• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.130-136
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• 1991

In present paper, we investigated the changes in lipid components of skipjack and Alaska pollack meat by thermal processing at high temperature. TBA values and peroxide values of both fish meats decreased markedly by heat treatment; decreasing range of TBA and peroxide values in skipjack meat was larger than those of Alaska pollack meat. Also carbonyl value of skipjack meat was decreased by thermal processing, contrary, that of Alaska pollack meat was increased. Total lipid(TL) of skipjack and Alaska pollack meat consisted of $61.9\%,\;49.6\%$ non-polar lipid(NL), $38.1\%,\;50.4\%$ polar lipid(PL), respectively. When the samples were heated at the Fo values of 5 or higher, contents of NL were increased, while that of PL were decreased. In fatty acid composition of NL and PL in both fishes, NL revealed higher contents in saturates and monoenes such as 16:0, 18:1, while PL showed higher contents in polyenes such as 20:5, 22:6; percentages of polyenes such as 22:6 especially in both fishes decreased with increasing of Fo values. The remaining ratio of PUFA(20:5+22:6/16:0) of Fo 20 samples in skipjack and Alaska pollack meat were $73\%$ and $65\%$, respectively. However, when the samples were heated at $98^{\circ}C$ for 30 minutes, no appreciable changes occured in fatty acid composition of TL, NL and PL in both fish meats examined.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.864-875
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• 2015

This study investigated the sanitary characteristics of commercial salted semi-dried convict grouper Epinephelus septemfasciatus (SSD-CG) and longneck croaker Pseudotolithus typus (SSD-LC) and suggested standards for salted semi-dried fish (SSD-F), based on the domestic standards for salted mackerel (Scomber japonicus or kwamegi) and salted dried yellow corvenia (Pseudosciaena manchurica), and sanitary characteristics of commercial SSD-F. For the commercial SSD-CG and SSD-LC, respectively, the moisture content ranged from 64.6-76.1 and 65.7-77.5%, salinity from 2.7-8.2 and 1.5-4.9%, volatile basic nitrogen (VBN) from 22.1-88.2 and 13.5-87.4 mg/100 g, peroxide value (POV) from 17.2-195.0 and 28.5-190.2 mEq/kg, and viable cell counts from 6.1-8.4 and 5.4-7.2 log (CFU/g). No Escherichia coli was detected in six kinds of SSD-CG or three kinds of SSD-LC. The standard for controlling the quality of SSD-F is the moisture content (>68%), salinity (>3%), VBN content (>50 mg/100 g), POV (>60 mEq/kg), viable cell counts (>$10^6$ CFU/g), E. coli (>MPN/100 g), and others. Using the established standards, no commercial SSD-F passed. The chemical, microbial, and other results for commercial SSD-F suggest that provisions for controlling the quality of high-quality SSD-F should be established.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.713-717
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• 1999

In order to utilize protein hydrolysate produced from hoki (Johnius Belengeri) frame among many different fish processing wastes, hoki frame peptide (PHFP) and phosphorylated hoki frame peptide (PHFP) were prepared, and their calcium absorption accelerating effects were investigated in comparison to control and casein phosphopeptide (CPP). In in vitro experiment, HFP and PHFP inhibited calcium phosphate formation as high as 1.5-fold and 2.5-fold, respectively, comparing to control, In addition, the inhibition rate of calcium phosphate precipitation as increasing concentrations of HFP and PHFP was risen and was similar to that of CPP at 2.0 mg/ml of PHFP concentration, In in vivo experiment using the rats, the groups fed HFP and PHFP indicated significantly increased calcium content in the femur. In particular, the calcium content in the small intestine of the rat fed PHFP was higher than that of control group by approximately $60\%$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.598-605
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• 2010

This study investigated the physicochemical and enzymatic properties of unmarketable bastard halibut (Paralichthys olivaceus) cultured in different regions (i.e., Jeju, Wando, and Geoje) as a potential source of surimi and surimi gel. The proximate composition of unmarketable bastard halibut cultured in different regions did not differ significantly at P<0.05. Compared to Alaska pollock muscle, all of the unmarketable bastard halibut muscle had a 4% higher crude protein content and 5% lower moisture content. The collagen content of bastard halibut muscle cultured in Jeju was 1.96 g/100 g, which was higher than in fish cultured in other regions. Regardless of the region where cultured or pH, the enzymatic activities of the crude extracts from unmarketable bastard halibut muscle ranged from 0.30.0.48 U/mg for casein and hemoglobin, 11.9.13.7 U/mg for LeuPNA, 5.6.6.7 U/mg for ArgPNA, 2.8.4.7 U/mg for SAAPFNA, and 0.1.0.2 U/mg for BAPNA. Regardless of region, no mercury or lead was found in any of the unmarketable bastard halibut muscle, except for lead in fish cultured in Geoje. The strength of surimi gels from unmarketable bastard halibut cultured in Jeju, Geoje, and Wando was 1059, 988, and 900 g${\times}$cm, respectively. The surimi gel from unmarketable bastard halibut cultured in Jeju was stronger than commercial Alaska pollock surimi, which was grade SA.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.541-548
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• 2010

In this study, contamination levels of 7 N-nitrosamine were investigated in processed meat products (n=51), processed fish products (n=62), salted fish pickles (n=20), and beer and malt beverages (n=21) using a GC/PCI-MS/MS method. The limits of detection (LOD) of the N-nitrosamines ranged from 0.2 to 0.5 ${\mu}g$/kg. In addition, methods were used to estimate the recovery of 7 N-nitrosamines, which ranged from 84 to 112%. N-nitrosamines were detected in 89 (58%) out of 154 samples. The exposure of an entire population group to N-nitrosamines through food intake was estimated using the average body weight of the total population and average daily food consumption, to perform risk assessment based on reports of a national health and nutrition survey. The results indicated that the daily intake of N-nitrosamines over a life time was $4.92{\times}10^{-7}$ mg/kg b.w./day. The margin of exposure (MOE) for the general population, estimated using the benchmark dose lower confidence limit 10 ($BMDL_{10}$) of N-nitrosodimethylamine, was 208,939, which was found to be safe.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1427-1433
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• 1999

The Microbiological, chemical and sensory analyses were carried to evaluate the quality of commercial salted and fermented seafoods and to establish a standardization. The results showed that amino nitrogen(AN) and volatile basic nitrogen(VBN) contents were appropriate in evaluating the quality of shrimp jeotkal. In the range of $150{\sim}300\;mg%\;and\;25{\sim}70\;mg%$, AN and VBN contents were highly correlated to sensory scores, respectively. In the case of squid jeotkal, pH and VBN contents were appropriate to evaluate quality. The coefficients of the correlation between pH and sensory evaluation was 0.84 and the sensory acceptability was high and above pH 6.0. In addition, the coefficients of the correlation between VBN contents and sensory evaluation was 0.95, and the sensory acceptability was high but below 30 mg%. In the case of shell-fish jeotkal, the coefficient of the correlation between VBN content and sensory evaluation was 0.94, and sensory acceptability was high but below 40 mg%.

• Journal of fish pathology
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• v.25 no.3
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• pp.249-256
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• 2012

Disease occurrence and dead cell ratio of Porphyra cultivated at Seocheon area were studied. Seaweed samples were collected monthly at 12 cultivating sites of Porphyra from Nov. 2008 to Mar. 2009. Although disease occurrence was low at the beginning of cultivation at the most of collecting sites, the occurrence increased with time. The most common symptom of Porphyra disease in this area was diatom attachment, followed by white rot disease. Licmophora sp. was the most common species of diatom and its attachment was the highest on November, the beginning of cultivation. Although the occurrence ratios of green spot disease and white rot disease were high on November, chytrid disease was increased at the end of cultivation period. Dead cell ratio of Porphyra thalli was different at each study site and cultivating time, but normally the ratio was high at the end of cultivating season. The changes of dead cell ratio could be related to the nutrition supplement and currents, and the more precise reason of dead cell ratio would be revealed by further research related to cultivating environment conditions.

• Journal of fish pathology
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• v.26 no.3
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• pp.265-274
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• 2013

The growth, reproduction, gametophyte(G)/tetrasporophyte(T) ratio, and diseases of Chondrus ocellatus populations were examined at 3 sites (Samcheok, Youngduk, Pohang) of East coast and at 2 sites (Hakampo, Manripo) of West coast in between July and August, 2013. Average plant lengths were 6.10~9.69 cm and it was minimum at Manripo and maximum at Pohang population. In general, average plant length and weight of C. ocellatus were greater on East coast than West coast populations. The proportion of vegetative plant was between 26.7~66.7 %, and G/T ratio of total plants including vegetative plants after testing resorcinol method was 3:2 on the East coast where is gametophyte dominant area. However, G/T ratio was 1:1 at Hakampo and 1:2.3 at Manripo representing tetrasporophyte dominance. In the present study, Korean C. ocellatus have various diseases (white colour and green colour), an endophytic alga(Ulvella sp.), and many epiphytic macroalgae and diatoms. Healthy C. ocellatus plants were about 20~40 % in summer population and most of plants had disease. Chondrus ocellatus had a filamentous green alga, endophytic Ulvella sp. which was not identified. The endophyte is easily observed in C. crispus growing in Europe and Canada and it is recognised as a pathogen destroying population and reducing yield of C. crispus. Thus more interest and research on the endophytic algae and disease of C. ocellatus are required.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.520-524
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• 1999

The rose bitterling (Rhodeus uyekii), aboriginal fish of Korea, have beautiful nuptial colors on the body and fins in their spawning season. So, this species has high possibility to become a new ornamental Bish. However, nothing is known about the color composition of body colors of this species. Therefore, this study was conducted to investigate the color component of the skin and fins of the bitterling collected from natural environment. The major component of the nuptial colors was carotenoids according to the present study. Amount of total carotenoids on the skin and fins, had a tendency to be higher during the spawning season than the non-spawning season; it was $44.9mg\%$ during spawning season and $41.8mg\%$ during non-spawning season. The composition of carotenoid during spawning season was $36.7\%$ of zeaxanthin $30.1\%$ of $\beta$-carotene, and $16.4\%$ of diatoxanthin. The composition of carotenoid during non-spawning season was $41.2\%$ of $\beta$-carotene, $18.1\%$ of diatoxanthin, and $14.0\%$ of isocryptoxanthin. The major component of the carotenoid during spawning season turned out to be zeaxanthin while the major component of the carotenoid during non-spawning season was $\beta$-carotene.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.606-614
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• 2023

This study was conducted to optimize the size of olive flounder Paralichthys olivaceus (OF) as a material of sikhae and to investigate the quality characteristics. The results on the protease activity of OF meat, protein and ash contents of the bone, and yields and hardness of fish bone during fermentation time suggest that the suitable fish weight for sikhae was less than 250 g. The proximate compositions of the OF sikhae fermented under optimum condition (fermentation for 9 days at 15℃), were 73.0% moisture, 12.0% crude protein, 1.3% crude fat and 2.4% ash. The salinity, titration acidity and amino acid nitrogen contents per 100 g sikhae were 1.7 g, 2.46 g, and 311.3 mg, respectively. The lactic acid bacteria concentration in the sikhae were 8.84 log CFU/g, which were higher than those (5.78-6.62 log CFU/g) of 5 kind of commercial flounder sikhae. The functional properties, such as ACE inhibitory activity (69.0%), antioxidative activity (69.3%), α-glucosidase inhibitory activity (22.7%), xanthine oxidase inhibitory activity (88.2%), and nitrite scavenging activity (96.4%) of the sikhae were superior to those of 5 kind of commercial flounder sikhae.