• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.4 no.4
• /
• pp.146-153
• /
• 2023

This study aimed to conduct a comprehensive survey of social wasp diversity and its impacts on remote Ulleungdo Island, South Korea. A total of 12 wasp traps were placed across the island, and specimens were collected monthly from May to October. Additional collection was conducted by thoroughly inspecting the areas surrounding the traps. The traps yielded a total of 5,068 individuals, representing two genera and two species. A total of 3,961 Vespa simillima simillima Smith individuals (78.2%) were collected, and 1,107 individuals (21.8%) were identified as Vespula flaviceps flaviceps Smith. Additionally, five individuals of Polistes snelleni de Saussure were collected through sweeping, bringing the total to 5,132 individuals of three genera and three species. It is worth noting that our findings indicate potential misidentifications in the species list of Vespidae found in the literature. Emergency services call centers reported the removal of 60 social wasp nests on Ulleungdo Island between 2018 and 2022, with the highest number of reports occurring from July to September, accounting for 87% of all cases. Dodong-ri and Jeodong-ri, with the highest populations, reported the most incidents, although fortunately, there have been no recent injuries. Past incidents involving the destruction of dried squid products by Vespula species have resulted in significant economic losses, underscoring the need for preventative measures. Furthermore, ongoing surveillance of hornet invasions is essential to safeguard the Jangwon bees being reared on Ulleungdo Island.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.26 no.6
• /
• pp.1063-1067
• /
• 1997

This study was performed to assess the levels of the trace elements(Fe, Cu, Zn, Cr, Co, Mn, Pb, and Cd) in salt-fermented fish products from some areas of the west coast in Korea. Seven samples were Shrimp(Seawoo-jeot), Clam(Jogai-jeot), Oyster(Orikul-jeot), big eyed horring(Bendeng-ie jeot), Mysis(Gonjeng-ie jeot), Hwangandali(Hwangsegi-jeot), and Squid, Han Chi(Han chi-jeot). They were ashed with ternary solution. After ashing the samples, the amount of trace elements in the samples were measured by ICP. The moisture content of the 7 samples before freezing dry were 68.36, 71.52, 81.19, 62.27, 71.30, 64.27, and 66.74%, respectively. Jogai-jeot and Gonjeng-ie jeot contained the most amount of moisture among the samples. Fe contents were 66.46, 309.10, 27.03, 23.01, 132.45, 35.75, and 9.72ppm, respectively. Jogai-jeot contained the most amount of Fe among the samples. Cu contents were 4.60, 4.36, 3.75, 2.21, 10.36, 2.71, and 58.15ppm, respectively. Hanchi-jeot contained the most amount of Cu among the samples. Zn contents were 16.02, 75.06, 37.43, 28.43, 132.45, 35.75, and 9.72ppm, respectively. Gonjeng-ie jeot contained the most amount of Zn among the samples. Cr contents were 0.80, 1.61, 0.84, 0.96, 1.12, 0.96, and 0.59ppm, respectively. Jogai-jeot contained the most amount of Cr among the samples. Co contents were 0.13, 0.54, 0.31, 0.46, 0.50, 0.63, and 0.35ppm, respectively. Hwangsegi-jeot contained the most amount of Co among the samples. Mn contents were 7.30, 10.69, 14.87, 4.12, 8.03, 2.94 and 1.54ppm, respectively. Origkul-jeot contained the most amount of Mn among the samples. Pb contents were 1.80, 4.30, 2.53, 4.61, 3.08, 5.04, and 2.74ppm, respectively. Hwangsegi-jeot contained the most amount of Pb among the samples. Cd contents were 0.005, 0.03, 0.06, 0.005, 0.01, 0.00, and 0.10ppm, respectively. Hanchi-jeot contained the most amount of Cd among the samples. This study is limited within 7 samples caught and producted from the some areas of the west coast in Korea. Therefore, I hope there will be broader experiments concerned with this study to make clear not only nutritional aspect(the contents of Fe, Cu, Zn, Cr, Co, and Mn) but also toxicological aspect(the contents of Pb and Cd).

• Analytical Science and Technology
• /
• v.22 no.4
• /
• pp.336-344
• /
• 2009

This survey was carried out to estimate the contents of heavy metals (Hg, Pb, Cd, and As) in 10 kinds of dried marine products (n=189) which are closely related to food resources. The contents of heavy metals were estimated by inductively coupled plasma spectrometer (ICP) and mercury analyzer. The values of heavy metals in dried marine products were as follows (Mean${\pm}$SD (range), mg/kg). The average contents of heavy metals in the dried marine products were Hg $0.058{\pm}0.069$ (0.002~0.502) mg/kg, Pb $0.178{\pm}0.598$ (ND~5.130) mg/kg, Cd $0.306{\pm}0.610$ (ND~6.802) mg/kg, As $5.282{\pm}6.158$ (ND~71.760) mg/kg. The range of heavy metal contents in dried marine products are low level, except of lead contents (n=2). In the comparison of heavy metal content by anchovy size, it was shown that cadmium, mercury and arsenic were meaningfully different. The contents of heavy metals by the shape of shrimp and Alaska Pollack were shown that the result of each group was meaningless. In the comparison imported production with domestic production, in the case of common squid, cadmium and arsenic were meaningfully different. The weekly average intakes of Hg, Pb and Cd from dried marine products takes about 1.17~11.52% of PTWI (Provisional Tolerable Weekly Intakes) that FAO/WHO Joint Food Additive and Contaminants Committee has set to evaluate their safeties.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.8
• /
• pp.2408-2412
• /
• 2013

We demonstrate herein the synthesis and modification of magnetic nanoparticles and its use in the immobilization of the lipase. Magnetic $Fe_3O_4$ nanoparticles (MNPs) were prepared by simple co-precipitation method in aqueous medium and then subsequently modified with tetraethyl orthosilicate (TEOS) and 3-aminopropyl triethylenesilane (APTES). Silanization magnetic nanoparticles (SMNP) and amino magnetic nanomicrosphere (AMNP) were synthesized successfully. The morphology, structure, magnetic property and chemical composition of the synthetic MNP and its derivatives were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) analysis, X-ray diffraction, superconducting quantum interference device (SQUID) and thermogravimetric analyses (TGA). All of these three nanoparticles exhibited good crystallization performance, apparent superparamagnetism, and the saturation magnetization of MNP, SMNP, AMNP were 47.9 emu/g, 33.0 emu/g and 19.5 emu/g, respectively. The amino content was 5.66%. The AMNP was used to immobilize lipase, and the maximum adsorption capacity of the protein was 26.3 mg/g. The maximum maintained activity (88 percent) was achieved while the amount of immobilized lipase was 23.7 mg $g^{-1}$. Immobilization of enzyme on the magnetic nanoparticles can facilitate the isolation of reaction products from reaction mixture and thus lowers the cost of enzyme application.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.6
• /
• pp.1010-1015
• /
• 1995

Extent of reduction in protein digestibility by Godulbaegi(lxeris sonchifolia H.) kimchi powder appeared to be related to the kimchi weight-to-protein weight ratio, the kind of protein sources, part of plants and fementation period. In vitro digestibilities of protein were significantly(p<0.05) reduced as the freeze dried kimchi powder weight-to-protein ration increased from 0.5 : 1.0 to 1.0 : 1.0 for all Godulbaegi samples and protein sources. Overall digestibility of protein sources in the presence of kimchi powder, the reduction ranked in the following order : soybean>casein>beef>squid. Lower(p<0.005) reduction occurred for each protein source when raw plant was exchanged for kimchi products. Some greater reduction of digestibility was noted in young plants and leaf samples than ripe or root samples. Trypsin inhibitor, which expressed as soybena trypsin inhibitor, was inversely related(r=0.8437) to in vitro protein digestibility of casein in the presence of Godulbaegi kimchi powder. More than three times of total polyphenols contained in leaves than in roots. Young leaves had 30% more total polyphenols(37.64mg/g sample) than that in ripe ones. Soaking in 5% NaCl solution for 24 hrs was markedly reduced in total polyphenols as 73% for leaves and 33% for roots. Remarkable reduction in total polyphenols was not checked during fermentation followed after soaking. Trypsin inhibitor content correlated well(r=0.8873) with total polyphenols in all of Godulbaegi samples.

• Journal of the Society of Disaster Information
• /
• v.18 no.1
• /
• pp.194-201
• /
• 2022

Purpose: This study investigated the relationship between climate factors and the catches in Korean offshore fisheries in recent three decades (1981 to 2010). Method: This study focused on seven types of fish species preferred in Korean cuisine. In the study, 10-year moving averages were used so that long-term trends could be easily identified. Results: Both air temperature and sea surface temperature (SST) on the coast of Korea rose in the period (p < 0.05). The rise in SST was significantly correlated with the rise in air temperature (p < 0.05), but not with precipitation. In the 2010s compared to in the 1981, catches of anchovy and squid greatly increased (p < 0.05), while catches of Alaska / walleye pollock has been almost extinct over the past 30 years. As such, cold-water fish species decreased or disappeared, and their fishing ground was replaced by warm-water fish species. Conclusions: These findings indicate that fish species caught in offshore fisheries of Korea have changed due to climate change, especially warming. This suggests that the warming of the Korean Peninsula may have a significant impact on the supply of fishery products and food security to Koreans in the near future.

• Applied Biological Chemistry
• /
• v.41 no.1
• /
• pp.67-72
• /
• 1998

As a part of basic investigation for utilizing by-products derived from seafood processing as a food source, a chemical characteristics of fish bones (cod bone, Alaska pollack bone, yellowfin sole bone, hoki bone, conger eel bone and mackerel bone) were investigated. The crude protein (40.7% on the dry basis) and collagen contents (5.86%, on the dry basis), imino acid composition (189 residues/1,000 residues) of hoki bone were higher than those of the other fish bones, but were lower than those of the animal bone. The crude lipid contents and EPA and DHA compositions of yellowfin sole, conger eel and mackerel bones were $22.8{\sim}43.9%$ on the dry basis and $15.6{\sim}23.8%$, respectively and were lower than those of squid viscera. The major ash components of the fish bones were found to be calcium and phosphorus and the contents in 100 g crude ash were $37.1{\sim}38.6%$ and $18.0{\sim}18.5%$ respectively. The calcium and phosphorus contents in 100 g crude ash of cod and Alaska pollack bones were more than those of the animal bones, as well as the others. It may be concluded, front these results, hoki bone can be effectively utilized as a processing materal of collagen or gelatin and cod and Alaska pollack bones as a calcium source.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.147-153
• /
• 1982

Nitrate and nitrite, which readily produce N-nitrosamines by reaction with secondary amines, are widely distributed in natural products such as vegetables and cereals, and are also used as a color fixation in meat products or fish roes. This experiment was carried out to determine the contents of nitrate and nitrite in foods such as fermented sea foods and fresh vegetables purchased at markets in Korea. The contents of nitrate were $0.74\sim13.81\;ppm$ for fermented sea foods and $4.0\sim1,572.5\;ppm$for fresh vegetables. As for vegetables, the nitrate levels of edible herbs were relatively higher than those of greens, fruits and rootcrops. The nitrite contents in fermented demoisells(Chromis notatus), fermented shrimp, fermented small squid, fermented anchovy and salted Alaska pollack roe were very little, while those in fermented hairtail and fermented entrails were not detected. As for vegetables, nitrite levels found for cabbage and lettuce were relatively as high as 3.8 ppm and $2.5\sim2.9\;ppm$, respectively, but were not detected in Korean cabbage, green perilla leaf, pepper, garlic and burdock. Of vegetables, the nitrate values in the outer part of Korean cabbage, stems of water cress and leaves of green onion were higher than in the other parts. Little variety of the nitrate levels were found during 4 days storage. In the comparison of low temperature storage and room temperature storage, lettuce, pumpkin and spinach contained higher levels of nitrate at low temperature storage, while eggplant and green onion, at room temperature storage.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.4
• /
• pp.470-475
• /
• 1999

This study was conducted to evaluate the utilization of animal by-product mixture (ABPM) as a dietary animal protein source of fish meal replacer, and to determine the effect of dietary chromic oxide in growing rainbow trout, Oncorhynchus mykiss. ABPM is a mixture of five anmial by-products such as meat and bone meal (MBM) feather meal (FM), squid live, powder(SLP), poultry by-product (PBP) and blood- meal (BM) at a specific weight based ratio. Diet 1 and 2 were formulated on a isonitrogenous and a isocaloric basis of $46.5\%$ crude protein and 16.7 KJ/g diet; diet 1 (WFM 100), $100\%$ of the animal protein source came from white fish meal; diet 2 (ABPM 40), $60\%$ WFM+$40\%$ ABPM as the animal protein source; diet 3 (-Cr) commercial diet without chromic oxide; diet 4 (+Cr), commercial diet with chromic oxide. After eight weeks of feeding trials, fish fed diet 2 had a significantly lower body weight gain (WG) and feed efficiency (FE) than that of fish fed the other diets (P<0.05). When comparing diet 3 with diet 4, no significant differences were found in WG and FE (P>0.05). There were no significant differences on condition factor, hematocrit level, serum phosphorus, bone phosphorus, whole body phosphorus, and bone ash among fish from all four diet groups. Fish fed diet 4 had a significantly higher whole body lipid than that of fish fed the other diets (P<0.05), These results indicated that ABPM could be used less than $40\%$ in growing rainbow trout with a sufficient period of acclimation, In addition, the $0.5\%$ of chromic oxide can be used to determine the apparent digestibility of the nutrients in the feed without any adverse effects on growth and body composition.

• The Journal of the Korea Contents Association
• /
• v.22 no.10
• /
• pp.658-675
• /
• 2022

With the advent of the OTT platform, the world has become an era in which the same media content is shared and reacted in real time by being grouped into one culture. This study attempts a producer study of web novel writers, who are producers of the web novel market that is expanding into webtoons, dramas, and movies with IP (intellectual property rights) of the original story at a time when Korean K-content such as "Squid Game" and "Weird Lawyer Woo Young-woo" leads the global market. In this study, web novel writers were viewed as producers of commercial media content, not just 'Novelist', and their identities and characteristics of the labor process were examined. Web novel writers began writing web novels as a side job or two jobs, and cited the fact that they can make profits alone without barriers to entry and without incurring capital or facility costs. Although there is no barrier to entry, most writers experience severe failure in their first work, which is attributed to the misunderstanding that the word "writer" is someone who writes what they want in any genre. Web novels are different, so writers go through the process of realizing that in order to succeed by writing web novels, they must be thoroughly in the audience's shoes and write them according to the trends and codes they want. Web novel writers expressed their identity as "story sellers," "story producers," "people who can produce IP alone," and "people who satisfy fantasies that cannot be achieved in reality," and in common, there was a strong sense of being a person who provides stories and makes profits or sales. Regarding the burden of writing a huge amount of web novels, the writer with a high income expressed a generous position that "the income is higher than the effort," but ordinary writers complained of difficulties in the hard work, saying, "It seems like I am working hard on writing that I have to write constantly.