• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.413-418
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• 2002

The dough was frozen either before or after fermentation at the five different freezing and storage conditions. Although fermentation before freezing was effective for rapid freezing, it reduced bread volume of the dough frozen at both air freezer and liquid immersion freezer. Freezing at the air freezer set to $-70^{\circ}C$ took more time for freezing and resulted in lower bread volume than freezing at the immersion freezer set to $-20^{\circ}C$. Therefore, the freezing in the liquid immersion freezer was more effective to reduce the freezing time and increase the bread volume. At the liquid immersion freezer, the higher temperature was more effective than lower temperature. The doughs frozen in a liquid immersion freezer set to $-10^{\circ}C$ and fermented after de-frosting produced higher bread volume than control unfrozen dough. And also there was no significant difference in bread volume between the control unfrozen dough and the dough frozen in a liquid immersion freezer set to $-10^{\circ}C$, fermented before freezing and re-fermented after defrosting. The longer proof time and greater loaf volume obtained for the dough frozen and stored at the air freezer set to $-70^{\circ}C$. Therefore the optimum process for freezing the dough was freezing immediately after mixing, storing at $-10^{\circ}C$ in a liquid immersion freezer and fermented after defrosting.

• Food Science and Preservation
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• v.24 no.6
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• pp.746-757
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• 2017

This study was performed to evaluate the effect of different freezing conditions and storage periods on physicochemical and microbial characteristics of garlic. Garlics were washed, dried, sliced to 0.3 cm then packed in LDPE+LLDPE film bags. They were treated with still-air freezing at $-20^{\circ}C$ (SAF20), $-40^{\circ}C$ (SAF40) and immersed-liquid freezing at $-40^{\circ}C$ (ILF40). Frozen garlics were stored under frozen storage conditions for 7 months at $-20^{\circ}C$ and quality characteristics were measured monthly during the frozen storage. Freezing rate of garlic was the fastest in ILF 40 (10 min), SAF40 (40 min) and SAF20 (1,600 min) sequentially. In ILF40, drip loss, cutting force, total aerobic bacteria count and pH were the lowest, whereas pyruvic acid and allicin content were the highest (p<0.05) during frozen storage, these results were the most similar characteristics with the fresh garlic. During frozen storage, drip loss, color difference and total organic acid content were significantly fluctuated in SAF20 (p<0.05), while they were not changed in ILF40. Overall, total aerobic bacteria count and pH decreased, cutting force, pyruvic acid and allicin content remained unchanged in all groups. In conclusion, the optimal freezing conditions for garlic with the least quality changes was considered to be ILF40 (immersed liquid freezing), keeping quality characteristics up to 7 months by freezing storage.

• Journal of the Korean GEO-environmental Society
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• v.16 no.1
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• pp.37-43
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• 2015

Korea has four distinct seasons, showing hot and humidity in summer and cold weather lasted in winter. Domestic research on earth work has been developed according to the seasonal characteristics, and most of research topics have focused on the effect of freezing-thawing on the performance of geo-materials. However, the previous research was performed on the ground compacted at room temperature and therefore, the effect of the sub-zero temperature at the time of construction was not fully investigated. The ground characteristics compacted at freezing temperature can be different from those at room temperature and show different characteristics of strength and deformation caused by freezing and thawing. Therefore, the compaction tests on sandy materials were conducted under various temperature at $-3^{\circ}C$ and $-8^{\circ}C$ with various fine contents of 0%, 5%, 10% and 15% in weight fraction. The effectiveness of soil compaction at below-freezing temperatures were compared with the compaction at room temperature at $18^{\circ}C$ in terms of the maximum dry unit weight and optimum water contents. Based on the test results, the maximum dry unit weight tends to decrease with the freezing temperature and the relative compaction at $-8^{\circ}C$ can not be satisfied with general specification standard.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.691-696
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• 2012

We conducted this study to investigate the quality characteristics of mashed red pepper(MRP) with different freezing(-20, -30, -40, -50, -60 or $-70^{\circ}C$) and thawing(4, 10, 20, 30, 40 or $50^{\circ}C$) temperature. Frozen and thawed MRP was evaluated for ascorbic acid contents(AsA), capsaicinoids contents, free sugar contents, ASTA value, and flavor patterns. The AsA of frozen MRP with freezing temperature showed a range of 67.08~80.35 mg/100 g FW, and the mean AsA losses after frozen were 57~64% compared to raw red pepper. Capsaicinoids contents, free sugar contents, and ASTA values of frozen MRP with freezing temperature were no significant difference compared to raw red pepper. The AsA of thawed MRP with thawing temperature showed a range of 70.34~81.59 mg/100 g FW, and the mean AsA losses after thawed were 45.12~52.69% compared to raw red pepper. Capsaicinoids contents and free sugar contents of thawed MRP with thawing temperature were no significant difference compared to raw red pepper, whereas the ASTA value decreased according to the increasing of thawing temperature. Flavor patterns of thawed MRP after $20{\sim}50^{\circ}C$ thawing were clearly different from the raw red pepper. Overall, it is recommended that the best freezing and thawing temperature for preserving the quality of MRP is freezing at $-20^{\circ}C$ and thawing at $10^{\circ}C$.

• Journal of the Korean association of regional geographers
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• v.7 no.1
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• pp.97-106
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• 2001

There are a few interesting areas which show freezing during summer season in Korea, three of them are especially important. They are located at Milyang(Gyungnam province), Uisung and Chungsong(Gyungbook province). They are named Eoleumgol(ice-valley) or Binghyul(ice-cave). The purpose of this study is to clarify geomorphological and geological characteristics about the distribution areas of freezing during summer season in Korea in relation to previous works, which have been studied in hydrological or micro-climatological viewpoints. The main results are summarized as follows. 1) The main geomorphological and geological characteristics in the distribution areas of freezing during summer season (1) Thick debris accumulated slope within deep valley (2) North facing slope (3) The component debris of volcanic rock such as andesite or rhyolite 2) The ice-cave as a system that give rise to freezing phenomenon in summer season is closely related to talus slope. The ice-cave has thick accumulated debris and lots of vacant spaces within the rock deposits, some of vacant spaces are very big and connected with underground water system. 3) A partly freezing within underground water system is required freezing phenomenon in summer season. Judging from this point of view, two ideas are suggested; one is the evaporation theory, another is that the frozen condition in winter remains untill late summer.

• Journal of the Korean Geosynthetics Society
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• v.13 no.1
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• pp.41-52
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• 2014

Decomposed granite soil is likely to lose its strength when exposed to air or water. Such a geomaterial is weathered by wetting-drying or freezing-melting. In this study, resonant column tests were conducted to figure out the dynamic characteristics of granite soil that has affected by environmental changes like weathering condition. The results show that wetting-drying weathering condition is the most affective parameter on the dynamic characteristics of granite soil. In the meantime, artificial weathering conditions such as freezing-melting has less affection at first and getting increase as the process repeats constantly.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.4
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• pp.69-79
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• 1992

To estimate soil behavior and structural characteristics under the conditions of cyclic loading, freezing & thawing and initial state, several testing was performed and obtained following results. 1.After repeated freezing and thawing processes, original soil structure was destroyed and changed to globular structure from honeycomb or tube in its structure types. Also above processes resulted increasing the soil compression strain while decreasing the failure stress in stress-strain relationship and reached the soil structure into the mode of brittle fracture. Under cyclic loading conditions, soil cluster which was originally dispersed structure colloided with each other, seperated, and finally the soil failed due to the effect of overcompaction. 2.Through the stabilization processes seperated by four steps, the structure of soil skeleton was changed to quite different globular type. The degree of compressibility of soil was decreased in the normally consolidated zone, while the strength against external load increased due to soil particle stabilization. 3.Soil stress-strain chracteristics were largely influenced by repeated up and down processes of temperature. The maximum deformation was obtained in the case of temperature between 0 10˚C by the reseon of particle cluster reformation. 4.Soil compressibility was largely influenced by the optimum moisture content. Under freezing process, swelling could be found and its magnitude was proportional to the density of soil. 5.Density of soil was decreased as increasing the number or repeated freezing and thawing processes and the largest decreasing rate was found at the first turning point from freezing to thawing cycle.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.597-603
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• 2014

In this study, the physicochemical and sensory quality characteristics due to the influence of various thawing methods on electro-magnetic and air blast frozen pork were examined. The packaged pork samples, which were frozen by air blast freezing at $-45^{\circ}C$ or electro-magnetic freezing at $-55^{\circ}C$, were thawed using 4 different methods: refrigeration ($4{\pm}1^{\circ}C$), room temperature (RT, $25^{\circ}C$), cold water ($15^{\circ}C$), and microwave (2450 MHz). Analyses were carried out to determine the drip and cooking loss, water holding capacity (WHC), moisture content and sensory evaluation. Frozen pork thawed in a microwave indicated relatively less thawing loss (0.63-1.24%) than the other thawing methods (0.68-1.38%). The cooking loss after electro-magnetic freezing indicated 37.4% by microwave thawing, compared with 32.9% by refrigeration, 36.5% by RT, and 37.2% by cold water in ham. The thawing of samples frozen by electro-magnetic freezing showed no significant differences between the methods used, while the moisture content was higher in belly thawed by microwave (62.0%) after electro-magnetic freezing than refrigeration (54.8%), RT (61.3%), and cold water (61.1%). The highest overall acceptability was shown for microwave thawing after electro-magnetic freezing but there were no significant differences compared to that of the other samples.

• Journal of the Korea Institute of Building Construction
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• v.13 no.3
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• pp.202-208
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• 2013

The method used to test lightweight aggregate concrete for its resistance to freezing and thawing is different in each country. In Korea, the method of KS F 2456 on normal concrete is adopted for lightweight aggregate concrete, while the testing method of ASTM C 330 lightweight aggregates for structural concrete is used in the majority of overseas countries. In this study, we identified differences between KS F 2456 and ASTM C 330 in terms of the testing method for freezing and thawing resistance, and we studied the influence of this on the freezing and thawing resistance of lightweight aggregate concrete. The results of this study were as follows: Blocked lightweight aggregates had a slight collapse of shape and lost weight by repeated freezing and thawing, but unblocked lightweight aggregates were badly collapsed. And while the freezing and thawing resistance tests of normal concrete showed similar results despite the difference in the KS and ASTM testing method, the results for lightweight aggregate concrete were very different. So the KS test method shows evaluation results that are much lower than the ASTM test method.

• Atmosphere
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• v.25 no.3
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• pp.389-405
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• 2015

In this study, the occurrence circumstances of 3 cases (12 Jan 2006, 11 Jan 2008, 22 Feb 2009) when the freezing rain was observed at more than two observatories in a day with more than three times each observatory, were investigated. Following the advanced study about the same cases, we have tried to find more delicate differences in using the Korea Local Analysis and Prediction System (KLAPS; 5 km reanalysis data) that has the smallest grid scale at current situation. As results, three common characteristics are found: (1) Just before the occurrence of the freezing rain, the wind direction was consistently continuous and the wind speed was constant or gradually increased for at least 3 hr more. (2) Surface air temperature (Relative humidity) was respectively $3.08^{\circ}C$ (28.76%), $0.47^{\circ}C$ (50.07%) and $-3.60^{\circ}C$ (71.07%) 3 hr ago to break out the freezing rain. It means the freezing rain occurs in a wide range of atmospheric environments. However, the closer it got to the occurrence time of the freezing rain, the closer the surface air temperature was to $0^{\circ}C$, and the bigger the humidity of the surface air was. (3) The liquid precipitation formed in the upper atmosphere, met a cold advection bellower than 950 hPa level and suspected to be changed to the super-cooled condition.