• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1407-1414
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• 2014

Physicochemical properties of rice-based expanded snacks extruded with rice flour, high amylose starch, and isolated soy protein were investigated using a twin-screw extruder. The ingredients were extruded at various feed moisture contents (19~23%) and screw speeds (200~400 rpm) at a constant feed rate (43.4 kg/hr). Bulk density and apparent density of rice snacks were 0.06~0.21, and 0.55~0.65 respectively. Bulk density, apparent density, water absorption index, and breaking strength of rice snacks increased with increasing feed moisture content and decreasing screw speed. However, expansion and water solubility index of rice snacks increased with decreasing feed moisture content and increasing screw speed. Hunter's color L values of rice snacks was lower with increasing screw speed at feed moisture contents of 19% and 21%, but was not significantly different from a feed moisture content of 23%. On the other hand, a and b values of rice snacks were higher with increasing screw speed a feed moisture content of 19%. X-ray diffraction intensity of rice snacks decreased with decreasing feed moisture content and increasing screw speed. X-ray diffraction of rice snacks was V-type at feed moisture contents of 19% and 21% and screw speeds of 300, and 400 rpm. In the microstructure of the cross section of rice snacks, air cells in rice snacks were not well formed, and cell walls were thicker with increasing feed moisture content and decreasing screw speed.

• Korean journal of food and cookery science
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• v.22 no.4 s.94
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• pp.419-427
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• 2006

The purpose of this study is to promote the substitution of rice flour for wheat flour in making bread and thus the consumption of rice by examining the effect of particle size of rice flour on leavening rice bread. For this purpose, several experiments were carried out. With regard to particle size distribution, 59.45% of wheat flour had passed 200 mesh and 3 kinds of rice flour milled to penetrate into 20, 35, and 45 mesh (S1, S2 and S3) had passed 21.88%, 33.1% and 36.38% of those for 200 mesh, respectively. To leaven the rice flour dough to bread, 25% of vital gluten was needed. To determine the optimal water quantity for rice bread dough, the hardness of wheat and rice flour dough was measured by rheometer. The appropriate water quantity for S1, S2 and S3 was set at 285 ml , 295 ml and 335${\sim}$340m1, respectively. The loaf volume index of the wheat flour bread was 6.24, while that of and rice flour bread S1, S2 and S3 was 5.38, 5.50 and 5.75, respectively. These results indicated that the loaf volume index of rice flour bread is lower than that of wheat flour bread, but that the volume of rice flour bread was increased with fuel particle size of rice flour. Scanning electron microscopy (SEM), image of the wheat bread tissue at a magnification of 35 times showed long, large, oval-shaped, air cells and thin cell membrane, as well as small air cells, whereas the images of rice flour showed angular, circular, air cells and rough and thick cell membrane. The size and number of air cells in the rice bread were larger in S2 and S3 with fuel particle flours than in S1. In particular, the bread made with S3 contained many air cells that were as large as those in the wheat bread were. In addition, when the inner cell wall was magnified 1500 times, almost no small air cell was observed in C and S3, whereas many fine air cells were observed in the cell wall of S1 and S2.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.1-8
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• 1993

Extruded defatted soy flour (DSF) with twin screw extruder was compared with steam treated DSF for soy sauce fermentation. Independent variables of response surface methodology (RSM) for extrusion were barrel temperature $(145{\sim}165^{\circ}C)$, feed moisture content $(25{\sim}35%)$, and feed rate $(20{\sim}30\;kg/hr)$. Extrusion conditions for production of the extrudates having highest water absorption capacity, lowest bulk density and highest expansion ratio were obtained by regression analysis of each dependent variable. Electron photomicrographs revealed significant increase of porosity inside the koji made from extruded DSF. Therefore, growth of fungi inside the koji made from extrudates of DSF was accelerated to achieve higher activities of protease, ${\alpha}-amylase$, and glucoamylase compared to the koji made from steamed DSF. Although amino acid composition of soy sauces prepared from two different DSF did not show any significant difference, the content of free amino acids in soluble nitrogen compounds was higher $(13%{\pm}2)$ in soy sauce made from extruded SDF. During the whole period of fermentation color of soy sauce made from extrudates of DSF was darker. Sensory evaluation did not reveal any serious off-odor and off-taste in the soy sauce fermented from extruded DSF.

• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.385-391
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• 2006

Physicochemical properties of hydroxypropylated waxy rice starches were investigated to reduce steeping-time of yukwa (Korean oil-puffed rice snack) processing. Swelling power of hydroxypropylated waxy rice starch increased at relatively higher temperature $(60^{\circ}C)$ than native waxy rice starch $(70^{\circ}C)$. Solubility of hydroxypropylated waxy rice starches increased with increasing propylene oxide content. Pasting temperature $(66.3-66.9^{\circ}C)$ and peak viscosity (216-232 RVU) of hydroxypropylated waxy rice starch were higher than those of native starch (179 RVU) and increased with increasing propylene oxide content. DSC thermal transitions of hydroxypropylated waxy rice starches shifted toward higher temperature. Amylopectin melting enthalpy of hydroxypropylated waxy rice starch (8.4-9.2 J/g) was similar to native starch (9.0 J/g). X-ray diffraction patterns of native and hydroxypropylated waxy rice starches showed typical A-type pattern with no significant differences between them, suggesting hydroxypropylation only affected amorphous region. Results suggest hydroxypropylated waxy rice starch is not applicable for yukwa due to low puffing efficiency and dark color.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.1-11
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• 2010

This study was carried out to investigate the influence of stem materials such as black stem on the quality of expended stem and cigarettes. Normal and black stem were separated by tobacco scan and then, those stems were expanded after treating with their respective stem casings. Total sugar, ether extract, ash contents and pH were slightly low in black stem compared with normal stem. However, the number of bacteria and fungi ratio were remarkably higher in black stem than that of normal stem. As compared with normal stems, ratio of rushed stem in rolled process was approximately 2 times higher in black stem with the consequency that the filling capacity of black stem was decreased. The ratio of large particles (> 3.35 mm) of expanded black stem showed decreasing tendency and small particles rate (1.40 mm <) was increased compared with normal stem. When expanded stems were prepared using stem containing 5 levels (0, 10, 20, 30 and 100 %) of black stem, the filling capacity was decreased and static burning rate was significantly decreased with increasing expanded black stem rate. However, the weight and hardness of cigarettes were slightly increased with increasing expanded black stem rate. The contents of phenol compounds, aromatic amines and carbonyl compounds in the cigarette mainstream smoke from the cigarette which was manufactured with various ratio of expended black stem, were gradually increased with increasing expanded black stem rates. Also, the cytotoxicity and the mutagenicity of the TPM were significantly increased with increasing expanded black stem rate. The sensory test result showed that cigarettes blended with 10 and 30 % level of black stem rate was exhibited significantly high sensory attributions such as off-taste, impact, hotness, bitterness and irritation as compared with cigarette blended with normal stem, while smoke fullness and cleanness were slightly decreased with increasing expanded black stem rates. The number of brown spots on cigarettes paper was 2 to 3 times high in cigarettes containing black stem than that of cigarette made from normal stem and were high with increasing black stem rate. The overall assessment in this study suggest, that black stem should not be used because of bad quality of expanded stem and high toxicological activity of cigarette mainstream smoke.

• Journal of the korean veterinary medical association
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• v.25 no.10
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• pp.595-606
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• 1989

항원제시세포(APC)와 보조T세포 간의 협력작용에 의하여 활성화된 작동세포(NK세포, CTL, K세포, 대식세포, 과립구 등)의 종양세포, 이식장기 및 세포내기생세균에 감염된 각종 세포에 대한 세포독성작용은 생체방어를 위한 중요한 세포성면역기전이다. 지난 몇 년간 세포성면역기전에 관한 많은 연구에도 불구하고 T림파구매개성 세포독성작용의 면역생물학적기전은 확실히 밝혀있지 않다. 지금까지 알려진 중요한 연구내용을 요약하면 다음과 같다. 1. 세포독성작용을 나타내는 작동세포로는 NK세포, CTL, K세포, 대식세포/단핵구 및 과립구가 있다. 2. T세포의 세포표면항원분자군(CD)으로는 $CD_{2},\;CD_{3},\;CD_{4}[Ly_{3}T_{4}],\;CD_{5}[=Ly_{1}],\;CD_{7},\;CD_{8}[Ly_{2,3}]$가 있으며 $CD_{4}$는 보조Ttpvhdml 특이마커이고 $CD_{8}$는 세포독성 T세포 및 억압T세포의 특이마커이다. 주요 T세포수용체(TCR)는 $CD_{4}$ 또는 $CD_{8}$ 분자와 가까이 연합된 이향체($TCR-{\alpha}{\beta}/TCR-{\gamma}{\delta}$이며 보조 T세포 $CD_{4}$(마우스 $L_{3}T_{4}$)는 수용체와 연합되어 있는반면 억압 T세포 $CD_{8}(Ly+_{2,3})$는 항원수용체와 연합되어 있다. 3. T세포는 Ti-$CD_{3}$(항원/MHC) 복합체를 통한 '항원가교'에 의한 자극(항원인식)과 $CD_{2}$를 통한 비특이경로에 의하여 활성화(분화증식)된다. 비특이경로를 통한 활성경로에서 T세포($CD_{4}$ 및 $CD_{8}$)가 활성화되기 위하여는 보조T세포가 생산하는 IL-2을 요구하며 IL-2의 자극으로 분화증식된 $CD_{8}$는 세포독성능을 나타내지만 $CD_{4}^{+}$는 여전히 세포독성능을 나타내지 못한다. 4. 보조T세포는 class II MHC분자와 연합된 항원을 식별하는 반면 세포독성T세포는 class I MHC 분자와 연합된 항원을 식별한다. 5. 림파구 매개성 세포독성은 접촉(conjugati-on), 탈분극(depolarization), 용해계획(progra-mming), 용해(lysis) 및 재순환(recycling)의 단계를 거쳐 진행된다. 6. 표적세포살해매체로는 perforin / PFP / cy-tolysin, lymphopores, lymphotoxins, protone, cytolytic enzymes가 알려졌으며 세포독성작용은 이들 이외에도 여러 가지 매체를 통한 복합작용으로 추정된다. 7. CTL 매개성 표적세포의 주요 대사변화는 actomyocin ATPase의 증가, phosphocreatine과 ATPase의 소모, ATP 의존성 $Na^{+}/K^{+}$ 펌프작용의 중지, ATP 의존성 $Ca^{2+}$ 유출감소 및 세포내 축적이 관찰된다. 8. $Ca^{2+}$의 축적으로 세포막 교질 침투손상을 주어 수분의 유입을 증가시킴으로써 수포형성, 핵붕괴, 사립체팽화 및 정상세포 구조상실(Zeiosis)이 있다. 결론적으로 CTL 매개성 세포독성작용은 PFP, LT, TNF, 유사 TNF / LT 및 기타 매체를 통한 복합작용이며 세포살해기전은 지속적 대사소모와 정형적 세포구조(핵 및 세포질)의 파괴에 의한 것이다.

• Korean Journal of Rural Living Science
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• v.2
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• pp.1-23
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• 1991

농촌주민들의 영양 섭취실태에 대한 동향을 요약해 보면 1. 총 섭취식품중 약 90% 정도를 식물성식품으로써 섭취하고 있으며, 곡류가 차지하는 비율은 점차 감소되는 반면 콩류, 채소류 및 과일류의 섭취 비율은 현저히 증가하고 있다. 2. 총 열량섭취는 감소하는 추세이고 총열량에 대한 탄수화물 :단백질 :지방의 비율이 74 : 12 : 12의 수준이다. 총 단백질 섭취에 대한 동물성 단백질 섭취율은 36%로써 질적으로 바람직하게 변화되고 있다. 칼슘의 섭취수준이 권장량의 90%정도로서 조금 부족한 듯 하지만 철분, 비타민 등 대체로 영양섭취상태는 많이 개선되었음을 알 수 있다. 3. 농촌 영아들의 경우는 모든 영양소가 권장량에 현저히 미달되는 상태이다. 이유식품 개발 및 이유 방법에 대한 상담 지도가 적극 필요한 실정이다. 4. 새마을 유아원의 설치 및 유아급식의 혜택으로 농촌 유아들의 영양 섭취 상태는 두드러지게 개선되었으나 철분섭취 상태는 권장량에 미달되는 실정이다. 취학전 아동의 영양향상을 위해서는 유아 교육시설 확충 및 간식의 중요성에 대한 농촌 주부 대상의 영양 교육 확대 실시가 요청된다. 5. 국민학교 아동들에게서는 빈혈의 발생 빈도가 높게 나타났다. 성장 발육기에 있는 이들의 심신발달에 필요한 영양공급 및 올바른 식습관 형성을 위해서는 학교에서 일정한 지도 목표를 설정하여 계획적으로 실시하는 학교 급식의 필요성이 강조된다 하겠다. 6. 청소년기 및 임신 수유부의 경우도 철분의 섭취상태가 부족하기는 하지만, 철 결핍성 빈혈증상이 나타날 정도는 아니고 영양섭취상태도 대체로 양호하다. 7. 노인들의 식품 영양 섭취실태는 권장량에 크게 미달되는 실정이기는 하지만 혈액검사의 수치들이 대체로 정상인 범위에 있고 건강상태도 양호한 편이다. 식품 개발 및 조리법에 관해서 요약해 보면 1. 식량수급의 안정을 기하고자 다수확 품종인 통일계통 쌀의 취반 및 가공적성에 대한 검토가 진행되었으며, 잡곡류 및 감자류의 효과적인 이용을 위해 복합분의 사용에 의한 식품가공 적성에 대한 연구들이 실시되었다. 2. 콩류에 대한 연구로는, 기름을 추출하고 남은 탈지대두박의 단백질 식품으로의 이용을 위해 추출법의 검토 및 탈지대두박을 이용하는 두부제조법 등 다각적으로 식품에의 적용에 관해 연구가 진행 되었다. 3. 발효식품 중 김치에 대해서는 농촌지역에서 제조되는 김치의 종류와 섭취실태에 관한 연구 및 김치의 저장성을 증진시키기 위한 일련의 검토가 있다. 간장, 고추장, 된장에 대해서는 Koji를 이용한 개량식 제조법 및 팽화시킨 곡분을 사용하는 간편 제조법, 비용 절감을 위한 대체원료 이용에 대한 연구 등이 진행되었다. 4. 이밖에도, 병조림 제조방법, 어린이를 위한 고영양 보충식 개발, 생선의 폐기 부분을 이용하여 칼슘 급원 식품으로서의 유용성에 관한 조리과학적 검토 등이 실시되었다. 식습관 및 식생활 관리 지도에 관한 연구에 의하면, 농촌여성의 농업역할이 가중되면서 자녀들의 식생활을 방임하기 쉬운 실정이므로 유아 교육시설 및 학교 급식 등을 통해서 바람직한 식습관 형성을 위한 프로그램이 개발되어져야 하며, 한편, 식생활 담당자인 농촌주부에 대한 규칙적이고 정확한 영양교육이 이루어져야 하리라 본다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.988-993
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• 2012

The objective of this study was to investigate the physicochemical properties of Yukwa bases with different quantities of Soju during long-term storage. We examined Yukwa bases with 5 different quantities (0%, 25%, 50%, 75%, and 100%) (v/w) of Soju after intervals of 10 days up to 50 days at $30{\pm}1^{\circ}C$. The L and a values of all Yukwa bases decreased as storage time increased. The b value of Yukwa bases with 0% Soju increased as storage time increased, but Yukwa bases with 25~100% Soju decreased. The compression and shared force decreased as storage time increased for all subjects, but those with bases of 50% and 75% Soju changed less during storage. The acid values of all Yukwa bases increased significantly during storage. In addition, the peroxide values of all Yukwa bases significantly increased during storage time. Yukwa bases with 0% Soju showed great change of the peroxide value during long-term storage. The peroxide values of all Yukwa bases changed less as the quantity of Soju increased.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.3
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• pp.21-29
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• 1985

An effective technique of sludge separation is required for concentrated activated sludge process. The dissolved-air flotation (DAF) has been shown to be efficient process for sludge separation. The factors affecting DAF process for activated sludge separation are type and concentration of sludge, air/solid ratio, ratio of pressurized water flow, pressure, sludge detention time, temperature, sludge and hydraulic loading rate, recycle flow rate of sludge and type and quantity of chemical aid. In order to study the optimal operation condition for sludge separation, the influence factors such as type and concentration of sludge, ratio of pressurized water flow and pressure are investigated by the batch and continuous reactor experiments of DAF and sedimentation test. By the experimental investigation, the results are as follows; 1. For the bulking and concentrated sludge, DAF is more effective than sedimentation for the sludge separation. 2. In DAF, the critical ratio of pressurized water flow exist. The critical value varies with the pressure in the tank. That is, according to the pressure changes from 3 to $5kg/cm^2$, the critical value varies from 0.25 to 0.67 accordingly. 3. Pressure affects the ratio of pressurized water flow, but it does not show any influence upon the DAF efficiency directly. 4. Continuous experimental results was not better than those of batch.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.2
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• pp.117-124
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• 2003

The purpose of this study was to investigate the optical conditions to satisfied the salt concentration of 1% below of compost produced by using the material of foodwaste and sawdust. We changed the mixing ratios of foodwaste : sawdust from 7:3 to 3:7 and the ratios of foodwaste : rice hull from 6.5:3.5 to 4:6. We analyzed C/N, pH, temperature, water content, volatile solid, salt, heavy metals to check the degree of composting. The running conditions of composting were $80{\sim}133{\ell}/min{\cdot}m^{3}$ of air flow rate, 1:4 of time interval(on:off) and 7days of turning interval. Running times were 28days. The optical mixing ratio of foodwaste : sawdust was 6:4 when we compared many factors. Especially when the mixing ratios of foodwaste : sawdust or foodwaste : sawdust were 7:3 or 6:4, the composting was not accomplished by the reason of low C/N. The concentrations of heavy metal were sufficiently low to satisfied the satandard of organic compost. The salt concentration was 0.43%-0.46% that was the half of initial concentration. The rice hull was the good in pore rate and 통기성, and so it can used alternative material.