• Korean journal of food and cookery science
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• v.16 no.4
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• pp.352-357
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• 2000

This study was conducted to investigate the effect of the lipid and collagen content and drip volume on the hardness of fish meat. Red sea bream (cultured and wild) and flounder (cultured, cultured with obosan and wild) were used for this study. Textural differences between cultured and wild meats were determined by the measurements of hardness, lipid and collagen content, and drip volume. Lipid content of the dorsal muscle was higher especially in cultured red sea bream (3.32%) than in wild one. Cultured and wild flounder contained lower content of lipid than red sea bream. The content of collagen was higher in cultured flounder fed with obosan (8.37 mg/g muscle) and wild flounder (8.02 mg/g muscle) than others. Drip volume was the highest in cultured flounder fed with obosan (8.67%). The hardness of raw meat was correlated with the contents of lipid (r= -0.7063) and collagen (r= 0.8307), significantly. Cultured fish contained more lipid and less collagen than wild one. So, the hardness of these fish meats was lower than wild one. However, cultured flounder fed with obosan showed no difference in hardness compared with wild one. In the cooked meat, there was no relationship between the hardness of fish meat and the contents of lipid and collagen. But, the drip volume was significantly related with the hardness (r= 0.6870). From these results, the factors contributing the textural difference between wild and cultured fish meat would be the lipid and collagen contents, and two ways to improve the texture of cultured fish meat could be suggested. One is to lower the lipid content by feed control, and the other is to raise the collagen content by inducing more fish movement.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.549-554
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• 2001

Thermal measurements were made for connective tissues of 5 different fish muscles by using a differential scanning calorimeter(DSC), and connective tissues between muscle fibers and the cross sections of muscle fibers were observed by a light microscope. Red sea bream(cultured and wild) and flounder(cultured, cultured with obosan and wild) were used in this study. It was found that the connective tissues of cultured and frozen fish muscle required less endothermic enthalpy and the endothermic peak temperature was lower than those of wild and fresh ones when they were shrunken and denatured. Therefore, it is likely that the former are more unstable to heat than the latter. The cultured flounder fed with obosan and wild flounder which contained more collagen than cultured flounder and the wild red sea bream showed clear connective tissues between fibers. The cross-section of cultured fish muscle fiber was larger than that of wild one. From these results, collagen content and thermal properties of collagen, cross section of muscle fibers seemed to contribute to the textural difference between wild and cultured fish.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.517-522
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• 2001

Changes of nucleotides and their related compounds in raw, cooked and frozen fish muscle were studied with HPLC. Red sea bream(cultured and wild) and flounder(cultured, cultured with Obosan(equation omitted) and wild) were used for this study. In nucleotides, contents of ATP was similar to that of IMP and some of H$\times$R(inosine) and H$\times$(hypoxanthine) were existed in fresh muscle. ATP was decomposed rapidly and contents of IMP became different between cultured and wild fish after 6 hours. The content of IMP was lower in the cultured red sea bream(3.39$\mu$ mole/g) and flounder(3.17$\mu$ mole/g) than in the wi1d red sea bream(7.31$\mu$ mole/g) and flounder(5.03$\mu$ mole/g). But, the flounder cultured with Obosan contained the largest amounts of IMP After 24 hours, K values of cultured fish muscle(27.7%, 28.2%) were higher than that of wild ones(22.8%, 24.3%). The K value of cultured flounder fed with 0.3% Obosan(equation omitted)(25.7%) was between cultured and wild flounder. IMP was the one which existed the most in cooked and frozen muscle. Amounts of H$\times$R and H$\times$ were more in cooked and frozen muscle. than in raw muscle. From these results, we could suggest that the wild one was more palatable and fresher than the cultured one and the palatability of cultured one seemed to be improved depanding on the feed.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.161-166
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• 1999

The rigor-mortis progress of cultured olive flounder spiked at the brain started much faster than that of wild one. They attained full rigor state after 30 hrs at $0^{\circ}C$, 36 hrs at $5^{\circ}C$ and 50 hrs at $10^{\circ}C$ in the cultured flounder, while after 36 hrs at $0^{\circ}C$, 50 hrs at $5^{\circ}C$, and 60 hrs at $10^{\circ}C$ in the wild. ATP concentration in the muscle was around $5.9\mu mol/g$ for wild and $6.2\mu mol/g$ for cultured flounder. ATP breakdown progressed rapidly in $0^{\circ}C$ samples, followed by $5^{\circ}C$ and $10^{\circ}C$ samples. $Mg^{2+}$-ATPase activity of myofibrillar protein in the presence of 0.25mM CaCb was higher in cultured myofibri1lar protein than in wild one. $Mg^{2+}$-ATPase activities of myofibrillar protein increased during storage in samples stored at $0^{\circ}C$ and $5^{\circ}C$ while decreased in samples stored at $10^{\circ}C$. The level of breaking strength of muscle immediately after death was higher in the wild muscle than in the cultured muscle. The breaking strength reached maximum level at 10 hrs after death in both samples.

• Journal of Life Science
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• v.7 no.1
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• pp.17-23
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• 1997

This study was designed as a part of efforts to investigate the biochemical pollutant markers for diagnosis of maine pollutions by changes in cholinesterase activity of the flounder (Paralichthys olivaceus)in Yellow Sea of Korea. Acetylcholinesterase (AChE) activities in brain and muscle of cultured flounders in Yellow Sea were remarkably lower (40-50% and 40-55%, respectively)than those of wild flounder in Pohang (control) of East Sea, but AChE activities in brain and muscle of wild flounders in Yellow Sea were significantly lower(15-40% and 25-35%, respectively)than those of wild flounder in Pohang of East Sea. Butyrylcholinesterase(BChE) activities in barin and muscle of cultured flounders in Yellow Sea were remarkably lower(70-75% and 65-75%, respectively) than those of wild flounder in Pohang of East Sea, but BChE activities in barin and muscle of wild flounders in Yellow Sea were significantly lower (15-40%and 25-35%, respectively)than those of wild flounder in Pohang of East Sea. Lactate dehydrogenase (LDH) activities in serum of cultured flounders in Yellow Sea were significantly 10-50% higher than those of wild flounder in Pohang of East Sea, but LDH activities in serum of wild flounders in Yellow Sea were significantly 20-25% higher than those of wild flounder in Pohang of East Sea. It suggests that AChE and BChE activities in brain and muscle of cultured and wild flounders of Yellow Sea may be used as the most effective mean in a biochemical markers for diagnosis of pollutant effects by organophosphorus pesticides.

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.135-141
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• 2014

Olive flounder (Paralichthys olivaceus) has a great potential value for aquaculture in Korea. The theoretical sex ratio of this flounder is close to 1:1 as it is in many other type of fish. However, according to the size selection during artificial seedling production, there is a possibility of unbalanced sex ratio. The actual flounder culturing needs female seedlings because of faster growth than male in economically. However, little is known about the sex ratio of cultured flounder. The six populations consisted of three wild populations and three cultured populations were analyzed for investigating the sex ratio. The sex ratio of wild populations ranged from 1.10 to 1.93 in female and 0.52 to 0.91 in male. And the sex ratio of cultured populations ranged from 0.20 to 2.15 in female and 0.46 to 4.88 in male. This result indicated that the sex ratio of cultured flounder varies depending on the size selection method.

• Journal of fish pathology
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• v.25 no.3
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• pp.263-270
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• 2012

This study surveyed for the prevalence of parasites, bacteria and viruses in four fish species, olive flounder (Paralichthys olivaceus), red sea bream (Pagrus major), black sea bream (Acathopagrus schlegeli) and black rockfish (Sebastes schlegeli) in 2010. The survey was aimed to compare the pathogens detected from wild and cultured fish for an epidemiological study. Anisakis sp. was predominantly detected from wild olive flounder and red sea bream (58.6% and 41.7% respectively), but not from the cultured fishes, suggesting anisakid infection is rare in cultured fish. The wild fish get in contact with the anisakids through their prey such as small fishes or crustaceans which carry the anisakids; whereas the cultured fish are fed with formulated feed, free of anisakids. Bacterial detection rates from the wild fishes examined in the study were lower than those of cultured fishes. Vibrio sp. dominated among detected bacterial population in cultured olive flounder (18%). Since vibriosis is known as a secondary infection caused by other stressful factors such as parasitic infections, handling and chemical treatment, it seems that cultured olive flounder are exposed to stressful environment. Viruses diagnosed in the study showed difference in distribution between wild and cultured fishes; hirame rhabdovirus (HRV) (0.1%) and lymphocystis disease virus (LCDV) (3.9%) were detected in the cultured olive flounder, but not in the wild fish, and marine birnavirus (MBV) (1.7%) and red sea bream iridovirus (RSIV) (3.2%) were detected from the wild and cultured red sea bream, respectively. From the survey conducted, it can be concluded that even though some pathogens (Trichodina sp., Microcotyle sp., etc.) are detected from both the wild and cultured fish, pathogens such as Anisakis sp., Vibrio sp. and LCDV showed difference in distribution in the wild and cultured host of same fish species and this can be attributed to their environmental condition and feeding.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.407-413
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• 1992

Difference of carotenoid pigments in integuments of the wild and cultured flounder, Paralichthys olivaceus and yellowtail, Seriola quinqueradiata were studied. Total carotenoid contents in integuments of the wild and cultured flounder were 1.38mg% and 1.l6mg%, respectively. The main carotenoids in integuments of the wild flonder were zeaxanthin (19.22%), $\beta$-carotene type triol (17.80%), tunaxanthin C (17.77％), lutein (16.44%) and tunaxanthin B (13.70%). In addition, tunaxanthin A (5.42%), $\alpha$-cryptoxanthin (4.80%), astaxanthin (0.69%) and $\beta$-cryptoxanthin (0.24%) were also contained in small amounts. But in the cultured flounder, lutein (38.21%) and zeaxanthin (29.69%) were contained as main carotenoids. In addition, $\beta$-carotene type triol (7.80%), tunaxanthin C (7.05%), $\alpha$-cryptoxanthin (4.34%), tunaxanthin B (4.21%), as-taxanthin (2.40%) and $\beta$-cryptoxanthin (1.30%) were present in small amounts. Consequently, the wild flounder contained higher amounts of tunaxanthin and trios but contained lower amounts of lutein and zeaxanthin than the cultured flonder. The contents of carotenoids from integuments of wild and cultured yellow-tail were 1.08mg% and 0.09mg%. Wild and cultured yellowtail have similar carotenoid patterns, consisting of tunaxanthin C (44.11%, 43.37％), tunaxanthin B (33.56%, 29.23%) and tunaxanthin A (18.22%, 21.68%), respectively.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.878-882
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• 1988

The lipid components of cultured bastard(Paralichthys olivaceus) were analyzed and compared with those of wild one and flounder(Pleuronichthys cornutus). Total lipid(TL) content of dorsal muscle in wild and cultured bastard, flounder was 2.0%, 1.6%, and 1.9%, respectively. Wild bastard and flounder were higher in neutral lipid(NL) and glycolipid(GL) contents, while lower in phospholipid(PL) content than those of cultured one. The NL was mainly consisted of triglyceride(70.7-72.6%), and PL was mainly occupied by phosphatidylcholine(53.6-58.3%), phosphatidyl-ethanolamine(25.9-29.5%). In fatty acid composition of TL, cultured bastard showed higher content in polyenes such as docosahexaenoic acid. and lower in monoenes such as palmitoleic, oleic acid than those of wild one. Flounder was higher in Percentage of arachidonic, eicosapentaenoic acid compard with bastard. The major fatty acids of these fishes were palmitic, docosahexaenoic, oleic, eicosapentaenoic and palmitoleic acid in order. These fatty acid composition of NL, GL and PL fractions were not significantly different among wild and cultured bastard, flounder.

• Journal of Aquaculture
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• v.7 no.2
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• pp.109-122
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• 1994

The cultured olive flounder larvae given nutrient enriched rotifer, Artemia nauplii and commertial micro diet were investigated the changes of lipid content, fatty acid composition and vitamin E content in whole body with growth stages in order to compare with those of the wild one. The results obtained are as follows. 1) Lipid and vitamin E contents of the cultured larvae were higher than those of the wild one. 2) Clear differences of fatty acid composition with growth stages, especially 18: 2n-6 and 22 : 6n-3, were recognized between the wild and cultured olive flounder larvae. 3) Changes of lipid content, fatty acid composition and vitamin E content were found to be affected by dietary composition given to fish. 4) The wild olive flounder larvae were found to obtain natural live foods containing of low lipid content and high concentration 22: 6n-3 based on the fatty acid composition of the fish.