• Title/Summary/Keyword: vacuum Co2

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Effect of Modified Atmosphere Packaging on Quality Preservation of Rice Cake (Ddukgukdduk) (떡국 떡의 품질유지에 미치는 변형기체포장(MAP) 효과)

  • Jung, Soo Yeon;An, Duck Soon
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.1
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    • pp.9-14
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    • 2022
  • Packages of different atmospheres (air (control), 100% CO2, vacuum, and vacuum + O2 absorber) were prepared for 0.4 kg rice cake (ddukgukdduk) using gas-barrier plastic film and stored at 10℃ for 11 days. The stored products were evaluated in their packages atmosphere, total aerobic bacteria, yeast and molds, texture and sensory quality during storage period. In the air package, the O2 concentration decreased from initial 21% to 16% on storage 4 days and the CO2 concentration increased to 23% on storage of 11 days, which resulted from the growth of microorganisms. CO2 concentration decreased from initial 98% to 36% on storage 11 days in the 100% CO2 package. It is reasoned that CO2 was dissolved into the product reducing the volume of the package. Vacuum and vacuum +O2 absorber package maintained shrunk vacuum condition until 11 days of storage. Total aerobic bacteria count increased significantly in the control package (6.41 log (cfu/g) after 11 days) compared to the 100% CO2 package (4.96 log (cfu/g) after 11 days). Yeast and molds were 6.66 in control package, 3.43 in 100% CO2 package, 4.66 in vacuum package, and 3.78 in vacuum + O2 absorber package after 11 days. There was no significant difference between control and the other treatments for the texture of the stored products. Sensory quality was the worst in control package on the storage of 8 days. All treatment groups except control improved the quality preservation, but vacuum and vacuum + O2 absorber packages suffered from cracking of the product. Thus 100% CO2 flushing is suggested as a desired packaging condition.

Effect of Modified Atmosphere Packaging Varying in CO2 and N2 Composition on Quality Characteristics of Dry Fermented Sausage during Refrigeration Storage

  • Ameer, Ammara;Seleshe, Semeneh;Kang, Suk Nam
    • Food Science of Animal Resources
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    • v.42 no.4
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    • pp.639-654
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    • 2022
  • The current study investigated the effects of the most suitable modified atmosphere packaging (MAP) on the physicochemical, microbiological, and sensory properties of fermented dry sausages during 45 days of refrigeration (4℃) storage period. Treatments were vacuum-packed (control), 25% CO2/75% N2 (MAP1), 50% CO2/50% N2 (MAP2), 70% CO2/30% N2 (MAP3), and 100% CO2 (MAP4). All MAP samples regardless of their CO2 composition significantly (p<0.05) decreased in pH, aw, total plate count, and lactic acid bacteria count values as compared to the vacuum-package during storage. The Enterobacteriaceae count in all MAP packaging was significantly (p<0.05) lower than the vacuum-packed samples and counts in MAP3 and MAP4 samples were markedly (p<0.05) lower than all other treatments in prolonged storage of 15 and 45 days. Based on the thiobarbituric acid reactive substance content at day 15 and 30 storage time, treatments are ranked as follows: Vacuum-packed>MAP1>MAP2>MAP3>MAP4. The a* of MAP4 was higher than all other treatments. In the final storage days, no variation was exhibited (p>0.05) among treatments in lactic acid aroma and sourness, and MAP2 samples had the lowest (p<0.05) overall acceptability. The use of MAPs with an increase in the CO2 from MAP1 to MAP4 samples can help in better microbial inhibition than vacuum package, and 70% CO2/30% N2 (MAP3) and 100% CO2 (MAP4) were effective to maintain several quality parameters (aw, pH, microbial inhibition, stability against lipid oxidation, and instrumental color traits) and extend the shelf life of dry fermented sausage.

High vacuum packaging and vacuum evaluation for field emission display

  • Jung, S.J.;Woo, K.J.;Lee, N.Y.;Ahn, S.;Moon, G.J.;Kim, K.S.;Kim, M.S.
    • Journal of Korean Vacuum Science & Technology
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    • v.3 no.1
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    • pp.95-97
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    • 1999
  • A 3.12" FED panel was packaged successfully using the anode plate on which phosphors and black matrix were coated and cathode plate containing emitter arrays. The vacuum level of the panel was investigated during panel evacuation, tip-off and getter activation process. The packaged panel exhibited vacuum level below 2${\times}$10-6 Torr. Similar experiments were carried out for 10" panel made of bare plates. In addition, the vacuum level of two panels was compared continuously after tip off process; one with the getter and the other without it.

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Consolidation of Binderless and Low-Binder WC hardmetal by Vacuum Sintering (진공 소결공정에 의한 고밀도 바인더리스 및 극저바인더 초경합금의 제조)

  • Min, Byoung-June;Park, Young-Ho;Lee, Gil-Geun;Ha, Gook-Hyeon
    • Journal of Powder Materials
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    • v.14 no.5
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    • pp.315-319
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    • 2007
  • Pure WC or WC with low Co concentration less than 0.5 wt.% is studied to fabricate high density WC/Co cemented carbide using vacuum sintering and post HIP process. Considering the high melting point of WC, it is difficult to consolidate it without the use of Co as binder. In this study, the effect of lower Co addition on the microstructure and mechanical properties evolution of WC/CO was investigated. By HIP process after vacuum sintering, hardness and density was sharply increased. The hardness values was $2,800kgf/mm^2$ using binderless WC.

Infrared spectroscopy of the effect of metal electrode on adsorbate under electric field: Electrochemical model study of CO on Pt(111) with ice film capacitor method in ultrahigh vacuum

  • Kang, Hani;Shin, Sunghwan;Park, Youngwook;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.143.2-143.2
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    • 2016
  • The influence of electric field on CO adsorbed on Pt(111) was investigated with reflection-absorption infrared spectroscopy (RAIRS) in ultrahigh vacuum system. The ice film capacitor method was used to apply electric field to the amorphous ice film with CO on Pt(111). Two systems were compared by measuring the change of the CO stretching vibrational mode under applied electric field; one is CO on Pt(111), and the other is CO buried inside an ice film on Pt(111). By comparing them, we were able to calculate the additional effect of adsorption of CO on Pt(111) on peak shift. The CO adsorbed on Pt(111) has shown larger peak shift than CO adsorbed with H2O when we applied stronger electric field. Additionally, the differences were observable when the applied electric field exceeds $1{\times}10V/m^8$.

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Prohibition of Boundary Image Sticking in AC Plasma Display Panel Using Vacuum Sealing Method

  • Tae, Heung-Sik;Park, Choon-Sang;Kwon, Young-Kuk;Heo, Eun-Gi;Lee, Byung-Hak
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1688-1691
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    • 2007
  • This paper shows that the boundary image sticking can be prohibited completely by using the vacuum sealing process, which means that the residual impurities such as nitrogen or oxygen can be a critical factor inducing the boundary image sticking. The production of boundary image sticking was checked in the test panel fabricated by the $N_2$ or $O_2$ flow during the vacuum sealing process. As a result, the boundary image sticking did not appear in the case of $N_2flow$, whereas the boundary image sticking was observed in the case of $O_2$ flow even though the test panel was fabricated by the vacuum sealing process.

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