• 제목/요약/키워드: Temperature stability time

검색결과 875건 처리시간 0.026초

농축단호박 분말을 대체한 혼합분과 반죽의 특성 (Rheological Properties of Composite Flour and Dough with Concentrated Sweet Pumpkin Powder)

  • 이찬호;김문용;전순실
    • 한국식품조리과학회지
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    • 제24권4호
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    • pp.511-516
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    • 2008
  • In this study, composite flour and dough were prepared with concentrated sweet pumpkin powder(CSPP) at varying concentrations of 3, 6, 9, 12, and 15%. The samples and a control were then compared with regards to quality characteristics, including moisture, protein, and ash contents, farinogram characteristics, amylogram characteristics, and falling number of flour and extensogram characteristics of dough, in an effort to determine the optimal ratio of CSPP in the formulation. As the CSPP content increased, the moisture and protein contents of the flour increased, whereas the ash contents decreased. With regard to the farinogram characteristics of flour, water absorption, development time, and stability decreased with increasing CSPP content, while weakness increased. The control group evidenced a significantly higher beginning temperature of gelatinization as compared to the CSPP samples. The temperature of maximum viscosity, maximum viscosity, and falling number of flour decreased with increasing CSPP content. With regard to the extensogram characteristics of dough, extensibility decreased with increasing testing time and CSPP content, whereas resistance, maximum resistance, and R/E ratio increased. In conclusion, these results show that $6{\sim}9%$ CSPP may prove very useful as a substitute for wheat flour in the production of hardroll bread, and may provide good nutritional and functional properties.

친환경 공정에 의한 봉상형 육티탄산칼륨 입자의 제조 (Eco-Friendly Synthesis of Rod-Like Potassium Hexatitanate Particles)

  • 이총민;장한권;장희동
    • 한국입자에어로졸학회지
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    • 제13권4호
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    • pp.183-189
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    • 2017
  • Potassium hexatitanate ($K_2Ti_6O_{13}$) with high thermal insulating capacity, good mechanical properties, and excellent chemical stability are promising functional materials in the field of reinforcing material, heat insulating paints and automotive brake linings. In this study, we successfully synthesized rod-shaped potassium hexatitanate ($K_2Ti_6O_{13}$) by aerosol spray drying and post heat treatment as an eco-friendly process. The $KHCO_3-TiO_2$ porous particles were firstly synthesized from a colloidal mixture of $K_2CO_3$ and $TiO_2$ via aerosol spray drying. Size of $KHCO_3-TiO_2$ porous particles was ranged from $1{\mu}m$ to $5{\mu}m$. The porous particles were then heated to fabricate rod-type $K_2Ti_6O_{13}$. The length and width of rod-type composites were affected by temperature and heating time. The length and width of $K_2Ti_6O_{13}$ were increased by 830 nm and 500 nm, respectively, as the reaction temperature and time increased.

Improved Responsivity of an a-Si-based Micro-bolometer Focal Plane Array with a SiNx Membrane Layer

  • Joontaek, Jung;Minsik, Kim;Chae-Hwan, Kim;Tae Hyun, Kim;Sang Hyun, Park;Kwanghee, Kim;Hui Jae, Cho;Youngju, Kim;Hee Yeoun, Kim;Jae Sub, Oh
    • 센서학회지
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    • 제31권6호
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    • pp.366-370
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    • 2022
  • A 12 ㎛ pixel-sized 360 × 240 microbolometer focal plane array (MBFPA) was fabricated using a complementary metaloxide-semiconductor (CMOS)-compatible process. To release the MBFPA membrane, an amorphous carbon layer (ACL) processed at a low temperature (<400 ℃) was deposited as a sacrificial layer. The thermal time constant of the MBFPA was improved by using serpentine legs and controlling the thickness of the SiNx layers at 110, 130, and 150 nm on the membrane, with response times of 6.13, 6.28, and 7.48 msec, respectively. Boron-doped amorphous Si (a-Si), which exhibits a high-temperature coefficient of resistance (TCR) and CMOS compatibility, was deposited on top of the membrane as an IR absorption layer to provide heat energy transformation. The structural stability of the thin SiNx membrane and serpentine legs was observed using field-emission scanning electron microscopy (FE-SEM). The fabrication yield was evaluated by measuring the resistance of a representative pixel in the array, which was in the range of 0.8-1.2 Mohm (as designed). The yields for SiNx thicknesses of SiNx at 110, 130, and 150 nm were 75, 86, and 86%, respectively.

발효쌀겨의 첨가에 따른 식빵 반죽의 물리적 특성 (Effect of Fermented Rice Bran on Rheological Properties of White Bread Dough)

  • 박현실;한기동
    • 한국식생활문화학회지
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    • 제25권1호
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    • pp.82-90
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    • 2010
  • In this study, the rheological properties of doughs blended with 5% to 20% fermented rice bran (FRB) were investigated using farinographs, amylographs, extensographs, and SEM. In the farinograph analysis, the water absorption decreased and the replacement ratio of FRB increased over the time of development of the dough. The stability time of the dough was shortened, and the degree of softening decreased with added volume of FRB. The amylograph analysis showed that the temperature at the beginning of gelatinization showed a tendency to increase with increasing replacement ratio of FRB, but the gelatinization temperature showed no significant difference between the FRB-added groups and control group. The extensograph analysis showed that when the replacement ratio of FRB was over 10%, the extension of the dough decreased while the resistance was increased. In the SEM analysis, the added dough with less than 10% FRB had similar characteristics in gluten matrix and gas bubbles to those of the control of wheat flour alone. It was concluded that an added FRB volume of below 10% is most suitable for bread making.

벤토나이트 완충재의 열수거동 및 장기건전성 연구 (Hydrothermal Behaviors and Long-term Stability of Bentonitic Buffer Material)

  • 이재완;조원진
    • 방사성폐기물학회지
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    • 제5권2호
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    • pp.145-154
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    • 2007
  • 벤토나이트 완충재의 열수거동 실험에서는 고준위폐기물처분장 완충재로 유력하게 고려되고 있는 국산 벤토나이트를 대상으로 열수특성을 규명하고, 또 그 결과를 바탕으로 KRS 처분환경에서 벤토나이트 완충재의 장기건전성을 평가하였다. 실험결과, 벤토나이트 완충재의 열수반응은 주 구성광물인 스멕타이트의 일라이트화를 통해 진행되었으며, 온도, $K^+$농도, pH는 이러한 일라이트화에 중요한 열수반응인자 역할을 하였다. KRS 처분환경에 대한 국산벤토나이트 완충재의 장기건전성을 분석한 결과, 정상상태에서는 벤토나이트 완충재가 오랜 기간 동안 방벽재기능을 유지하였지만, 보수적인 조건에서는 약 $5{\times}10^4$년이 경과했을 때 벤토나이트 완충재를 구성하는 스멕타이트의 50%이상이 일라이트로 전환되어 방벽재로서의 팽윤능력을 상실할 수 있음을 예상할 수 있었다.

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고온가열 과정 중 대두경화유의 산화안전성에 관한 연구 (Oxidative Stability of Hydrated Soybean Oil during Heating at High Temperature)

  • 김명애
    • 한국식생활문화학회지
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    • 제23권1호
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    • pp.26-32
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    • 2008
  • : In this experiment, three samples of oils were used. These oils were hydrated soybean oil, pure soybean oil and regular soybean oil. Oil was used after heating at $235-240^{\circ}C$ every four hours term and total heating hours was 16 hours. The physio-chemical analysis and sensory evaluation were performed on these oils. The hydrated soybean oil showed lower acid, peroxide and carbonyl value than the other two oils (p<0.05 or p<0.001). The other two oils were more affected in rancidity than the hydrated soybean oil. In color test, whereas L value lowed during the heating time, a and b value increased during the heating time. The tendency of high L value and low b value in a long-time heating was more apparant on the pure soybean oil and the regular soybean oil than on the hydrated soybean oil (p<0.05). In sensory evaluation, color and rancidity order increased during the heating time. The hydrated soybean oil showed color and rancidity order than the other two oils. In overall quality test, the pure and regular soybean oil that had been used for 12 and 16 hour were not preferable. The hydrated soybean oil that had been used for 16 hour were not preferable. In sensory evaluation, the hydrated soybean oil, the pure and regular soybean oil did not show a apparent difference, although the hydrated soybean oil had a little better scores on the overall quality.

Quality Improvement of Oil Palm Trunk Properties by Close System Compression Method

  • Hartono, Rudi;Wahyudi, Imam;Febrianto, Fauzi;Dwianto, Wahyu;Hidayat, Wahyu;Jang, Jae-Hyuk;Lee, Seung-Hwan;Park, Se-Hwi;Kim, Nam-Hun
    • Journal of the Korean Wood Science and Technology
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    • 제44권2호
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    • pp.172-183
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    • 2016
  • Densification of the inner part of oil palm trunk (OPT) by the close system compression (CSC) method was performed in this study. The effects of the compression temperature and time on the anatomical, physical and mechanical properties of OPT were evaluated. The inner part of OPT with an initial average density of $0.3g/cm^3$ was used as samples. Oven-dried samples were immersed in water and vacuumed until fully saturated and then compressed by CSC at 120, 140, 160 or $180^{\circ}C$ for 10, 20, 30 or 40 min. The anatomical characteristics of transverse and radial sections before and after compression were compared by optical microscopy. The physical and mechanical properties, including the density, recovery of set (RS), modulus of elasticity (MOE), modulus of rupture (MOR), and compression parallel to grain were examined. It was observed that the anatomical characteristic of the inner part of OPT (i.e., vascular bundles, vessels, and parenchyma tissue) became flattened, fractured, and collapsed after compression by CSC. The RS decreased with increasing compression temperature and time. The lower RS indicated high dimensional stability. The physical and mechanical properties (i.e., density, MOR, MOE, and compressive strength) of the inner part of OPT increased with increasing compression temperature and time. Compression by the CSC method at $160^{\circ}C$ for 40 min was the optimum treatment.

저장온도 및 Blanching 처리가 유자의 저장성에 미치는 영향 (Effects of Storage Temperature and Blanching Treatment on the Storage Stability of Citron (Citrus junos))

  • 김현구;박무현;이영철;김흥만;장학길
    • 한국식품과학회지
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    • 제27권3호
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    • pp.342-347
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    • 1995
  • 저장온도 및 blanching 처리가 유자의 저장성에 미치는 영향을 밝혀 유자의 적정 저장조건을 설정함으로서 유자의 저장성을 향상시키고자 하였다. 유자의 저온장해 현상은 $0^{\circ}C{\sim}5^{\circ}C$ 범위에서 나타나지 않았고, 유자의 호흡은 저장시간에 따라 증가하는 climacteric 특성으로 분류될 수 있었고 유자 호흡량의 $Q_{10}$값은 $2.3{\sim}2.4$의 범위였다. 유자의 부패율은 blanching 처리보다는 저장 온도가 유자의 저장성에 영향이 컸다. 유자의 중량감소율은 처리구에 따라서 중량감소율의 변화는 크지 않았으나 온도에 따라서는 그 영향이 지대하였다. 유자 저장중 과실의 맛을 결정하는 당산비는 $3^{\circ}C$에서 완만하게 증가하고 $20^{\circ}C$에서 급격히 증가하다 감소하였는데, 이는 산함량의 증가보다는 당도의 증가에 의한 영향이 큰 것으로 판단되었다. 유자저장중 갈변도는 과육보다 껍질부분의 갈변정도에 따라서 유자전체의 갈변에 크게 영향을 미치고 있으므로 껍질부분이 갈변의 지표가 됨을 확인할 수 있었다.

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Hansen Solubility Parameter 를 통한 W/O 형 자외선차단 제형의 유화 안정성에 관한 연구 (A Study on the Emulsifying Stability of W/O Type Sunscreen Cream by the Hansen Solubility Parameter)

  • 김동희;이진재
    • 대한화장품학회지
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    • 제47권4호
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    • pp.273-280
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    • 2021
  • 자외선차단 제형은 내수성이 중요하므로 수상이 유상에 분산되는 water-in-oil (W/O) 에멀젼으로 만드는 것이 바람직하다. 이 경우에는 오일 특유의 무겁고 끈적이는 사용감 때문에 이를 보완하는 방법으로 실리콘계 오일을 사용한다. 이러한 오일은 유기 자외선차단제와의 상용성이 낮아 에멀젼의 안정성에 문제가 되고 있다. 본 연구에서는 자외선차단 제형의 W/O 에멀젼에서 다양한 오일들 간의 상용성을 Hansen solubility parameter(HSP)를 이용하여 수치적으로 도출하였다. HSP는 물질의 분산, 극성 및 수소 결합을 나타내는 지표로 물질간의 상용성을 판단하는데 유용하다. 본 연구에서는 HSP가 다른 다양한 오일을 선정하여 W/O 에멀젼을 제조하고 제형의 시간에 따른 점도 변화 및 안정성을 조사하여 HSP 수치와의 상관관계 또는 일치성을 고찰하였다. HSP를 이용하면 상용성이 높은 오일 선택을 용이하게 할 수 있었다. 또한, W/O 에멀젼에서 유상의 상용성이 높으면 점도의 경시변화가 작았으며 freeze-thaw cycle (-15 ℃ ~ 45 ℃) 조건에서 안정성이 향상된 것을 확인하였다. 향후 HSP를 통해 성분 구성을 최적화한다면 사용감이 우수하면서 안정성을 확보한 W/O형 자외선차단 제형 개발에 도움이 될 것이라 기대된다.

가열온도, 가열시간, 단백질농도가 혈장단백질과 근원섬유단백질 혼합물의 gel 특성 및 열안정성에 미치는 영향 (Effect of Heating Temperature, Time and Protein Concentration on the Gel Properties and Heat Stability of a Mixed System of Pork Myofibrillar and Plasma Proteins)

  • 김천제;한의수;고원식;최도영;이치호;정구용;최병규
    • 한국식품과학회지
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    • 제25권3호
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    • pp.295-298
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    • 1993
  • 식품산업 특히 육가공산업에 돈혈액의 이용을 위하여 가열온도 가열시간 및 단백질 농도가 혈장단백질과 근원섬유단백질 혼합물의 gel 특성과 열안정성에 어떠한 영향을 미치는지를 규명하기 위하여 실시되었다. 혈장단백질과 혼합물(plasma+myofibrillar protein)의 용해성은 가열온도가 $70^{\circ}C$에서 $90^{\circ}C$로 증가함에 따라 크게 감소하였으며, 근원섬유단백질은 $40{\sim}60^{\circ}C$에서 용해성이 서서히 감소하였다. 또한 gel 강도와 혼탁도는 이 온도범위에서 크게 증가하였다. 가열온도 $75^{\circ}C$에서 가열시간이 경과함에 따라 혈장단백질과 혼합물의 용해성은 감소하였으나 gel 강도와 혼탁도는 증가하였다. 근원섬유단백질은 $75^{\circ}C$에서 가열시간이 경과함에도 용해성, 혼탁도, gel 강도의 변화가 거의 나타나지 않았다. 근원섬유단백질, 혈장단백질, 혼합물의 gel 강도는 단백질 농도가 5%에서 9%로 증가함에 따라 증가하였다.

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