• Korean Journal of Environmental Biology
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• v.27 no.3
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• pp.297-305
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• 2009

The Asian paddle crab, Charybdis japonica (A. Milne-Edwards) is an important fishery resource in Korea. Despite its common occurrence and commercial importance, few studies have been carried out on the life cycle and trophic ecology of these populations inhabiting on the tidal flat. Food habits of C. japonica populations were investigated on the Jangbong tidal flat, Incheon, Korea. Monthly samples were taken using a modified otter trawl from November 1999 to January 2001. Based on the examination of stomach contents from 257 individuals, the frequencies of occurrence and the relative volumes of food items were analysed. As a result, the crustaceans (the brachyura, the cirripedia and the harpacticoid copepoda), the echinoderms (the ophiuroidea) and the molluscs (the cephalopoda Loligo beka, the bivalves Bivalvia unid. and Mytilus galloprovincialis) were important food for this species. To examine ontogenetic shifts in diets, individuals of C. japonica were categorized into 2 different size classes (${\leq}60mm$ and ${\geq}61mm$ in carapace width) representing sexually premature and mature stages. The food items of the small crabs (${\leq}60mm$) were dominated by the crustaceans with the harpacticoid copepods constituting 84.6% of total prey number. The next group was the bivalves and the brachyurans. On the other hand, the large crabs (${\geq}61mm$) mainly feed on the bivalvia (Mytilus galloprovincialis and Bivalvia unid.), the brachyurans (Crab unid.) and occasionally the cephalopods and fishes. The difference in proportions of the main prey items among these two size classes was statistically significant. Therefore, the feeding habits of the portunid crab, C. japonica changed with growth.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.183-198
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• 2014

This study aims to suggest useful information for tteokbokki franchise businesses to enter foreign markets by market testing and surveying preferences of foreign consumers with various kinds of tteokbokki. For this research, a survey was conducted from July 16 to August 20, 2012, targeting the people who live in Beijing, Tokyo, Singapore. The data was collected and analyzed using SPSS for Windows Version 18.0. The relationship between the general details of consumers and the results of the market test were analyzed using canonical correlation analysis. Research results and utilization plans are expected to use for improving the image of the country and ripple effects on exporting agricultural and fishery products, along with the effect of increasing spread of overseas personnel export and domestic Korean overseas supply of cultural content. Nurturing restaurant franchise business, creating jobs, and contributing to the increase in the income of the rural economy are also expected. Fermented tteokbokki franchise business should create new added value. The development of fermented tteokbokki will build a new culture of consumption, expand consumption, academic cooperation and joint technology development, and activate employment linked. Consequently, it is necessary to understand eating habits of local consumers from a variety of perspectives such as texture, taste, and colors of sauce when globalizing Korean food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.957-964
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• 2017

This study was carried out to investigate the effects of garlic extract on histamine reduction in mackerel meat stored at $4^{\circ}C$ and $15^{\circ}C$, respectively. The number of total bacteria in mackerel meat treated with 7.5% garlic extract was ten times lower than that of the control stored for 6 days of $4^{\circ}C$. However, there was no difference among the samples after 9 days of storage. Reduction of eicosapentaenoic acid (C20:5) and docosahexaenoic acid (C22:6) contents was observed in the normal control group at both temperatures. However, contents of these two polyunsaturated fatty acids slightly increased in garlic extract-treated fish. Amounts of volatile basic nitrogen increased over time in the control group, but decreased in the garlic extract-treated meat, indicating that garlic extract might suppress decomposition. No histamine was detected initially in all samples. However, a small amount of histamine (42.87 mg/kg) was detected in the control at 3 days after storage at $4^{\circ}C$. Histamine content increased continuously with storage period but was lower in mackerel meat containing garlic extract, in which histamine suppression was proportional to the concentration of garlic extract. It can be concluded that garlic extract could be utilized to extend the storage period of mackerel.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.280-288
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• 2018

In this study, an approach for the analysis of the five cephalopod species (octopus, long-arm octopus, squid, wet-foot octopus, beka squid) consumed in the Republic of Korea is developed. The samples were collected from the Southeast Asian countries Thailand, Indonesia, Vietnam, and China. The SYBR-green-based real-time qPCR method, based on the mitochondrial DNA genome of the five cephalopods was developed and validated. The intergroup variations in the mitochondrial DNA are evident in the bioinformatic analysis of the mitochondrial genomic DNA sequences of the five groups. Some of the highly-conserved and slightly-variated regions are identified in the mitochondrial cytochrome-c-oxidase subunit I (COI) gene, 16s ribosomal RNA (16s rRNA) gene, and 12s ribosomal RNA (12s rRNA) gene of these groups. To specify each five cephalopod groups, specific primer sets were designed from the COI, 16s rRNA and 12s rRNA regions. The specific primer sets amplified the DNA using the SYBR-green-based real-time PCR system and 11 commercially secured animal tissues: Octopus vulgaris, Octopus minor, Todarodes pacificus, Dosidicus gigas, Sepia esculenta, Amphioctopus fangsiao, Amphioctopus aegina, Amphioctopus marginatus, Loliolus beka, Loligo edulis, and Loligo chinensis. The results confirmed by a conveient way to calculate relative amplification levels between different samples in that it directly uses the threshold cycles (Ct)-value range generated by the qPCR system from these samples. This genomic DNA-based molecular technique provides a quick, accurate, and reliable method for the taxonomic classification of the animal tissues using the real-time qPCR.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.3
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• pp.259-268
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• 2010

Data on squid catches by the Korean jig fishery in sea blocks ($30'{\times}30'$), water temperatures at depth(30m, 50m and 100m) and zooplankton biomass in the East Sea from 1980 to 1999 were analyzed to examine the mechanism of formation of the high density stock area. Japanese common squid (Todarodes pacificus) catch in the East Sea was low in 1980s, while the catch was high in 1990s. The five sea blocks (No. 76, 82, 83, 87, 88) of the southern part in the eastern coastal waters of Korea showed high levels of percentage of total catch (35.1%), whereas the four sea blocks (No. 65, 71, 72, 78) of the coastal waters of Uleung Island showed high levels of percentage of CPUE (61.2%) for 20 years. Squid catches showed monthly fluctuations according to the vertical distribution of optimum water temperature for fishing ($14^{\circ}C{\sim}19^{\circ}C$). High total catch and high CPUE area matched well with $10^{\circ}C$ isothermal lines at 100m depth indicating northern limiting of Tsushima Warm Current, and temporal and spatial change in $10^{\circ}C$ isothermal line caused the change in total catch and CPUE. Horizontal distribution of zooplankton biomass by sea block was not matched well with those of total catch and CPUE, however pattern of time-series change in total zooplankton biomass was similar to that in total squid catch.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.31-38
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• 1997

Changes in bile acid binding rapacity in vitro and physical properties of alginate extracted from sea tangle (Laminaria spp.) and residue after extracting alginate (RAEA) were investigated. For the purpose, extraction conditions controlled under 1, 3 and $5\%$ of sodium carbonate solution, and 1, 3, 5 and 10 hours of extraction time at $60^{\circ}C$. The less sea tangle had particle size and the higher concentration of sodium carbonate solution increseded, the more yield of alginate gained. High concentration of sodium carbonate solution and long extraction time resulted in weakly binding capacity in vitro by alginate. Among four bile acids, binding capacites with alginate were in the order of cholic, taurocholic acid>glycocholic acid>deoxycholic acid. The binding capacity of RAEA was rated at almost same degree of alginate. For increasing the binding capacity of bile acids by alginate, it was subject to high viscosity and degree of polymerization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.161-171
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• 1970

1. The higher the temperature of the sea water, and the smaller the size of the oriental brown shrimp, the higher the feeding rate of the shrimp will be as long as the temperature ranges from $19^{\circ}\;to\;30^{\circ}C$, and each shrimp weighs from 1.6 to 14.9 grams. The average daily feeding rate is between 18 to 44 percent. 2. The nighttime feeding rate is always higher than the daytime feeding rate. However, the daytime feeding rate can be raised to from 22 to 37 percent of the daily feeding rate iii the non-sediment, dark or direct-sunshine-shielded conditions. Growth can thus be accelerated to that extent under such conditions. 3. When anchovy and short-necked clam meats were simultaneously used as food, a greater quantity of anchovy meat was consumed than short-necked clam meat both during the daytime and nighttime. When anchovy and short-necked clam meats were simultaneously given, the averaged daily feeding rates of anchovy and short-necked clam meats were 12.9 percent and 10.3 percent, respectively. 4. The following equation applies to the relationship between the freight of the oriental brown shrimp (W in grams) and their daily growth rate (DGR in percent): log DGR=0.7035-0.7864 log W. The daily growth rate is in inverse proportion to the size of the shrimp. 5. The efficiency of food conversion of the oriental brown shrimp fluctuates between 2.8 and 7.8 percent without extensive difference depending on the size of the shrimp. This was very small as compared with the corresponding figures so far known for fish and cuttlefish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.227-234
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• 1985

The present study was carried out for making clear the organic acids composition of some shellfishes and their boiled-dried products. Three species of shellfish such as top shell, hard clam and abalone were chosen as the experimental samples and analysed for their nonvolatile organic acids composition by gas liquid chromatography (GLC). Eight kinds of nonvolatile organic acid were identified in raw and boiled-dried top shell, major ones were succinic, malic and pyroglutamic acid. Out of nine kinds of nonvolatile acid was determined in raw and boiled-dried of hard clam, abundant ones were succinic, lactic and malic acid, And seven kinds of nonvolatile organic acid were detected in boiled-dried abalone while eight kinds in raw sample, abundant ones were succinic, lactic and pyroglutamic acid, respectively. In all samples, the total amount of nonvolatile organic acid was the most abundant in hard clam while the least in abalone, and the content of succinic acid was appeared as the most abundant one. In dried samples, the total amount of the nonvolatile organic acid was determined to be about half-decrease after the boiled-dried treatment of the raw samples, of which abalone showed the highest decreasing을 rate whereas hard clam was the lowest. In general, the decreasing rate of each acid was the higher in fumaric, malic and citric acid than in maleic, oxalic and succinic acid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.1
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• pp.47-54
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• 1984

From the four tuna purse seiners operating in the western equatorial Pacific waters 370 tuna schools were sampled on attribute of the school, fishing operation of purse seine sit and catch. The data were tabulated and subjected to the statistical tests of independency on the associated object and availability of the school, and catch per set of purse seine fishery as well. The resultant inferences are as follows. 1. Most frequent attributes of the tuna schools found on the surface are associated with sea birds, bait fishes and the flotsams. 2. In fishing operations of purse seine sets on the flotsam-associated schools, the settings were more frequently performed at dawn than in day-time. In fishing operations on the sea-birds-associated schools, the siftings were more frequent in day-time than at dawn. 3. From the flotsam-associated schools the successful sets were significantly more frequent. 4. In the fishing operations of purse seine sets, some of the flotsam-associated schools were subjected to the supplementary sets in success to the initial sets until the schools were consummated. 5. The fish-attracting effect of the flotsam is correlated with structure of the flotsam, but not with length of the flotsam. The flotsams, which tend to attract large tuna schools are the complicated-structure flotsams, i, e. driftwoods with roots or branches or with both of them, otherwise a bunch of uprooted bamboo shrubs, while a log without roots and branches tend to be an attractant inferior to the flotsam of complicated structure.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.71-76
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• 2001

Recently, sludge disposal becomes one of the most serious environmental problems. Because the landfilling and ocean dumping of sludge materials will be prohibited in the near future, the proper treatment?disposal methods should be investigated. Also, oyster shells, piled at the coast, cause adverse effects in coastal fishery, public water surface, natural landscape, public health and so on. Thus, the purpose of this study is to evaluate the dissolution characteristic of metal compounds during soil application experiment using sewage treatment sludge mixed with oyster shells. The dissolution experiment conducted 100days under artificial rainfall and farming soil, mixed with sewage treatment sludge and oyster shells, was put into the pots(approx. 0.5L). The results from dissolution experiment as follows. 1. K, Na was $5{\sim}20mg/{\ell}$, and Ca was less than $90mg/{\ell}$. 2. Heavy metals such as Cd, Cu, As, Pb, Cr, Hg are dissoluted far less than the soil pollution guideline. The application of sewage sludge mixed with oyster shells increases pH(soil acidity)and buffer capacity(CEC) of farming soil, and heavy metals are thought to be attached to soil as insoluble forms.