• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.109-117
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• 1986

For the purpose of obtaining basic data which can be applied to processing of retort pouched shellfishes, retort pouched seasoned ark shell, Anadara broughtonii, was prepared. The frozen ark shell was thawed and seasoned with a mixed seasoning powder prepared with $10.0\%$ of sorbitol, $2.0\%$ of table salt and $0.5\%$ of monosodium glutamate at $5^{\circ}C$ for 10 hours, and then dried at $45^{\circ}C$ for 4 hours. The dried seasoned ark shell was coated with $1.0\%$ sodium alginate solution, dried with cola air blast for 2 hours and then vacuum-packed in the laminated plastic film bag (polyester/casted polypropylene= $12{\mu}m/70{\mu}m,\;15{\times}16cm$), and finally sterilized up to Fo=6.0 in hot water circulating retort at $121^{\circ}C$ for 10 minutes. The major fatty acids of raw ark shell and retort pouched seasoned ark shell products were 16:0, 20:5, 22:6, 18:0 and 18:3, and predominant free amino acids of those were lysine, arginine, glycine, alanine, glutamic acid and leucine. In nucleotides and its related compounds of raw ark shell and retort pouched seasoned ark shell products, the most abundant one was AMP, and total extract-N of those was chiefly consisted of free amino acids, betaine and nucleotide and its related compounds. During the processing procedure such as drying and sterilization, unsaturated fatty acids slightly decreased while saturated fatty acids increased, and total extract-N content decreased about a half. From the results of chemical and microbial experiments during storage, it was concluded that the products could be preserved in a good condition for 100 days at room temperature, and their duality could be improved by the coating treatment of sodium alginate solution.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.369-375
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• 2011

The aim of this study was to evaluate the effect of ${\alpha}$-tocopherol on blastocysts development and subsequent cryosurvival of the vitrification. The ${\alpha}$-tocopherol(0, 100, 200, 400 ${\mu}M$) was added in to culture medium for the bovine embryos. The blasocysts from the ${\alpha}$-tocopherol and untreated control groups were then frozen-thawed, and their cryosurvival was assessed by in vitro culture for 48 h. There were no differences in the overall cleavage rate($56.14{\pm}4.66$, $58.18{\pm}4.70$, $62.97{\pm}6.86$ and $51.17{\pm}7.28$) among four treatment groups. However, in blastocyst development and total cell number were significantly higher in ${\alpha}$-tocopherol 200 ${\mu}M$ ($38.60{\pm}7.12$; $106.33{\pm}3.50$) to culture medium than other treatment groups($29.30{\pm}5.24$, $31.60{\pm}7.12$ and $26.37{\pm}4.18$; $101.36{\pm}5.12$, $97.27{\pm}2.87$, and $91.23{\pm}7.52$ respectively). Before and after vitrification, the total cell number and blastocyst development of embryo were significantly higher in July to August than September to October. In conclusion, addition of ${\alpha}$-tocopherol 200 ${\mu}M$ to in vitro bovine embryo culture medium was beneficial for improving embryo quality by decreasing the embryo damage blsstocysts cell number and improving the tolerance of the embryos to cryopreservation.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.111-117
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• 1996

This experiment was designed to evaluate the effect of transforming growth factor-$\beta$ (TGF-$\beta$) and insulin-like growth factor-I (IGF-I) in bovine oocyte maturation in the presence or absence of serum on subsequent fertilization and embryo development. In addition, various concent rations of these growth factors were evaluated for the ability to promote development of eight-cell stage embryos to the blastocyst stage. Cumulus-oocyte complexes were recovered from 2 to 6 mm follicles obtained from slaughterhouse ovaries and cultured at 38.5$^{\circ}C$ for 24 hours in TCM-199 (HEPES Modification) with or with out 20 % fetal bovine serum (FBS) to which the following growth factors were added TGF$\beta$ IGF-l or TGF $\beta$ + IGF-I, all at 10 ng/ml each. The matured oocytes were fertilized in IVF-TL medium with frozen-thawed semen at a concentration of 1 ${\times}$ 10$^6$ cells/ml of fertilization medium following Percoll separation. After 24 hours of sperm-egg incubation, the embryos were transferred to CZB medium without glucose for 48 hours and then cultured in TCM-199 with 20% fetal bovine serum (FBS) for 96 hours. The addition of growth factors to IVM medium in the presence of serum had no effect on cleavage and subsequent embryo devlopment to blastocyst. In the absence of serum, TGF- improved cleavage and development to blastocyst compared to control's(p<0.05) and no synergistic effeet of IGF-I + TGF-$\beta$ was observed. In the second experiment, eight-cell embryos obtained by in vitro maturation (IVM) in TCM-199 + 20% FBS without growth facrors and in vitro fertil-ization (IVF) were cultured in the in vitro cuiture (IVC) medium supplemented with 5, 10 ng/ml TGF-$\beta$ or 5, 10, 50, 100 ng/ml IGF-I. Cleavage rate and development to the blastocyst stage was observed during seven days of incubation. The supplementation of 10 ng/ml TGF-$\beta$ to lVC medium for eight-cell embryos improved development to blastocyst (p<0.05) compared to control. In conclusion, these data indicate that the supplementation of growth factors to IVM medium in the presence of serum does not influence cleavage and subsequent embryo development. However, significantly more oocytes matured in serum-free TCM-199 and eight-cell embryos cultured in lVC medium developed to blastocyst with supplementation of 10ng/ml TGF-$\beta$.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.207-218
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• 1970

Studies were carried out to develope the most economical and practical methods of packaging and preservation of kimchi, so commercialization of kimchi manufacture could proceed rapidly. The results obtained may be summarized as following. (1) It is generally established that the acceptable range of lactic acid content of kimchi is between 0.4% and 0.75%. Based on sensory evaluation, kimchi having lactic acid content below 0.4% and above 0.75% was not edible, and the time of optimum taste corresponded to the vicinity of 0.5% of lactic acid content. For the refrigeration storage with or without preservatives, the packaging kimchi in plastic film must be done at the lactic acid content of 0.45%, for lactic acid fermentation will continue slowly after the packaging. However, for the heat sterilized kimchi the packaging should be done at the 0.5% of lactic acid content for the best because lactic acid fermentation is completely stopped after the packaging. (2) Polyethylene, polypropylene, and polycello were chosen as suitable packaging materials. Polyethylene is cheapest among them but kimchi packaged in this film was damaged frequently in handling process and gave off kimchi flavor. On the other hand polypropylene also gave off kimchi flavor, but its higher mechanical strength gave better protection to kimchi and it had superior display effect due to the transparancy. Therefore polypropylene made much better packaging material. Polycello proved to be the best packaging material from the standpoint of physical characteristics but its price is higher than that of other plastic films. To be effective, the thickness of plastic films for packaging kimchi must exceed 0.08mm. (3) Keeping property of kimchi appeared to be excellent by means of freezing. However, by the time the frozen kimchi was thawed out at room temperature, moisture loss due to drip was extensive, rendering the kimchi too stringy. (4) Preservation of kimchi at refrigerated temperatures proved to be the best method and under the refrigerated condition the kimchi remained fresh as long as 3 months. The best results were obtained when kimchi was held at $0^{\circ}C$. (5) In general, preservatives alone were not too elective in preserving kimchi. Among them potassium sorbate appeared to be most effective with the four fold extension of self-life at $20^{\circ}C$ and two fold extension at $30^{\circ}C$. (6) In heat sterilization the thickness of packaged kimchi product had a geat effect upon the rate of heat penetration. When the thickness ranged from 1.5 to 1.8cm, the kimchi in such package could be sterilized at $65^{\circ}C$ for 20 minutes. Kimchi so heat treated could be kept at room temperature as long as one month without apparent changes in quality. (7) Among combination methods, preservation at refrigerated and heat sterilization could be favorably combined. When kimchi was stored at $4^{\circ}C$ after being sterilized at $65^{\circ}C$ for 20 minutes, it was possible to preserve the kimchi for more than 4 months.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.21 no.1
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• pp.21-29
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• 1988

This study was carried out to develop the powdered Katsuobushi (a kind of boiled, smoked, and dried fish product which is used for seasoning soup as it is.) using skipjack as a natural flavoring substance. The processing conditions of the powdered Katsuobushi and the changes of taste compounds during processing of the products were examined. In preparation of the powdered Katsuobushl, frozen skipjack was thawed, beheaded, gutted, filleted and then sliced to 1cm of thickness. The silted meats were boiled in skipjack extract for 20 minutes, and then it was smoked for, 3 times to $10\~12\%$ moisture content at $80^{\circ}C$ for 8 hours. The smoked - dried meats were followed to be 50 mesh of particle size. The effect of slicing and boiling in skipjack meat extract on enhancing flavor and on preventing lipid oxidation of product during processing were observed. The moisture content and crude lipid content of the powdered Katsuobushi was in the range of 11 to $12\%$ and 4.3 to $4.8\%$, respectively. The taste compounds of the product were nucleotides and their related compounds, 1135.8mg/100g ; free amino acid and related compounds, 2210.2mg/100g ; non-volatile organic acids, 1148.0mg/100g ; and total creatinine. 592.1mg/100g on dry basis, and small amount of betaine and TMAO. The major elements of mineral in the product were found to be K, Mg, Na, and Ca. The content of IMP was 542.0mg/100g, and major free amino acids were found to be histidine, anserine, taurine, carnosine and alanine of which occupied to $83.6\%$ of total free amino acids. In non -volatile organic acids, major ones were lactic acid, succinic acid, pyroglutamic acid and $\alpha-ketoglutaric$ acid. From the results of the chemical experiments and sensory evaluation, we may conclude that the flavor of the product from present experiment is more desirable than that of conventional products although the processing time used were much shortened than that of conventional method, and it can be commercialized as a seasoning powder.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.1-12
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• 2002

Objective: In order to acquire the technique for the establishment of human embryonic stem cells (ESe) derived from the human frozen-thawed embryos produced in IVF-ET program, this study was performed to establish mouse ESC derived from the in vitro fertilized embryos. Materials and Methods: After Fl hybrid (C57BL female $\times$ CBA mael) female mice were superovulated with PMSG and hCG treatment, their oocytes were retrieved and inseminated, and the fertilized embryos were cultured for 96-120 hours until the expected stages of blastocysts were obtained. To isolate the inner cell mass (ICM), either the blastocysts were treated with immunosurgery, or the whole embryos were cultured for 4 days. Isolated ICMs were then cultured onto STO feeder cell layer, and the resultant ICM colonies were subcultured with trypsin-EDTA treatment. During the subculture process, ESC-like cell colonies were observed with phase contrast microscopy. To identify ESC in the subcultured ESC-like cell colonies, alkaline phosphatase activity and Oct-4 (octamer-binding transcription factor-4) expression were examined by immunohistochemistry and RT-PCR, respectively. To examine the spontaneous differentiation, ESC-like cell colonies were cultured without STO feeder cell layer and leukemia inhibitory factor (LIF). Results: Seven ESC-like cell lines were established from ICMs isolated from the in vitro fertilized embryos. According to the developmental stage, the growth of ICMs isolated from the expanded blastocysts was significantly better than that of ICMs isolated from the hatched blastocysts (80.3% vs. 58.7%, p<0.05). ESC-like cell colonies were only obtained from ICMs of expanded blastocysts. However, the ICMs isolated from the embryos treated with immunosurgery were poorly grown and frequently differentiated during the culture process. The established ESC-like cell colonies were positively stained with alkaline phosphatase and expressed Oct-4, and their morphology resembled that observed in the previously reported mouse ESC. In addition, following the extended in vitro culture process, they maintained their expression of cell surface markers characteristic of the pluripotent stem cells such as alkaline phosphatase and Oct-4. When cultured without STO feeder cell layer and LIF, they were spontaneously differentiated into the various types of cells. Conclusion: The findings of this study suggest that the establishment of mouse ESC can be successfully derived from the in vitro fertilized embryos. The established ESC-like cells expressed the cell surface markers characteristic of the pluripotent stem cells and spontaneously differentiated into the various types of cells.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.1-7
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• 2007

This study was conducted to examine the role of intact cumulus cells during in vitro fertilization (IVF) on sperm penetration, male pronuclear (MPN) formation and subsequent embryo development of oocytes matured and fertilized in vitro. Cumulus-oocyte complexes obtained from the slaughtered gilt ovaries were matured for 44 h in TCM199 containing 10% porcine follicular fluid, epidermal growth factor and hormones. After maturation culture, denuded oocytes or oocytes with intact cumulus cells were coincubated with frozen-thawed boar semen for 8h in a modified tris-buffered medium containing 5mM caffeine and 10mM calcium chloride. Putative zygotes were fixed and examined for sperm penetration and MPN formation (Experiments $1{\sim}3$), or cultured in North Carolina State University-23 medium fo. 156 h (Experiment 3). In Experiment 1, sperm penetration was examined after insemination of denuded oocytes and oocytes with intact cumulus cells at the concentration of $7.5{\times}10^5$ sperm/ml. Optimal sperm concentration for IVF of cumulus-intact oocytes was determined in Experiment 2 by inseminating intact oocytes with $2{\sim}5{\times}10^6$ sperm/ml. In Experiment 3, denuded or intact oocytes were inseminated at the concentrations of $7.5{\times}10^5$ and $4.0{\times}10^6$ sperm/ml, respectively, and in vitro embryo development was compared. Sperm penetration was significantly (p<0.01) decreased in cumulus-intact oocytes compared to denuded oocytes (35.2% vs. 77.4%). Based on the rates of sperm penetration and normal fertilization, the concentration of $4.0{\times}10^6$ sperm/ml was optimal for the IVF of intact oocytes compared to other sperm concentrations. The presence of intact cumulus cells during IVF significantly (p<0.05) improved embryo cleavage (48.8% vs. 58.9%), blastocyst (BL) formation (11.0% vs. 22.8%) and embryo cell number $(22{\pm}2\;vs.\;29{\pm}2\;cells)$ compared to denuded oocytes. In conclusion, these results suggest that intact cumulus cells during IVF inhibit sperm penetration but improve embryo cleavage, BL formation and embryo cell number of porcine embryos produced in vitro.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.24-33
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• 2009

This study investigated the microbial contamination levels of raw meats used for short-ripened salami and changes in the microbial and physico-chemical properties of the product during storage at 10 and $25^{\circ}C$ for up to 120 days. The microbial counts of raw meats ranged between 2 and 4 Log CFU/g. Frozen-thawed sow meat showed higher total aerobe and Enterobacteriaceae counts than fresh chilled pork and pork back fat. Staphylococcus aureus was found in all raw materials except fresh chilled pork samples, and Clostridium perfringens was detected in a sample stored for 21 days at $25^{\circ}C$. The counts of total aerobes, lactic acid bacteria and Staphylococcus spp. decreased more rapidly at $25^{\circ}C$ than at $10^{\circ}C$ when the storage time was extended. The growth of Enterobacteriaceae, Pseudomonas spp., Clostridium spp., yeast, and mold were restricted to levels below 2 Log CFU/g during storage. The contents of salt, water, crude protein, crude fat, and ash of salami samples were 3.4, 33.4, 30.8, 32.7, and 4.3%, respectively, which were not affected by storage time or temperature. The pH value of the salami was initially 4.79 and increased to 5.02 and 5.26 after 120 days of storage at 10 and $25^{\circ}C$, respectively, whereas the water activity values decreased from an initial value of 0.91 to 0.90 and 0.88 after 120 days at 10 and $25^{\circ}C$, respectively. The TBA and VBN values increased slowly during storage. The redness value of the salami samples stored at $25^{\circ}C$ decreased more significantly than the samples stored at $10^{\circ}C$. With increased storage time, the values for the rheological characteristics of the salami in terms of hardness, brittleness, elasticity, cohesiveness, gumminess, and adhesiveness tended to decrease more remarkably at $25^{\circ}C$ than at $10^{\circ}C$. Based on sensory evaluation scores, it appears that short-ripened salami is no longer acceptable after 90 days at $10^{\circ}C$ and 30 days at $25^{\circ}C$.

• Korean Journal of Animal Reproduction
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• v.24 no.1
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• pp.69-76
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• 2000

This study was carried out to improve of effective culture system on development of IVM/IVF/IVC bovine embryos. The cumulus-oocyte-complexes (COCs) collected from Korean cattle ovaries harvested at a local abattoir were matured in 50 ${mu}ell$ of TCM199 supplemented with 10% fetal bovine serum (FBS) and hormones (35 $\mu\textrm{g}$/$m\ell$ FSH, 10 $\mu\textrm{g}$/$m\ell$ LH, 1$\mu\textrm{g}$/$m\ell$ estradiol 17 $\beta$ under paraffin oil at 39$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. At 24 hrs after culture, matured oocytes were fertilized in vitro for 22~24 hrs with motile semen in which obtained by centrifugation of a frozen thawed semen on Percoll-density gradients (45% vs. 90%) at 500 g for 20 min. The presumptive zygotes were divided into three experimental groups. Single egg (Group 1), 25 (Group 2) or 50 eggs (Group 3) were cultured on cumulus cell in 50 ${mu}ell$ TCM199 supplement with 10% FBS for 6~9 days after fertilization. In vitro developmental rates into the blastocysts in the groups 2 and 3 were significantly (P＜0.05) higher than those of group 1 (37,27 vs. 6%, respectively). Cell number of blastocysts obtained in groups 2 and 3 at day 8 were significantly (P${mu}ell$) resulted in higher developmental competence and cell number of bovine blastocysts produced in vitro than those the culture of single embryos with cumulus cells.

• Korean Journal of Animal Reproduction
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• v.25 no.4
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• pp.339-347
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• 2001

Sperm-mediated DNA transfer has a potential to markedly simplify techniques for the generation of transgenic animals. The exogenous DNA transfer by intracytoplasmic sperm injection (ICSI) procedure has been recently introduced in the production of transgenic animals. In this study, the developmental competence and tile expression rates of transgene were investigated after injection of spermatozoon or sperm head with enhanced green fluorescent protein (EGFP) gene into the mature porcine oocytes. The porcine oocytes were injected with intact sperm, membrane-disrupted sperm or sperm head. After injection. embryos were cultured in NCSU23 medium up to the blastocyst stage, and the developmental competence and expression rates were studied. The developmental rate (67.0%) of sperm injection group was higher than that (59.7%) of sperm head injection group, and the rates of EGFP expression were also significantly different between sperm injection and sperm head injection groups (42.1 vs 20.0%) (F＜0.05). In the porcine oocytes injected with sperm treated with different methods of membrane disruption, the removal of sperm membrane did not alter the developmental competence of embryos. The rate of blastocysts at 7 days after injection with intact and membrane disrupted sperm were 15.0 and 14.2%, respectively. The EGFP expression rates, 38.4% in embryos injected with frozen-thawed sperm was higher than that, 22.4% of embryos injected with the Triton X-100 treated sperm. Prior to injection, sperm were cultured in different EGFP gene concentrations from 0.Ol to 1ng/u${mu}ell$. However, no significant difference in developmental rates of embryos among different concentrations of EGFP gene were observed. The highest expression rate of EGFP gene, 37.4% was obtained from the embryos injected with spermatozoa treated with 0.1 ng/${mu}ell$ EGFP gene. These results suggested that exogenous DNA could be attached to the membrane disrupted sperm, and that these sperm could be used as a vector carrying foreign DNA into embryos.