• Journal of Nutrition and Health
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• v.38 no.1
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• pp.20-29
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• 2005

This study is conducted to determine the effects of dietary levels of corn and tuna oils on the formation of preneoplastic lesions in die-thylnitrosamine (DEN) induced rat hepatocarcinogenesis. Weanling male Sprague-Dawley rats were fed 2.5, 5, 15, 25% (w/w) corn or tuna oils. Hepatocellular carcinogenesis was induced by DEN (200 mg/kg body weight) and two-thirds partial hepactectomy was carried out 3 weeks later and were sacrificed 8 weeks after DEN initiation. Tuna oil group showed smaller area of placental glutathione S-transferase (GST-P) positive foci than com oil group. Com oil group of 25% (w/w) showed the widest area of GST -P positive foci, and tuna oil group showed significantly smaller area of GST-P positive foci than com oil in 25% (w/w) level but had no differences between oil levels. Thio-barbituric acid reactive substances (TBARS) content was the highest in 25% (w/w) level of tuna oil group fed long chain and highly polyunsaturated fatty acids. Also serum ${\gamma}$ -glutamyltranspeptidase (GGT) activities in 25% level of tuna oil group were significantly higher than by other levels. As oil contents increased, glucose 6-phosphatase (G6Pase) seems to decrease in com oil groups but remained the same in tuna oil groups. Glutathione reductase (GR) activities were significantly higher in tuna oil group, and the higher the level of tuna oil, the higher GR activities. But Cu/Zn superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities didn't seem to be influenced by levels and kind of dietary fats. Therefore, as oil levels increased, com oil rich in n-6 fatty acids promoted carcinogenesis but tuna oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of n-3 fatty acids suppressed. Although lipid peroxidation products were elevated in 25% (w/w) tuna oil group, GST-P positive foci didn't increase. Therefore pre-neoplastic lesions might be reduced through mediation of a lipid peroxidation process in tuna oil. As fat contents of tuna oil increased, elevated GR activities may give a rise to produce more reduced glutathione in order to protect against free radical attack, and high G6Pase activities remained the same and they contributed to membrane stability. So tuna oil diet seems to protect hepatocarcinogenesis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.3
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• pp.95-100
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• 2006

Synthesis of the non-swelling property micas was carried out by hydrothermal method. In order to artificially induce the diffusion of ions, a rotating system was attached to the hydrothermal apparatus and by adding 0.7 mm zircon beads, synthesis of the non-swelling property micas could be performed in a low temperature area. The hydrothermal conditions for the preparation of micas were a reaction temperature of $260^{\circ}C$, for 72 hrs, using $1K_2O,\;1Al(OH)_3,\;4Mg(OH)_2\;and\;6SiO_2$ as the starting materials and a 8M-KOH solution as the hydrothermal solvent. The micas obtained under these conditions were a plate shape with a size of $2.89{\mu}m$ and showed a whiteness of over 97 %. Also, through the FT-IR analysis, because the absorption peak of the $Mg_3OH$ vibration was observed at approximately $3700cm^{-1}$, it could be known that it was phlogopite of non-swelling property showing the chemical composition of $KMg_3AlSi_3O_{10}(OH)_2$. This result was very consistent with the EDS analysis where O (41.34 %), Mg (3.88 %), Al (11.45 %), Si (17.62 %) and K (25.71%) elements were detected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.635-641
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• 2000

In order to utilize the protein source from a fish proessing by-product, cod was hydrolyzed with various enzymes such as tuna pyloric caeca crude enzyme (TPCCE), a-chymotrypsin, trypsin, papain and pronase E. The TPCCE hydrolysate acquired the highest sensory properties on taste, odor and color. The resultant cod rfame protein hydrolysate (CFPH) which was hydrolyzed with TPCCE, was separated through a series of ultrafiltration membranes with molecular weight cut-off (MWCO) of 30, 10, 5 and 1 kDa, and four types of permeates in cluding 30 K (permeate from 30 kDa membrane), 10 K (permeate from 10 kDa membrane), 5 K (permeate from 5 kDa membrane) and 1 K (permeate from 1 kDa membrane) were obtained. The natural sauces were prepared with 30 K, 10 K, 5 K and 1 K hydrolysate, and the sauce prepared with 1 K hydrolysate was the best score in sensory evaluations. In addition the mixed sauce prepared with 1 K hydrolysate and commercial soy sauce was similar to commercial sauce in sensory properties. These results suggest that the mixed sauce would be utilized as the substitute of acid-hydrolysis sauce.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.546-555
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• 1996

Level of nitrogenous compounds in dried shellfish related to the formation of flavors during processing and storage was investigated. Fresh samples of blue mussel, short-necked calm and pacific oyster showed relatively low levels of ATP, ADP and AMP, but high levels of iMP and inosine. Relatively high content of TMAO in fresh samples was markedly reduced in the samples broiled samples, but TMA content was rather elevated in the samples broiled, which was a lowered result of TMAO content. The degree of reduction of TMAO and enhancement of TMA contents was relatively small in the hot-air dried samples during storage periods. Glycinebetaine content in fresh samples was slightly decreased by boiling and broiling. Contrast to glycinebetaine content, hormaline and trigonelline contents were severely reduced by boiling and broiling. Twenty-nine kinds of amino acids and their derivatives were identified in the sample of blue mussel, short-necked calm. Among them, glycine, alanine, arginine, glutamic acid and lysine were major amino acids, but contents of these amino acids was greatly decreased in the samples after drying and boiling processes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.776-784
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• 2014

Tuna cooking juice concentrate (TCJC) is by-produced during the canning processing of skipjack tuna Katsuwonus pelamis and it is well known that TCJC contains various nutritional components. Therefore, the immuno-stimulating activity of TCJC was investigated using macrophage RAW 264.7 cell line and the spleen cell isolated from BALB/c mice. The TCJC increased the production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ in a dose-dependent manner compared to the control in RAW 264.7 cells without any toxicity. In particular, the production of TNF-${\alpha}$ was increased over 300-fold. The production of both Th1 cytokine (such as IFN-${\gamma}$, TNF-${\alpha}$, IL-2, and IL-12) and Th2 cytokine (IL-4, IL-6, IL-10) was also increased by TCJC treatment in splenocytes. Moreover, the TCJC increased the splenocyte proliferation in a concentration-dependent manner compared to control. These results indicate that TCJC may enhance immune function by promoting various cytokine production.

• KSBB Journal
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• v.23 no.6
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• pp.489-493
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• 2008

Although the seafood cooking drips were the byproducts from the fishery industry and being wasted, it had many nutrients including proteins. In this study, the effect of a gamma irradiation on the cooking drips from Hizikia fusiformis, Enteroctopus dofleni and Thunnus thynnus were investigated. The cooking drips were extracted with 70% ethanol solution, and the extracts were analysed for the protein concentration by three different methods of Lowry, BCA and Kjeldahl. The extracts were irradiated with different doses and the protein contents were compared with respect to the absorbed doses. Total content of the proteins was increased with increasing irradiation dose. The change of protein pattern in the irradiated cooking drips was also confirmed by SDS-PAGE analysis. These results shown that the proteins in cooking drips could be unfolded or aggregated by the irradiation. Therefore, gamma irradiation could be considered as an effective method for extracting useful proteins.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.96-105
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• 2019

The mugilidae fishes are common euryhaline species that live in coastal marine waters to freshwater areas. The taxonomy and nomenclature of the mugilidae fishes still remain unresolved because of their morphological similarities. Among the mugilidae fishes, most commonly consumed in Korea, are grey mullet (Mugil cephalus) and red lip mullet (Chelon haematocheilus). It is generally called 'mullet' without distinguishing between two mullets. Therefore, the aim of this study is to examine the scientific names and common names of mullet species used in Korea from the domestic journals and Korean old documents. The scientific name of grey mullet is M. cephalus, but that of redlip mullet is C. haematocheilus. But the genus of redlip mullet is still mixed with Chelon, Mugil, and Liza. The standard name of two mullet is not distinguished in the Korean dictionary, but they were clearly distinguished in the Japanese, English, and Chinese dictionaries. In the ancient Korean references, the mullet was called 'Chieo' or 'Sueo'. In most of the old literature, the distinction between grey mullet and redlip mullet is not clear. However, in Jasaneobo, it was written separately from grey mullet and redlip mullet, and attaching "ga" was different from now. The Korean standard name of redlip mullet is 'gasungeo', however, the fishermen in Jeollado and Gyoungsangdo call it 'chamsungeo'. Considering the negative perception of 'ga' character, it is proposed to change 'cham(眞)' instead of 'ga(假)' to improve economic value of red lip mullet.

• Korea Trade Review
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• v.48 no.2
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• pp.129-151
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• 2023

This study explores whether market share matters for ERPT and also for the effects of FTA on ERPT among exporting countries in the four major fishery import markets - frozen pollock, frozen mackerel, frozen tuna, and frozen spawn in South Korea. In addition, I investigate whether market share matters for price competition among exporting countries. For this, I estimate the export price equation based on the maximum likelihood method by utilizing data on export price in terms of Korean currency, and the cross rate between South Korea and the exporting countries from 2010:M1 to 2019:M12 for the four major fishery import markets. According to the findings, the market share of exporting countries in the import markets matters for the positive effects of FTA on ERPT; however, it is hard to find the relation between the market share of exporting counties and ERPT. In addition, I find little evidence on the effects of market share on price competition structures among exporting countries. I believe that this study helps domestic fishery producers to understand that ERPT, the effect of FTA on ERPT, and price competition structures among exporting countries would be affected by the market share of each exporting country in the major fishery import markets in South Korea. Also, this study would help domestic fishery producers to think about how to deal with the effects of the change in the exchange rate on fishery markets for each FTA partner according to its market share after FTA is effective.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.2
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• pp.116-121
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• 2024

The meats of tuna Thunnus albacares and swordfish Xiphias gladius are ideal for fish patty production, offering high nutrition and other health benefits. Although red fish meat, including tuna, is added for cost-effectiveness, swordfish white meat is also used, as its aroma resembles that of market-sold beef patties. Here, we assessed the different blending ratios of tuna red meat and swordfish white meat (60:40, 40:60, 20:80, and 0:100) to find the optimal combination for fish patty production. Regarding color, the heated fish patties exhibited increased redness (a*) and yellowness (b*) compared with those of non-heated ones, with similar brightness (L*). The heated patties also scored higher concerning hardness, springiness, gumminess, and chewiness. A higher proportion of swordfish white meat resulted in a softer texture, particularly in patties with a ratio of 40% red meat to 60% white meat. Considering the results of the texture comparison analysis, it is recommended that the texture be improved by increasing the physical property "softness." Sensory evaluations revealed that the addition of white meat led to increased scores in terms of smell, beef taste, texture, and elasticity. These results suggest that swordfish white meat, with improved overall quality, is a suitable raw material for fish patties. Accordingly, the recommended ratio of 20% tuna red meat to 80% swordfish white meat is optimal for fish patty production.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.50-55
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• 2013

Since 1 June 2012, it is prohibited to sell oilfish as a food material but there are still many illegal cases of selling oilfish as if it is tuna or grilled Patagonian toothfish. So it is absolutely crucial to construct the system to distinguish the real food material from oilfish. There are two sorts of oil fish called Ruvettus pretiosus and Lepidocybirium flavobrunneum involved in Percifomes order and Gempylidae class. 16S DNA gene region in mitochondria was selected to design the specific primers. For design species-specific primer, the theoretical experiment were performed for the sequences of R. pretiosus, L. flavobrunneum, Thunnus thynnus, Thunnus albacores, Makaira mitsukurii and Xiphias gladius, registered at the Gene bank from the National Centre for Biotechnology Information, using BioEdit 7.0.9.0. program. Through the analysis of the result from experiments, it was possible to design the 4 kinds of primers to distinguish R. pretiosus and L. flavobrunneum. As a comparison group, 3 kinds of tuna and 4 kinds of billfishes were selected and experimental verification was performed. As a result, for R. pretiosus and L. flavobrunneum, R.P-16S-006-F/R.P-16S-008-R and L.F-16S-004-F/L.F-16S-006-R primers were selected eventually and PCR condition was established. In addition, 178bp and 238bp of PCR products were confirmed from the established condition and non-specific band was not amplified among similar species. Therefore, the species-specific primers developed in this study would be very useful and used in various ways such as internet shopping mall and illegal distributions with fast and scientific results.