• 한국식품영양학회지
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• 제21권1호
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• pp.43-50
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• 2008

This study used Omija extract as a natural congelation to compare and analyze soybean curd's physicochemical and sensory quality characteristics in order to improve functional benefits and taste of soybean curd. When Omija extract concentration increased, protein content went up considerably while crude fat and yield significantly decreased. In the pH change, the group with Omija extract were lower than control and the change was not much noticeable but slightly checked as the storage period was extended. The turbidity tended to increase as the storage period was longer. In the acidity change, the group with 0.5% Omija extract showed rapid increase on the 4th day after starting storage, and it can be interpreted that decomposition started at the moment. As the storage period was extended, brightness and yellowness remarkably decreased and redness considerably enhanced: higher concentration Omija extract worked to decreased brightness and to increase yellowness and redness. In accordance with the storage period, hardness, brittleness and gumminess increased and springness decreased, but there was no considerable change in cohesiveness: in accordance with the concentration, hardness, brittleness and gumminess significantly increased, but there was no considerable change in cohesiveness. In terms of sensory quality, the group with 1% of Omija extract showed the best appearance, flavor, taste and after swallowing results. The group with 1% Omija extract was the most preferred, $4.89{\pm}0.32$ in the overall preference. In conclusion, adding Omija extract can improve soybean curd's physicochemical and sensory quality characteristics. Moreover, the extracts can be expected to play an important role in encouraging Omija's value and widening its appliances to various food.

• 한국식품과학회지
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• 제24권3호
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• pp.289-293
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• 1992

본 연구에서는 시판 breakfast cereals의 품질 특성을 비교 검토하였다. Breakfast의 water absorption index(WAI)가 클수록 water soluble index(WSI)는 감소하는 경향을 나타내었으며, Bowl life는 WSI가 클수록 길어지는 경향을 나타내었다. 시판 breakfast cereals의 Bowl life는 제품의 WSI 이외에도 크기, 모양 및 조직 등의 영향을 받는 것으로 나타났다. 품질 표현용어의 조사에 따르면 시판 breakfast cereals의 중요한 관능적 품질요소는 고소한 맛, 단 맛, 굳기, 부서지는 정도 및 먹은 후 입속에 남는 느낌으로 구분되며, 특히 부서지는 정도가 가장 중요한 요소임을 알 수 있었다. 단 맛과 고소한 맛은 강한 음의 상관관계를 나타내어 첨가물에 의한 단 맛 강화는 오히려 고소한 맛을 감소시켰다. 전체적인 관능적 품질은 색, 고소한 냄새, 고소한 맛과 강한 양의 상관관계를, 입안에서의 마찰 정도, 부착성, 첨가물 맛과는 강한 음의 상관관계를 나타내었다. 이들 결과로 미루어 볼 때 좋은 색과 고소한 맛, 바삭바삭한 조직감을 갖는 breakfast cereal이 좋은 품질의 제품으로 평가되었다.

• Structural Engineering and Mechanics
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• 제76권2호
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• pp.153-162
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• 2020

Aiming at the mechanical and structural characteristics of the contact zone composite rock, the shear tests and numerical studies were carried out. The effects of the differences in mechanical properties of different materials and the normal stress on shear properties of contact zone composite samples were analyzed from a macro-meso level. The results show that the composite samples have high shear strength, and the interface of different materials has strong adhesion. The differences in mechanical properties of materials weakens the shear strength and increase the shear brittleness of the sample, while normal stress will inhibit these effect. Under low/high normal stress, the sample show two failure modes, at the meso-damage level: elastic-shearing-frictional sliding and elastic-extrusion wear. This is mainly controlled by the contact and friction state of the material after damage. The secondary failure of undulating structure under normal-shear stress is the nature of extrusion wear, which is positively correlated to the normal stress and the degree of difference in mechanical properties of different materials. The increase of the mechanical difference of the sample will enhance the shear brittleness under lower normal stress and the shear interaction under higher normal stress.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.137-140
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• 2008

FRP rebar와 콘크리트의 취성적인 재료특성때문에 FRP rebar를 사용한 콘크리트 휨 부재는 균형 보강비 이하의 저보강 설계시 극한상태에서 FRP rebar의 파단에 따른 급작스런 취성파괴가 발생한다. 따라서 일반철근콘크리트와 달리 균형보강비 이상으로 설계한다. 또한 부족한 연성을 보완하고 충분한 예비강도를 확보하기 위하여 철근콘크리트보다 안전한 휨 강도감소계수가 요구된다. ACI 440.1R-06에서는 FRP rebar의 사용한 콘크리트 휨 부재의 파괴형태에 따라 서로 다른 휨 강도감소계수를 제안하고 있으며, 또한 다양한 재료로 개발되어진 모든 FRP rebar에 동일한 휨 강도감소계수를 적용하고 있다. 이는 FRP rebar로 균형보강비 이상 보강된 콘크리트 휨부재의 휨 강성 증대효과를 고려하지 못하는 것이며, 다양한 FRP rebar 사용을 제한하는 것이라 할 수 있다. 따라서 다양한 FRP rebar의 종류와 보강비의 변화에 따라 다른 휨 강도감소계수를 적용하는 것이 바람직한 것으로 판단되며, 본 논문에서는 GFRP rebar로 보강된 콘크리트보의 휨 강도감소계수 보정식을 신뢰성해석을 통하여 제안하였다.

• 한국식품과학회지
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• 제34권1호
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• pp.91-95
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• 2002

본 연구의 목적은 동결건조된 김치를 시료로 선정하여 동결건조 시간이 건조된 김치제품의 미생물학적인 특성, 관능적 특성 및 다른 품질에 미치는 영향을 조사하여 "건조김치"의 제조에 적합한 동결건조 시간을 알아내는 것이다. 김치를 24, 48, 72시간 동결건조한 후, 건조제품의 젖산균수, pH, 관능적 특성, 파쇄도, 복원성 및 수분함량, 배추조직의 미세구조를 관찰하여 동결건조 시간이 건조김치의 품질에 미치는 영향을 조사하였다. 원시료에 비하여 24시간 건조시킨 제품의 생균수 및 pH가 현저하게 변화하였으나, 그 후에는 72시간까지 거의 변화가 없었다. 24시간 건조김치보다 48시간 또는 72시간 건조김치의 전반적인 기호성이 우수하였다. 동결 건조 시간이 24시간에서 48시간, 72시간으로 증가할수록 건조김치의 파쇄성은 증가하였다. 동결건조 시간이 경과할수록 건조김치의 복원성이 개선되고, 건조김치의 중량과 함유된 수분함량은 감소하였다. 본 실험의 조건하에서는 건조김치의 제조에 적합한 동결건조 시간은 미생물학적인 측면에서 보면 24시간도 큰 문제는 없으나, 관능적 특성과 건조제품의 품질특성의 측면에서 판단하면 48시간이 보다 바람직하였다.

• 동아시아식생활학회지
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• 제8권4호
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• pp.469-480
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• 1998

This study was carried out in order to investigate the processing adaptability of Jeung-pyun. We used rice materals that were developed domestically for improving the utilization of rice. Six cultivars (Ilpoombyeo, Hwasungbyeo, Dasanbyeo, Daeribbyeo 1, Hyangmibyeo 1, Hyangmibyeo 2) of rice were used for making Jeung-pyun. In physicochemical properties of rice, Hwasungbyeo had the highest amylose content (20.4%) and Hyangmibyeo 2 had the lowest one(14.9%). Lipid content was 0.23%(Daeribbyeo 1)-0.43%(Ilpoombyeo), protein content was 7.94%(Ilpoombyeo) -8.43%(Dasanbyeo), and ash content was 0.15%(Hyangmibyeo 2)-1.24% (Daeribbyeo 1). In volume and specific volume of the 3 hour fermented Jeung-pyuns, Ilpoombyeo, Hwasungbyeo, Hyangmibyeo 2 were higher, but in the 7 hour fermented Jeung-pyuns, Dasanbyeo, Daeribbyeo 1, Hyangmibyeo 1 were higher, In the sensory evaluation of the test Jeung-pyuns, the overall quality of the 3 hour fermented Jeung-pyuns was not significantly different among the rice cultivars, whereas in the 7 hour fermented Jeung-pyuns Hyangmibyeo 2 had the lowest values. When the 7 hour fermented Jeung-pyuns were stored at 2$0^{\circ}C$, the hardness and brittleness of Jeung-pyuns were respectively increased, the cohesiveness was respectively decreased. The elasticity was not significantly different among the rice cultivars with storage days, and the gumminess was significantly difference between rice cultivars, respectively increasing during storage, but Hyangmibyeo 2 was the lowest, not increased. In insturmental characteristics of Jeung-pyuns, the hardness was correlated with amylose content and the brittleness and gumminess were highly correlated with the hardness.

• 한국식품조리과학회지
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• 제21권1호
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• pp.33-39
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• 2005

The present study was carried out to develop sausage using Leuconostoc citreum which was isolated from Kimchi. Leuconostoc citreum was added to sausage at three concentrations of 1, 3 and $5\%$, and was stored at $10^{\circ}C$ for 40 days. The pH of the sausage containing Leuconostoc citreum was similar to the control group. The TBA value of the group containing Leuconostoc citreum was lower than the control group. However, the TBA value of the control group steadily increased after 10 days of storage, and there were only minor changes in the groups containing Leuconsostoc citreum. In addition, the TBA value of the sausages employed for the present study was either 0.46MA mg/kg or less than that over the entire period of storage. The residual nitrite value was 47.1 ppm at the beginning of the storage in the control group and was 32.5, 32.2 and 30.9 ppm in the groups containing Leuconostoc citreum. The sausages with TBA values higher than 70 ppm are not permitted in Korea. With regards totexture characteristics, it was observed the hardness was lower in the groups containing Leuconostoc ctireum than in the control group while springiness was almost the same in both the groups, but the group containing $1\%$ Leuconostoc citreum showed the best springiness. Both gumminess and brittleness were lower in the groups containing Leuconostoc citreumthan than in the control group. It was inferred that with an increase in the concentration of Leuconostoc citreum there was a decrease in the value of gumminess and brittleness. The results of the sensory evaluation were generally better in the groups containing Leuconostoc citreum than the control group. The sausage containing $3\%$ Leuconostoc citreum obtained the most excellent scores.

• 한국식품조리과학회지
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• 제29권5호
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• pp.469-478
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• 2013

The effects of tapioca starch (TS) and tapioca modified starch (TMS) as additives on the quality characteristics of rice cookies were investigated in this study. The amounts of TS and TMS replaced were 5, 10 and 15%(w/w) based on 100 g of rice flour. At the result of rapid viscosity analyser (RVA) properties of rice flour added with starches, peak, trough, and final viscosity of rice flour added with TMS decreased significantly(p<0.05). Hardness of dough and cookies as measured by Texture analyzer (TA) significantly decreased upon addition of TMS, and hardness of cookies significantly decreased upon addition of TS, hardness of cookies TMS lower than TS. L value of dough and cookies increased upon addition of TMS, whereas a value decreased upon addition of TMS. Spreadability of cookies increased upon addition of TMS, 10% TMS is the highest. Bulk density of dough decreased upon addition of TMS, bulk density of cookies decreased upon addition of TS and TMS, and bulk density of TMS cookie lower than TS cookie. In sensory evaluation, 10% TS added rice cookies showed the highest score in overall acceptability, hardness, brittleness, color, softness, taste and flavor, and 15% TS added rice cookies showed the highest score in appearance. And 15% TMS added rice cookies showed the highest score in overall acceptability, taste, brittleness, flavor, and 10% TMS added rice cookies showed the highest score in hardness, flavor, taste and color. It is indicated that the quality characteristics and sensory characteristics of the rice cookie can be improved by adding TS and TMS.

• Korea-Australia Rheology Journal
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• 제19권3호
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• pp.125-131
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• 2007

Biodegradable polymeric blends are expected to be widely used by industry due to their environmental friendliness and comparable mechanical and thermal properties. Poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) are such biodegradable polymers which aim to replace commodity polymers in future applications. Since cost and brittleness of PLA is quite high, it is not economically feasible to use it alone for day to day use as a packaging material without blending. In this study, blends of PLA and PBS with various compositions were prepared by using a laboratory-scale twin-screw extruder at $180^{\circ}C$. Morphological, thermal, rheological and mechanical properties were investigated on the samples obtained by compression molding to explore suitability of these compositions for packaging applications. Morphology of the blends was investigated by scanning electron microscopy (SEM). Morphology showed a clear phase difference trend depending on blend composition. Modulated differential scanning calorimetry (MDSC) thermograms of the blends indicated that the glass transition temperature ($T_g$) of PLA did not change much with the addition of PBS, but analysis showed that for PLA/PBS blend of up to 80/20 composition there is partial miscibility between the two polymers. The tensile strength and modulus were measured by the Instron Universal Testing Machine. Tensile strength, modulus and percentage (%) elongation at break of the blends decreased with PBS content. However, tensile strength and modulus values of PLA/PBS blend for up to 80/20 composition nearly follow the mixing rule. Rheological results also show miscibility between the two polymers for PBS composition less than 20% by weight. PBS reduced the brittleness of PLA, thus making it a contender to replace plastics for packaging applications. This work found a partial miscibility between PBS and PLA by investigating thermal, mechanical and morphological properties.

• 동력기계공학회지
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• 제4권1호
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• pp.81-87
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• 2000

In this study, CT specimens were prepared from ASTM SA516 Gr. 70 which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C,\;-60^{\circ}C,\;-80^{\circ}C\;and\;-100^{\circ}C$ and in the range of stress ratio of 0.05 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\Delta}K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range ${\Delta}K$ in the stable of fatigue crack growth (Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm $d{\alpha}/dN\;-{\Delta}K$ in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate $d{\alpha}/dN$ is rapid in proportion to descend temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.