• Journal of Aquaculture
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• v.11 no.4
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• pp.573-580
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• 1998

Red spotted grouper, Epinephelus akaara is distributed in the south and west coasts of Korea. The natural stocks of the fish are decreasing sharply year by uear because of reckless overfishing. This research was carried out to understand general informations on maturation, sex composition and sex-reversals of the fish. Annual fishing uields of red spotted grouper in the castal area of Byonsan Peninsular of Kora decreased over 10% from 1992 to 1994. The main fishing season was from May to July with fishing gear of Hand-lines. Gonadosomatic index (GSI) and condition factor were highest on early and late July, respectively, thus main spawning reriod was assumed from late July to early August. The relationship between total length (X) and body weight (Y) for wild adults was represented as a regression, Y=$0.0169X^{2.9705}$, ($r^2$=0.96). Frequency of sex of wild red spotted gouper showed that the number of female below 38cm in total length was more than that of male, and hermaphrodite mainly occurred from 28cm to 32cm in total length the frequency of male and female were almost same. Also hermaphrodite occurred mainly between 25~29cm. Sex reversal ration of the adults reared in a tank for a year with different sexual compositions revealted that the frequency of female reversed from male was more than that of male reversed from female at 1:1 and 1:2 stocking densities of female and male, respectively. Also, about 20% of female was reversed to male when all females were reared. And the size of the fish reversed to male was larger than that of non-reversed female.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.3
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• pp.410-424
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• 2011

This study was investigated for the purpose of obtaining basic data which can be applied to processing of canned sea mussel using tomato paste. Shell were washed, and then steamed and shucked. Sea mussel meat was prepared with ratio of sea mussel 90g, tomato paste sauce 65g(tomato paste 42%, gum guar 1.0%, salt 2.0%, starch syrup 2.0%, cooking wine 1%, water 52%). The sea mussel meats were packed with vacuum seamer in 301-3 can, and then sterilized for various F0 value(F0 8-12 min.) in a steam system retort at $118^{\circ}C$. The factors such as pH, VBN, amino-N, total amino acid, free amino acid, chemical composition, color value (L, a, b), texture profile, TBA value, mineral, sensory evaluation and viable bacterial count of the canned sea mussel produced with various sterilization condition(F0 8-12 min.) were measured. The same element was also measured during preservation. The results showed that the product sterilized at F0 8 min. and preserved for 90 days were the most desirable.

• Food Science and Preservation
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• v.22 no.3
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• pp.458-463
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• 2015

Many Koreans, who are resident in Uzbekistan and Central Asia, are still avid fans of the Korean traditional soybean paste. No research study has been conducted on the Korean-Uzbekistanis soybean paste. The purpose of this study was to investigate the quality characteristics of the Korean-Uzbekistanis fermented soybean paste. Nine kinds of soybean pastes prepared by Korean-Uzbekistanis were collected, and their physiochemical properties (protease activity, amylase activity, amino type nitrogen content, reducing-sugar contents, and aerobic bacterial count) have been analyzed. The Korean-Uzbekistanis' fermented soybean paste (KU-SP) showed higher protease activity than the Korean fermented soybean paste (K-SP). The protease activities of KU-SP B, D, and H were 832, 807 and 630 unit/g, respectively, which were significantly different from others. In addition, the content of amino-type nitrogen in KU-SP B, D, and H were 777 mg%, 686 mg%, and 705 mg%, respectively. In the meanwhile, ${\alpha}$-amylase activities showed wide ranges starting from 10.82 to 47.98 unit/g. The KU-SP values, except for the KU-SP C, have shown higher activities than the K-SP. The reduced sugar content and totoal aerobic bacteria number were within the range of 0.55~3.43%/g and 7.24~8.79 log CFU/g, respectively. Finally, this research provided the basic data and information for the quality characteristics of commercial soybean paste prepared by the Korean-Uzbekistanis. These basic data can be useful for understanding the Korean food culture in Central Asia.

• Food Science and Preservation
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• v.18 no.5
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• pp.786-794
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• 2011

To investigate the sanitary-quality level of commercial kimchi in South Korea, the pH, acidity, and microbial-flora changes in the kimchi were determined. Samples of kimchi produced by three different manufacturers (a small grocery store, a small/medium-sized enterprise, and a large food company) were collected. Freshly made kimchi was purchased and fermented at $10^{\circ}C$ for 10 days. The pH of the commercial kimchi on the purchased day was approximately pH 5.8, and that on the $10^{th}$ day of fermentation was ${\simeq}pH$ 4.1. The kimchi purchased from a large company showed a more rapid decline in pH level during fermentation. The saltiness of the kimchi purchased from a medium-sized company was slightly higher than those of the other commercial kimchi samples. The saccharinity index of the kimchi produced by a small grocery store was higher than those of the other samples, and its value deviation was also higher than those of the other commercial kimchi samples. A higher total viable-cell count and a higher lactic-acid bacteria (LAB) count were detected in the kimchi from the large food company at the beginning of fermentation compared to the samples of the two other kimchi manufacturers. The highest cell numbers of gram-positive bacteria (except LAB) and coliform bacteria were detected from the small-grocery-store kimchi, but the coliform bacteria count gradually decreased during fermentation although such bacteria were still detected until the $10^{th}$ day of fermentation. In contrast, coliform bacteria were not detected in the samples from the medium-sized and large food companies. Yeast, which is detected in over-ripened kimchi, was detected in the unfermented kimchi from the small grocery store, which had a below-0.36% acidity level. The gram-positive bacteria (except LAB) that were detected in all the tested commercial kimchi samples were determined to be Bacillus spp., and the gram-negative bacteria were determined to be Escherichia coli, Enterobacter spp., Sphingomonase spp., and Strenophomonas spp. The proportions of all the aforementioned bacteria in the kimchi samples, however, were different depending on the samples that were taken. These results indicate that a more sanitary kimchi production process and a more systematic kimchi production manual should be developed to industrialize and globalize kimchi.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.243-254
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• 1986

This study was conducted to select the appropriate types of drop cone for measuring soil hardness and to determine the cone index for the actual field on which rice will be transplanted. One type of drop cone was selected from the results of indoor tests and the selected drop cone was tested at the 56fields of the five different districts in Korea. The results of this study were summarized as follows; 1. Cone type D shows a significant penetrating depth variation comparing the other types of cone on the indoor tests. 2. Six types of cone were tested on the similar state of the actual puddling field. The penetrating depth variation was not significant among the cones but cone type F seemed to be suitable to evaluate the state of puddling because cone type F showed the least repeat variations during the tests. 3. The actual field test from 56 fields showed that the penetrating depth was approximately 11.0-14.4cm on the puddling day and it was 9.2-13.7cm on the transplanting day of which one to three days after puddling. 4. The above results show that the selected drop cone could be used to formulate the state of puddling.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.225-231
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• 1998

Purpose : To determine whether TNF-$\alpha$ increases the antitumor effect of radiotherapy in murine syngeneic tumor system. Materials and Methods : Syngeneic murine tumors of MCa-K or MCa-4 (mammary carcinoma), OCa-I (ovarian carcinoma), or HCa-I(hepatocarcinoma were grown in hind legs of C3Hf/HeJ mice. When tumors were grown to 6 mm in mean diameter mice were treated with TNF-$\alpha$, radiation, or combination of the both. Gamma-radiation was given as a single dose of 30 Gy for HCa-I and 15 Gy for other tumors using Cobalt-60 teletherapy unit. A novel TNF-$\alpha$ mutein developed in Korea, was intraperitoneally administered daily at a dose of 10 ug per mouse for 7 days. In combination of radiation and TNF-$\alpha$, the drug was started 1 hour after radiation. Tumor growth delay assay was used to measure the tumor response to the treatment. Results : Among 4 tested tumors, TNF-$\alpha$ alone showed significant antitumor activity in MCa-K and OCa-I tumors, which showed absolute growth delay (AGD) of 5.0 days and 6.5 days, respectively. In combination with radiation, TNF-$\alpha$ showed significant delay of AGD (41.1 days) in OCA-I compared to AGDs of TNF-$\alpha$ alone and radiation, i.e., 6.5 days and 26.9 days, respectively(p<0.05). Enhancement factor was 1.29 in OCa-I, which showed supraadditive effect. TNF-$\alpha$ did not show significant delay of AGDs in the remaining 3 tumors compared to AGDs of TNF-$\alpha$ alone and radiation. Conclusions: TNF-$\alpha$ alone showed antitumor effects in MCa-K and OCa-I. In combination with radiation, TNF-$\alpha$ acted in supraadditive way in OCa-I only. The results of this study imply that the combination of TNF-$\alpha$ and radiation has different therapeutic potential depending on tumor model and further study is advocated.

• The Korean Journal of Pesticide Science
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• v.18 no.3
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• pp.202-209
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• 2014

RNA interference (RNAi) is the method which controls phenotypes of gene in live cells. Chitinase is the enzyme helping digestion and absorption of old cuticles during the ecdysis of insects. In order to investigate molting-inhibition effect with the chitinase related gene in Spodoptera litura, RNA was extracted from the $5^{th}$ instars. cDNA was synthesized and then we obtained about 700 bp size chitinase. After PCR products were cloned into a pGEM T-easy vector, colonies were picked. DNA was extracted from the colony cultures. EcoR I enzyme was used to check whether PCR products were inserted or not. And then we confirmed vector band of about 3 kb and insert band of about 700 bp. To synthesize the dsRNA, each DNA was cut with Spe I and Nco I enzymes (Circular DNA became lineared DNA). After synthesis of dsRNA, approximately 5 ul dsRNA was injected into the $3^{rd}$ abdominal segment of S. litura $4^{th}$ larvae. The concentration of dsRNA was about $10{\mu}g/{\mu}l$. We confirmed larval-larval molting : there were phenotypically abnormal individuals - for instance malformation, molting inhibition and change of integument color. Pupaadult molting : there were phenotypically abnormal individuals - for instance molting inhibition, change of wings and malformation. Also we could investigate the pupation, emergence and variation about noninjection, treated with DW and dsRNA. Each pupation was non-injection 83.3%, DW 78.3% and dsRNA 66.7%. Each emergence was non-injection 90.0%, DW 72.3% and dsRNA 65.0%. So we considered that chitinase dsRNA induced molting inhibition effect. But each variation was non-injection 8.9%, DW 2.9% and dsRNA 19.2%. Therefore dsRNA group showed the highest variation value. When 18 hours after injecting dsRNA, we could obtain abnormal individual.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.250-256
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• 1998

D-Tagatose production from D-galactose was investigated using 35 type strains of American Culture Type Collection (ATCC) and Korean Collection for Type Cultures (KCTC) which have potential to produce D-tagatose. Enterobacter agglomerans ATCC 27987 was selected as a D-tagatose producing strain due to its short fermentation time and high production of D-tagatose. Optimization of the culture conditions for D-tagatose production by E. agglomerans ATCC 27987 was performed. Among various carbon sources, D-galactose was the most effective carbon source for D-tagatose production. As the D-galactose concentration was increased, cell growth and D-tagatose production increased. Effect of nitrogen sources on D-tagatose production was studied. Of inorganic nitrogen sources, ammonium sulfate was effective one for D-tagatose production and yeast extract was the most suitable organic nitrogen nutrient. The concentrations of inorganic compounds such as KH$_2$PO$_4$, K$_2$HPO$_4$, and MgSO$_4$$.$7H$_2$O were also optimized for D-tagatose production. The optimal medium was determined to contain D-galactose of 20 g/l, yeast extract of 5.0 g/l, (NH$_4$)$_2$SO$_4$ of 2.0 g/l, KH$_2$PO$_4$ of 5.0 g/l, K$_2$HPO of 5.0 g/l, and MgSO$_4$$.$7H$_2$O of 5 mg/l. The optimal environmental conditions in a 250-$m\ell$ flask were found to be pH of 6.0, temperature of 30$^{\circ}C$, and agitation speed of 150 rpm. D-tagatose of 0.41 g/l could be obtained in 24 h from 20 g/l D-galactose at the optimal culture condition without induction and cell concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.643-658
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• 1994

The sedimentary records of anthropogenic metal loads in the Suyeong Bay, Pusan were determined by combining the Pb-210 dating technique with the measurements of heavy metals in the sediment cores. The sedimentation rates of sediment particles ranged from $0.12\;to\;0.20\;g/m^2/yr\;or\;2.4{\sim}4.0\;mm/yr$ in accumulation rates. The lowest sedimentation rate was observed at station S3 which was characterized by a bottom with relatively low organic matter contents(e.g. TIL and TOC). Heavy metals showed generally higher concentrations at station S1 and S2 near the mouth of the Suyeong River than at station S3 and the outmost station S4. The contents of copper, lead and zinc in the sediment cores especially from station S1 and S2 began to increase around 1930, and were at their highest levels in the $1960{\sim}1970$ period as a result of increasing industrial activities. Concentrations of these heavy metals have slightly decreased since 1970, probably due to regulation of pollution discharge. The natural background levels of copper, lead and zinc in the sediments of this bay ranged $18{\pm}4ppm,\;28{\pm}6ppm\;and\;74{\pm}9ppm$, respectively, by averaging the contents in the sediment depths corresponding to periods between about 1900 and 1920 at the four stations. The total amounts of anthropogenic loads deposited in the sediments since about 1930 were estimated to be $9{\sim}291{mu}g/cm^2$ for lead, $165{\sim}1122{mu}g/cm^2$ for zinc and $20{\sim}208{mu}g/cm^2$ for copper. These values were remarkably high at stations S1 and S2 relative to the other two stations. At stations S1 and S2, the anthropogenic loads of lead, copper and zinc constituted $29{\sim}30\%,\;32{\sim}42\%\;and\;28{\sim}35\%$ of the total sedimentary inventories at the present day, respectively. These metal contents have a good correlation(r>0.7) with each other and cadmium measurements also show a positive linear relation with nickel or total organic nitrogen.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.476-481
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• 1997

For the effect of water-soluble degraded chitosan on the shelf-life of tofu, sterilized distilled water, 0.5% degraded chitosan, 0.5% fumaric acid and 0.5% lactic acid used as an tofu-immersion solutions were investigated by microbial counts, pH, and turbidity during the periods of storage at $4^{\circ}C$. After 2 weeks storage, total aerobic microbial counts in tap water and sterilized distilled water used as an immersion solution were $3.8\;{\times}\;10^8$ and $1.8\;{\times}\;10^8\;CFU/mL$, respectively. In 0.5% fumaric acid and 0.5% lactic acid immersion solutions, the microbial counts were around $10^7\;CFU/mL$ after 2 weeks while the microbial population in 0.5% water-soluble degraded chitosan were, however, $1.6\;{\times}\;10^5\;CFU/mL$ after 2 weeks and $1.7{\times}10^7\;CFU/mL$ after 3 weeks. The lag phase of initial contaminated microbes in 0.5% degraded chitosan solution was longer than those of other treatments. The addition of 0.5% fumaric acid and 0.5% lactic acid decreased the initial pH to pH 5.0, while those of tap water, sterilized distilled water and 0.5% degraded chitosan stabilized the immersion solution at around pH 7.2. All initial pH values were decreased during storage and then slowly increased as storage time was increased. The turbidities in all treatments were increased during storage, but the addition of 0.5% degraded chitosan showed the lowest change, compared to other treatments, showing that the water-soluble degraded chitosan has a good antimicrobial effect and has a potential use to extend the shelf-life of tofu product.