• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.230-238
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• 2016

This study examined the effects of freezing and thawing conditions on quality of Hanwoo bottom round. The beef samples were frozen by air blast freezing at $-20^{\circ}C$ or ethanol immersion freezing at $-70^{\circ}C$ and then stored at $-20^{\circ}C$ for 10 days. After 10 days of storage, the frozen samples were thawed with air blast thawing at $4^{\circ}C$ or water immersion thawing at $4^{\circ}C$ and subjected to subsequent analyses of drip loss, water holding capacity, thiobarbituric acid reactive substance (TBARS), volatile basic nitrogen (VBN), total aerobic bacteria, and microstructure. Drip loss significantly increased in samples treated with air blast freezing compared to ethanol immersion freezing, whereas freezing and thawing processes had no significant impact on water holding capacity of the samples. Thawing conditions had a much stronger influence on the TBARS and VBN of the samples than freezing conditions. There was no significant difference in the population of total aerobic bacteria among the four samples subjected to one freeze-thaw cycle. In addition, to analyze the effects of freeze-thaw cycle on the quality of beef, three freeze-thaw cycles were performed during storage. Multiple freeze-thaw cycles increased drip loss, TBARS, and VBN and decreased water holding capacity, accelerating microstructural damage. These data indicate that Hanwoo bottom round can be rapidly frozen and thawed by using ethanol immersion freezing and water immersion thawing methods with minimal impact on meat quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.107-117
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• 1975

Alaska pollack caught in the Northern Pacific Ocean and frozen aboard vessel are skipped to the plant and processed into frozen fillets. In the present paper quality changes during thwaing, refreezing and storage at $-20^{\circ}C$ are discussed. Natural, running-water, vacuum and steam thawing were employed as thawing methods. And contact plate, air blast, immersion in dry ice-alcohol solution freezing and storage at $-5^{\circ}C$ were applied to refreeze the thawed fillets. As quality factors content of drip released, salt-extractable protein, VBN, DNA in the drip and pH were determined. In addition, bacteriological tests were also carried out along with the whole process. In thawing of round material, the vacuum thawing was more effective than any other method, resulting in drip, salt-extractable protein $(N\%)$, VBN and DNA as $4.4\%,\;1.82\%,\;16.21mg\%$ and $13.70\;{\mu}g/ml$, respectively. Storage at $-5^{\circ}C$ as refreezing method yielded lower in drip and DNA content but similar to or slightly higher in both salt-extractable protein and VBN, which might postulate that the quality of the frozen fillet depends not largely on the secondary freezing but on the conditions of thawing and primary freezing. It seemed that most of the bacterial flora in thawed fillet came from skin and viscera of fish, worker's hands, utensils and other processing facilities, since sanitary indicative bacteria were not detected in the frozen flesh of round Alaska pollack. Bacterial quality of fillet varied with thawing methods, vacuum thawing appeared more sanitative compared with other methods as natural, running-water, and steam thawing. Bacterial colonies isolated from the thawed fillet were composed of $73.8\%$ Gram negative rod shape, $4.9\%$ Gram positive rod shape, $18.0\%$ cocci, and $3.3\%$ yeast. Decreasing rate of coliform group of the fillet during the storage at $-20^{\circ}C$ for 30 days was more than $70\%$ and that of plate count was less than of coliform group.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.420-430
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• 2000

These studies were preformed to investigate the freezing conditions to achieve good post-thaw viability of spend and the practical methods of artificial insemination frozen canine semen. Semen were collected from nine male dogs which had been proved to be fertile in the past and the semen were treated for freezing procedure. Post-thaw motility and viability of canine sperm were evaluated to investigate individual tolerance of freezing, difference among freezing extenders, dif-ference among freezing equipments and freezing conditions, difference between fast and slow cooling rate, difference according to different glycerol concentration, effect of seeding on post-thaw viability, difference according to cutting part of straw, difference according to thawing temperatures, and dif-ference according to media added to thawed semen. Thawed semen for insemination were added with equal volnme of canine capacitation medium (CCM) and the volume of semen and the number per insemination were adjusted as 2-3 ml and $20-30 {\times}10^7,$ respectively. The semen were inseminated in vagina using balloon catheter and en17ryos were cellected from 9 to 11 days after the second Al to d determine fertilization.

• Food Science and Preservation
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• v.18 no.3
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• pp.302-309
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• 2011

This study was performed to analyze the physicochemical and sensory properties of Acanthopanacis cortex and Aralia elata according to their blanching conditions and thawing methods. In terms of their Hunter colors, the A. cortex and A. elata that were blanched without adding salt to them for 7 min and 4 min, respectively, had the highest L values. The chlorophyll content (148.7 mg%) of A. cortex that was blanched with 1% salt for 4 min was higher than those of the other samples, and the chlorophyll content of A. elata was 32.4 mg% when it was blanched for 4 min without salt addition. The sensory test results showed the highest overall preference for the sample that was blanched without salt for 4 min among all the samples. The Hunter color of A. cortex did not significantly differ with different thawing methods, but the value of A. elata that was thawed in a microwave oven was higher than those of the other samples. The chlorophyll contents of A. cortex and A. elata that were thawed in a microwave oven were the highest among all the samples. As for the overall preference for the samples according to the thawing method, A. cortex and A. elata scored highest in the case of thawing at $25^{\circ}C$ and in a microwave oven, respectively.

• Food Science and Preservation
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• v.30 no.1
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• pp.88-97
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• 2023

As livestock consumption in Korea has been gradually increasing, the quality of the final products has been improved to meet this increased demand. In particular, maintaining the water holding capacity (WHC) and minimizing the drip loss during the thawing of frozen meat are of utmost importance. This study investigated the physicochemical properties of frozen pork subjected to thawing under different conditions: at room temperature (20℃, under air), at a low temperature (4℃ refrigerator, under air), under water (20℃, under water in a vacuum bag), under microwave (microwave-thawing, 260 W), and under low-pressure tumbling (20℃, 0.015 bar, tumbling). The shortest thawing time for frozen pork was recorded upon low-pressure tumbling thus indicating a fast heat transfer. The lowest drip loss (0.2%) and highest WHC (94.5%) were also recorded under this condition. A significantly higher drip loss was observed upon microwave- (1.0%) and water-thawing (1.2%), which resulted in the lowest WHC in microwave thawing (87.2%). The highest total count of aerobic bacteria and coliform group were observed upon room temp thawing while the low pressure tumbling and thawing resulted in the lowest aerobic bacteria (1.90 log CFU/g) and coliform (0.78 log CFU/g) count. Consequently, thawing by low pressure tumbling afforded the best food quality.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.46-55
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• 2021

Concrete structures can cause various problems as the number of common years increases when exposed to external extreme climate conditions. Among these problems, freezing and thawing occur due to the action of extreme climate factors such as heavy rain and heavy snow, which have become the most problematic in recent years. In this study, we present a rapid freezing and thawing test method of concrete in the air, referring to KS F 2456, as Seoul exhibits very dry weather during the period of freezing and thawing. Concrete test specimens and RC beams were fabricated to perform rapid freezing and thawing of 0, 100, 200, and 300 cycles, and the performance evaluation confirmed the degradation of each subject in material and member units. The design strength of 24 MPa, which performs rapid freezing and thawing in the air up to 300 cycles, decreases by 5.24 MPa (21%), and as rapid freezing and thawing in the air increases the stress burden on reinforced concrete bending members, reducing the energy absorption (dissipation) ability of structures due to earthquakes.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.12
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• pp.1716-1721
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• 2006

The present study was conducted to observe the effect of osmolality of glycerolated TEST-yolk glycerol extenders on post-thawing sperm kinematics of ram spermatozoa of the native Malpura breed maintained in a semi-arid tropical environment. Good quality semen obtained from adult rams was pooled, split and diluted to 1,000 million spermatozoa per ml in complete TEST-yolk-glycerol extenders of 900, 1,200, 1,500 and 1,800 mOsm/kg osmolality. Diluted semen samples were loaded in 0.25 ml straws and cooled down to $-125^{\circ}C$ freezing temperature at the rate of $-25^{\circ}C$ per minute under controlled conditions before plunging into liquid nitrogen for storage. The thawing of straws was performed at $50^{\circ}C$ in a water bath for 10 seconds and sperm kinematics of the frozen-thawed spermatozoa were assessed by a computer-assisted sperm analysis technique. Osmolality of diluent had no significant effect on post-thawing % motility, % rapid, % medium and % slow moving frozen-thawed spermatozoa but significantly (p< 0.05) affected the % linearity and % straightness. The post-thawing % motility and % rapid motile spermatozoa were highest in samples extended in diluent of 1,500 mOsm/kg osmolality and lowest in 900 mOsm/kg. The curvilinear velocity of spermatozoa was significantly (p<0.05) higher for samples extended in 1,800 mOsm/kg, compared to those in 900 and 1,200 mOsm/kg, but the effect was not significantly different to those extended in diluent of 1,500 mOsm/kg osmolality. The study indicated that ram spermatozoa could tolerate a wide osmolality range for dilution in the complete TEST-yolk-glycerol extender for their cryosurvival. The highest recovery of motile spermatozoa following thawing was achieved in samples extended in the TEST-yolk-glycerol diluent of 1,500 mOsm/kg osmolality.

• Journal of the Korean GEO-environmental Society
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• v.19 no.3
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• pp.5-13
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• 2018

Recently, construction disasters in thawing season are increasing due to the ground collapse and it is related to the improper compaction during winter season. Compaction at sub-zero temperature reduces the compaction effect and the research of mechanical properties of thawed soil after winter compaction can be used as useful data to understand the behavior of the ground in the thawing season. On the other hand, the research interest in the unsaturated soil mechanics has been increasing in the field of the geotechnical engineering. Therefore, it is expected that the research of unsaturated characteristics under the compaction of sub-zero temperature and freezing & thawing condition provides information to the researchers in the related fields. Therefore, in this research, unsaturated soil-water characteristics test and unsaturated uniaxial compression test were conducted on the specimens compacted at sub-zero temperature and continuous freezing & thawing condition to investigate change of unsaturated characteristics and matric suction. Based on the test results, the change of matric suction and the decrease of strength and stiffness were observed with the freezing & thawing conditions. Especially in case of the weathered soil, the strength and matric suction were significantly reduced with lower temperature and more repetition of freezing & thawing cycles. This result implies that compaction of sub-zero temperature and freezing & thawing cycles will have a considerable influence on the stability of the ground.

• Food Science and Preservation
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• v.19 no.2
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• pp.201-208
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• 2012

The sensory properties of $Kalopanax$ $pictus$ and $Cedrela$ $sinensis$ shoots were analyzed according to their blanching conditions and the thawing methods used. For the Hunter colors, the $K.$ $pictus$ that was blanched without adding salt for 6 min had the highest L value, and the $C.$ $sinensis$ that was blanched with 1% salt for 6 min had the highest L value. The chlorophyll content of $K.$ $pictus$ was 141.1 mg% when it was blanched for 3 min with 2% salt, and the chlorophyll content of $C.$ $sinensis$ that was blanched without adding salt for 6 min was highest (124.8 mg%). When $K.$ $pictus$ and $C.$ $sinensis$ were blanched without salt addition for 3 min, their texture showed a higher value than that of the other samples. The sensory test result showed the highest overall preference for the sample that was blanched without adding salt for 3 min, among all the samples. The L value of the $K.$ $pictus$ that was thawed in a microwave oven was significantly higher than that of the other samples, but the L value of the $C.$ $sinensis$ that was thawed at $4^{\circ}C$ was higher than that of the other samples. As for the overall preference for the samples according to the thawing method used, $K.$ $pictus$ and $C.$ $sinensis$ scored highest in the case of thawing in a microwave oven.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.57-65
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• 2012

PURPOSES: It is important to consider the long-term performance of concrete pavement, because concrete pavement is more exposed to the various environmental conditions than any other concrete structures. One of the several methods to evaluate the long-term performance of concrete during winter is KS F 2456. Relative dynamic modulus of elasticity shows the resistance to freezing and thawing. METHODS: To measure relative dynamic modulus of elasticity, ultra sonic is generally used. But in this study, to measure the relative dynamic modulus of elasticity, both ultra sonic and shear wave were used and then compared each other. RESULTS: The results from the measurement by ultrasonic wave and shear wave were divided into three types. Type 1 : Specimens are good and relative dynamic modulus of elasticity did not decrease until 300 cycle. Type 2 : The relative dynamic modulus of elasticity decreased from the late cycle.(about 150 cycle later) Type 3 : The relative dynamic modulus of elasticity consistently decreased from the beginning. As a result of ANOVA, there is no difference according to measuring method, in type 2 and 3. But there is a difference according to measuring method, in type 1's relative dynamic modulus of elasticity. CONCLUSIONS: It is proved that shear wave can be used to understand the damage tendency of relative freezing and thawing and to measure the relative dynamic modulus of elasticity.