• 농업과학연구
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• 제44권3호
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• pp.416-423
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• 2017

This study aimed to identify milling characteristics depending on the rotating speed of the main shaft of the cutting-type rice milling machine which can minimize the conventional milling process. Brown rice, which was produced in Gunsan-si, Jeollabuk-do, Republic of Korea, in 2016, was used as the experimental material. The milling characteristics of white rice were measured under four different rotating speeds of main shaft: 950 - 1,050 rpm, 1,000 - 1,100 rpm, 1,050 - 1,150 rpm, and 1,100 - 1,160 rpm. For each shaft speed, 300 kg of brown rice was processed, and the milling characteristics were measured according to the whiteness, grain temperature, cracked rice ratio, broken rice ratio, turbidity, and energy consumption. The whiteness of rice grain was found to be consistent at around $40{\pm}0.5$ only when milled at the shaft speed of 950 - 1,050 or 1,000 - 1,100 rpm. The grain temperature during the milling process increased by 11.35 to $11.85^{\circ}C$, showing little differences amongst shaft speeds. The cracked rice ratio increased by 8.2 to 10.4% at all conditions. The broken rice ratio ranged from 0.58 to 0.76%, reflecting a low level. The turbidity after milling was 54.8 ppm when milled at 1,000 - 1,100 rpm. Energy consumption of 12.98 and 12.18 kWh/ton were recorded at the shaft speed of 1,000 - 1,100 and 1,050 - 1,150 rpm, respectively. The result of this study indicates that the optimal rotating speed of main shaft would be 1,000 - 1,100 rpm for a cutting-type rice milling machine.

• Journal of Biosystems Engineering
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• 제26권2호
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• pp.115-122
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• 2001

An impact-type seed-metering device was developed for the planting of rice-pellets. In this study, new design of pellet-metering device focused on simplicity and precision seeding for the planting of rice-seed pellets. In addition of seed-metering device, several devices were also developed such as seed-guiding device, seed-supplying tube and furrow opener for precision pellet planting. Field test was conducted to estimate the planting performance of the developed metering device. As a cam rotates, the impact bar of the metering device pushes a rice-seed pellet so that the seed can be discharged from the seed-supplying tube in the impact-type seed-metering device. Results of the tests showed that mean seeding spacing was 12cm at the traveling speed of 1.0m/s, corresponding to a target spacing for planting of rice-seed pellets. Also, both miss-seeded rate and damaged-seed rate were less than 2.0%, indicating acceptable levels for the precision planting. The developed mechanism of the impact-type metering device can be directly applied to the design of metering devices for the precision pellet planting of other crops.

• Journal of Biosystems Engineering
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• 제6권1호
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• pp.73-82
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• 1981

The physical properties of grain are very important for the design of handling, sorting, processing, and storage system. On the physical properties of grain, volume, bulk density, true density, specific gravity, and porosity arc the major factors affecting the thermal properties of grain. This study was conducted to determine experimentally the above physical properties of rough rice (3 Japonica-type, 3 Indica-type) and barley (covered, naked) as a function of moisture content ranged from about 10% to 25% (w.b). The results of this study are summarized as follows; 1. The volume of grain kernel increased with moisture content for both rice and barley. The volume of those grain kernel was in the range of $2.2068{\times}10^{-8}{\sim}3.3960{\times}10^{-8}m^3$ at the moisture content of 14%. 2. The bulk density of rice increased linearly with moisture content for Japonica-type rough rice and quadratically for Indica-type rough rice, but the bulk density of barley decreased linearly with moisture content. The bulk density of the grain was in the range of 501.14~689.13kg/$m^3$ at the moisture content of 14%. 3. The true density of whole grain decreased linearly with moisture content, and was in the range of 1019.49~1139.75kg/$m^3$ at the moisture content of 14%. 4. The porosity of rice decreased linearly with moisture content for Japonica-type rough rice and quadratically for Indica-type rough rice, but the porosity of barley increased linearly with moisture content. The porosity of the grain was in the range of 39.51~50.83% at the moisture content of 14%. 5. The regression equations of the physical properties such as volume, bulk density, true density, and porosity of the grain were determined as a function of moisture content.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.253-253
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• 2017

Recently, strong interest in the well-being and healthy food trends lead a spreading of rice processing products such as rice noodles, rice breads, and rice cakes. However, most of rice varieties developed in Korea showed very limited processing properties in processing of noodles compare to that of wheat flour. Moreover, low competitiveness as a raw processing materials due to high price give poor evaluations for rice noodles processing. To cope those barriers, 'Saemimyeon' a Tongil type high yielding variety with a high amylose contents was developed in RDA. 'Saemimyeon' showed about 10~32 % of increase in yield as 7.08MT/ha and 26.7% of high amylose contents together with easy grinding property of 65.7% of high chalkiness ratio. The both of milled as well as brown rice of 'Saemimyeon' were well fit for processing properties in rice pasta where the contents of rice flour for rice pasta was 99% (1% of Tapioka starch was intermixed in to the rice flour). A spaghetti type for wet noodles and macaroni type for dry noodles were developed, respectively. Each of pasta were showed relatively more or less an equal quality and panel test compare to that of durum wheat pasta products. Finally, rice pasta products could suggest an alternative idea for a new rice processing items where rice noodles market was stagnant.

• Asian-Australasian Journal of Animal Sciences
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• 제24권3호
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• pp.421-428
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• 2011

Low-fat sausages with or without 10% hydrated rice flour were made from duck, chicken and pork and their physical and sensory properties were compared. Results showed that moisture content did not differ significantly among the sausage batters. However, crude protein, crude fat and total ash content were significantly lower in the group with added rice flour compared with the no flour group. Crude protein and crude fat were the highest in pork sausages without rice flour (p<0.05). Adding 10% rice flour reduced total expressible fluid in all meat type sausages. Cooking loss was also decreased when 10% rice flour was used in making sausages from chicken and pork. However, no changes in cooking loss were found in duck meat by adding rice flour. Again, the highest cooking loss was in pork sausages without rice flour and lowest in chicken sausages with 10% rice flour. The pH of the meat from different animal species differs significantly, although no significant difference was found within meat types with or without rice flour. Lightness ($L^*$) increased, while redness ($a^*$) decreased with adding rice flour in all meat type sausages. Results showed that hardness was significantly reduced when 10% rice flour was added to pork, chicken and duck meat (p<0.05). This may be due to increased water retention of rice flour after cooking. Sensory evaluation indicated that the overall acceptability of pork and chicken sausages with or without rice flour was the same, but duck sausages without rice flour had the highest off-flavor score among the sausages. Addition of rice flour increased the overall acceptability of duck sausage to that of pork and chicken sausages.

• 한국작물학회지
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• 제44권1호
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• pp.64-69
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• 1999

Gelatinization characteristics of 111 glutinous rice varieties were evaluated by Rapid Visco Analyzer. Gelatinization viscosity of glutinous rice tested varied with ecotypes or varietal groups: indica, japonica, and Tongil type. Indica rice showed the highest average value of initial pasting temperature. The average values for peak, hot, and cool viscosities were highest in Tongil-type rice, and lowest in japonica rice. Japonica showed the lowest breakdown and consistency, but the highest setback value. Indica was lower in alkali digestion value (ADV), and shorter in gel length after gelatinization thanjaponica and Tongil-type. Glutinous rices tested could be divided into six groups by cluster analysis based on their gelatinization characteristics. Group I-A was mostly early maturing japonica varieties while I-B was mostly indica and Tongil-type rices. Groups II-A and II-B were consisted of very early maturingjaponica, and III-A and III-B included medium or medium late maturingjaponica varieties. Group III-A showed the lowest average values of peak, hot, cool, and consistency viscosities, and also in breakdown and setback ratios. Group I-B revealed the highest values in peak, hot, cool, breakdown, and consistency viscosities. ADV was low in groups I-A, I-B, and II-B, and gel consistency was not different among the six varietal groups. Principal component analysis using seven traits related with gelatinization produced four effective components, and the first and second components were highly correlated with all the gelatinization characters evaluated.

• 한국식생활문화학회지
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• 제36권5호
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• pp.484-491
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• 2021

This study investigated the effect of dry heat treatment (DHT) on the physicochemical properties of hard type (HR) and floury type (FR) rice to improve the processing aptitude of rice flour. The rice flour was heated at 130℃ for 0, 2 and 4 hours, and the color value, water absorption index (WAI), water soluble index (WSI), swelling power, solubility, pasting properties, particle shape and the X-ray diffraction were measured. After DHT, the L value of rice flour decreased, and the b value increased. The WAI, WSI, swelling power and solubility of HR and FR increased with the increase of treatment time. The cold viscosity and setback increased, while breakdown decreased. Cracks and lumps formed with fine particles were observed. The X-ray diffraction pattern was A-type, while the diffraction intensity decreased. According to the results of the two-way analysis of variance (ANOVA) test, the hydration and pasting properties were significantly different between HR and FR and were affected by DHT time. The results suggest that the properties of modified rice flour by DHT can be used in the food industry.

• 농업과학연구
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• 제48권2호
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• pp.273-281
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• 2021

These days, different types of yogurt are being manufactured by adding various starters and functional ingredients for health. The purpose of this study was to prepare yogurt added with rice followed by fermentation with two types of starters and to examine its attributes. Ten percent of skim milk powder and 0, 2.5, 5.0, 7.5, or 10% rice were mixed in water (w/v) and then inoculated with two types of starter: 1) Type A, Streptococcus thermophiles and Lactobacillus delbrueckii ssp. bulgaricus as starter; and 2) Type B, Streptococcus thermophiles, Lactobacillus acidophilus, and Bifidobacteium animalis ssp. lactis as starter. The pH of B type yogurt was lower (p < 0.05) than that of A type yogurt from 6 hours to 14 hours after fermentation. The number of microorganisms in all fermented milk showed maximum increases at 2 and 6 hours of fermentation (p < 0.05). The number of microorganisms in fermented milk peaked at 6 hours after fermentation and maintained this level thereafter. There was no effect of rice addition on microbial growth or acidity of the fermented milk. Sensory attributes of yogurt samples with and without added rice were not significantly different. This experiment showed that the production efficiency of yogurt with added rice was not different when two different types of starters were used to manufacture yogurt.

• 한국식품과학회지
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• 제33권5호
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• pp.540-544
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• 2001

거대배아미 4품종과 각각의 일반미 4품종 등 8품종의 현미를 이용하여 간편식인 flake 제조에 대한 품질특성을 비교하였다. 쌀눈의 영양성분을 그대로 섭취할 수 있는 곡립상 현미 flake을 제조하기 위하여 우선 수침온도와 시간별 용출된 환원당함량, 수분흡수율, 쌀알의 경도를 측정하여 $60^{\circ}C$에서 5시간 수침한 후 곡립상 현미 flake을 만들었다. 일반품종으로 제조한 flake들에 비해서 거대배아미 품종으로 제조한 flake가 팽화도가 높고, 경도는 낮으며, 아삭아삭한 정도가 높은 바람직한 물성을 나타내었다. 거대배아미 품종으로 제조한 flake들의 bowl life가 일반품종들에 비해서 긴 경향이 있었으며, 특히 화청찰거대배아미로 제조한 현미 flake의 bowl life가 가장 길고, 화청벼로 제조한 현미 flake의 bowl life가 가장 짧았다. 제조된 flake의 전반적인 기호도는 메벼, 찰벼에 상관없이 거대배아미 품종으로 제조한 것들이 높았으며, 일반 품종간에서는 찰벼로 제조한 것이 메벼로 제조한 것보다는 유의적으로 높았다. 수침에 따른 수분흡수율은 제조된 flake의 bowl life 및 아삭아삭한 정도와 정의 상관성을 가지며 현미 flake의 수분흡수지수는 팽화도 및 bowl life와는 정의 상관성이 있었다. 관능검사상의 경도와는 부의 상관성이 있음을 알 수 있었다. 따라서 시험된 8개의 품종중에서 신선찰거대배아미 및 화청찰거대배아미 품종이 flake 제조에 가장 적합하였다.

• Journal of the Korean Wood Science and Technology
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• 제31권3호
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• pp.42-49
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• 2003

The objective of this research was to investigate the possibility of using rice husk flour as a partial substitute for the wood particles used as the raw material for manufacturing particleboards, by examining the physical and mechanical properties of the rice husk flour-wood particleboard as a function of the type of urea-formaldehyde resin used. Commercial wood particles and two types of rice husk flours (A type (30 ㎛), B type (300 ㎛)) were used. E₁ and E₂ class urea-formaldehyde resin was used as the composite binder, combined with 10 wt.% NH₄Cl solution as a hardener. Rice husk flour-wood particleboards with dimensions of 27×27×0.7 (cm) were manufactured at a specific gravity of 0.7 with rice husk flour contents of 0, 5, 10, and 15 (wt.%). We examined the physical properties (specific gravity and moisture content), mechanical properties (three point bending strength and internal bonding) of the composite. In general, it can be concluded that composites made from rice husk flours are of somewhat poorer quality than those made from wood; however, blending in small amounts of rice husk flour (e.g., 5% to 10% by weight) may have no significant impact on quality.