intermittent drying on the quality of paddy rice and explore the feasibility of establishing a quality evaluation method, intermittent drying experiments were conducted with variety Nanjing 9108 (Oryza sativa L.). The paddy samples were dried from an initial moisture content of 23.10% to 14% wet basis (w.b.). The paddy samples were initially dried at 60°C to various moisture contents without tempering. These pre-dried samples were then dried using different drying temperatures to obtain specific moisture content reductions, tempered, and then dried again at 60°C to the final moisture content of 14% w.b. without tempering. After drying, the quality parameters of the paddy samples were measured and analyzed. The R2 values of the head rice yield (HRY) prediction model, chalkiness prediction model, and protein prediction model established in this study were 0.75, 0.44, and 0.26, respectively. The HRY prediction model was shown to accurately predict HRY in the intermittent drying experiments. Within the range of the model parameters, the effectiveness of the HRY prediction model was explored by constant-temperature intermittent drying and variable-temperature intermittent drying. The results showed that if the summation of the predicted changes in HRY is large, then the measured HRY will be large. Therefore, the HRY prediction model can be used as a performance index for rolling optimization of the paddy drying process. Keywords: Head rice yield, Intermittent drying, Prediction model, Rice quality.

Head rice yield response to low and high drying and tempering conditions

2013 ◽  
Vol 27 (2) ◽  
pp. 219-223 ◽  
Author(s):  
M. Sadeghi ◽  
E. Nasrnia ◽  
A.A. Masoumi ◽  
A. Hemmat
Keyword(s):  
Moisture Content ◽  
Rice Yield ◽  
Yield Response ◽  
Rice Varieties ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield ◽  
Yield Values ◽  
High Head ◽  
Drying Conditions

Abstract The influence of drying and tempering conditions on head rice yield of long- and medium-grain rough rice varieties was investigated. The head rice yield values for the medium-grain variety at high drying conditions and 1.5 and 3% points moisture content removal were even significantly higher than the corresponding values for the long-grain variety at low drying conditions. 1.5% points moisture content removal yielded the least damage to the rough rice. Under low drying conditions, tempering had no meaningful effect on head rice yield for all drying durations. For both varieties, using high drying conditions with 6% points moisture content removal at first drying stage associated with 120 min tempering duration could be suggested as a rapid and energysaving operation to achieve high head rice yield values.

scholarly journals Modified Steaming Method for Parboiled Rice Production

2020 ◽  
pp. 30-34
Author(s):  
Thatchapol Chungcharoen ◽  
◽  
Anupong Meekotekong ◽  
Warunee Limmun ◽  
Naruebodee Srisang
Keyword(s):  
Thermal Properties ◽  
Moisture Content ◽  
Rice Yield ◽  
Initial Moisture Content ◽  
Experimental Results ◽  
Drying Process ◽  
Rice Sample ◽  
Parboiled Rice ◽  
Head Rice ◽  
Head Rice Yield

A modified steaming method (steam using the revolved sieve; SRS) was applied to produce parboiled rice and the qualities of parboiled rice, namely, thermal properties (enthalpy; ΔH and degree of starch gelatinization: DG), head rice yield (HRY) and whiteness index (WI) were investigated under various steaming times and temperatures. The experimental results indicated that time and temperature during steaming step affected the parboiled rice qualities significantly. Prolonged time and increase of temperature during steaming provided the higher initial moisture content and grain temperature of rice sample after steaming, leading to longer time in drying process for decreasing the moisture content in the rice sample to 22% (d.b.). This provided the decrease of ΔH, leading to increase in the DG and resulting in the higher HRY and lower WI values.

Exploration of Rough Rice Head Yield Subjected to Drying and Retention Durations in a Fluidized Bed System

2018 ◽  
Vol 34 (5) ◽  
pp. 877-885 ◽  
Author(s):  
Kaushik Luthra ◽  
Sammy Sadaka ◽  
Griffiths G Atungulu
Keyword(s):  
Thermal Stress ◽  
Energy Consumption ◽  
Moisture Content ◽  
Fluidized Bed ◽  
Rice Yield ◽  
Retention Period ◽  
Fluidized Bed Dryer ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield

Abstract.Several researchers have reported that drying freshly harvested rough rice to safe storage moisture content of 14.9% d.b. in fluidized bed dryers resulted in a decrease in head rice yield, as compared with traditional drying methods. This phenomenon was attributed to the high thermal stress that affects rice kernels. The present study hypothesized that drying rough rice in fluidized bed dryers subjected to retention duration would maintain the rice quality as it may reduce the thermal stress. Therefore, the goal of this research was to investigate the effects of heating and retention durations on the dried rice head yield and energy consumption in a fluidized bed dryer. A bench-scale fluidized bed dryer was developed and tested. The effects of drying duration of 10, 20, and 30 min and the retention duration of 0, 15, 30, 45, and 60 min on rough rice moisture content, drying rate, head rice yield, and energy consumption were investigated. During the retention period, paddy released a considerable amount of moisture. This moisture reduction, achieved during retention period, was obtained without any additional heating cost and was a supplement to the overall drying process. The retention period helped with thermal stress management within rice kernels and resulted in maintaining the head rice yield as compared to the rice dried without retention duration. Considering all the studied heating and retention durations, the head rice yield values of rice samples varied from 46.0% to 51.0%. The lowest energy consumption of 3.31MJ/kg waterremoved was achieved at the heating duration of 10 min and the zero retention duration. This value represents 1.44 folds of the theoretical energy required to remove 1 kg of moisture from organic matter. Keywords: Drying, Energy consumption, Head rice yield, Moisture content, Retention duration, Rough rice.

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