• Journal of Biosystems Engineering
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• 제37권3호
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• pp.184-191
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• 2012

Purpose: This study was conducted to investigate the storage and quality characteristics of brown rice under the low temperature warehouse conditions using ambient cold air in the winter. Methods: This new technique maintains rough rice warehouse temperature below $15^{\circ}C$ without cooling operation until the end of May. Four hundred tons of rough rice were stored in the low temperature grain warehouse, and were aerated from the top to the bottom using ambient cold air in February. The quality of rough rice was evaluated from February through October. Results: The results were as followings. Moisture contents of rough rice in the low temperature storage had decreased less than the ordinary temperature storage. Cracked rate of brown rice in the ordinary temperature storage and low temperature storage increased by 4~10.8% and 1.6~7.2%, respectively. The germination rate of rough rice under the ordinary and the low temperature warehouse decreased by 15.0~25.0% and 1.7~8.0%, respectively. The acid value of brown rice under the ordinary and the low temperature warehouse increased by 3.67~6.72 KOH mg/100g and 3.08~4.08 KOH mg/100g, respectively. Conclusions: The result indicates that low temperature storage using ambient winter air showed better maintaining germination of rice, less change of physiological activities and cracked kernel, and better maintaining of rice quality, comparing the ordinary temperature storage.

• Journal of Biosystems Engineering
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• 제23권5호
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• pp.465-472
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• 1998

In this study short gain rough rice(Chu-cheong) with initial moisture content of around 12%(w.b.) was exposed to 3 levels of relative humidity(70, 80 and 90%) and 3 levels of temperature(20, 25 and 3$0^{\circ}C$) of the air, in order to evaluate the adsorption characteristics of rough rice and the rate of cracked kernels which will serve as the basic data when developing the quality adjusting equipment. The result showed that the moisture content of rough rice increased rapidly during the early stages of moisture adsorption like other grains, and at least 70% of the adsorption occurred within the first 24 hours of exposure to the humid environment. Adsorption rate was more related to relative humidity than the temperature of air stream, and the higher the relative humidity, the higher the adsorption rate. And the Page's equation predicted best the adsorption process of this study. Experimental results for the crack generation during the adsorption process showed that the higher the relative humidity the more the cracked kernels, and that the temperature had little effect. An empirical equation was developed to predict the crack ratio for the conditions of this study, and Nishiyama model predicted better the crack generation than Hoerl model.

• Journal of Biosystems Engineering
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• 제16권1호
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• pp.49-59
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• 1991

A numerical model was developed to predict grain temperature, moisture content, and drymatter loss of rough rice in a grain storage bin. This model simulated conduction, natural convection, and mass transfer occuring inside a storage bin. The results obtained from the study were as follows. 1. The predicticted results agreed well with the measured results. 2. Rough rice could be store safely for one year in Suweon, Dajeon, and Jingu area. 3. Aeration of 5-day was required to control grain temperature and moisture content rise early in Jun and July, respectively.

• 한국작물학회지
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• 제51권spc1호
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• pp.12-20
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• 2006

정조 함수율과 저장온도에 따른 쌀 품질 변화를 구명하고자 신동진벼와 동진1호를 함수율 $13{\sim}14,\;15{\sim}16,\;{\sim}18%$로 조절하여 상온 및 저온에서 저장기간에 따른 품질관련 특성을 조사하였다. 1. 정조 함수율이 많고 저장온도가 높을수록 호흡율이 높았으며 함수율에 의한 호흡율의 차이가 저장온도에 의한 차이보다 컸다. 2. 발아율은 16개월 저온저장후 80%이상을 유지하였으나 상온에서는 저장기간이 경과함에 따라 급격히 감소하였으며 12개월 저장까지는 함수율이 높은 $17{\sim}18%$에서 발아율이 높았으나 그 이후에는 $15{\sim}16%$에서 높았고, $13{\sim}14%$에서는 16개월 저장후 10%이하의 낮은 발아율을 나타냈다. 3. 밥의 윤기치는 저장 초기에 급격히 감소하다가 그 후 완만해졌으며 저온에서 상온에 비하여 높았고 함수율이 많을수록 높게 유지되다가 12개월 후에는 큰 차이가 없었다. 4. 현미지방산도는 저장기간이 경과할수록 8개월까지 급격히 증가하였으며 저온에서 상온보다 낮았고, 신동진벼가 동진1호에 비하여 낮은 경향이었다. 5. 식미관능평가치는 상온에 비하여 저온저장에서 양호하였고 신동진벼가 동진1호에 비하여 높았으며 저온저장 16개월 후 신동진벼는 함수율 $17{\sim}18%$에서, 동진1호는 $15{\sim}16%$에서 우수하였으며 상온저장시는 신동진벼와 동진1호 모두 함수율 $15{\sim}16%$에서 좋았다. 6. 식미관능평가치는 현미색도 b값 > 밥의 윤기치 > 현미 색도 L값의 순으로 각각 0.731**, 0.625*, 0.615*의 정의 상관성을 나타냈으며 강하점도, 최고점도, 호화개시온도, 현미 지방산도와는 각각 -0.864**, -0.795**, -0.786**, -0.779**의 고도로 유의한 부의 상관성을 나타냈다.

• Journal of Biosystems Engineering
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• 제14권2호
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• pp.115-122
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• 1989

The objective of this study was to develop a portable auger for handling rough rice in bulk. For this purpose, a system analysis was taken for the systems of harvesting, drying, storage and transportation of rough rice and an optimal handling capacity of portable auger was determined. Then a portable auger of which capacity is 9.2 $m^3/h$ (Indica type rough rice, 19.5%, w.b.) was designed and manufactured by design requirements and tested. Test results showed that the performance of portable auger developed satisfied most design requirements.

• Journal of Biosystems Engineering
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• 제36권4호
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• pp.267-272
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• 2011

The latent heat of vaporization in rough rice, brown rice, white rice and rice hull was calculated by Clausius-Clapeyron equation, which does not require complex constraints as in Othmer method. Equilibrium relative humidity and ratio of the latent heat of vaporization with ln$P_{\upsilon}$ and ln$P_S$ were estimated with moisture contents ranging from 10% (d.b.) to 36% (d.b.) with 2% (d.b.) increment and temperatures ranging from $10^{\circ}C$ to $50^{\circ}C$ with $2.5^{\circ}C$ increment. An empirical equation for calculating the latent heat of vaporization in rice was developed as a function of moisture content and temperature. The equation agreed well with the calculated results. The ratio for latent heat of vaporization were the greatest for white rice while they were similar among rough rice, brown rice and rice hull.

• 한국작물학회지
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• 제36권3호
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• pp.266-270
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• 1991

미곡의 장기보관에서 보관면적과 소요비용을 절약하려면 정조보관보다 현미 또는 백미로 보관하는 것이 용이하다. 그러나 미곡의 고미화와 식미 악화가 우려되어 본 연구에서는 20개월간 정부창고에서 보관된 벼품종들을 정조, 현미, 백미로 가공하고 각각 지대, PP대, PE대에 포장하여 수확 후 32개월째에 발아력, 지방산도, 식미를 검정하였다. 1. 발아율은 장기 보관함에 따라 감소하였고 밀양 2003보다 추청의 감소가 심하였다. 가공상태에 따라 현미로 제현하여 보관하면 발아율 감소가 현저하였고 포장재질에 따른 차이는 없었다. TTC검정도 유사한 경향을 보여 발아력의 간접검정법으로 이용될 수 있었다. 2. 지방산도는 정조<백미<현미 순으로 높아졌고 포장재료에 따라서는 PP대<지대<PE대 순으로 증가되었다. 특히 현미 보관은 지방산도가 KOH 30mg 이상에 달하여 고미화 특성을 보였고 이를 방지하려면 정조를 지대 또는 PP대에 보관하거나 백미는 지대, PP대, PE대에 보관하여 도 무난하였다. 3. 저장미곡의 식미는 도정보관에 따라 악화되었고 특히 현미보관에서 백미보관 보다 불량하였는데 호분층에 포함된 지방의 산패 때문이었다. 또 품종별로 지방산도가 증가함에 따라 식미는 불량하여 졌다.

• Journal of Biosystems Engineering
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• 제25권1호
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• pp.33-38
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• 2000

This study was performed to investigate airtight storage characteristics of rough rice using airtight flexible pve container. A storage test of rough rice of 4 tonnes was carried out to determine the changes of gas composition of air in the container, grain moisture content, air temperature and relative humidity , the presence of insects ,germination rate, crack ratio , fat acidity , 1000-kernel weight, and brown rice recovery over storage period of 5 months in Suwon. Concentration of oxygen was decreased from 20% to 16% and carbon dioxide was increased of from 0.03% to 1.6%. The grain moisture content was decreased from 14.4%(w.b) to 14.1%(w.b) for 5 months storage period . Insect population levels were low but these increased after 5 months storage. Most of insects were dead, Fat acidity increased from 7.5(mg KOH/100g) to 10.2(mg KOH/100g). Other storage factors such as germination rate, brown rice recovery and 1000-kernel , and 1000-kernel weight slightly decreased and crack ratio was slightly increased. Qualities of rough rice during 5 months storage period under hemetic air conditions were maintained fairly good considering the above changes of quality factors during storage.

• 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.

• Food Science and Biotechnology
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• 제16권6호
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• pp.1006-1010
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• 2007

This study investigated changes in the chemical and functional components of germinated rough rice for the development of functional foods. The chemical components that were determined for 'Ilpum', 'Goami2', 'Keunnun', and 'Heugkwang' rough rice cultivars included dietary fiber, free sugars, free amino acids, and functional components such as tocopherols and ${\gamma}$-oryzanol. The crude protein, fat, total dietary fiber, and free sugar contents of the rough rice increased significantly after germination. The essential amino acid content was particularly increased. After the germination of the 'Ilpum', 'Goami2', 'Keunnun', and 'Heugkwang' varieties, the following increases were found: ${\gamma}$-aminobutyric acid increased 2.4, 2.5, 6.1, and 3.4 times, respectively; ${\alpha}$-tocopherol, ${\alpha}$-tocotrienols, and ${\gamma}$-tocotrienols increased significantly; and ${\gamma}$-oryzanol content increased 0.8, 1.1, 1.5, and 1.2 times, respectively. Thus, germinated rough rice has the potential to be used as a healthy and functional food ingredient.