• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.111-115
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• 2008

The aim of this study was to examine more effective cryoprotectant for the cryopreservation of mouse preantral follicles. Enzymetically isolated preantral follicles from 12-day-old mice were cryopreserved by a slow freezing protocol with 1.5 M propanediol (PROH), dimethyl sulphoxide (DMSO) or glycerol (GLY) and then grown and matured in vitro for 11 days after thawing. The survival of preantral follicles immediately after freezing and thawing was not different among the PROH (68.2%), DMSO (72.4%) and GLY (72.1%). After grown and matured in vitro, the rates of survival and metaphase II oocytes were 54.9% and 36.6% for PROH which was significantly higher rates (p<0.05) compared with the rates obtained from DMSO (16.9% and 9.0%) and GLY (16.3% and 7.5%). The diameter of metaphase II oocytes from pre antral follicles frozen in PROH ($67.4{\pm}1.8\;{\mu}m$) was significantly (p<0.05) smaller than that of the fresh preantral follicles ($69.1{\pm}2.3\;{\mu}m$). The results from the present study revealed that PROH is more suitable cryoprotectant for the cryopreservation of mouse preantral follicles.

• Korean Journal of Animal Reproduction
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• v.16 no.3
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• pp.217-224
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• 1992

These studies were carried out ot investigate on the transferred embryo development following ultrarapid frozen for 8-cell and morula of in vitro fertilization mouse embryos. The post-thaw embryo survival was evaluated and compared by cell stage of embryos and by equilibration time before ultrarapid freezing. The results obatined were summerized as follows: 1. The effects of equilibration time of 3 vs. 6 minutes before ultrarapid freezing and after thawing on the morphological survival and the viability of 8-cell and morulas embryos were not significant. 2. When the ultrarapid frozen-thawed 32 eight-cell and 33 morula embryos, and 30 fresh blastocysts were transferred to pseudopregnant recipient mice, the number of normal offsprings produced were 9(28.1%), 14(42.4%) and 18(60.0%), respectively. From the above resutls, it was concluded that the optimal conditions of pH osmolality of the media for mouse IVF and embryo culture, and the period of sperm preincubation might be 7.1, 310 mOsm and 120 min., respectively,a nd somewhat high conception rate might be resulted from transfer of frozen embryos of morula stage and fresh embryos of blastocyst stage.

• Korean Journal of Poultry Science
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• v.43 no.4
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• pp.197-206
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• 2016

This work was carried out to investigate effects of the freezing/thawing method on duck meat kept in a freezer for a month. The meats used were breast muscle collected from Korean native ducks (KND) that were fed for 8 weeks (2.8 kg of live weight). Forty-five samples were used after being frozen in storage for one month and were then divided into 5 treatments (3 replications/treatment, 3 samples/replication). Five treatments (CON, FFFT, FFST, SFFT and SFST) were control groups (CON) and four were experimental groups, using $2{\times}2$ complex factors with two freezing methods (fast freezing, FF, $-50^{\circ}C$ in a deep freezer; slow freezing, SF, $-20^{\circ}C$ in a common freezer) and two thawing methods (fast thawing, FT, 5 h $12^{\circ}C$ with flow water; slow thawing, ST, 24 h $5^{\circ}C$ in a refrigerator). Lightness of KND meat in FF and FT groups was lower than that of control (P<0.05). Yellowness of KND meat of the ST group was higher than that of control (P<0.05). Cooking loss (CL) and water holding capacity (WHC) of KND meat in the control were lower than those of the freezing and thawing groups (P<0.01, P<0.05), but shear force (SF) of the control was higher than that of other groups (P<0.01). Moisture content of the ST group was higher than that of the FT group (P<0.05), and protein content of the FF group was higher than that of control (P<0.05). Stearic acid (C18:0) of the SF group was higher than that of the FF group (P<0.05). Arachidonic acid (C20:4n6) of control was higher than that of the SF and ST groups (P<0.01, P<0.05). Alanine, aspartic acid, glutamic acid, serine, and tyrosine content of the control were lower than that of the freezing and thawing groups (P<0.05). These results show that freezing and thawing methods affect meat color, shear force, cooking loss, and WHC-related water content.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1291-1295
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• 2004

Histology and transmission electron microscopy studies were carried out on buffalo muscles that were subjected to repeated freeze-thaw cycles at -10 and $-18^{\circ}C$. In the first freeze thaw cycle ($-10^{\circ}C$) structures of muscle showed slight change and closely resembled to those of normal muscle. There were frequent gaps in the half way across the fibres and some cracks in individual fibre were also noticed in second freeze thaw cycle. In the muscle frozen at $-18^{\circ}C$, more pronounced shrinkage with extensive damage of fibres with tearing was observed. The interfibrillar gaps were wider, shrinkage and tearing of the fibres were more distinct after second freeze-thaw cycle. After the second cycle, the interior portion showed large scale degradation of the ultrastructure. Our studies of buffalo muscle showed that under the proper condition, little structural damage takes place in the meat histology and ultrastructure under repeated freeze-thaw conditions. This study adds continued weight to the evidence that limited freeze-thaw cycles will not deteriorate the quality of meat.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1553-1558
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• 2002

This study was carried out to obtain informations regarding the effect of N-acetyl-D-glucosamine in the LEY (lactoseegg yolk) diluent according to incubation time in 5 ml maxi-straw and the effects of freezing rate, thawing temperature and thawing time in the LEN (lactose-egg yolk and N-acetyl-D-glucosamine) diluent on acrosome morphology and motility of frozen-thawed boar sperm. The study showed that the LEN diluent was higher post-thaw NAR (normal apical ridge) acrosome than the LEY diluent for 0.5 h incubation at 37$^{\circ}C$. However, there were no differences between the LEN and LEY diluents on post-thaw sperm motility according to incubation time. The straws frozen from 5.0 cm (20$^{\circ}C$/min) to 17.0 cm (1$^{\circ}C$/min) above the liquid nitrogen surface did not show any significant differences on post-thaw sperm motility. However, the straws frozen above 5.0 cm from the liquid nitrogen surface were higher NAR acrosome than those frozen above 17.0 cm. The post-thaw percentages of motile sperm and NAR acrosome were significantly higher (p<0.05) for the maxi-straws submerged for 40 or 45 sec in a 52$^{\circ}C$ water bath than for 30, 35, 50 or 55 sec. The mean sample temperatures of maxi-straws after 40 or 45 sec submersion were 20.7 or 26.4$^{\circ}C$. In conclusion, the sample temperature of the thawed semen was very important for post-thaw sperm survival in the LEN diluent of 5 ml maxi-straw. When the temperature of the thawed semen was 20.7$^{\circ}C$, the percentages of motile sperm and NAR acrosome were highest.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.507-515
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• 2009

A series of experiments were conducted to determine the suitable freezing and thawing temperatures for the freezing of boar semen in 5 ml maxi-straws. The ultrastructure, in vitro fertilization (IVF) and artificial insemination (AI) of frozen-thawed semen were also be evaluated. The 5 cm freezing height gave the best results not only in post-thaw motility rate (54.00%), but also in normal acrosome morphology rate (NAR) (80.23%). There was no significant difference in the post-thaw motility between different thawing temperatures and corresponding thawing times (p>0.05); the group of $52^{\circ}C$ and 25 s gave the highest motility rate (45.00%). As a whole, not only from the motility but also the NAR, thawing at $42^{\circ}C$ was better than the other two treatments. In the freezing packages, 5 ml maxi-straw gave a little lower mobility (40%), viability rate (49.58%), plasma membrane integrity rate (53.91%) and NAR (52.65%) than the 0.25 ml straw, but there was no significant difference between the two straw volumes (p>0.05). The IVF capacity of frozen-thawed semen in this experiment was similar to fresh semen. From ultrastructure observation, the main damage to boar spermatozoa after freezing was seen in the acrosome, such as swelling and formation of vesicles. After AI in recipient Shanghai White sows, frozen-thawed semen from 5 ml maxi-straws and pellets produced 72.2% and 80% conception rate and 7.8 and 8 litter sizes, respectively, and there was no significant difference between the 5 ml maxi-straw and the pellet (p>0.05).

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.739-751
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• 2021

The thawing process is usually essential for imported pork because this product is typically distributed frozen. Consumers prefer fresh pork because discoloration, nutrient spills, and microbial contamination are high during the thawing process. The illegal act of selling frozen pork by disguising it as fresh pork through various methods can occur for the benefit of the difference in the sales price. However, there is some difficulty in securing systematic and objective data, as sensory tests are generally performed on imported pork. In the experiment conducted here, the electrical conductivity and dielectric properties of pork neck and pork belly products were measured. The amounts of change before and after freezing were compared through a statistical analysis, and a new method for determining frozen meat was proposed based on the analysis results. The weight was reduced compared to that before freezing due to the outflow of drips from the thawing process, but there was no difference in the drip loss level due to the thawing method. Vacuum packaging was found to lead to more drip loss than regular packaging, but the difference was not statistically significant. Frozen pork neck meat can be determined by measuring the electrical conductivity in the lean parts and the dielectric characteristic in the fatty parts. Frozen pork belly is determined by measuring the dielectric constant of the part closest to the outer fat layer.

• Asian Journal of Turfgrass Science
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• v.4 no.1
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• pp.42-48
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• 1990

Experiments were conducted to investigate the soil freezing depth and pattern with freezing measuring instruments during 1988-l989 winter season in Kangwon province. Freezing measuring instrument was made with acrylic pipes which were consisted of inner and outer parts. Inner pipe was filled with 0.01 % methylene blue solution and rubber hose to protect pipe breakdown by solution freezing. Freezing measurements were carried out by observing discoloration of methylene blue solution. Moisture content of evergreen trees and ground cover plants was also examined in the winter season. The observed results are as follows: 1.In the land of I OOM above sea level, soil freezing depth became deeper as the sum of Accumulated degree-days of temperature below 0˚C(0˚C . day) increased: Soil freezing depth was 30-40cm at l00˚C, 42-43cm at 150˚C, and 47cm at 200˚C day 2.Soil freezing with vinyl mulching was less developed by l3cm at l00˚C with sum of subzero temperature, by l7cm at 200˚C than that of the bare ground. Soil of rich hulls mulching with 4Ocm was not frozen until soil freezing at the bare ground was developed to 25cm depth. 3.Cashmeron mulching was more effective than felt mulching in the heat insulation of soil. 4.Thawing of soil was done from the lowest part of the frozen in the ground to upward in the beginning and after that it was done from the surface of frozen soil to downward. Finally thawing was completed at the middle of frozen soil.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.3
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• pp.283-289
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• 2000

Objective: The study was performed to compare the survival rate and the development of day 2 mouse embryos which had freezing procedures done. Methods: We used three different vitrification solutions (EFS, VS14, DPS) and a ultrarapid freezing solution (UFS) for cryopreservation of day 2 mouse embryo. Results: We tested toxicity by exposing embryos to vitirification solutions and a ultrarapid freezing solution. The survival rates are 100%, 97.8%, 95.6% and 100% (EFS, VS14, DPS and UFS). After cultured for 96 hours, hatching rates of each group are 93.5% (no freezing), 95.6% (EFS), 86.4% (VS14), 93.0% (DPS), and 93.0% (UFS). There is no significant differences among groups. The survival rates after thawing cryopreserved embryos are 80.2%, 91.7%, 69.5%, 0% and 91.8% (slow freezing, EFS, VS14, DPS and UFS). Also cultured for 96 hours, the hatching rates are 93.5% (no freezing), 84.1% (slow freezing), 93.9% (EFS), 48.5% (VS14) and 70.1% (UFS). Conclusion: The survival rates of vitrification in EFS solution and ultrarapid freezing are higher than slow freezing (p<0.05). The hatching rate of vitrification in EFS solution cultured for 96 hours is highest, so vitrification of day 2 mouse embryos in EFS solution considered as more effective for cryopreservation.