• 한국식품과학회지
• /
• 제22권4호
• /
• pp.434-438
• /
• 1990

동결방지제를 첨가하여 붉은생고추 페이스트 및 딸기 펄프의 저온저장 실험을 한 결과, 붉은생고추 페이스트는 줄기만을 제거한 후 NaCl 15%, citric acid 0.5%를 첨가하면 $-9.6^{\circ}C$에서 미동결 상태로 저장할 수 있었고, 딸기펄프는 dextrose 25%, fructose 17%, sorbitol 8%, ascorbic acid 0.2%를 첨가했을 때 $-15^{\circ}C$까지도 미동결 상태로 저장할 수 있었다. 또한 동결방지제를 이용한 시료는 무처리한 시료에 비해 저장소요시간이 약 1/2 정도 걸리며, 소요에너지도 약 $70{\sim}80%$의 절감효과를 얻을 수 있었다. 따라서, 동결방지제를 이용하면 저온저장시 빙결정 생성에 따른 조직손상을 억제할 수 있을 뿐만 아니라 에너지 절감효과도 얻을 수 있는 것으로 사료되며, 이와 같은 결과를 일시에 다량 수확되는 과채류에 적용할시 농산물의 저장법 개선에 상당한 효과가 있을 것이다.

• 한국식품영양과학회지
• /
• 제22권1호
• /
• pp.62-67
• /
• 1993

절임 배추와 숙성된 김치의 동결저장 가능성을 조사하였다. 생배추의 조직은 급속침지동결이나 예비건조하면 완만공기동결이나 건조하지 않은 것에 비해 우수하였다. 절임 배추는 생배추에 비해 동결손상이 적었고 급속동결이나 예비건조에 의해 조직이 개선되지 않아 조직특성은 숙성된 김치와 비슷하였다. 김치는 동결시 동결하지 않은 것에 비해 약간 질겼으나 전체적인 품질에서는 유의적인 차이를 보이지 않았다. 동결저장시 절임배추는 3개월후 약간의 핑크색을 띄었으나 김치는 6개월 저장동안 이런 현상이 나타나지 않았고 품질도 거의 변화가 없었다.

• 한국임상수의학회지
• /
• 제8권2호
• /
• pp.183-190
• /
• 1991

Pellet and straw methods in canine semen freezing are compared with respect to motility, viability and acrosome demage of sperm during each of the two major processing steps, to prior-freezing and to frozen-thawing. Senen was extended with a tris-buffered egg yolk contained 4% glycero1 Pellet freezing in the hole of dry ice and straw freezing on the surface of liquid nitrogen were carried out, respectively. The frozen semen 10 days after storage in liquid nitrogen container. wao thawed. In the comparison of two freezing methods, the straw freezing method with 42.7% in motility. 49.2% in viability and 0.186 acrosome score after thawing seems to be superior to the pellet freezing method with 31.2%, 34.5% and 0.314%, respectively. Sperm motility of processing step to frozen-thawing against decrease rate 12.67% to Prior freezing appeared of 33.84% and 49.37% in straw and pellet freezing and increase of 0.02 in acrsomal score to prior freezing appeared of 0.08 and 0.21 in straw and pellet freezing method to frozen-thawing

• 한국식품영양학회지
• /
• 제11권5호
• /
• pp.482-487
• /
• 1998

This study was carried out to investigate the effects of freezing temperature on quality of thawed beef loin. In case of thaw drip loss, the freezing of -3$^{\circ}C$ and -2$0^{\circ}C$ were higest by 3.4% to 30 days and by 1.8% to 60 days, respectively. And the thaw drip loss of -3$^{\circ}C$ freezing was more than -2$0^{\circ}C$ freezing. The cooking loss of water bath and pan boiling were increased significantly during freezing than the beginning of freezing, but were not different -3$^{\circ}C$ and -2$0^{\circ}C$. The salt soluble protein extractability was decreased during freezing, the -2$0^{\circ}C$ freezing was higher than -3$^{\circ}C$ freezing. The water soluble protein extractability of -3$^{\circ}C$ freezing was not significant different during freezing storage, that freezed at -2$0^{\circ}C$ was increased during freezing. The "L" value of the beginning of freezing was higher than during freezing, the "a" value was not different during freezing, and the "b" value during freezing was higher than the beginning of freezing. The myoglobin denatured percentage of the -3$^{\circ}C$ and -2$0^{\circ}C$ freezing were highest by 94.4% to 45 days and by 94.0% to 15 days, respectively. The shear force value during freezing was higher than the beginning of freezing, the myofibrillar fragmentation index was not significant different during freezing. The pH was increased to freezing 30 days, after that was decreased.ays, after that was decreased.

• 한국식품과학회지
• /
• 제20권2호
• /
• pp.200-204
• /
• 1988

생체(生體) 마늘의 영하 조건에서의 저장 가능성을 검토하기 위하여 생체 인편에 대한 내한특성(耐寒特性)을 조사한 결과 마늘 인편의 빙점은 $-4^{\circ}C{\sim}-5^{\circ}C$로 산지별로 차이가 크지 않았으나 수확 후 처리 조건 및 저장 기간의 경과에 따라 다소 차이를 보여 예건전(豫乾前) $-3.5^{\circ}C$, 예건후(豫乾後) $-4.5^{\circ}C$, 저장 5개월 후 $-5.5^{\circ}C$로 나타났다. 그러나 동결치사한 마늘 인편의 빙점(氷點)은 $-2.5^{\circ}C$로 생체조직(生體組織)에 비하여 높았다. 생체(生體)마늘을 $-4^{\circ}C{\sim}-15^{\circ}C$사이의 5개 저장고(貯藏庫)에서 동결치사율(凍結致死率)을 조사(調査)하였던 바 $-4^{\circ}C$구에서는 0%, $-6.5^{\circ}C$구에서는 건전율(率) 80% 치사율(致死率) 20%였으며 $-15^{\circ}C$구에서는 70%의 치사율(致死率)을 나타내고 있어 생체(生體)마늘의 동결치사(凍結致死) 임계온도는 $-6.0^{\circ}C$ 정도로 판단되었다. 저장온도(貯藏溫度) 조건(條件)에 따른 호흡률의 변화는 온도(溫度) 하강($-4^{\circ}C$까지)에 따라 감소하는 경향을 보였고$Q_{10}$값은 $-4.0^{\circ}C{\sim}5.0^{\circ}C$ 범위에서 2, $5^{\circ}C{\sim}15^{\circ}C$에서 3, $15^{\circ}C{\sim}37^{\circ}C$에서 1.2를 보였다. 기존의 저온 저장 조건으로 제시된 ASHRAE의 $0^{\circ}C$, 75% RH, 빙점 $0.8^{\circ}C$는 한국산 마늘의 경우 재검토되어야 할 것으로 사료된다.

• 한국태양에너지학회 논문집
• /
• 제24권1호
• /
• pp.47-52
• /
• 2004

An experimental investigation was performed to compare ice making characteristics of ice storage system with smooth and spiral tube. During the freezing processes in the shell and tube type ice storage tank with smooth tube, heat resistance of the ice layer caused a decrease in freezing rate. Also, the phenomena of bridging made the increasing rate of ice making less. In order to improve the ice making rate, spiral tube(pitch=6mm) was used in the present study. The ice making rate and the decreasing of bridging for the spiral tube were higher than those for the smooth tube.

• 한국식품저장유통학회지
• /
• 제23권3호
• /
• pp.438-444
• /
• 2016

본 연구는 국내산 농산물의 안정적인 저온저장온도 결정을 위하여 동결점을 분석하고 품질에 따른 저장온도 설정에 대한 기초자료를 제공하고 과냉각 한계점 측정을 통하여 과냉각 저장 가능성을 모색하고자 수행되었다. 동결점 및 과냉각 한계온도를 분석하기 위하여 국내산 마늘, 오이, 대파, 고추, 참외, 메론, 복숭아, 자두 등의 국내산 농산물을 자체 제작한 송풍식 냉동기를 이용하여 완만 냉각시키면서 농산물 내부에 삽입된 온도센서를 이용하여 열방출을 측정하였다. 또한 일반 품질특성 인자들이 각 농산물 동결점에 미치는 영향을 분석하기 위하여 당도, 산도, 함수율 및 경도를 측정하였다. 열방출 최고점을 기준으로 판단한 농산물의(동결점/과냉각 한계점)은 마늘(-1.6/-$7.8^{\circ}C$), 대파(-0.5/-$3.7^{\circ}C$), 오이(-0.5/$3.3^{\circ}C$), 풋고추(-0.7/-$4.9^{\circ}C$), 포도(-1.6/-$5.7^{\circ}C$), 참외(-1.6/-$4.6^{\circ}C$), 메론(-1.3/-$2.8^{\circ}C$), 복숭아(-0.8/-$3.3^{\circ}C$), 방울토마토(-0.3/-$5.9^{\circ}C$), 자두(-1.1/-$4.2^{\circ}C$), 무(-0.3/-$0.8^{\circ}C$), 단감(-1.7/-$4.7^{\circ}C$), 사과(-1.5/-$3.2^{\circ}C$), 고구마(-1.5/-$3.7^{\circ}C$), 감귤(-0.8/-$4.7^{\circ}C$), 배(-1.5/-$4.2^{\circ}C$), 딸기(-0.9/-$3.4^{\circ}C$)이었다. 이러한 동결점은 각 농산물의 이화학적 특성분석에 비추어 볼 때 당 성분에 따른 동결점 내림 경향과 일치하여 당도분석을 통한 저장온도 설정 가능성을 제시하였다.

• 설비공학논문집
• /
• 제8권4호
• /
• pp.451-462
• /
• 1996

In this study, which focuses on ice storage, a fundamental study in cooling and solidification was performed, including the interesting phenomena of density inversion, supercooling and dendritic ice. A numerical study was performed for natural convection and ice formation considering existence of subcooling and dendritic ice were analyzed numerically by using finite difference method and boundary fixing method. In the mesh, the solid fraction was introduced with adding as a term to the energy conservation equation. A flow in the dendrite was modelled as a flow in a porous medium, and the momentum conservation equation was modified to incorporate resistance forces involved in flows through porous media. A numerical solution of the time dependencies of dendrite area and dense ice front was successfully obtained, and the numerical results were good agreement with experimental results. Based on this methodology, a discussion was made of phenomena and characteristics of cooling and freezing processes under various conditions.

• 한국식품저장유통학회지
• /
• 제6권1호
• /
• pp.81-86
• /
• 1999

The textural characteristics of nonxaxy rice flour gels and rice cake(Injolmi) with different water contents and additives were evaluated after freezing and microwave heating. As moisture content of rice flour gels increased from 45% to 55%, its hardness and gumminess decreased, but adhesive and cohesiveness had no significant difference. Microwave heating did not markedly affect the texture but frozen storage was very effective to prevent the hardening of products. Hardness of reheated rice gels increased more rapidly in non-packaged sample than in PE wrap film and affected by storage time of 24hrs at 20$^{\circ}C$. As sugar content of rice flour gels increased from 0% to 10%, its hardness, adhesiveness, and gumminess decreased, while cohesiveness did not change.

• 한국식품영양과학회지
• /
• 제26권3호
• /
• pp.450-455
• /
• 1997

Scallop, Patinopecten yessonensis(Jay), cultivated in the cold east coast of Kwangwon region, Korea, is expected to be producted to about 50,000 tones in 2000 year. Freezing is one of the most effective methods applied for soraging seafoods. But, the domestic refrigerator with an automatic defrost system shows the temperature fluctuation during defrosting, thus might result in the deterioration of the frozen foods. In this study, the domestic refrigerator with an automatic defrost system, temperature fluctuation from -18 to -5$\pm$1$^{\circ}C$ and fluctuation intervals from 16 to 20 hr, was used for storing scallop. pH was decreased rapidly after 3 month storage, while the content of amino nitrogen was increased continuously. The TMA content of open state was increased very rapidly on 3 month storage and then increased slowly, whereas that of vinyl package increased slowly. The VBN content was increased almost constantly with no significant differences between storage methods. The TBA content was increased up to 3 month storage with the higher value in open state than vinyl package in the beginning periods of storage, and then decreased very rapidly. The number of total viable cell was increased continuously during storage with higher number in open state than vinyl package. The estimated shelf-lives of frozen scallop with open state and vinyl package stored at -18$^{\circ}C$ in the domestic refrigerator with an automatic defrost system were 3.55 and 3.78 months, respectively.