• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.226.1-226
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• 2003

최근 쌀 소비량이 감소되고 쌀중심 식생활의 영양적 우수성을 인식하지 못하여 쌀은 주식으로서 위치가 흔들리고 있다. 그동안 쌀의 영양특성에 관한 연구로서 주로 탄수화물 급원으로서의 당질에 관한 연구와 미강을 중심으로한 식이섬유, 미강유등에 관한 연구결과들이 발표되었다. 특히 미곡 부산물인 미강으로부터 다양한 유효성분들이 확인되어 그 효능이 보고되고 있으며 일부가 기능성 소재로서 제품화되기도 하였다. 그러나 실제 우리의 식생활에서 섭취되고 있는 백미 또는 현미상태에서의 유효성분의 분포 및 함량에 대한 연구는 미진한 상태이다. 본 연구에서는 쌀의 영양적우수성을 규명하고자 유효성분 중 phenolic acid와 폴리페놀 함량을 품종 및 도정도에 따라 조사하였다. 조생종인 오대와 만생종인 남평 품종으로부터 현미와 7분도, 10분도 및 12분도로 도정도를 달리한 백미, 도정도별 미강을 각각 제조하였다. Ferulic acid 등 쌀과 미강에 존재하는 phenolic acid 는 알칼리로 추출한 후 pH를 조정하고 에틸아세테이트로 반복 추출하여 HPLC로 분석하였다. 현미에 함유된 phenolic acid는 ferulic acid가 가장 많아 50％ 내외를 차지하였으며 p-coumaric acid, benzoic acid, sinapinic acid 순으로 검출되었다. 오대 현미의 총 phenolic acid 함량은 65.9 mg%로서 남평 현미의 57.2 mg%보다 높았으며 도정도가 증가할수록 백미 중의 총 phenolic acid 함량은 감소되었다. 미강 중에는 백미의 10배 량에 해당하는 phenolic acid가 검출되었고 benzoic acid와 m-hydroxy benzoic acid는 미강 시료에서만 검출되었다. 도정한 백미 중의 phenolic acid는 28.8∼51.7 mg%, 미강에서 321.4∼438.4 mg% 범위로 나타났다. 현미, 백미 및 미강에 함유된 총 폴리페놀의 함량을 표준 페놀화합물로 카테친을 사용하고 비색법에 의하여 측정하였을 때 오대 현미의 폴리페놀 함량은 78.4 mg%, 남평 현미 88.8 mg% 였다. 도정한 백미 중의 총 폴리페놀 함량은 30.3∼56.9 mg%, 미강이 541.5∼472.6 mg%의 범위였다. 이상과 같이 쌀에는 phenolic acid 및 총 폴리페놀이 상당량 함유되어 있으며 특히 배유보다는 강층에 많이 존재하므로 이들 성분의 효율적인 이용을 위한 쌀의 섭취방안이 필요한 것으로 나타났다.

• Journal of Food Hygiene and Safety
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• v.26 no.3
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• pp.198-202
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• 2011

Rice has been the most important staple food in everyday meals of Korean people for thousands of years. Nowadays, it is getting increasingly used as flour ingredients in a variety of processed foods, so that it is consumed in more diversified ways. As a consequence, production volume of rice flour to manufacture rice cakes, noodles, breads, or confectioneries is recently getting increased in Korea. But there are not sufficient research outcomes to guarantee Korean consumers microbiological qualities of rice flour as well as rice. As a preliminary experiment, therefore, the microbiological profiles (aerobic mesophilic bacteria (AMB), spore-forming aerobic bacteria (SAB), lactic acid bacteria (LAB), yeasts and molds (YM), and Escherichia coli and coliforms) have been monitored for nine retailed white rice samples in this study. AMB counts ranged $10^2-10^6$ CFU/g for all the nine white rice samples. All the nine rice samples have SAB counts within a narrow range $(1.0{\times}10^2-2.5{\times}10^3$ CFU/g). LAB was detected in two white rice samples ($4.0{\times}10^2$ and $3.7{\times}10^3$ CFU/g), YM was detected in one white rice sample ($2.0{\times}10^2$ CFU/g) only. E. coli was not detected from all the nine samples. Coliforms were detected in one white rice sample ($4.1{\times}10$ CFU/g) only. All the rice samples were conclusively considered to have various microorganisms, though most of them are harmless and some, such as coliforms, may be harmful.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.29-32
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• 2005

This experiment aimed to estimate the effect of imperfect rice on rice palatability. Rice cultivar, Ilpumbyeo, was cultivated by direct-seeding on flooded paddy surface with 11 kg/10a nitrogen application. Palatability of harvested rice was measured by NIR spectroscope. Brown rice was divided according to their appearance namely, perfect, discolored, green-kerneled, and immature opaque with a composition ratio of $75.7\%,\;11.0\%,\;8.0\%,\;and\;5.3\%$ respectively. When the perfect brown rice was milled, the grain were composed of head, cracked, and white core & belly, at $64.7\%,\;25.3\%\;and\;10.0\%$ respectively. The milled rice of discolored brown rice had similar composition with the perfect rice. The milled green-kerneled vice, on the other hand, had $36\%$ head rice and $64\%$ white core & belly rice. The immature opaque brown rice, when milled, had $25.3\%$ white core & belly and $74.7\%$ damage & opaque rice. With the respect to grain quality, the viscosity of white core at belly rice and damaged & opaque rice was lower than that of head rice. In contrast, their protein content was a little higher than that of head rice. The palatability value of pure imperfect rice was much lower than head rice. The palatability value of damaged & opaque rice was the lowest among the imperfect rices. When mixed with head rice, the damaged & opaque rice impacted on the deterioration of vice palatability. Mixing $1\%$ each of white core at belly rice and damaged h opaque rice decreased the palatability value by $5\%$ as compared with the head rice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1726-1734
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• 2004

Response surface methodology on sensory evaluation was used to optimize cooking condition of cooked short grain rice (CSR) and cooked short grain rice containing grainy sea-tangle patch (CSTR). Texture profile analysis and nutritional evaluation were also performed. For maximizing overall acceptability, it can be predicted sea-tangle patch 14%, added water 1.67 times of rice and sea-tangle amount and steeping time 47 min as optimum cooking conditions from sensory evaluation conducted by the forties panelist. Hardness of pressure cooked short grain rice containing grainy sea-tangle patch (CSTR) were lower than cooked short grain rice (CSR), but it showed similar as CSR in adhesiveness, chewiness and higher in springiness and cohesiveness. In addition CSTR was delayed retrogradation compared with CSR. The nutritional Quality of CSTR showed higher level in total dietary fiber, protein, ash than CSR, but lower in protein digestibility, C-PER, gelatinization degree compared with CSR.

• Korean journal of food and cookery science
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• v.13 no.1
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• pp.64-69
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• 1997

The experiments of rice bread processing were carried out to compare the varietal difference in processing adaptability to rice bread between brown and milled rice flour, and to analyze the interrelations among chemical properties of rice grain and some characteristics relevant to rice bread processing and quality There was varietal difference in adaptability to rice bread processing in both brown and milled rice, but there was not significant adaptability difference between brown and milled rice flours to rice bread processing. However, there was remarkable adaptability difference between brown and milled rice flours to rice bread processing in some rice varieties. Three high-amylose rices AC 27, IR 44, Suweonjo showed high quality of milled rice bread among tested rice materials. Brown rice revealed better adaptability to rice bread processing compared with milled rice in all varieties except the above three varieties. Especially, the glutinous rice Hangangchalbyeo failed to normal formation of rice bread from milled rice flour, but it showed the successful formation of rice bread from brown rice flour. The interrelations among chemical components of rice grain and some characteristics relevant to rice bread processing and quality exhibited quite different tendency between brown and milled rices. In the case of rice bread processing by brown rice flour, the larger volume expansion of dough during fermentation made the more springy rice bread and the more moist rice bread showed the more soft and cohesive physical property. In the case of rice bread processing by milled rice flour, the lower protein of rice flour was closely associated with the more moistness of rice bread and the higher lipid led to the more uniformal air pore distribution, the smaller pore size and the lower springiness of rice bread. Also, the larger volume expansion of dough during fermentation made the better loaf formation and the larger pore size of rice bread. The better loaf formation of rice bread revealed the softer hardness and the lower chewiness, and the lower springiness was closely correlated with the more uniformal size distribution of air pore and the smaller pore size in rice bread.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.245-251
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• 2021

We determined the quality characteristics, acrylamide concentration, and antioxidant activity of Nurungji prepared using white rice, brown rice, gamma-aminobutyric acid (GABA) brown rice, oats, and barley. The moisture content of Nurungji prepared using white rice was the lowest (1.48%) and the highest (6.53%) was obtained in barley Nurungji. The brightness (L^*) of white rice Nurungji was the highest, whereas that of GABA brown rice Nurungji was the lowest. The acrylamide concentration was the lowest (37.24 ㎍/g) in white rice Nurungji and the highest (255.50 ㎍/g) in oats Nurungji. The levels of total polyphenol and total flavonoid were the lowest in white rice Nurungji and high in oats and GABA brown rice Nurungji. The antioxidant activity was higher in Nurungji prepared using oats, GABA brown rice, brown rice, and barley than that using white rice. It is necessary to select an appropriate grain when preparing Nurungji by considering the amount of acrylamide produced.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.211-216
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• 1988

Brown rices were abrasively milled to give 92% yield, and hydration and cooking rates of brown and milled rices were investigated. Diffusion coefficients of Japonica brown and milled rices at $30^{\circ}C$ were smaller than those of J/Indica counterparts. The bran layer controlled the diffusion coefficients of brown rices at initial stage of hydration. The diffusion coefficients for Japonica and J/lndica milled rices were $107{\sim}114$ and $74{\sim}87$ times greater than those for brown rices, respectively. The terminal points of cooking of brown and milled rices at $110^{\circ}C$ were similar among varieties. The cooking rate constants of milled rices were about 2-fold compared with those of brown rices.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.672-677
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• 1999

The saccharification and sensory characteristics of Sikhe, Korean traditional beverage of saccharified rice, made of three cultivars of pigmented rice (Suwon 415, Iksan 427, Suwon 432) were examined. During saccharification, sweetness and reducing sugar of Sikhe made of pigmented rice were observed to be lower by $0.5{\sim}2%$ and by 20%, respectively, than those of Sikhe made of white rice. The changes in pH during saccharification were not much different between Sikhe made of white rice and those made of pigmented rice. For color changes, the redness (a value) of Sikhe was measured as -0.26, 10.45, 0.88 and 0.13 for those in Sikhe made of white rice, Suwon 415, Iksan 427 and Suwon 432, respectively, when rice was saccharified for 6 hours. Sensory evaluation showed that sweetness and flavor of Sikhe made of 50% or 25% pigmented rice were similar with those of Sikhe of white rice. The overall acceptability of Sikhe made of pigmented rice was slightly lower than that of Sikhe made of white rice.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.632-636
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• 2010

The level of ${\gamma}$-aminobutyric acid (GABA) in pigmented rice was quantitatively and qualitatively determined by high pressure liquid chromatography/fluorescence detection (HPLC/FLD). In this study, the recovery rate and limit of detection (LOD) of GABA were 122.4${\pm}$2.4% and 0.23 ${\mu}g/g$, respectively. The geminating pigmented rice samples, which were harvested in Paju, Korea, were soaked in water at $18^{\circ}C$ for 20 hr. After soaking, the samples were germinated at $30^{\circ}C$ for about 24 hr. GABA content was highest (293.0 ${\mu}g/g$) in the germinated red rice. Furthermore, GABA levels in the germinated rice increased significantly by up to 11.1 and 24.7-fold as compared to non-germinated rice and milled rice, respectively. The GABA concentrations of non-germinated rice, with the exception of red rice, were significantly higher than those of milled rice by 7.6-20.6-fold.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.31-42
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• 1990

Storage ecosystems of rough rice, brown rice and polished rice were analyzed form Feb. 1987 to Nov. 1988 to investigate structures and ecological successions in the arthropod communities as well as changes in energy of the systems. The changes in temperature of stored rice showed high degree dependence on the temperature of storage room with time lag of about four weeks. Moisture content of rough rice, brown rice and polished rice during the period were in the range of 12.7$\pm$0.4, 13.1$\pm$0.4 and 13.5$\pm$0.3%, respectively. The arthropod communities in rough rice, brown rice and polished rice were qualitatively and quantitatively different. In rough rice, dominant species changed from Leptinotus reticulatus Endlein to Liposcelisentomophilus Endlein, while in brown rice from Pyralis farinalis L. to Sitophilus oryze (L.), unidentified parasitic wasps, Anisopteromalus calandrae Howard and Tribolium castaneum Herbst and finally to S. oryzae. In polished rice, the arthropod community showed an ecological succession similar to that in brown rice except for a transient dominance of two psocidspecies. Thearthropod community in rough rice was rather simple and unstable in comparison with those in brown rice and polished rice. The 1000 kernel weight of brown rice decreased slightly during the period when the arthropods were active (summer season), while that of rough rice and polished rice remained at the similar level. However, the ash content per unit volume of brown rice as well as rough rice and polished rice showed no increase during the period.