• Journal of Biosystems Engineering
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• v.8 no.1
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• pp.47-60
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• 1983

상온통풍(常溫通風)을 이용(利用)한 In-bin drying에 대(對)한 많은 실험결과(實驗結果)에 의(依)하면 우리나라 10월(月)의 기상조건(氣象條件)은 저온건조(低溫乾燥) system에 적합(適合)한 건조능력(乾燥能力)을 가지고 있는 것으로 나타났다. 최근(最近) Computer를 이용(利用)한 Simulation model이 개발(開發)되어 건조현상(乾操現象)에 관(關)한 경제적(經濟的)이고 효율적(效率的)인 분석(分析)이 가능(可能)하게 되었다. 이러한 분석결과(分析結果)에 의(依)하면 초기함수율(初期含水率)이 높은 벼를 Full-bin을 이용(利用)한 상온통풍건조(常溫通風乾操)를 할 경우(境遇) 건조기간(乾燥期間)이 길어지며 bin내(內)의 상층부(上層部) 곡물(穀物)이 변질(變質)되는 문제점(問題點)이 발생(發生)하였다. 또한 벼의 수확작업체계(收穫作業體系)가 관행(慣行) 및 Binder작업체계(作業體系)에서 점차(漸次) Combine작업체계(作業體系)로 전환(轉換)되어감에 따라 포장(圃場)에서의 건조(乾燥)가 어려우며 예취(刈取), 탈곡작업과정(脫穀作業過程)에서의 기계적(機械的)인 곡물(穀物) 손실(損失)을 줄이기 위(爲)하여 함수율(含水率)이 비교적(比較的) 높은 벼를 수확(收穫)하여야 한다. 본(本) 연구(硏究)의 목적(目的)은 상온통풍건조(常溫通風乾燥)에 있어서 건조능력(乾燥能力)을 증가(增加)시키기 위(爲)하여 곡물(穀物)을 일정기간(一定期間) 나누어서 bin에 넣고 건조(乾燥)를 하는 Layer drying의 Simulation model을 개발(開發)하고 이 Model에 수원지방(水原地方)의 7년간(年間) 평균(平均) 기상자료(氣象資料)를 입력(入力)시켜 곡물(穀物)의 초기함수율(初期含水率), 투입량(投入量), 투입기간(投入期間)의 변화(變化)에 따른 Layer drying현상(現象)을 규명(糾明)하는데 있다. Simulation에 사용(使用)된 bin의 크기는 직경(直徑) 2m, 깊이 1.5m이며 송풍(送風)팬의 용량(容量)은 0.5HP이었다. Simulation분석(分析) 결과(結果)를 요약(要約)하면 다음과 같다. (1) Layer drying의 Simulation model을 개발(開發)하였으며 이 Model은 벼의 상온통풍건조(常溫通風乾燥) 실험(實驗)에서 함수량(含水量) 변화(變化)의 이론치(理論値)와 실제실험치(實際實驗値)가 잘 일치(一致)하였다. (2) 곡물투입기간(穀物投入期間) 1일(日)을 Full-bin drying으로 간주(看做)할 때 Layer drying의 건조성능(乾燥性能)은 Full-bin보다 높은 것으로 나타났다. (3) 연속송풍(連續送風)(24시간(時間))을 할 경우(境遇) 곡물투입기간(穀物投入期間)이 증가(增加)함에 따라 건조기간(乾燥期間)의 감소경향(減少傾向)은 단속송풍(斷續送風)인 경우(境遇)보다 적었지만 건조기간(乾燥期間)은 단축(短縮)되었다. 그러나 건조(乾燥)에너지의 소모(消耗)는 단속송풍(斷續送風)일 때보다 크게 나타났다. (4) 단속송풍(斷續送風)(9 : 00AM~6 : 00PM)일 경우(境遇) 곡물투입기간(穀物投入期間)을 증가(增加)시키면 건조기간(乾燥期間)이 크게 줄어 들었다. (5) 곡물(穀物)의 초기함수율(初期含水率)이 21% 이하(以下)일 경우(境遇) 연속(連續) 및 단속송풍(斷續送風)에서 건조기간(乾燥期間)의 차이(差異)가 별로 없었다. (6) 곡물(穀物)의 초기함수율(初期含水率)이 높으면 Full-bin drying에서는 상부층(上部層)에 곡물(穀物)이 변질(變質)될 우려(憂慮)가 있으나 Layer drying에서는 곡물투입량(穀物投入量)을 조절(調節)하면 이것을 방지(防止)할 수 있었다. (7) 건조(乾燥)가 완료(完了)된 후(後) 층별(層別) 최종곡물(最終穀物) 함수율(含水率)은 모든 건조조건(乾燥條件)에서 동일(同一)하였으나 bin의 하부층(下部層)은 과건조(過乾燥) 물상(物象)을 일으켰다.

• Journal of Biosystems Engineering
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• v.3 no.1
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• pp.47-63
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• 1978

This study was conducted to obtain a basic information necessary to assess present rice milling technology in Korea The profiles for milling plants was analyzed by survey work.For the private custom-work mills, which process about 80 percent of domestic rice consumption ,their actual milling test for the identical samples as used for filed mills was conducted. Two rice varieties Japonica and Tongil-type were associated with the experiments. The results are summarized as follows: 1. Analyses for private custom-work mills showed their general aspects as; about 91 percent of the mills belonged to an individual owner ship ; more than 93 percent of the mills was established earlier than 1950 ; about 80 percent of the mills was powered with electric motor; mills having less than two employees were about 75 percent; about 45 percent of the mills provided for warehouse in storing customers cereal grains. 2. The polishers installed in 1,255mills within the surveyed area (7 counties) have been supplied by 44 different domestic manufacturers ;in but about 60 percent of which was supplied by 6major manufacturers. The polishers could be classified into two categories in terms of principles of their polishing actions ;jet-pearler and friction types. About 51 percent of the mills was equipped with the former which has been recognized as giving greater milling recovery than the friction types. 3. Reason for owners of private mills to supplement new machines was due mainly to pgrading their mills to meet the requirements that established by the Government. However, about 60 percent of the mill owners intended to replace with new pearler by their own needs to meet with new high yielding varieties. 4. Processing systems of each previate rice mills surveyed could be classified into three categories, depending upon whether the systems posessed such components as precleaner and paddy separator or not. Only 36.7 percent of mills was installed with both precleanr ad paddy seperrator, 5.0 percent of mills did have neither percleaner nor paddy seperator, and rest of them equipped only one of the two. Hence,it is needed for about 63% of rice miils to be supplemented with these basic facilities to meet with the requirements for the standaized system. 5. Actual milling capacity measured at each field rice mills was shown a wide variation, having range from about 190 to 1,210 kg/hr. The percentages of mills classified according to daily milling capacity based on this hourly capacity were 24.3% for the capacity less than 3 M/T a day; 20.0% for 3-4 M/T; 15.6% for 4-5 M/T; 6.7% for 5-6 M/T; 22.3% for 6-7 M/T; and 11.0% for more than 7 M/T a day. 6. Actual amount of rice processed was about 310 M/T a year in average. About 42% of total milled rice was processed during October to Decembear, which formed a peak demand period for rice mills. The amount of rice milled during January to May was relatively small, but it had still a large amount compared to that during June to September. 7. Utilization rate of milling facility, i. e., percentage of the actual amount of milled rice to the capacity of rice mills, was about 18% on the year round average, about 41% in the peak demand season, and about 10% during June to September. Average number of operating days for mills surveyed was about 250 days a year, and about 21 days a month. 8. Moisture contents of paddy at the time of field mill tests were ranged 14.5% to 19.5% for both Japonica and Tong-i] varieties, majority of paddy grains having moisture level much higher than 1530. To aviod potential reduction of milling recovery while milling and deterioration of milled rice while storage due to these high grain mJisture contents, it may be very important for farmers holding rice to dry by an artificial drying method. 9. Milling recovery of JapJnica varieties in rice mills was 75.0% in average and it was widely ranged from 69.0% to 78.0 % according to mills. Potential increase in milJing recovery of Japonica variety with improvement of mill facilities was estimated to about 1.9%. On the other hand, milling recovery of Tong-il varieties in the field mill tests was 69.8% in average and it ranged from 62% to 77 %, which is much wider than that of Japonica varieties. It is noticed that the average milling recovery of Tong-il variety of 69.8% was much less than that of the Japonica-type. It was estimated th3.t up to about 5.0% of milling recovery for Tong-il variety could be improved by improving the present lo'.ver graded milling technology. 10. Head rice recoveries, as a factor of representing the quality of commercial goods, of Japonica and Tong-il varieties were 65.9% and 53.8% in average, and they were widely ranged from 52% to 73% and from 44% to 65% , respectively. It was assessed that head rice recovery of Japonica varieties can be improved up 3.3% and that of Tong-il varieties by 7.0% by improving mill components and systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.35-41
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• 2006

This study was conducted to establish the post-harvest management system in rice. Harvested hulled rice was gathered into large-scale bag and combine bag, in which the rice quality and the influence on quality change were investigated on various storage periods and moisture contents. Moisture content of hulled rice ranged from 23.7% to 28.8% on different harvest times, which grew lower as harvesting time was delayed. When desiccation was retarded hulled rice in large scale bag was changed in color and emitted an of offensive odor in 3 days and that in combine bag showed similar symptom in 4 days. Inner temperature in large scale bag was changed a lot when the storage period was prolonged and also the moisture content was higher while that in combine bag increased regularly corresponding to the moisture content at the time of harvest. Moisture content of hulled rice stored in large-scale bag increased 2 days after harvest and the more moisture content showed the more increased tendency, while in the case of combine bag the moisture content was not changed much whether the hulled rice contained low or high moisture content in harvesting. As desiccation was delayed fatty acid increased much more in large-scale bag than in combine bag even though protein and amylose contentwere not changed. As desiccation was delayed more and hulled rice contained moisture more in harvesting head rice ratio of brown rice decreased and green-kerneled rice and damaged grain ratio increased and quality of milled rice also became deteriorated. As a result, desiccation day to minimize the deterioration of rice quality was estimated 1-2 days in large scale bag and 2-3 days in combine bag after harvesting.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.177-181
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• 2008

Mycotoxins produced by molds isolated from discolored sun-dried red pepper fruits were determined and the toxicity to animals was also tested by feeding mold-grown unpolished rice to rats. Among the mold species tested, only Alternaria alternata was toxic to experimental animals, while other mold species belonging to the genera of Colletotrichum, Diaporthe, Diaporthopsis, Botryosphereia, Aspergillus and Fusarium were not. Rats fed Alternaria-grown rice lost weight and died within two weeks of feeding period. Succumbed rats during the process of feeding study showed extreme cases of enlargements of stomach, small intestine and liver. Among the 17 Alternaria isolates, 8 species produced considerable amount of tenuazonic acid along with small amounts of other toxins including alternariol and monomethyl ether derivative of alternariol in both red pepper homogenate and unpolished rice. It is therefore advised that red pepper fruits infested by molds during the sun-drying process be discarded to avoid unnoticeable health hazards.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.164-169
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• 2004

We had screened the Monascus strain capable of producing monacolin K dominantly among 29 Monascus strains. Red yeast rice was prepared by culturing each Monascus sp. with 200 g of steamed rice (12$0^{\circ}C$, 20 min) at 3$0^{\circ}C$ for 10 days and drying at 8$0^{\circ}C$ for 20 min. As a result, red yeast rice cultured by M. purpureus ATCC16457, M. purpureu IFO 32316, M. purpureus IFO 32228, M. kaoliang ATCC 46595 and M. kaoliang ATCC 46596 produced lots of red pigment and monacolin K. An unidentified Monascus sp. showed the highest productivityof red pigment and monacolin K among 29 Monascus strains. Its production of red pigment and monacolin K was 1.3∼39 times and 2.4∼8 times higher than other strains, respectively. Although the morphological characteristics of unidentified Monascus strain were a little different from the typical M. purpureus, it was identified as M. purpureus CBS 281.34 from the result of sequencing of ITS (Internal transcribed spacer) and 28S ribosomal RNA (partial).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.157-160
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• 1998

To find out the effects of humidification and hardening of rice (Oryza sativa L. cv. Ilpumbyeo) seeds on the germination, both normal and artificially aged seeds with 60% germination rate were humidified at 40, 60, and 80% RHs and $25^{\circ}C$ for five weeks or hydrated for 6, 12, 18, and 24 hours at $25^{\circ}C$ from one to five cycles for hardening. Relative humidity and duration of humidification did not affect the germination rate of normal seeds, while reduced the time to get 50% germination rate ($T_{50}$) by 1.0～1.6 days compared to that of normal seeds at $25^{\circ}C$. Aged seeds humidified at 40 and 60% RHs did not affect the germination rate and $T_{50}$ regardless of relative humidity and duration of treatment, while at 80% RH, the germination rate decreased and $T_{50}$ increased significantly with the duration of humidification. Hardening of normal seeds reduced $T_{50}$ by 0.7～1.1 days without changes in the germination rate. However, the germination rate and $T_{50}$ of aged seeds soaked in water for 6, 12, and 18 hours were similar regardless of soaking/drying cycles, while hardening of artificially aged seeds with 1～4 cycles in 24 hours soaking increased the germination rate by 11-16% and reduced $T_{50}$ by 1.4～2.0 days.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.449-457
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• 2016

Purpose: The study was conducted to analyze the change in quality characteristics of Ddukguk Garaedduk and Ddukgukdduk by the frequency of extruding rice dough. Methods: Ddukguk Garaedduk samples were made by extruding and shaping rice flour dough 2, 3, and 4 times; while Ddukgukdduk samples were made by drying the Ddukguk Garaedduk at room temperature for 48 hours and slicing them in slices of 0.3 cm thickness. Results: Significant differences were not found in water content by the extrusion frequency for Ddukguk Garaedduk and Ddukgukdduk. The adhesiveness and springiness of Ddukguk Garaedduk with a 4 times extrusion were significantly higher than those of Ddukguk Garaedduk with a 2 times extrusion. Ddukgukdduk with a 4 times extrusion generated finer cells and a more even distribution of cells than the other samples, as observed by scanning electron microscopy. Upon boiling, significantly more water was absorbed in Ddukgukdduk of a 2 times extrusion than in that of a 4 times extrusion. Hardness and adhesiveness scores of the cooked Ddukgukdduk were the highest, and springiness was the lowest in the sample with the 4 times extrusion. Conclusion: The extrusion of rice dough makes the structure of Ddukguk Garaedduk finer and more even, which results in the increased adhesiveness of Ddukguk Garaedduk. When cooking Ddukguk, Ddukgukdduk that has been extruded more absorbs less water and dissolves less solids, which maintains the chewiness and structure of cooked Ddukgukdduk.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.152-157
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• 2006

Enterobacter sakazakii, designated as an unique microbial species in 1980, may cause bacteremia, necrotizing enterocolitis and infant meningitis. The distribution and the thermostability of E. sakazakii in unprocessed ready-to-eat (RTE) agricultural products of 252 and in 25 powdered infant formulas (PIF) were analyzed. Eighty one, 50, 43, and 47% of brown rice, pumpkin, potato, and carrot samples, respectively, had aerobic plate counts (ARC) in the range of 5 log CFU/g or more. Almost all the other products sampled had APC of approximately 2 log CFU/g. Fifty three, 75, 67, and 68% of banana, pumpkin, soybean, and carrot had Enterobacteriaceae counts approximating 3 log CFU/g. Sixty six percent of the brown rice tested had Enterobacteriaceae counts approximating 5-6 log CFU/g. E. sakazakii was isolated from 3/25(12%), 4/23(17%), 1/24(4%), and 1/27(4%) of PIF, brown rice, laver, and tomato samples, respectively. D-values were 3.52-4.79 min at 60 and $D_{60}-values$ were similar as the isolates reported. Thermal inactivation of four thermovariant E. sakazakii strains during the rehydration of PIF with hot water were investigated. At $50^{\circ}C$, the levels of E. sakazakii decreased one log CFU/g for 4-6 min and thereafter the levels remained stable for 20 min. At $60^{\circ}C$, inactivation by about 2 log CFU/g occurred for 20 min. Therefore, the unprocessed agricultural products might be a source of contamination for PIF when used as an ingredient after drying and pulverization. Rehydration of PIF for infant feeding with a water temperature of $60^{\circ}C$ rather than $50^{\circ}C$, as recommended by the manufacturers, may be helpful in the reduction of potential E. sakazakii risk.

• Korean journal of applied entomology
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• v.22 no.2 s.55
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• pp.52-66
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• 1983

The brown planthopper, N. lugens (Stal), has become a serious pest of rice in tropical Asia during the last decade. At high pest density, its feeding damage causes 'hopperburn' or complete wilting and drying of the rice plant. It also transmits grassy and ragged stunt virus diseases. The estimated losses caused by the pest in tropical Asia exceed $US\$300$ millions. While cultivation of resistant rice varieties has proved to be highly effective against the pest, their long-term stability is threatened because of the evolution of prolific biotypes which can destroy these varieties. At present, identification of biotypes is based principally on the differential reactions of host rice varieties to the pest and on host-mediated behavioral and physiological responses of the pest. Recent findings of morphological differences in adult rostrum, legs, and antennae, body parts that possess receptors for host plant location and discrimination, and cytological differences in N. lugens populations maintained as stock cultures strongly complement other biotype studies. So far, three N. lugens biotypes have been identified in the Philippines. Biotype I can survive on and damage varieties that do not carry and genes for resistance, while Biotype 2 survives on resistant varieties carrying Bph 1 gene and Biotype 3 on varieties carrying gene bph 2. However, none of these biotypes can survive on varieties with genes Bph 3 or bph 4. Several varieties which are resistant in the Philippines are susceptible in India and Sri Lanka as the South Asian biotypes of N. lugens are more virulent than Southeast Asian biotypes. To monitor the pest biotypes in different geographical regions and to identify new sources of resistance, an International Brown Planthopper Nursery has been established in many cooperating countries. The evolution of biotypes is an exceedingly complex process which is governed by the interactions of genetic and biological factors of the pest populations and the genetic makeup of the cultivated varieties. While the strategy for sequential release of varieties with major resistance genes has been fairly successful so far, the monegenic resistance of these varieties makes them vulnerable to the development of the pest biotypes. Therefore, present breeding endeavors envisage utilizing both major and minor resistance genes for effective control of the pest.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.697-704
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• 1995

This experiment was carried out to elucidate the effect of the midsummer drainage times and some growth regulators on lodging characters, lodging and yield in puddled-soil drill seeding in rice. Dongjinbyeo, the mid-late maturing rice variety was seeded at May 11 by seeding machine with 4cm of furrow depth. Experimental plots were divided two main treatment without midsummer drain and two time drains (30 and 50 days after seeding), Inabenfide(IBF) was applied 40days before heading(DBH) and IBP was applied at 30DBH, respectively. Culm length was shorten, the wall of N$_4$ was thicken, and the breaking weight was increased at two time drainage and growth regulators applied in order of Inabenfide, IBP, and Control. Lodging wasn't occurred at two time drainage but it was occurred at none drainage in the order of Control, IBP, and Inabenfide applied. Yield was higher at two time drainage compared with none drainage and higher in order of Inabenfide, IBP and Control in none drainage but wasn't significantly different among growth regulators applied in two time drainage. Therefore, two times midsummer soil drying is recommendable management method for puddled -soil drill seeding of rice. Rice, Direct seeding, Puddled-soil, Drill seeding, Midsummer drainage, Growth regulator, Lodging.