• 제목/요약/키워드: Quick freezing

검색결과 44건 처리시간 0.025초

포장방법이 동결계육의 저장성 및 미생물의 증식에 미치는 영향 (Effect of Packing Method on Shelf-life and Microbiology of Frozen Chicken)

  • 박구부;하정기;이성기;정선부;김홍국;조규석;조규석;신택순;박태선
    • 한국가금학회지
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    • 제23권4호
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    • pp.203-207
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    • 1996
  • This experiment was carried out to find out the effects of packing methods on shelf-life and hy-giene of breast and thigh meats in chicken. The carcass weights were about 1.6 kg per bird, and chilled by air spray method. The breast and thigh meats were packed by either vacuum or atmosphere packing methods. Samples were analyzed at 1, 4, 8, 12 and 16 wk after quick freezing at -45˚C for 35 min. Regardless of packing method. The thiobarbituric acid(TBA) values of thigh meats after 1 wk of storage were higher than those of breast meats. The TBA values of both treatments were increased as storage period extended. In addition, the TBA values of vacuum packed meats were lower than those of atmosphere packed meats. The VBN(volatile basic nitrogen) values, regardless of packing method, at 1 wk of storage were higher than those of breast meats. The VBN contents of breast and thigh meats after 16 wk of storage increased markedly, but failed to show significant difference between the two packaging methods. Total plate counts of breast and thigh meats were increased gradually as storage period extended, and the total plate count of breast meat was higher than that of thigh meat. The coliform bacteria were not detected until 16 wk after storage.

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냉동, 냉장 시스템에서 NH3 누출 사고 시 장외영향평가를 위한 피해범위 및 대피거리 산정에 관한 연구 (Recommended Evacuation Distance for Offsite Risk Assessment of Ammonia Release Scenarios)

  • 박상욱;정승호
    • 한국안전학회지
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    • 제31권3호
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    • pp.156-161
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    • 2016
  • An accident of an ammonia tank pipeline at a storage plant resulted in one death and three injuries in 2014. Many accidents including toxic gas releases and explosions occur in the freezing and refrigerating systems using ammonia. Especially, the consequence can be substantial due to that the large amount of ammonia is usually being used in the refrigeration systems. In this study, offsite consequence analysis has been investigated when ammonia leaks outdoors from large storages. Both flammable and toxic effects are under consideration to calculate the affected area using simulation programs for consequence analysis. ERPG-2 concentration (150 ppm) has been selected to calculate the evacuation distance out of various release scenarios for their dispersions in day or night. For offsite residential, the impact area by flammability is much smaller than that by toxicity. The methodology consists of two steps as followings; 1. Calculation for discharge rates of accidental release scenarios. 2. Dispersion simulation using the discharge rate for different conditions. This proactive prediction for accidental releases of ammonia would help emergency teams act as quick as they can.

고등어 보통육의 냉동저장중(冷凍貯藏中) 지질(脂質)의 변화(變化)에 관한 연구(硏究) (Chemical Changes in the Lipids of frozen Mackerel ordinary Muscle during low Temperature Storage)

  • 안명수;정태영;이상건
    • 한국식품과학회지
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    • 제10권2호
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    • pp.203-208
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    • 1978
  • 고등어 보통육을 ascorbic acid 및 NaCl을 처리하여 냉동저장시 지질의 변화를 산가, 과산화물가 및 지방산조성의 변화 등을 통하여 고찰한 결과는 다음과 같다. 1. 고등어보통육(肉)의 냉동저장기간동안 AV와 POV는 무첨가구에 비하여 As A첨가구는 AV 및 POV가 낮고 NaCl첨가구는 높은 AV 및 POV를 나타내었다. 2. 고등어 육지질(肉脂質)의 지방산조성은 GLC법으로 분석한 결과 $C_{16:0}$산, $C_{18:0}$산, $C_{18:1}$산은 냉동저장기간중 계속 증가되며 $C_{18:3}$산, $C_{20:4}$산, $C_{22:5}$산, $C_{22:6}$산과 같은 불포화도가 높은 지방산은 계속적으로 감소되었다. 3. $C_{22:6}$산의 감소율은 저장초기에는 As A첨가군 : 무첨가군 NaCl첨가군이 1: 2: 3의 비율로 그 감소율이 높았으나, 저장후기에는 유의성이 없었다. 4. 전반적으로 고등어의 냉동저장중 육지질(肉脂質)의 산화 양상에 있어서 무첨가구에 비하여 As A첨가구는 산화를 억제시켰고, NaCl은 산화를 촉진하는 결과를 보였다.

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환원슬래그를 사용한 모르타르의 저온에서의 초기동해 방지에 관한 기초적 실험 (A Fundamental Experiment on Preventing Frost Damage at Early Age of Mortar in Low Temperature using Reduction Slag)

  • 민태범;문영범;김형철;최현국;김재영;이한승
    • 한국건축시공학회지
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    • 제16권1호
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    • pp.1-7
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    • 2016
  • 본 연구에서는 $-5^{\circ}C$이하에서도 가열 양생이 없이 수화 반응시 수화열이 높게 발생되는 환원슬래그를 시멘트 분체와 치환사용 하여 영하의 온도에서도 콘크리트의 자체 발열로 인해 압축강도를 재령 3일 이내 5MPa를 발현시켜 초기동해를 방지시키는 것이 최종 연구의 목적이며 이에 대하여 환원슬래그의 물리적 특성 평가와 열적 특성 평가를 실시한 결과 환원슬래그는 높은 수화열을 발생시키기 때문에 저온에서도 압축강도 발현이 우수함을 알 수 있었다. 이는 환원 슬래그의 성분 중 $C_{12}A_7$$C_3A$에 의해 수화열이 높게 발생됨 저온에서도 압축강도가 발현되는 것으로 나타났다. 하지만 환원슬래그 단독 치환하였을 경우 $SO_3$함량 부족으로 급결이 발생하는 것을 알 수 있었다. 급결을 방지하기 위해서는 석고의 사용이 필수적으로 사용되어야 한다. 따라서 본 연구 결과 환원슬래그와 석고를 3성분계로 사용하였을 경우 저온에서도 재령 3일에서 5MPa 압축강도를 나타나는 것으로 보아 저온에서도 콘크리트의 초기동해를 방지할 수 있을 것으로 판단된다.

포장방법이 동결계육의 이화학적 특성에 미치는 영향 (Effect of Packing Method on Physico-chemical Properties of Frozen Chicken)

  • 박구부;하정기;박범영;이상진;박용윤;박태선;신택순;이정일
    • 한국가금학회지
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    • 제23권4호
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    • pp.193-201
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    • 1996
  • This experiment was carried out to find out the effect of packing methods on physico-chemical properties of breast and thigh meats in chicken, which was dried by air spray chilling method. The chicken carcass was cut into breast and thigh muscles, which were either vacuum packed or atmosphere packed, and stored at -2O˚C for 1, 4, 8, 12 and 16 wk after quick freezing at -45˚C for 35 min. The pH values of atmosphere-packed breast meat and vacuum-packed breast meat after one wk of storage were higher than those of atmosphere-packed thigh meat and vacuum-packed thigh meat(P< .05). The pH values increased as storage period extended, but no significant difference was detected between two packing method(vacuum vs. atmosphere). Total moisture contents of breast meats after one wk of storage were higher than those of thigh meats. The total moisture contents decreased slowly as storage period extended, but no significant difference was detected between two packing method(vacuum vs. atmosphere). The shear force value of thigh meat was higher than that of breast meat. The shear force values of both meats decreased as storage period extended, regardless of packing method. The water soluble protein extractability of thigh meats was higher than that of breast meat, and the water soluble protein extractability of all treatments decreased until 8 wk after storage, but increased gradually after 8 wk of storage period. The salt soluble protein extractability of breast meat was higher than that of thigh meat, and the salt soluble protein extractability of all treatments decreased as storage period extended. With regard to the packing method, the vacuum packing showed higher value than that of atmosphere packing method until 8 wk of storage. Total lipid contents of atmosphere- and vacuum-packed thigh meats at 1 wk of storage were higher than those of breast meats, and the total lipid contents of all of treatments decreased as storage period extended. However, no significant difference was detected between two packing methods. The fatty acid contents of breast and thigh meats were in order of o1eic(33,5~42.4), palmitic(19.7~30.8) and linoleic acid(10.8~17.4).

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토양 고형화를 위한 인산염 마그네시아 시멘트 적용 연구 (The application of Phosphate Magnesia Cement for Solidification of Soil)

  • 최훈;최준옥;송명신;문창열
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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    • pp.533-536
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    • 2008
  • 최근 농촌의 생활환경 개선 및 소득기반 조성을 위한 문화마을, 밭 기반 정비사업의 도로포장사업에서는 토양 고형화를 이용한 기계화 경작로 시공이 이루어지고 있다. 기계화 경작로 포장은 도로로서의 기능을 장기적으로 유지할 수 있는 소요강도 및 내구성을 확보할 수 있어야 하며, 금후 추진될 사업량에 대비하여 경제성, 내구성, 유지관리의 용이성, 환경 친화성 등을 만족시킬 수 있는 공법의 개발이필요하다. 본 연구는 이러한 농어촌 기계화 경작로를 대상으로 속경성이며, 수화 특성이 우수한 인산염 마그네시아 시멘트의 토양 고화재로서의 적용여부에 대해 연구하였다. 연구 결과 인산염 마그네시 시멘트 배합은 인산염 마그네시아(MAP:MgO)의 배합이 4 : 6에서 W/B = 50 wt%일 때 14MPa로 가장 큰 압축강도와 높은 수화열 특성을 나타냈으며, 대상토-고화재 동결융해 저항성 실험 결과, 인산염마그네시아 시멘트(MAP:MgO=4:6), W/B=50wt%를 기준으로 치환시료(점성토:표준사=4:6, 3:7) 배합이가장 우수하였으며, 인산염 마그네시아 시멘트(MAP:MgO=4:6):대상토의 비율이 4:6과 5:5 배합이 동결융해 후의 압축강도 값이 7.0 MPa 이상으로써 가장 우수한 것으로 나타났다.

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Comparison of Two Vitrification Methods of In Vitro Development Oocytes Collected from Porcine Antral Follicles Using Open Pulled Straw (OPS) Techniques

  • An, Mihyun;Hong, Daewuk;Son, Dongsoo;Seok, Hobong
    • 한국수정란이식학회:학술대회논문집
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    • 한국수정란이식학회 2002년도 국제심포지엄
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    • pp.84-84
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    • 2002
  • The advantages of the OPS techniques(Vajta G et al, Mol Reprod Dev 51: 53-58,1998) give 1) high survival rates of various types of eggs, 2) quick and simple process, 3) inexpensive equipment and reduced chilling injury. The efficiency of IVM/IVF technique in the porcine species is relatively lower than that obtained in other species such as ruminants. Two experiments were designed to investigate the effects of in-vitro fertilization of porcine oocytes matures using different OPS protocol for chilling and warming of vitrification. Porcine oocytes from ovaries collected at abattoir were matured for 44 hours in TCM199 Earle's salt supplemental with pyruvate, pff, L-cysteine, hormones and gentamycin. Oocytes were denuded and fertilized with frozen boar semen by common method. Porcine embryos produced routinely by in-vitro culture system of NCSU23 medium. The vitrification and the warming were conducted by OPS method with the glass micropipette instead of straw vessels and modified the protocol of G.Vajta(1999). In Exp 1, Chilling/Warming:Holding Medium(HM)+EG+DMSO/HM +sucrose Medium(SM) at 39$^{\circ}C$ warm stage. In Exp 2, : PBS+CS+EG+Ficoll+ Trehalose/PBS+Trehalose at 25$^{\circ}C$ stage. Filling, freezing, packing, thawing out and further culturing were performed to follow the basic protocol of G Vajta. During IVM-lVC and post-warming, fertilization parameter and developmental potential were compared to and statistically analysed. It was not significantly different from Exp 1 and Exp 2 but 25$^{\circ}C$ of stage was slightly higher on the morula/blastocyst forming rate and better atmosphere for worker than that at 39$^{\circ}C$ stage.

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Use of Chicken Meat and Processing Technologies

  • Ahn, D.U.
    • 한국가금학회지
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    • 제31권1호
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    • pp.45-54
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    • 2004
  • The consumption of poultry meat (chicken and turkey) grew the most during the past few decades due to several contributing factors such as low price, product research and development, favorable meat characteristics, responsive to consumer needs, vertical integration and industry consolidation, new processing equipments and technology, and aggressive marketing. The major processing technologies developed and used in chicken processing include forming/restructuring, tumbling, curing, smoking, massaging, injection, marination, emulsifying, breading, battering, shredding, dicing, and individual quick freezing. These processing technologies were applied to various parts of chicken including whole carcass. Product developments using breast, thigh, and mechanically separated chicken meat greatly increased the utilization of poultry meat. Chicken breast became the symbol of healthy food, which made chicken meat as the most frequent menu items in restaurants. However, the use of and product development for dark meat, which includes thigh, drum, and chicken wings were rather limited due to comparatively high fat content in dark meat. Majority of chicken are currently sold as further processed ready-to-cook or ready-to-eat forms. Major quality issues in chicken meat include pink color problems in uncured cooked breast, lipid oxidation and off-flavor, tenderness PSE breast, and food safety. Research and development to ensure the safety and quality of raw and cooked chicken meat using new processing technologies will be the major issues in the future as they are now. Especially, the application of irradiation in raw and cooked chicken meat products will be increased dramatically within next 5 years. The market share of ready-to-eat cooked meat products will be increased. More portion controlled finished products, dark meat products, and organic and ethnic products with various packaging approaches will also be introduced.

A Deep Learning Approach for Covid-19 Detection in Chest X-Rays

  • Sk. Shalauddin Kabir;Syed Galib;Hazrat Ali;Fee Faysal Ahmed;Mohammad Farhad Bulbul
    • International Journal of Computer Science & Network Security
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    • 제24권3호
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    • pp.125-134
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    • 2024
  • The novel coronavirus 2019 is called COVID-19 has outspread swiftly worldwide. An early diagnosis is more important to control its quick spread. Medical imaging mechanics, chest calculated tomography or chest X-ray, are playing a vital character in the identification and testing of COVID-19 in this present epidemic. Chest X-ray is cost effective method for Covid-19 detection however the manual process of x-ray analysis is time consuming given that the number of infected individuals keep growing rapidly. For this reason, it is very important to develop an automated COVID-19 detection process to control this pandemic. In this study, we address the task of automatic detection of Covid-19 by using a popular deep learning model namely the VGG19 model. We used 1300 healthy and 1300 confirmed COVID-19 chest X-ray images in this experiment. We performed three experiments by freezing different blocks and layers of VGG19 and finally, we used a machine learning classifier SVM for detecting COVID-19. In every experiment, we used a five-fold cross-validation method to train and validated the model and finally achieved 98.1% overall classification accuracy. Experimental results show that our proposed method using the deep learning-based VGG19 model can be used as a tool to aid radiologists and play a crucial role in the timely diagnosis of Covid-19.

저장기간에 따른 동결채소의 품질 변화 (Changes in the quality of frozen vegetables during storage)

  • 이혜옥;이영주;김지영;권기현;김병삼
    • 한국식품저장유통학회지
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    • 제20권3호
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    • pp.296-303
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    • 2013
  • 본 연구에서는 동결채소의 저장 중 품질 변화를 측정하여 동결채소의 장기저장 가능성과 이용 가능성을 모색해 보고자 하였다. 수확직후 여러 가지 채소는 선행실험을 통한 최적 조건에서 blanching 처리한 후 $-40^{\circ}C$에서 24시간 동안 급속동결시켜 $-20^{\circ}C$에서 저장하면서 분석하였다. 동결시킨 취나물, 콩나물, 얼갈이배추, 애호박 및 대파는 저장 기간 12개월 동안 색도의 증가와 감소가 크게 나타나지 않았다. 취나물, 애호박 및 대파의 경도는 저장기간 동안 비슷한 수준을 유지하였고, 얼갈이배추는 약간 증가하는 경향을 나타내었다. 반면에 콩나물의 자엽부와 배축부는 저장 6개월째에 경도가 큰 폭으로 증가하는 경향을 나타내었다. 저장기간 동안 취나물의 총균수는 $10^3$ CFU/g 수준을 콩나물, 얼갈이배추, 애호박 및 대파는 $10^2$ CFU/g 수준을 유지하였으며, 대장균군은 모든 시료에서 검출되지 않았다. 관능검사는 외관, 색, 이취, 조직감 그리고 맛 등의 전반적인 품질 요소들을 종합하여 전체기호도를 조사한 결과 5점을 marketable의 한계점으로 두었을 때 저장기간에 따른 동결채소의 상품성에는 큰 문제가 없는 것으로 나타났다. 따라서 동결 취나물, 콩나물, 얼갈이배추, 애호박 및 대파는 동결저장 12개월까지 저장 안전성이 있는 것으로 판단된다.