• 한국식품영양과학회지
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• 제37권7호
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• pp.815-819
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• 2008

본 연구에서는 흑미 두 품종(흑진주벼와 흑광벼)의 도정 분획별 메탄올 추출물의 항산화 성분과 항산화 활성을 비교 분석하고자 하였다. 흑미의 항산화 성분으로 polyphenolic, flavonoid, anthocyanin과 ${\gamma}$-oryzanol, tocopherol 및 tocotrienol 함량을 측정하였으며 항산화 활성은 DPPH와 ABTS radical 제거능을 측정하였다. 각 도정 분획별 메탄올 추출물에서 rice bran 층에서 약 $15.3{\sim}15.5%$의 가장 높은 수율을 보였으며 endosperm 메탄올 추출물에서 약 $0.9{\sim}1.1%$의 가장 낮은 수율을 보였다. 실험결과 rice bran의 추출물에서 endosperm, whole grain의 추출물보다 높은 함량의 항산화 성분이 분포함을 확인할 수 있었다. 또한 이러한 항산화 성분이 다량 분포하는 rice bran 추출물의 우수한 항산화력을 측정할 수 있었다. 품종 간에는 흑진주벼의 rice bran층의 항산화 성분이 흑광벼보다 높은 함량을 나타내었다. 본 연구결과 흑미의 rice bran은 기능성식품의 성분으로 활용가능성이 높을 것으로 예상된다.

• 한국식품과학회지
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• 제30권1호
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• pp.241-243
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• 1998

쌀 도정시 분리되는 쌀눈은 영양학적 가치로보아 식품자원으로 활용할 수 있어 이에 필요한 기초 자료로 쌀눈의 일반성분과 함께 저장 중 문제가 될 수 있는 유지의 변화를 처리방법별, 저장온도별로 관찰 하였다. 쌀눈의 주성분은 당질 36.5%, 조지방 21.6%, 조단백질 18.7%였고 열풍$(80^{\circ}C)$으로 6 시간 건조한 쌀눈과 처리하지 않은 (비처리) 쌀눈을 $60^{\circ}C$에 저장하면서 산가를 비교한 결과, 비처리 쌀눈 중 유지의 산가가 2배 상승하는데 소요되는 기간이 약 2일 이었으나, 건조쌀눈의 겨우 31 일 경과 후에도 1.15배에 그쳐 안정화 되었고, 이때 추출된 유지의 산패유도기간은 처리별로 큰 차이를 보이지 않았다.

• 한국식품영양과학회지
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• 제39권4호
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• pp.624-630
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• 2010

본 연구에서는 여러 품종(삼광벼, 설갱벼, 큰눈벼, 화선찰벼, 홍진주벼, 흑광벼, 일품벼, 하이아미 및 녹미벼)의 도정부산물인 미강(쌀겨)과 식미에 나쁜 영향을 주어 이용되지 않는 싸라기에 대한 70% 에탄올 추출물의 항산화 성분(polyphenol, flavonoid, vitamin E, $\gamma$-oryzanol)과 항산화 활성(ABTS 라디컬 소거능, DPPH 라디컬 소거능, 환원력)을 비교 분석하여 기능적 가치를 평가함으로써 이용 가능성을 살펴보고자 하였다. 품종별 미강과 싸라기의 항산화성분을 측정한 결과 유색미인 홍진주벼에서 vitamin E(일품벼)를 제외하고는 항산화 성분이 가장 높게 측정되었으며, 더불어 흑광벼에서도 상당한 항산화 성분이 함유되어 있음을 알 수 있었다. 또한 싸라기 추출물보다는 미강 추출물에서 높은 함량의 항산화 성분이 분포함을 알 수 있었다. 항산화 활성 측정 결과 항산화 성분이 다량 포함되어 있는 미강추출물에서 높았으며, 그중 홍진주벼 추출물에서 가장 높은 활성을 나타내었다. 본 연구결과 유색미인 홍진주를 비롯하여 흑광벼의 미강은 기능성식품의 성분으로 활용 가능할 것이며 이를 통한 품종별 쌀의 기초 자료를 제공할 수 있을 것이라 생각된다.

• 한국식품영양학회지
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• 제17권2호
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• pp.199-205
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• 2004

파쇄미, 색채불량미와 일반미에 효모 Saccharomyces cerevisiae, 혼합 밀 누룩으로 Aspergillus oryzae와 Aspergillus niger mut. kawachii를 접종하여 만든 개량누룩으로 탁주를 2단 담금한 후 발효과정 중의 품질을 검토한 결과는 다음과 같다. pH는 3.5 정도로서 잡균에 의한 오염이 방지되면서 곰팡이가 생성한 당화 효소에 의해 2일에 당화되었고, 환원당이 알코올 발효되면서 ethanol 18%로 정상적으로 알코올 발효가 진행되었다. 유기산 함량은 일반미에서 citric acid가 매우 높게 나왔다. 탁주 술덧에 함유하는 미량의 알코올로서 n-propanol, 2-methyl-1-propanol, 1-butanol, 3-methyl-1-butanol이 검출되었다. 일반미에서만 1-butanol이 정량되지 않았다. 술덧의 유리당은 파쇄미, 색채불량미에 비해 일반미에서 sucrose함량이 현저히 낮게 나왔다. 유리아미노산 함량은 일반미 술덧이 단맛을 나타내는 serine, glycine, alanine과 쓴맛을 나타내는 leucine, isoleucine, phenylalanine의 함량이 낮게 나왔으며, 색채불량미와 파쇄미술덧은 이와 반대의 결과를 나타내었다. 색차기에 의한 색의 구분에서 뚜렷한 차이가 없었고, 발효후 5단계 평점법에 의해 맛, 향, 색등을 관능검사한 결과 모두 4.3 이상의 $\ulcorner$좋다$\lrcorner$로 평가되어 전통탁주의 이용이 가능할 것으로 사료된다.

• 한국식품과학회지
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• 제25권5호
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• pp.546-551
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• 1993

제분방법별(Pin mill, Colloid mill, Micro mill, Jet mill)로 제조한 쌀가루의 특성과 쌀 수제비 제조후 식미에 미치는 영향을 조사하였다. 지방, 회분, 단백질은 제분 방법에 따라 큰 차이를 보이지 않았다. 제분방법별 쌀 가루의 청값, 열수가용성 아밀로오스 함량, 그리고 전분 손상도는 Jet mill, Micro mill, Colloid mill, Pin mill의 순으로 높았음을 나타내었다. 수분흡수지수, 수분용해지수 및 보수력을 측정한 결과 전분손상도가 증가함에 따라 전체적으로 증가하였다. 또한 시료농도 15%의 겔을 형성하였을 때 Pin mill의 경우 강도에 있어서 가장 높음을 보여주었다. 아밀로그램을 이용한 호화개시온도와 최고점도는 입자가 미세하여 짐에 따라 점차 낮아지는 경향을 보였으며 Differential Scanning Colorimetry 측정에 의한 측정값도 아밀로그램에서와 동일한 양상을 나타내어 호화흡열의 면적에서 산출한 호화엔탈피$({\Delta}H)$가 Jet mill의 경우 0.83 kcal로 가장 낮았다. 즉 전분의 손상도가 증가함에 따라 호화엔탈피는 감소하였다. 쌀수제비 제조실험 결과는 Jet mill이 관능검사 결과 가장 우수한 것으로 판명되었고 반죽상태도 양호함을 보여주었다.

• Journal of Animal Science and Technology
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• 제57권7호
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• pp.26.1-26.5
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• 2015

Background: Rice bran is a by-product of the rice-milling process, which remains largely underutilized; however, efficient processing treatments may improve its feeding value for chickens. This is of great economic and environmental importance, as this can lower the production costs, and offer an opportunity for valorization of a low-quality agricultural by-product, to a high-value feed source. Methods: This experiment was conducted to study the effect of extruded rice bran on performance and phosphorous (P) bioavailability in broiler chickens. In a completely randomized design, 200 seven-day-old broilers (Cobb 500) were allotted to five treatments with five replicates per treatment and 8 chicks per replicate, and fed with their respective diet during the starter (8 to 21 days) and grower (22 to 42 days) periods. Diets were a basal corn-soybean based diet (T1), or diets containing 20 % rice bran (T2), 30 % rice bran (T3), 20 % extruded rice bran (T4), or 30 % extruded rice bran (T5). Results: Birds feeding on T4 and T5 diets had a higher body weight gain and lower feed-to-gain ratio compared to those feeding on T2 and T3 diets (p < 0.05). Birds receiving diets containing extruded rice bran had higher total P availability and tibia ash content, as compared with those receiving diets containing un-extruded rice bran (p < 0.05). Relative weight of the pancreas was higher in birds receiving T2 and T3 diets. Conclusions: The results confirmed the beneficial effect of extrusion treatment of rice bran on performance and P availability in broilers. Up to 30 % extruded rice bran may be included in the broiler diet without apparent adverse effects on the performance.

• Journal of Biosystems Engineering
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• 제4권2호
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• pp.10-24
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• 1979

It is understood that drum speed of threshers and the moisture content of paddy grains to be threshed, respectively, have a signific:mt effect upon rice recoveries. Threshing under an increased drum speed would give a high performance rate, which is the general practice in custom work threshing in association with the use of semiauto-t hreshers. In the connection, however, it may result in the promotion of grain cracks and brokens of the rice product after milling. No reference or determination for an opti mum drum speed of the thresher is made available for various grain moisture contents at the time of the threshing operation and for different rice varieties especially for the Tongil rice varieties. This study was Conducted to find out and determine effects of the drum speeds on grain losses. The grain loss was quantified in terms of recovery rates of rice grains after treatments. Samples of each of all treatments were taken from the grain sampling plate placed in the grain conveyor of threshers. The grain sample plate was specially provided for this experiment. The brown-rice, milling, and head-rice recJveries were tes ted in the laboratory mill, respectively. Two rice varieties, Akibare and Suweon 251, each with five levels of different moist\ulcornerure contents at harvest and six levels of different drum speeds of threshers, were selected and used for treatments in this experiment. Two conditions of materials were tested in the thresher. One condition was to thresh the experimental material immediately after cutting, referred to as the wet-material thr eshing in this study. The other was to thresh the experimental :material, dried to contain about 15-16 percent of the grain moisture under the shocking operation. This is referred to as the dry-material threshing in this study. In additioon, field measurements for the grain moistures and drum-sdeeds under actual operation practices of the traditional field threshing, were conducted with a view to comparing with results of the experimental treatments. The results of the study may be summarized as follows: 1. For threshing treatments of Japonica-type rice variety (Akibare) , the effect of drum speeds and levels of grain moisture at cutting upon brown-rice, milling, and head-rice recoveries were found statistically significant. No significant difference in these recovery rates was noticed regardless of whether the material was threshed right after cutting or after drying by the shocking operation. 2. For the Tongil-sister rice variety(Suweon 251), milling recovery for the varied drum-speed and the grain~moisture level at cutting was found statististically significant. Th milling recovery was much significant when associated with the wet-material thres\ulcornerhing compared to the dry-material threshing. 3. The optimum peripheral velocity to be maintained at the edge of teeth on the thr\ulcorneresher drum was determined and may be recommanded as that of about 12 to 13 meters per second in view of the maximum recovery rate of the milled rice. 4. The effect of the drum speed on the qualitative loss of the milled rice was much greater in the case of the Tongil variety than Japonica. This effect was also greater by the wet-material threshing than by the dry-material threshing. Therefore, to apply the wet-material threshing operation for the Tongil variety, in particular, it should be very important to introduce the kind of threshing technology which would maintain the drum speed at optimum. 5. A field survey for the actual drum speed of threshing operations for 50 threshers indicated that average peripheral velccity was 12.76m/sec., and that the range was from 10.50 to 14.90m/sec. Approximately, more than 30% of the experimented and measured threshers were being operated at speeds which exceeded the optimum speed determined and assessed in this study. Accordingly, it should be highly desirable and important to take counter-measures against these threshing practices of operational overspeed.

• Journal of Biosystems Engineering
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• 제4권2호
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• pp.9-9
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• 1979

It is understood that drum speed of threshers and the moisture content of paddy grains to be threshed, respectively, have a signific:mt effect upon rice recoveries. Threshing under an increased drum speed would give a high performance rate, which is the general practice in custom work threshing in association with the use of semiauto-t hreshers. In the connection, however, it may result in the promotion of grain cracks and brokens of the rice product after milling. No reference or determination for an opti mum drum speed of the thresher is made available for various grain moisture contents at the time of the threshing operation and for different rice varieties especially for the Tongil rice varieties. This study was Conducted to find out and determine effects of the drum speeds on grain losses. The grain loss was quantified in terms of recovery rates of rice grains after treatments. Samples of each of all treatments were taken from the grain sampling plate placed in the grain conveyor of threshers. The grain sample plate was specially provided for this experiment. The brown-rice, milling, and head-rice recJveries were tes ted in the laboratory mill, respectively. Two rice varieties, Akibare and Suweon 251, each with five levels of different moist?ure contents at harvest and six levels of different drum speeds of threshers, were selected and used for treatments in this experiment. Two conditions of materials were tested in the thresher. One condition was to thresh the experimental material immediately after cutting, referred to as the wet-material thr eshing in this study. The other was to thresh the experimental :material, dried to contain about 15-16 percent of the grain moisture under the shocking operation. This is referred to as the dry-material threshing in this study. In additioon, field measurements for the grain moistures and drum-sdeeds under actual operation practices of the traditional field threshing, were conducted with a view to comparing with results of the experimental treatments. The results of the study may be summarized as follows: 1. For threshing treatments of Japonica-type rice variety (Akibare) , the effect of drum speeds and levels of grain moisture at cutting upon brown-rice, milling, and head-rice recoveries were found statistically significant. No significant difference in these recovery rates was noticed regardless of whether the material was threshed right after cutting or after drying by the shocking operation. 2. For the Tongil-sister rice variety(Suweon 251), milling recovery for the varied drum-speed and the grain~moisture level at cutting was found statististically significant. Th milling recovery was much significant when associated with the wet-material thres?hing compared to the dry-material threshing. 3. The optimum peripheral velocity to be maintained at the edge of teeth on the thr?esher drum was determined and may be recommanded as that of about 12 to 13 meters per second in view of the maximum recovery rate of the milled rice. 4. The effect of the drum speed on the qualitative loss of the milled rice was much greater in the case of the Tongil variety than Japonica. This effect was also greater by the wet-material threshing than by the dry-material threshing. Therefore, to apply the wet-material threshing operation for the Tongil variety, in particular, it should be very important to introduce the kind of threshing technology which would maintain the drum speed at optimum. 5. A field survey for the actual drum speed of threshing operations for 50 threshers indicated that average peripheral velccity was 12.76m/sec., and that the range was from 10.50 to 14.90m/sec. Approximately, more than 30% of the experimented and measured threshers were being operated at speeds which exceeded the optimum speed determined and assessed in this study. Accordingly, it should be highly desirable and important to take counter-measures against these threshing practices of operational overspeed.

• Journal of Biosystems Engineering
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• 제25권1호
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• pp.39-46
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• 2000

This work was conducted to study the operating characteristics of a grinding system designed to obtain fine rice husk ash powder. To find better utilizing of rice husk, a valuable by-product from rice production, once the rice husk was incinerated and the thermal energy was recovered from the furnace, the ash was fed and pulverized in the grinding system resulting a fine powder to be used as a supplementary adding material to the portland cement manufacturing . The rice husk ash grinding system consisted of a high speed centrifugal fan for the preliminary coarse milling and a dry-type stirred ball mill for the subsequent fine grinding . Total grinding time 9 5, 15, 30, 45 min), impeller speed (250, 500, 750 rpm) , and mixed ratio (4.8, 7.9, 14.9) were three operating factors examined for the performance of a stirred ball mill used for the fine grinding of ash. With the stirred ball mill used in this study, the minimum attianable mean diameter of rice husk ash powder appeared to be 2 ${\mu}{\textrm}{m}$. During the find grinding, the difference in specific surface area of powder showed an increase and the grinding energy efficiency decreased with the increase in total grinding time, impeller speed ,and mixed ratio. For the operating conditions employed , the resulting mean diameter of fine ash powder, specific energy input, and grinding energy efficiency were in the range of 1.79 --16.04${\mu}{\textrm}{m}$, 0.072-5.226kWh/kg, an d1.11-12.15$m^2$/Wh, respectively. Grinding time of 30 min , impeller speed of 750 rpm, and mixed ratio of 4.8 were chosen as the best operating conditions of the stirred ball mill for fine grinding . At these conditions, mean particle diameter of the fine ash, grinding energy efficiency, grinding throughtput, and specific energy input were 2.73${\mu}{\textrm}{m}$, 3.95$m^2$/Wh, 0.25kg/h, and 1.22kWh/kg, respectively.

• 한국식품영양학회지
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• 제25권3호
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• pp.637-643
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• 2012

This study was performed to increase the utilization of rice and improve the productivity of jochung, traditional food in Korea. Two kinds of jochung products were prepared from steamed rice(SR) and wet-milled rice flour(WRF) by rice cultivated from 2006 to 2010. It is common to add a liquefying enzyme for rice liquefaction(4 $m{\ell}$/1,000 g rice, at $90{\sim}95^{\circ}C$, 3 h) and saccharogenic enzyme with malt(45 g/1,000 g rice, at $55{\sim}57^{\circ}C$, 6 h). In order to evaluate the quality characteristics of jochung, producing rate, pH, solidity, reducing sugar, dextrose equivalence(D.E.), viscosity, total phenolic compound, color value and sensory evaluation were carried out. In terms of the producing rate of jochung, WRF jochung was produced about 7.4% much more than SR jochung. There was no difference in producing rate between the jochung cultivated from 2006 to 2010 rice. The pH varied from 4.86~5.66, solidity was 79.48~82.28%. Color L value was 25.82~27.92, a value of 1.28~2.81, b value were 2.98~4.33. The results of sensory evaluation for jochung, as a whole, received higher score than for the commercial product(Daesang Co., Ltd, Seoul, Korea), overall acceptability score was the highest in the 2008SR. Reducing sugar, dextrose equivalence(D.E.) and total phenolic compounds were determined to be higher WRF jochung than SR jochung, while viscosity was lower WRF jochung than SR jochung. These results are thought to be due to increased surface area of rice by milling. SR jochung manufacturd by wet-milled rice flour will increase the producing rate for jochung, thereby saving manufacturing time and costs.