• Title/Summary/Keyword: Vacuum dry

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Yeast Cell Cultivation of Produce Active Dry Yeast with Improved Viability (생존능이 증진된 활성 건조효모 생산을 위한 효모세포배양)

  • Kim, Geun;Kim, Jae-Yun
    • KSBB Journal
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    • v.14 no.5
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    • pp.561-565
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    • 1999
  • Optimum conditions for vacuum-drying ad cultivation of yeast cells for the production of active dry yeast were examined. At lower temperature, more drying time was required to dry the yeast pellet to reach the desirable water content(8%). Optimum temperature of vaccum oven and time for drying was 63$^{\circ}C$ and 90 min, respectively. Optimum medium composition for flask culture using cane molasses as the substrate were 0.25% sugar, 0.013% $K_2$HPO$_4$, 0.1% $K_2$HPO$_4$. and 0.125% (NH$_4$)$_2$SO$_4$. Culture temperature $25^{\circ}C$ gave the highest survival rate of dired yeast. After finishing fed-batch culture and the culture was left in the fermentor without adding any sugar or nutrient, survival of the dried yeast harvested from the fermentor increased to 86.0% after 36 hr. It was also observed that the yeast cells with higher budding rates showed lower survival rate.

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Multilayer Coatings on Flexible substrate for Electromagnetic Shielding by Using Dry/Wet Hybrid Processes (건습식 혼합공정을 이용한 유연소재 상 전자파 차폐용 다층막 코팅)

  • Lee, Hoon-Seung;Lee, Myeong-Hoon
    • Journal of the Korean institute of surface engineering
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    • v.50 no.5
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    • pp.373-379
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    • 2017
  • Dry processes like evaporation and sputtering in vacuum chamber are difficult to make a uniform, large area and high quality film on thin PET substrate because of PET degradation and bad adhesion. On the other hand, wet processes like electro or electroless plating have complex processes and require high environmental cost. In this study, we successfully prepared $2{\mu}m$ Zn/Cu/Ni multilayers coated on $12{\mu}m$ polyethylene terephthalate (PET) substrate by using dry-wet mixing processes. Their surface electric resistances were evaluated around $0.2{\Omega}$ by using 4 probe measurements. Furthermore, their corrosion resistance also evaluated by natural potential test and compared with other wet, dry and mixing process samples.

A Study on the Thermal Characteristics of Aquatic Products by Low Temperature Vacuum Drying - Especially on the Sea Cucumber - (수산물의 저온진공건조 열적 특성에 관한 연구 - 해삼을 중심으로 -)

  • Choe, S.Y.;Kim, M.S.
    • Journal of Power System Engineering
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    • v.15 no.3
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    • pp.46-51
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    • 2011
  • Low temperature vacuum drying technique, whose drying time and quantity of exhausting energy is about 25~30% of hot air drying, is very excellent in the drying efficiency. This paper is made out in the aspects of heat engineering with the object of developing Korean drying machine which can dry once a large quantity of objects to be dried in the state of low temperature and vacuum. As the results, it took about 17 hours(3~4 days in case of hot air drying) for material to reach about 18% of the final moisture content in order to store products for a long time, from about 78~80% of the early moisture content at the beginning of drying, and maximum drying rate comes to about 0.35 kg/m2hr at about 400% of the moisture content.

Screw Vacuum Pump의 Screw 리드의 변화에 따른 성능평가 연구

  • Gang, Sang-Baek;No, Yeong-Ho;Yu, Jae-Gyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.153-153
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    • 2014
  • 건식 진공펌프(dry vacuum pump)는 기계적 저진공펌프 중 펌프 내부의 기체 배기통로에 오일을 전혀 사용하지 않는 펌프의 통칭으로써, 대개 비접촉형으로 여러 형태의 회전자가 고속으로 회전하면서 흡기구로부터 들어온 기체를 압축해 배기를 한다. 비접촉형에는 루츠(roots)형, 클로(claw)형, 스크류(screw)형, 스크롤(scroll)형 등이 있다. 그 중 스크류형 펌프는 큰 배기속도를 갖는 펌프의 설계에 유리하고 높은 운용온도가 가능하여 다수공정에 쉽게 적용할 수 있는 장점이 있다. 그러나 1단 펌프 구성을 갖게 됨에 따라 루츠형 대비 높은 소비전력 특성을 보이는 약점을 가지고 있다. 본 논문에서는 건식 진공펌프 중의 하나인 스크류형 진공펌프에 대하여, 기본적인 1단 펌프 구성에 스크류 리드(lead)의 변화를 주어 기존의 똑같은 리드의 스크류 진공펌프에 대한 소비전력 및 배기구 온도 등 스크류 형상에 대한 성능평가 연구를 진행 하고자 한다.

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Low temperature vacuum drying heat transfer characteristics of Korean raw oysters (한국산 굴의 저온진공건조 열전달특성에 관한 연구)

  • Kim, Kyung-gun;Song, Chi-sung;Choi, Se-hyun;Lee, Seo-Yeon;Mun, Soo-Beom
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.1
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    • pp.1-9
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    • 2016
  • Oysters are rich in nutrients with good flavor, and disease prevention is required in both the East and the West for high-quality seafood. The best way to store and transport mass-produced oysters is using dry techniques. Using both hot and frozen drying technologies to obtain a perfectly dried oyster often destroys much of the flavor and nutrients found with the oyster meat. This study uses a low temperature vacuum drying technology to investigate the final weight ratio of wild and farmed dried oysters. Additionally, the heat transfer characteristics of steamed oysters are discussed in this paper.

Storage Stability of Cured Cooked Boneless Chicken Drumette under Vacuum and Its Acceptability as Raw Material for Chuncheon Dakgalbi (춘천닭갈비 원료로서 염지 육계 어깨살의 저장특성)

  • Utama, Dicky Tri;Jeong, Hae Seong;Kim, Juntae;Lee, Sung Ki
    • ANNALS OF ANIMAL RESOURCE SCIENCES
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    • v.29 no.4
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    • pp.183-190
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    • 2018
  • This study was conducted to evaluate the acceptability of cured cooked boneless chicken drumettes as a raw material for Chuncheon Dakgalbi and to observe its effect on pH, lipid oxidation, volatile basic nitrogen (VBN) content and total viable count (TVC) during refrigerated storage under vacuum. Boneless chicken drumettes were dry cured with a mixed curing agent (0.20% w/w) consisting of sodium chloride (93.1%), sodium nitrite (5.9%) and sodium bicarbonate (1.0%) for 24 h at $2{\pm}2^{\circ}C$. Cured samples were cooked using an oven at $150^{\circ}C$ for 20 min and stored at $5.5{\pm}0.5^{\circ}C$ for 60 days under vacuum. Non-cured cooked sample was used as a control. Sensory evaluation was performed on day 2 of storage using 22 untrained panelists and samples were mixed with Dakgalbi sauce and reheated using a microwave for 2 min. There were no significant differences between control and treatment group on appearance, flavor, texture, juiciness and overall acceptability. Cured cooked boneless chicken drumettes had significantly (p<0.05) higher pH, lower lipid oxidation, VBN and TVC consistently during storage in comparison with control. These results suggest that dry curing could be applied to boneless chicken drumettes as raw material for Chuncheon Dakgalbi and could extend its shelf life during refrigerated storage under vacuum.