• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.145-155
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• 1980

An engineering design of the machines and equipment for processing grain as well as an understanding of processing itself need the knowledge of thermal properties of grain. Thermal properties of grain are thermal conductivity, thermal diffusivity and specific heat. Knowledge of any two and the bulk density of grain enables the third to be calculated. Several workers have investigated these properties, with special emphasis on thermal conductivity and diffusivity. However, some information is available on the specific heat of rough rice and barley but it is available only for a foreign variety of grain and for as a function of moisture content only. The objectives of this study were to develop a model for the specific heat of rough rice and barley which were a staple products in Korea as a function of initial temperature, moisture content and porosity of grain with cooling curve method, and to analyze the effect of these factors on the specific heat of rough rice and barley. The results of this study are summarized as follows; 1. The specific heat was $1.8209-2.7041kJ/kg\;^{\circ}K$ for Naked barley, 1.8862-2.5625 k.l/kg K for Covered barley, $1.5167-2.3779kJ/kg\;^{\circ}K$ for Japonica rice and $1.5260-2.3981kJ/kg\;^{\circ}K$ for Indica rice. 2. The model for the specific heat of rough rice and barley as a function of initial temperature, moisture content and porosity of grain was developed. 3. Specific heat of rough rice was decreased with initial temperature, but specific heat of barley was increased with initial temperature. 4. On the whole specific heat of sample grain was increased with moisture content of grain. 5. Specific heat of the grain was found to decrease with porosity except Indica rice.

• Journal of Life Science
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• v.24 no.6
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• pp.618-625
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• 2014

Rice flour is used in many food products. However, dough made from rice lacks extensibility and elasticity, making it less suitable than wheat for many food products such as bread and noodles. The high-molecular weight glutenin subunits (HMW-GS) of wheat play a crucial role in determining the processing properties of the wheat grain. This paper describes the development of marker-free transgenic rice plants expressing a wheat Glu-Dy10 gene encoding the HMG-GS from the Korean wheat cultivar 'Jokyeong' using Agrobacterium-mediated co-transformation. Two expression cassettes, consisting of separate DNA fragments containing Glu-1Dy10 and hygromycin phosphotransferase II (HPTII) resistance genes, were introduced separately into Agrobacterium tumefaciens EHA105 for co-infection. Each EHA105 strain harboring Glu-1Dy10 or HPTII was infected into rice calli at a 3: 1 ratio of Glu-1Bx7 and HPTII. Among 290 hygromycin-resistant $T_0$ plants, we obtained 29 transgenic lines with both the Glu-1Dy10 and HPTII genes inserted into the rice genome. We reconfirmed the integration of the Glu-1Dy10 gene into the rice genome by Southern blot analysis. Transcripts and proteins of the Glu-1Dy10 in transgenic rice seeds were examined by semi-quantitative RT-PCR and Western blot analysis. The marker-free plants containing only the Glu-1Dy10 gene were successfully screened in the $T_1$ generation.

• Journal of Life Science
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• v.26 no.10
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• pp.1121-1129
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• 2016

High-molecular-weight glutenin subunits (HMW-GSs) are extremely important determinants of the functional properties of wheat dough. Transgenic rice plants containing a wheat TaGlu-Ax1 gene encoding a HMG-GS were produced from the Korean wheat cultivar ‘Jokyeong’ and used to enhance the bread-making quality of rice dough using the Agrobacterium-mediated co-transformation method. Two expression cassettes with separate DNA fragments containing only TaGlu-Ax1 and hygromycin phosphotransferase II (HPTII) resistance genes were introduced separately into the Agrobacterium tumefaciens EHA105 strain for co-infection. Rice calli were infected with each EHA105 strain harboring TaGlu-Ax1 or HPTII at a 3:1 ratio of TaGlu-Ax1 and HPTII. Among 210 hygromycin-resistant T₀ plants, 20 transgenic lines harboring both the TaGlu-Ax1 and HPTII genes in the rice genome were obtained. The integration of the TaGlu-Ax1 gene into the rice genome was reconfirmed by Southern blot analysis. The transcripts and proteins of the wheat TaGlu-Ax1 were stably expressed in rice T₁ seeds. Finally, the marker-free plants harboring only the TaGlu-Ax1 gene were successfully screened in the T₁ generation. There were no morphological differences between the wild-type and marker-free transgenic plants. The quality of only one HMW-GS (TaGlu-Ax1) was unsuitable for bread making using transgenic rice dough. Greater numbers and combinations of HMW and LMW-GSs and gliadins of wheat are required to further improve the processing qualities of rice dough. TaGlu-Ax1 marker-free transgenic plants could provide good materials to make transgenic rice with improved bread-making qualities.

• Bulletin of Food Technology
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• v.26 no.2
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• pp.125-131
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• 2013

즉석 쌀국수는 쌀 함량을 10~30% 첨가하는 수준으로 출발하여 최근에는 쌀 함량 100% 생면 및 인디카 품종을 활용한 베트남 쌀국수 타입으로 점차 쌀 함량이 높아지고 있으나, 쌀 고유의 특성으로 면의 가공적성이 어려우며, 조리 시 전분 용출량이 많은 단점이 있다. 따라서 현재 국내 시판 쌀국수 5종을 구입하여 쌀 함량별로 분류하여 품질특성과 관능특성을 비교하여 즉석 쌀국수의 품질특성을 알아봄으로써 즉석 쌀국수 개발 연구에 기초 자료를 제공하고자 하였다. 품질특성 결과 감자전분, 찰옥수수전분을 첨가한 제품의 경우 수분흡수지수가 높게 나타났으며, 조직감 측정결과 밀가루가 첨가된 처리구가 밀가루 무첨가 처리구에 비해 높은 값을 나타내어 전분 및 밀가루 첨가에 따라 경도, 응집성 및 검성이 증가하였으며, 관능특성 결과 국내쌀을 사용한 처리구가 수입쌀을 사용한 처리구보다 높게 나타내어 국내쌀로 만든 쌀국수를 더 선호하는 경향이 있는 것으로 나타났다. 따라서 향후 쌀국수 제품 개발 적용 시 쌀가루 용도별 제분기술의 발달 및 감자전분, 찰옥수수전분, 타피오카전분 등의 전분류를 첨가하여 쌀국수 개발기술을 확보하면 품질이 우수하고 다양한 형태의 즉석 쌀국수 제품개발이 기대된다.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.85-91
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• 2021

The physicochemical properties of deodeok (Codonopsis lanceolate) was investigated in relation to the different steaming time and cycles of steaming and drying (S/D). Additionally, the quality characteristics of Makgeolli with different amount (0-0.45%) of steaming and drying deodeok (SD) were measured comparison to non-steaming and drying deodeok (NSD). L⁎ values of deodeok tended to decrease as the number of S/D cycles and steaming times increased, while BI showed the opposite trend for L⁎ values. Reducing sugar increased significantly from 1 to 3 S/D cycles and decreased thereafter (p<0.05). Also, processed with steaming for 4 h and 5 S/D cycles had the highest antioxidant properties. Principal component analysis (PCA) revealed that the S/D process notably influenced the properties of deodeok. Quality characteristics of Makgeolli showed that 0.45% SD resulted in higher antioxidant properties than control or NSD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1760-1766
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• 2009

Physical properties of Yukwa base extruded with glutinous rice flour, rice flour, defatted soy flour, and salt using an twin-screw extruder were investigated. The ingredients were extruded at various moisture contents (16-18%), screw speeds (300 & 400 rpm) at 43.4 kg/hr feed rate. Length and specific volume of Yukwa base increased with decreasing moisture contents. Hunter's color L* values of Yukwa base was higher whereas $a^*\;and\;b^*$ values were lower with increasing moisture content. Water absorption index of Yukwa base increased with increasing moisture contents. X-ray diffraction of Yukwa base showed B type moisture content of 16% and 17% while it showed A type moisture content of 18%. Degree of crystallinity and breaking strength of Yukwa base were the lowest in the moisture content of 16% while the lowest value for hardness was found in the moisture content of 16% and of 17% with screw speed 400 rpm for all samples. In the microstructure of cross section of Yukwa base, air cell size was larger and cell wall was thicker as moisture content increased. The sensory evaluation of the Yukwa base showed that color and flavor were not significantly different among samples, while taste, appearance, mouth feel, and overall preference were higher as moisture contents decreased.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1091-1095
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• 2009

The aim of this study investigated the fluctuations of 3 characters from 3 ecotypes [early ripening (ER), middle ripening (MR), and late ripening (LR)] of 20 Korean brown rice cultivars in different storage systems [time: 12 and 24 weeks, temperature: low ($10^{\circ}C$) and room ($25^{\circ}C$)]. With increase of storage time and temperature, lipoxygenase activity, and fat acidity increased, whereas germination rate was reduced. ER cultivars exhibited the highest lipoxygenase activity of $35.49{\pm}2.46$ unit/mg protein during 24 weeks storage at $25^{\circ}C$, followed by LR ($32.73{\pm}1.33$) and MR ($32.66{\pm}1.62$) cultivars. The amounts of fat acidity also were observed by the same order (ER: $20.40{\pm}2.12$>LR: $19.68{\pm}1.86$>MR: $19.64{\pm}1.35$ mg KOH/100 g). Germination rate slightly decreased with increase of time and temperature (MR>LR>ER), but MR and LR cultivars showed the most significant changes (ER: $60.90{\pm}23.47%$, MR: $32.66{\pm}13.95%$, and LR: $32.53{\pm}5.87%$). On the basis of above results, MR cultivars were evaluated the highest quality, because high lipoxygenase activity, high fat acidity, and low germination rate have deteriorated in quality and generated off-odor. Thus, MR cultivars might be very important sources in food processing and stored dietary supplement aspects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.15-21
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• 1984

In order to ascertain the practical possibility of home made retort pouches for production of retort pouch foods in factory, two kinds of retortable pouches, i. e. 3 ply film (polyester film/Al. foil/casting polypropylene) and 4 ply film(polyester film/Al. foil/nylon/casting poll·propylene) were developed in Korea, and then, their physical properties, such as physical strength, heat resistance during thermal processing and preservability of foods and sanitary safety, were tested and compared with the foreign made pouches. The results obtained were summarized as follows. a. The physical strength of home made retort pouches in processing model foods(soybean oil 5 %, acetic acid 2%, starch 5 % and water to 100 %) was equal to that of foreign made pouches at accelerated examination condition($38^{\circ}C$, 98 % RH). But the lamination strength of home made products was a little bit superior to that of foreign made products. b. Home made retort pouches(SAMA-4 ply and SAMA-3 ply pouch) packed with rice or curry was possible to bear the thermal processing at $135^{\circ}C$ and shelf-life was one year or more at ambient temperature($20^{\circ}C$). c. Sanitary safety test showed that these home made retort pouches were acceptable comparing to the regulation recommended by the Ministry of Health and Social Affairs.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.502-508
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• 1997

Rice bran dietary fiber extract, which was obtained after termamyl treatment of defatted rice bran contained $27.3{\sim}30.5%$ protein, $49.7{\sim}54.1%$ insoluble dietary fiber, and $1.9{\sim}2.7%$ soluble dietary fiber. Extrusion decreased the insoluble dietary fiber content but increased the soluble dietary fiber content, while roasting did not. Influence those content. Each mineral element content was depended upon heat processing method. Extrusion increased the water binding capacity and L value, while roasting reduced the water binding capacity and L value. Scanning electron microscopy showed damaged cell walls for extruded sample compared to roasted one which had fully collapsed cell walls. The increase of water absorption, developing time, and stability and the of MTI of wheat flour-dietary fiber extract composites with addition of dietary fiber extract were observed by Farinograph. Rice bran dietary fiber extract had an effect on the bread making resulting in increase of bread weight and color of crumb and crust, and decrease of bread volume and texture. As a result of sensory evaluation, appearance, texture, overall acceptability were significantly different from control but flavor and taste were not different significantly up to 6% level. Heat treated samples had differences in mean values, but not significant differences statistically.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.153-159
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• 1981

A study was carried out to determine the optimal sterilization conditions of cooked rice packed in retort pouch and processed in a steam-air system retort. The cooked rice packed in retort pouch in various thickness (15, 20 and 25 mm) was processed at various heating temperature (110, 115 and $120^{\circ}C$) with $F_0$-value 6.0. In order to evaluate quality change during the thermal prosessing, C-values, based on z-value $33^{\circ}C$ and $F_0$ value 6.0, were also calculated at surface, center and mass average temperatures. Subsequent storage study revealed that the cooked rice packed in 15 mm thickness and processed at $120^{\circ}C$ with$F_0$-value 6.0 could be held without any spoilage and color change, when stored for 6 months at $38{\pm}1^{\circ}C$ under saturation humidity.