• Journal of Biosystems Engineering
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• 제39권3호
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• pp.194-204
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• 2014

Purpose: The aim of this study was to develop long-term storage technology for Chinese cabbage in order to extend the period of availability of freshly harvested products. The scope of the paper deals with the use of a cooler with a remote monitoring and control interface in conjunction with use of packaging film. Methods: A cooler with a real time monitoring system was designed as a low-temperature storage facility to control temperature and relative humidity (RH). The effects of storage in high-density polyethylene (HDPE) plastic boxes, 3% chitosan dipping solution, polypropylene film (PEF) with perforations, and mesh packaging bags on physiological responses were investigated. The optimal storage temperature and humidity for 120 days were below $0.5^{\circ}C$ and 90%, respectively. Physiological and biochemical features of cabbage quality were also analyzed: weight loss, texture, and sugar salinity, chlorophyll, reducing sugar, and vitamin C contents. Results: The cooler with a remote monitoring and control interface could be operated by an HMI program. A $0.5^{\circ}C$ temperature and 90% humidity could be remotely controlled within the cooler for 120 days. Postharvest freshness of Chinese cabbages could be maintained up to 120 days depending on the packaging method and operation of the remote monitoring system. In particular, wrapping the cabbages in PEF with perforations resulted in a less than a 5% deterioration in quality. This study provides evidence for efficient performance of plastic films in minimizing post-harvest deterioration and maintaining overall quality of cabbages stored under precise low-temperature conditions with remote monitoring and a control interface. Conclusions: Packaging with a modified plastic film and storage in a precisely controlled cooler with a remote monitoring and control interface could slow down the physiological factors that cause adverse quality changes and thereby increase the shelf life of Chinese cabbage.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1995년도 춘계학술발표회 초록집
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• pp.213-222
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• 1995

Korean traditional Ondol with the sensible heat storage medium has been for a long time used as residential heating system, in these days the concrete Ondol without the heat storage medium was realized as the heating system in the private houses and the apartments. This floor heating system is good for our health. But the concrete Ondol is not desirable for the energy saving and for the maintenance of comfortable room temperature because the heat storage medium is not employed in the concrete Ondol. And as the hot water circulating pipes ate buried under the the concrete floor, the concrete Ondol system has some kind of problems to be improved. Therefore the new type of Ondol system was developed in this study. And the new Ondol was consisted of latent heat storage material as heat storage medium with a great heat capacity and bioceramics as medium to maintain comfortable room temperature. In this study, the heat transfer characteristics of latent heat storage-bioceramic Ondol was analyzed theoretically.

• 한국식품조리과학회지
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• 제17권4호
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• pp.391-398
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• 2001

녹두전분 겔을 온도(5$^{\circ}C$, $25^{\circ}C$) 및 기간(1, 24, 48, 72시간)별로 저장하여 겔의 열적 특성, 점도 특성, 효소소화도, X-선 회절도, 미세구조의 변화를 조사하였다. DSC 실험 결과 5$^{\circ}C$ 저장시 $25^{\circ}C$ 저장시보다 용융피크가 저온측에 있고, 용융엔탈피 값은 더 큰 값을 나타내어 저온에서 겔의 노화가 빠르게 진행됨을 나타내었다. RVA에 의한 점도 측정 결과 $25^{\circ}C$에서 3일간 저장한 시료를 제외하면, 5$^{\circ}C$ 및 $25^{\circ}C$ 저장 모두 peak 점도, 최종점도 등의 점도 특성이 저장에 의해 증가하였는데, 이러한 현상은 5$^{\circ}C$ 저장시 보다 현저하였다. 효소소화도는 저장기간이 경과함에 따라 감소했으며, 이러한 경향은 5$^{\circ}C$ 저장시 더 현저하였다. X-선 회절도는 $25^{\circ}C$ 저장시에는 매우 약한 피크가, 5$^{\circ}C$ 저장에서는 보다 강한 피크가 관찰되었지만, 동일 온도에서 저장한 시료 사이의 차이는 구별하기 어려웠다. 주사전자현미경에 의한 미세구조 관찰 결과 모든 겔에서 잘 발달된 망상구조가 관찰되었으며, $25^{\circ}C$에서 저장시에는 3일째에 전분쇄의 망상구조가 두꺼워졌고, 5$^{\circ}C$ 저장시는 저장 초기부터 망상구조가 두꺼워졌다.

• Journal of Advanced Marine Engineering and Technology
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• 제33권8호
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• pp.1116-1122
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• 2009

냉동냉장창고 내 열부하 감소를 위한 유압 구동식 냉각기의 특성을 실험적으로 평가한 결과 고내 온도강하에 있어서 초기에는 급격하게 이루어지고, 설정온도가 낮아질수록 온도 강하율은 적게 나타났다. 기존 전기 구동식과 비교한 결과 유압식이 더 빠른 온도 강하율과 냉동기 운전시간이 짧게 나타나 실제냉동창고의 경우, 입고 물품의 품질저하 방지 및 전력 절감에 기여할 수 있을 것으로 판단되었다. 그리고 고내 설정온도가 낮을수록 소비동력은 급격히 증가하였고, 유압식이 더 적은 동력을 소비하는 것으로 나타났으며, 두 방식 모두 설정온도에 도달함에 따라 성능계수는 지속적으로 저하하였고, 유압식이 최대 25%정도 높게 나타났다. 고내 온도유지에 있어서는 설정온도가 낮을수록 냉동기의 운전 횟수가 적고, 운전시간이 길어 소비동력이 많아지는 것으로 나타났으며, 유압식이 약 21~25%정도 적게 나타났다.

• 한국조리학회지
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• 제21권1호
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• pp.235-249
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• 2015

저장시간과 저장온도 및 천연첨가제를 달리하여 저장한 표고버섯의 향 변화를 6개의 metal oxide 센서가 장착된 전자코를 이용하여 분석하였다. MA 포장을 한 표고버섯의 품질을 유지하기 위하여 쑥, 약쑥, 녹차와 활성탄의 네 가지 천연첨가제를 사용하였다. 표고버섯은 각 처리구마다 폴리에틸렌 필름으로 포장하였고 5, 10, $20^{\circ}C$에서 저장하였다. 저장온도와 시간이 증가할수록 전자코의 저항비율값과 제1주성분 값이 감소하였는데, 이것은 높은 온도와 저장시간이 길수록 버섯의 품질이 낮아짐을 나타낸다. 표고버섯을 전자코와 주성분 분석(PCA)을 한 결과, 쑥 처리구(B)와 인진쑥 처리구(C)는 $5^{\circ}C$에서, 녹차 처리구(D)와 활성탄 처리구(E)는 $10^{\circ}C$에서 저장할 때 이취발생을 줄이고 선도를 유지하는 효과를 보여주었다. 그러나 $20^{\circ}C$에서는 대조구(A)와 처리구 간의 차이는 없었다.

• 한국식품과학회지
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• 제24권5호
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• pp.515-518
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• 1992

창평쌀엿의 최적 품질유지 조건을 찾고저 저장온도에 따른 관능검사, puncture force의 측정, 단면의 모양 변화 및 색도의 변화 등을 실험하고 종합 분석하여 본 결과 저장온도 $10^{\circ}C$까지는 품질의 변화를 찾기 어려웠다. $15^{\circ}C$ 이상에서는 품질특성이 나빠지기 시작하며 1주일 후에는 엿끼리 서로 들어붙기 시작하였다. 저장온도 $15^{\circ}C$ 이상에서는 각각의 엿이 서로 들어붙고, 먹을 때의 느낌도 좋지 못하며 치아에 들어붙어서 창평 쌀엿의 고유한 품질특성을 상실하였다. 따라서 창평쌀엿 고유의 품질을 최적상태로 유지하기 위한 한계 온도는 $12{\sim}13^{\circ}C$로 추정되었다.

• 한국식품저장유통학회지
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• 제11권2호
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• pp.257-262
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• 2004

본 연구는 벼의 함수율 및 온도별 안전저장기간을 구명하기 위하여 수행되었다. 벼의 함수율은 16.1∼22.2%범위에서 4수준, 온도는 10∼3$0^{\circ}C$에서 3수준으로 저장하면서 외관, 발아율, 지방산가를 측정하였고, 안전저장기간의 온도 및 함수율 의존성을 분석하였다. 그 결과를 요약하면 다음과 같다. 벼의 발아율은 저장온도가 증가할수록, 함수율이 높을수록 급격하게 저하한 반면, 지방산가는 저장기간에 따라 증가하였으나 온도보다는 함수율에 의한 영향이 크게 나타났다. 벼의 온도 및 함수율이 높을수록 변색립 및 곰팡이는 빨리 발현되었으며, 함수율 16.1%에서는 온도가 높아도 저장기간 내에 부패현상은 나타나지 않았다. 발아율, 지방산가 및 외관에 의한 저장가능기간 중 최소가 되는 저장기간으로 온도 및 함수율에 따른 안전저장기간을 제시하였다.

• Journal of Biosystems Engineering
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• 제27권1호
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• pp.39-44
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• 2002

In order to obtain the information of bio-environment control, the thermal characteristics of soil in the greenhouse heated by the heat pump and latent heat storage system were experimentally analyzed. The experimental systems were composed of the greenhouse with a heat pump and a latent heat storage system (system I), the greenhouse with a heat pump (system II), the greenhouse with a latent heat storage system (system III), and the greenhouse without auxiliary heating system (system IV). The thermal characteristics experimentally analyzed in each system were temperature of soil layers, soil heat storage and release, soil heat capacity and soil heat storage ratio. The results could be summarized as follows. 1. Time to reach the highest temperature at 20cm deep in soil layers of the crop routs in case of system I was shown to be delayed by 6 hours in comparison to the time of the highest temperature at the soil surface. 2. In the clear winter days, the stored heat capacity values fur the system I and the system II were shown to be 22.3% and 11.0% higher than the released heat capacity respectively, and the stored heat capacity values for the system III and the system IV were shown to be 6.2% and 29.6% lower than the released heat capacity respectively This confirms that the system I provided the best heat storage effect. j. The heat quantity values stored or released were shown to be highest at 5 cm depth of soil layers. And it was reduced with increasing of depth of soil layers until 20 cm and was not changed under the soil layer of 20 cm depth. 4. The heat absorption rates of soil, the ratio between supplied and stored heat energy, fur both the system I and system II were lower than 23%.

• International Journal of Industrial Entomology and Biomaterials
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• 제45권2호
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• pp.93-98
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• 2022

To assess the feasibility of silk sericin for non-textile application, the storage stability and biological safety of sericin were examined. It was extracted at 37℃, 70℃, 100℃, and 121℃ for 1, 3, and 5 h to elucidate the effect of extraction condition on the stability and safety of silk sericin. The solubility was increased till approximately 26% with extraction temperature of 121℃ for 1 h. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight distribution depended on the extraction conditions. Extracted sericin displayed typical UV absorption bands upon spectrometric analysis. To examine the reproducibility of its obtained conformation, sericin was extracted thrice and its circular dichroism (CD) spectra was measured each time. Most CD spectra showed reproducibility regardless of temperature and time except under 100℃ extraction condition. The diversity of CD spectrum showed gradual reduction and was finally coincident with extraction time from 1 to 5 h. Notably, sericin has a negative peak of approximately 200 nm attributed to random coil conformation, regardless of extraction condition. However, at the 100℃ extraction condition, sericin showed both bands to be negative bands of approximately 200 and 220 nm, respectively. Sericin was centrifuged to determine the stability of storage conditions. The sericin extracted at 100℃ and 121℃ for 1 h was found to form gel rapidly within 1 h, but at 121℃ condition, the gel fraction was approximately 20% within 1 h which retained its phase regardless of storage time. The gel fraction of sericin extracted at 100℃ for 5 h increased with time, however at the 121℃ for 5 h condition, the gel fraction was measured to be less than 10% regardless of increase in storage time. Petriflim^TM AC plates test showed that sericin was safe from aerobic bacteria activity by extraction under high temperature.

• Preventive Nutrition and Food Science
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• 제7권1호
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• pp.57-61
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• 2002

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose and storage time on the free radical concentrations in gamma-irradiated dried seasoning powder. Seasoning powders of dried squid flavor, shrimp flavors, kimchi flavor, spicy beef soup flavor and soy sauce flavor were irradiated with doses of 0, 1, 3, 5, 7 and 9 kGy at room temperature using a Co-60 irradiator. Characteristic signals of free radicals were observed in all the irradiated samples of this experimental while these signals were not detected in non-irradiated samples. Since the free radical concentrations linearly increased with the applied doses (1~9 kGy), highly positive correlation coefficients ($R^2$ = 0.9285~0.9965) were obtained between irradiation doses and free radical concentrations during all the storage times. Free radical concentrations of the irradiated flavored seasoning powder did not change even at 16 weeks of storage at room temperature, while those of dried squid, shrimp and spicy beef soup flavors decreased until 2 weeks of storage after irradiation with 5 kGy or over, and these of soy cause flavors slowly decreased until 8 weeks of storage after irradiation with 3 kGy or over. Although the free radical concentrations decreased with storage times, the characteristic signals of the irradiated seasoning powders of dried squid, shrimp, spicy beef and soy sauce flavors were observed even after 16 weeks of storage at room temperature.