• Korean Journal of Animal Reproduction
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• v.21 no.3
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• pp.287-292
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• 1997

This study was carried out to investigate the effects of concentration and kinds of cryoprotectants, equilibraction time, thawing temperature and time, sucrose concentration on the survival rates of frozen bovine demi-embryos. The bovine demi-embryos following dehydration by cryoprotectants a various concentration of sucrose were freezed by cell freezer and thawed in 3$0^{\circ}C$ water bath. Survival and in vitro developmental rates was defined as development rates on in vitro culture or FDA-test. The results are summarized as follows : 1. The high survival rates of demi-embryos after frozen-thawing in freezing medium was attained 2.0M glycerol. The high survival rates of demi-embryos after frozen-thawing in freezing medium was obtained using single cryoprotectant(25.0~30.0%) than mixed cryoprotectants(16.7~19.0%). 2. The survival rates of demi-embryos after frozen-thawing in freezing medium added 1.5M, 2.0M glycerol＋0.25M sucrose(37.5~33.3%) were higher survival rates than those of sucrose concentration of 0.50, 0.75M(12.5~26.7%). 3. The equilibration time on the survival rates of demi-embryos was attained after short period of time(30.0~35.0%) in the freezing medium higher than long period of time(21.1%). 4. The thawing temperature on the survival rates of demi-embryos was attained at 3$0^{\circ}C$ of thawing temperature(26.7~40.0%) higher than $25^{\circ}C$ or 37$^{\circ}C$ of thawing temperature(13.3~20.0%). 5. The thawing time on the survival rates of demi-embryos was attained at 1~5 minutes of thawing time(26.7~33.3%) in the freezing medium higher than 10 minutes of thawing time(13.3~18.8%).

• Korean Journal of Animal Reproduction
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• v.21 no.2
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• pp.103-109
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• 1997

The studies on the carried out to investigate to determine the optimum thawing temperature and equilibration time and 1 step straw method of frozen bovine embryos. The follicular oocytes were cultured in TCM-199 medium containing 10 IU/ml PMSG(Sigma, USA), 10 IU/ml hCG(Sigma, USA), 1 $\mu\textrm{g}$/ml $\beta$-estradiol(Sigma, USA) and 10% FCS for 24~48 hrs in incubator with 5% CO2 in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 12~18 hrs with motile capacitated sperm by preincubation of heparin. The bovine embryos following dehydration by cryoprotective agents and various concentration of sucrose were directly plunged into liquid nitrogen and thawed in 3$0^{\circ}C$ water. Survival and in vitro developmental rate was defined as developmental rate on in vitro culture or FDA-test. The results are summarized as followes : 1. The equilibration time on in vitro developmental rates of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (10~20 min.). 2. The temperature thawed at 3$0^{\circ}C$ after rapid freezing of bovine embryos resulted in a significantly higher in vitro developmental rate than did at 2$0^{\circ}C$ and 35$^{\circ}C$. 3. The thawing time on in vitro developmental rates of bovine embryos was attained after short period of time(1~5 min.) in the freezing mediuim higher than long period of time(10min.). 4. The in vitro developmental rates of bovine embryos after rapid frozen-thawing by 1 step straw method in the freezing medium added 1.5M, 2.0M glycerol, DMSO, propanediol and 0.25M, 0.50M, 0.75M, 1.00M sucrose were 12.5~19.4%, 10.0~15.6%, 9.1~13.8% and 6.7~12.9%, respectively.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.15-23
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• 1994

This study was carried out to investigate the effects of concentration, kinds of cryoprotectants, equilibration time, optimum thawing temperature on the survival rate of rapidly frozen porcine embryos. The porcine embryos following dehydration by cryoprotectants containing sucrose were directly plunged into liquid nitrogen and thawed in 30, 35 or 37$^{\circ}C$ water bath, Survival rate was defined as development rate on in vitro culture or FDA-test. The results are summarized as follows : 1. The high survival rate of porcine frozen embryos after rapidly thawed in freezing medium was attained 2.0M DMSO, 2.0M glycerol, 2.0M propanediol, 1.5M ethyleneglycol. 2. The high survival rate of porcine frozen embryos after rapidly thawed in freezing medium was obtained using single cryoprotectant(16.6~40.0%) than mixed cryoprotectants(12.5~33.3%). 3. The eqilibration time on the survival rate of rapidly thawed porcine frozen embryos was attained after short period of time(15.0~33.3%) in the freezing medium higher than long period of time(9.10~30.0%). 4. The thawing temperature on the survival rate of rapidly thawed porcine frozen embryos was attained at 3$0^{\circ}C$ of thawing temperature(33.3~40.6%) in the freezing medium higher than 25 or 37$^{\circ}C$ of thawing temperature.

• Korean Journal of Animal Reproduction
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• v.8 no.2
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• pp.79-86
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• 1984

This cepseiment was carried out to cerify the effect of thawing methods and preservative temperature on the sperm motility and fertility after thawing semen with plastic straws in fresh and warm water. Sperm motility in vitro stored at room temperature after thawing were conducted by the various storage hours. A field trial after thawing semen with warmed water in straws from Cheju native cows involving 4 technicians and 800 cows first (or second) services gave the following results. The thawing methods of warmed water for one minute in semen motility were considerably higher than that in iced water during 12 hours after thawing semen, however, the sperm survival index of ice-water shwed a better results according as the time passed away, but not significant differences. Preservative temperaure at 5$^{\circ}C$ (iced water) after thawing gave significantly better results than that of thawed at 3$0^{\circ}C$ (warmed water). The N R rate to 175 inseminations with semen thawed at 15-2$0^{\circ}C$ (fresh water) was 82.8%, 80.9% for 610 inseminations thawed in warm water. Conception rate ofthe semen thawed in warm water for 10-60 secs gave no significant difference among storage hours, because the semen used to be inseminated within one hour almost, but in decreased when semen thawed at the period of one minute over.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.967-972
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• 2001

In this study, the characteristics of freezing and thawing resistance, the compressive strength, and the change in height of cement mortar according to steam curing methods has been studied. To this end, the major test variables include the period of the early curing, curing temperature and the later curing. The strength test as well as volume variousness have been conducted to explore the characteristics of thawing and thawing resistance on the curing methods. The experimental results in the present study can be efficiently used to improve the characteristics of freezing and thawing resistance for concrete products carrying steam curing.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.234-240
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• 1998

This study attempted to determine the effect of various thawing methods and storage periods on the quality of froen cooked rice. Frozen cooked rice was thawed at four different methods, such as pressure cooking, conventional cooking, microwave heating and thawing at room temperature after 10 days, 30days and 90 days frozen storage. We conducted a physico-chemical analysis (moisture content, dehydration rates, degree of gelatinization, color value and texture) and sensory evalution on the frozen-thawed cooked rice. The study showed that there were no significant differences on the quality characteristics of frozen-thawed cooked rice during the storage period of 90 days. However, the thawing method of pressure cooking caused high moisture content, rapid dehydration rates, and a high degree of gelatinization on the cooked rice. Thus, the desirabililty for the rice diminished becaused of the excess moisture content and the change of appearance and testure in the rice due to the high temperature. There were similiar quality characteristics to the cooked rice after forzen-thawing whether by conventional cooking or by microwave heating and just after cooking. Thawing at room temperature also caused a significant decrease in quality characteristics.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.4
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• pp.487-495
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• 2013

The vacuum packaged ham and loin from low-fat pork cuts were frozen at $-20^{\circ}C$ for 3 months and thawed. Then, the thawed meat was chilled at $3^{\circ}C$, and impacts of chilling period on changes in physical properties of raw meat and cooked meat were investigated. In the case of raw meat, the pH value, $L^*$ value, drip losses, water holding capacity and gumminess of ham increased significantly on the 4th day compared with the 0th day of chilling after thawing. However the cooking losses, hardness and chewiness decreased significantly. The loin showed a similar tendency on the 2nd day of chilling after thawing. In the case of cooked meat, changes in physical properties during chilling period after thawing showed a similar tendency as raw meat, but pH value, $L^*$ value and $a^*$ value did not show significant difference. The springiness and cohesiveness of both raw meat and cooked meat did not show significant difference during chilling period after thawing. The sensory tenderness of ham and loin improved significantly on the 4th day and 2nd day during chilling after thawing, respectively.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.185-188
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• 2001

In this study, the characteristics of freezing and thawing resistance, the compressive strength, and the change in height of cement mortar according to a steam and taler curing conditions has been studied. To this end, the major test variables include the period of the early curing, curing temperature and the later curing. The strength test as well as volume variousness have been conducted to explore the characteristics of freezing and thawing resistance on the curing conditions. The experimental results can be efficiently used to improve the characteristics of freezing and thawing resistance for concrete products carrying steam curing.

• Food Science of Animal Resources
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• v.35 no.1
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• pp.27-34
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• 2015

The ultrastructure in the beef muscle of the electro-magnetic resonance and air blast freezing during the frozen storage, and the changes in the quality characteristics after thawing were evaluated. The size of ice crystal was small and evenly formed in the initial freezing period, and it showed that the size was increased as the storage period was elapsed (p<0.05). The beef stored by the electro-magnetic resonance freezing showed the size of ice crystal with a lower rate of increase than the air blast freezing during the frozen storage. The thawing loss of beef stored by the electro-magnetic resonance freezing was significantly lower than the air blast freezing during frozen storage (p<0.05), and it showed that the thawing loss of the round was higher than the loin. Water holding capacity decreased as the storage period became longer while the electro-magnetic resonance freezing was higher than the air blast on 8 month (p<0.05). As a result of sensory evaluation, the beef stored by the electro-magnetic resonance freezing did not show the difference until 4 months, and it showed higher acceptability in comparison with the beef stored by the air blast freezing. Thus, it is considered that the freezing method has an effect on the change in the ultrastructure and quality characteristics of the beef.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.22 no.3
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• pp.262-269
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• 2019

Purpose: As the importance of breastfeeding has been reinforced, human milk is often stored for practical reasons. Therefore, we evaluated optimal storage and processing methods for human milk from a nutritional standpoint. Methods: Human milk samples were collected between June 2017 and February 2018. Also, data about maternal information were collected. Human milk was analyzed for macronutrients and caloric content. The samples were subdivided into groups for nutrient analysis. The control group (fresh milk) was not stored or processed. The other groups (9 groups) consisted of samples analyzed based on different storage temperatures (room temperature, refrigerated, frozen), defrosting methods (bottle warmer, room temperature thawing, microwave oven), and storage period (1 week, 1 month, 2 months) and compared with the control group. Results: There was no statistically significant difference in the nutrient content of human milk among the collected samples. A significant change in the content of macronutrients in milk samples was observed under storage condition at different temperatures for 1 week with subsequent thawing with bottle warmer compared to fresh milk. Under storage at $-20^{\circ}C$ for 1 week with subsequent thawing with different defrosting methods, a significant change in the content of macronutrients in milk samples was observed compared to fresh milk. After storage at $-20^{\circ}C$ for different periods and thawing with a bottle warmer, a significant change in macronutrient content in milk samples was observed compared to fresh milk regardless of the storage period. Conclusion: Unlike previous guidelines, changes in macronutrient content in milk samples were observed regardless of the method of storing and thawing. Apparently, it is proposed that mothers should feed fresh human milk to their babies without storing.