• Title/Summary/Keyword: low temperature storage

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The Study on Improvement in Subcooling of TMA Clathrate for PCM in Ice Storage System (빙축열시스템 PCM용 TMA-포접화합물의 과냉도 개선에 대한 연구)

  • Kim, J.H.;Chung, N.K.;Kim, C.O.
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1663-1666
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    • 2003
  • TMA clathrate that is used by PCM of ice storage system in this research creates hydrate crystallization at higher temperature than pure water, and application is expected as PCM because having comparative big dormant temperature without phase separation phenomenon. In case this research uses TMA clathrate by PCM, choose admixture by purpose to control or remove subcooling of TMA clathrate and evaluated experimentally. Subcooling is improved and can expect contraction of freezing machine running time and increase of coefficient of performance as that add admixture to TMA clathrate conclusively. Also, may supply thermal storage system that apply low temperature potential heat thermal storage material that subcooling is improved more extensively laying stress on medium size building and small size building, can expect allowance through localization of ice storage system.

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Effect of Modified Atmosphere Packaging and Vacuum Packaging on Quality Characteristics of Low Grade Beef during Cold Storage

  • Hur, S.J.;Jin, S.K.;Park, J.H.;Jung, S.W.;Lyu, H.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.12
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    • pp.1781-1789
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    • 2013
  • Many studies have been carried out with respect to packaging methods and temperature conditions of beef. However, the effects of packaging methods and temperature conditions on the quality characteristics have not been extensively studied in low-grade beef. Low-grade beef samples were divided into 3 groups (C: ziplock bag packaging, T1: vacuum packaging, and T2: modified atmosphere packaging (MAP), $CO_2/N_2$ = 3:7) and samples were stored at $4^{\circ}C$ for 21 days. The water-holding capacity (WHC) was significantly lower in T1 than in the other samples up to 14 days of storage. The thiobarbituric acid reactive substances and volatile basic nitrogen values were significantly lower in T1 and T2 than in C after 7 to 14 days of storage. The total bacterial counts were significantly lower in T1 and T2 than in C after 14 days of storage. In a sensory evaluation, tenderness and overall acceptability were significantly higher in T1 and T2 than in C at the end of the storage period (21 days). We propose that the MAP method can improve beef quality characteristics of low-grade beef during cold storage. However, the beneficial effects did not outweigh the cost increase to implement MAP.

Aging of Fermented shrimp in underground cave (토굴을 이용한 새우젓의 숙성)

  • Lee, Eun Hyun;Lee, Eun Mi;Chang, Kyu Seob;Jang, Hae Dong
    • Korean Journal of Agricultural Science
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    • v.24 no.2
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    • pp.132-137
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    • 1997
  • Effective storage facilities are required to stabilize the price of agricultural and marine products to preserve their qualities due to the big fluctuation of shrimp price in Korea. It is easy to make the cave because of good conditions of the land configuration, soil and convenient transportation. The cave storage can save the cost about 40% in building site and equipment, and about 50% in maintenance comparing to existing low temperature storage facilities. The cave storage provide to improve the quality of their stored products with the low heat conductivity, the constant temperature and humidity year round. Therefore, more low temperature storage facilities are required because the items are expanded from potatoes, sweet potatoes, onions, garlics, apples and chestnuts to tangerines, grapes, cabbages, radishes, and wet ginsengs. The demands of the low temperature storage facilities can be substituted into the cave storage facilities. Thus, studies are conducted to observe the changes of the components of the pure and the seasoned salted shrimps with fermentation period during stored at room temperature in cave and to establish the storing at underground facilities to produce high quality salted fish to make profit.

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A study on the construction characteristic of bath cryostat (Bath cryostat의 제작특성에 관한 연구)

  • Kim, G.Y.
    • Journal of the Korean Society for Precision Engineering
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    • v.10 no.2
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    • pp.138-145
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    • 1993
  • The bath cryostat of cryogenic apparatuses which are generally used to study physical phenomena under low temperature and ultra low temperature has been desigened and constructed. The practical use of the cryostat is verified by the measurement of the storage life of liquid heloum and liquid nitrogen vessels. The cryostat consists of triple structure of high vacuum environment in order to minimize the evaporation rate of liquid helium and liquid nitrogen by thermal conductivity and radiant heat. The minimum thickness which can stand against inner and outer pressures is calculated from considering the strength of the material.

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Storage Stability of Freeze Dried Loach for Instant Choo-o-tang (즉석 추어탕을 냉동 건조미꾸라지의 저장성)

  • 류홍수;문숙임;이수정;문갑순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.153-160
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    • 1999
  • Storage stability of boiled and freeze dried loach and antioxidative effect of Zanthoxylum schinifolium were studied to confirm the possibility in development of instant choo o tang(Korean traditional loach soup). Packaging and storage temperature did not cause a measurable change in in vitro protein digestibility and trypsin indigestible substrate within 45 days of storage but remarkable quality changes were occurred in all samples stored after 60 days. Vacuum packaging and low temperature storage(4 oC) had some effect in retarding protein quality deterioration due to delaying polyunsaturated fatty acid oxidation. Maximum peroxide value and TBA value were reached in 15 days, and there were a slow(TBA value) and rapid reduction(POV) after peaks were reached. In contrast, increasing brown pigment development and fluorescence intensity continued until 90 days of storage. Treatment of ethanolic extracts from Zanthoxylum schinifolium prior to freeze drying could protect against lipid oxidation of freeze dried loach products.

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Effect of the Scalding Temperature at Slaughtering Process on Meat Quality and Storage Properties of Chicken (탕침 온도에 따른 닭고기의 저장성 및 품질 변화)

  • 채현석;안종남;유영모;박범영;함준상;김동훈;이종문;최양일
    • Food Science of Animal Resources
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    • v.24 no.2
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    • pp.115-120
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    • 2004
  • This study was carried out to investigate the effect of the scalding temperature at slaughtering process on meat quality and storage properties of chicken. The yellowness (b$\^$*/ value) of skin decreased at high scalding temperature (65-67$^{\circ}C$) and WHC (water holding capacity) increased from 67.04% at low temperature (53-55$^{\circ}C$) to 69.26% at high temperature. WBS (Warner-Bratzler Shear force) significantly increased from 1.70kg/0.5inch$^2$ to 2.54kg/0.5inch$^2$ as the scalding temperature increased (p<0.05). TBARS (Thiobarbituric Acid-Reactive Substance) values were 0.25mgMA/kg at low temperature, 0.24mgMA/kg at middle temperature (59-61$^{\circ}C$) and 0.27mgMA/kg on 3 days of storage. Total aerobic counts (TPC) were 4.99 logCFU/mL at low temperature, 4.88 10gCFU/mL at middle temperature and 4.05 logCFU/mL. Although TPC was decreased as the scalding temperature increased. The detection rate of feather at carcass inspection was low as the scalding temperature increased and the detection rate of large feather (>lcm) was not significantly different between middle temperature and high temperature. Exposed flesh was severe as the scalding temperature increased. In conclusion, meat color and physical properties of chicken were acceptable when the carcasses were scalded at low temperature, but they were microbiologically susceptible and uneasy to remove the feather. The yellowness (b$\^$*/ value) of skin decreased at high scalding temperature, and total aerobic counts (TPC) were decreased as the scalding temperature increased, and easy to remove the feather.

Effects of Storage Duration with Low Temperature and Wet Condition, Germination Temperature and Shading Rate on Germination of Aruncus dioicus var. kamtschaticus Seeds (저온습윤 저장기간, 발아온도 및 차광율이 눈개승마 종자의 발아에 미치는 영향)

  • Song, Ki Seon;Jeon, Kwon Seok;Choi, Kyu Seong;Kim, Chang Hwan;Park, Yong Bae;Kim, Jong Jin
    • Korean Journal of Medicinal Crop Science
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    • v.23 no.5
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    • pp.370-378
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    • 2015
  • Background : Aruncus dioicus var. kamtschaticus, functional wild vegetable, is perennial herb and young leaves with soft texture are generally used as edible food. So the demand for the vegetable has increased recently. This study was carried out to determine the effects of temperature and shading on germination characteristics of A. dioicus. Methods and Results : The experiment was performed by temperature and shading treatments. Seed pre-treatment before the germination experiment was carried out by the storage in low temperature ($4^{\circ}C$) under wet condition (LTW) for 0, 15, 30, 45 and 60 days and shading treatment were 35%, 50%, and 75% under control, BA (6-benzyladenine) and $GA_3$ (gibberellic acid) condition for 24 hours. Increasing the length of the storage periods led to increases seed germination percent in low temperature ($4^{\circ}C$) under wet condition (LTW), germination rate of A. dioicus seed was the highest at $15^{\circ}C$ with 60 days of seed pre-treatment. In the case of seeds pre-treatment with LTW, the more temperature went up, the more days to 50% of Germination of Final Germination Rate ($T_{50}$) went down. As a result of surveying shading treatment, germination rate was the highest in control of 35% shading and the next higher was in control of 50% shading. Conclusions : It is concluded that the temperature and shading are important factors to produce A. dioicus. Also, We suggest these results as basic data of A. dioicus for sexual propagation.

Development of an Environmental Control System for Agricultural Storage Facility (상온저장 시설의 환경 제어 시스템 개발)

  • 임종환;현명택
    • Food Science and Preservation
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    • v.4 no.2
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    • pp.101-113
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    • 1997
  • Temperature, relative humidity and ventilation are closely related one another, and they are the main factors to be controlled for the environmental control system of a storage facility. Conventional environmental control systems do not consider the interrelationship between temperature, relative humidity and ventilation, which results in low performance and high energy consumption. To overcome the inefficiency of the conventional ones, it was developed an on-off control system based on the interrelationship between the factors. The usefulness of the system was illustrated with the results produced by a set of experiments in a real world.

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The Influences of Temperature and Humidity in Storage Room, Moisture Content and Packing Weight of Leaf on the Carbonization of Processed Flue-cured Leaf Tobacco (저장실의 온습도, 제통수분함량 및 제통중량이 황색종 가공엽의 탄화에 미치는 영향)

  • 김상범;안동명;이윤환;김용규;복진영
    • Journal of the Korean Society of Tobacco Science
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    • v.23 no.1
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    • pp.19-30
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    • 2001
  • This study was carried out to investigate the influences of environmental condition in storage room, moisture content and packing weight of leaf on the carbonization of processed flue-cured leaf tobacco, and find out a regression model able to pre-estimate the degree of carbonization. The influence of temperature and humidity in storage room on the carbonization was high,, while that of packing weight was relatively low, However, high moisture content and packing weight of leaf accelerated the carbonization under the high temperature and humidity condition. Thus the leaf tobacco under the condition of 4$0^{\circ}C$, 7$0^{\circ}C$ R.H. in storage room, 16% moisture content and 286 kg/box of packing weight could be carbonized within one month. The pH, total sugar content, lightness(L) and yellowness(b) of leaf were closely related to carbonization of leaf during storage. There were significant regression and yellowness of leaf. It is considered that the certification and/or pre-estimation of carbonization during storage may be possible by applying the regression equation.

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Physicochemical Properties of Liquid Infant Formula Stored at Different Temperatures

  • Seo, Chan Won;Hong, Shik;Shin, Yong Kook;Kang, Shin Ho
    • Food Science of Animal Resources
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    • v.38 no.5
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    • pp.995-1007
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    • 2018
  • Changes in the physicochemical properties of ready-to-feed liquid infant formula (LIF) stored at different temperatures (10, 20, 30, and $40^{\circ}C$) for 6 mon, focusing on 5-hydroxymethylfurfural (HMF) content, color, pH, fat globule size distribution, and rheological properties were determined. The HMF content increased with storage time, and LIF stored at $40^{\circ}C$ had a higher HMF content than that of LIF stored at $10^{\circ}C$. The lightness ($L^*$) decreased while redness ($a^*$) and yellowness ($b^*$) increased with increasing HMF content. The fat globule size and pH of LIF stored at $10^{\circ}C$ did not change. However, in the case of LIF stored at $30^{\circ}C$ and $40^{\circ}C$, the fat globule size increased and the pH decreased during storage for 6 mon. LIF stored at $40^{\circ}C$ had a higher apparent viscosity (${\eta}_{a,10}$) than that of LIF stored at $10^{\circ}C$, and the shear-thinning behavior of LIF stored at higher temperature was stronger than that of LIF stored at low temperature. The physicochemical changes of LIF during storage were accelerated by Maillard reaction (MR) at higher storage temperatures. Therefore, even if LIF is aseptically manufactured, we recommend that sterilized LIF should be stored at low temperature in order to minimize quality changes during storage.