• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.1
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• pp.8-15
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• 2007

This study selected the optimal microalgal species for mass culture of a brackish water copepod Paracyclopina nana. Fifteen microalgal species were tested to examine nauplius production and the survival and maturation of brood females. Total and daily nauplius production were highest in P. nana fed Tetraselmis suecica followed Isochrysis galbana, Dunaliella tertiolecta, and Phaeodactylum tricornutum. With a monospecific microalgal diet, the total density was highest with P. nana fed I. galbana, at 63.3 inds./mL. With a mixed microalgal diet, the total density of P. nana fed T. suecica+I. galbana was higher than that fed other mixed diets, although there was no difference between a monospecific diet of I. galbana and a mixed diet of T. suecica+I. galbana. Examining the fatty acid composition of P. nana, the eicosapentaenoic acid (EPA) was highest in P. nana fed T. suecica at 5.4% while the docosahexaenoic acid (DHA) content was highest I. galbana diet at 31.9%. Although no DHA was detected in T. suecica, P. nana fed this microalgal species had a high DHA composition of 24.3%. We suggest that the optimal microalgal species for the mass culture of P. nana is T. suecica which is easy to culture on masse and has a high linolenic acid content.

• Fisheries and Aquatic Sciences
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• v.2 no.2
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• pp.113-121
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• 1999

Changes in lipid content, lipid class and fatty acid compositions of the cultured oysters in shallow-water, Bukman bay (Tongyeong, Korea), using both Korean and Japanese spats were investigated. The content of non-polar lipid (NL) comprised approximately $60- 80\%$ of total lipid (TL) in the cultured oysters. There was a positive correlation between NL content and meat weight, y=0.287lx-15.309 (r=0.834l, p<0.001). The prominent fatty acids of the oysters were 16:0, 20:5n-3 (eicosapentaenoic acid, EPA), 22:6n-3 (docosahexaenoic acid, DHA), 18:0, l8:1n-7, l8:1n-9, l6:1n-7, 14:0 and l6:4n-3. During the growth of the oysters, l6:4n-3 showed the highest coefficient of variation, accounting for $41.8\%$ for the Korean oyster and $32.3\%$ for the Japanese one, respectively. Both oysters showed low level of n-3 fatty acids such as DHA and EPA and high level of n-6 fatty acid, 20:4n-6, in the spawning period (August). During growth of the oysters, both EPA and DHA were the richest fatty acids in the harvest period (December, 314 mg/100g sample) and in the pre-spawning period (July, 237-247 mg/100g sample), respectively. Consequently, the cultured oyster with Japanese spat contained approximately two times more n-3 fatty acids per oyster individual than those with Korean one in the harvest season.

• KSBB Journal
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• v.15 no.1
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• pp.72-75
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• 2000

The hydrolysis characteristics of each fatty acid composing the fish oil by means of the lipase from Candida cylindracea was investigated. The saturated fatty acids, C14:0, C16:0 and C18:0, and the unsaturated fatty acids with one double bond, C16:1, C18:1(n-7), C18:(n-9), C20:1 and C22:1 were more easily hydrolyzed than the $\omega$-3 polyunsaturated fatty acids. when the number of carbon of the $\omega$-3 fatty acids was same but that of double bond was different, the hydrolysis of the $\omega$-3 fatty acids having lower number of double bond was more rapidly carried out. When the degree of polyunsaturation was same but the number of carbon was different, the lipase acted more rapidly upon the $\omega$-3 fatty acids with lower number of carbon. Docosahexaenoic acid(DHA) was most highly concentrated in the glyceride mixture after 120hr hydrolysis among the various $\omega$-3 polyunsaturated fatty acids. The weight percentage of DHA to the $\omega$-3 fatty acids in the fish oil was 31.87% but that in the glyceride mixture after 120hr hydrolysis was 51.89%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1467-1474
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• 2006

Fish-frames, which are left after obtaining fillets or muscle during fish processing, consists of useful food components, such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using conger eel frame (SF) for human consumption and also to elucidate food component characterization of the snack. The results of volatile basic nitrogen suggested that conger eel frame was a suitable material for preparing snack. Based on the results of sensory evaluation and costs, starch syrup was an optimal sweetener for preparing snack using conger eel frame. The starch syrup-treated SF appeared safe because the moisture content and peroxide value were below the safety limits described in the guideline of Korea Food and Drug Administration (KFDA). Starch syrup-treated SF was similar in the pattern of fatty acid composition to soybean oil, whereas EPA and DHA were detected in SF. The total content of amino acid in starch syrup-treated SF was 23.9% based on 100 g of raw material. The maj or amino acids were aspartic acid, glutamic acid, glycine and alanine. The total contents of calcium and phosphorus in starch syrup-treated SF were 4.9% and 2.8%, respectively. The Ca/P of starch syrup-treated SF was 1.9, which is a good ratio for absorption of calcium. The SF made with starch syrup was superior in EPA and DHA compositions, total amino acid, calcium and phosphorus contents to commercial snack using eel frame.

• Ocean and Polar Research
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• v.21 no.2
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• pp.109-116
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• 1999

Total lipid content, lipid class and fatty acid composition of the Antarctic krill Euphausia superba collected from the water of King George Island, Antarctica during austral summer of 1997-1998, were investigated. The overall lipid content of 5. superba was 72 mg/g dry mass similar to the reported values for most temperate species. The neutral lipid of E. superba was 29% of the total lipid and that of phospholipid was 71%. The majority of neutral lipid was triacylglycerols(31.6% of neutral lipids) while phosphatidyl choline (44% of phospholipid) was the most abundunt in phospholipids. The quantitative composition of the fatty acid in E. superba show consisting mostly of the saturated 16:0 (16.6% -22.1%), along with the polyunsaturated 20:5(n-3) (20.6% -22.1%) and 22:6(n-3) (14.9% -16.9%) acids.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.467-473
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• 2016

Several of our recent studies have focused on mass production of the marine Cladoceran Diaphanosoma celebensis, which can serve as a feed substitute for Artemia nauplii in the culture of larval marine fish. We compared the growth and survival rates of tiger puffer Takifugu rubripes fed D. celebensis with those fed Artemia. The group fed D. celebensis showed an increase in growth from 0.10 g to 1.78 g, while the group fed enriched Artemia had a growth from 0.10 g to 0.92 g. The survival rate of fish fed D. celebensis was 86.7% while that of fish fed enriched Artemia was 51.1%, indicating that the former group was superior to the latter both in growth and survival rate. Fatty acid analysis revealed that D. celebensis fed Nannochloropsis oculata and Schizochytrium sp. had an eicosapentaenoic acid (EPA) content of 16.42% and a docosahexaenoic acid (DHA) content of 3.93%. Meanwhile, juvenile tiger puffer fed D. celebensis had an EPA content of 9.12% and a DHA content of 10.69%. Juvenile tiger puffer fed D. celebensis had a similar n-3 highly unsaturated fatty acid content to that of tiger puffer fed enriched Artemia which had an EPA content of 5.82% and a DHA content of 15.90%, indicating that no additional enrichment was required.

• ALGAE
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• v.34 no.2
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• pp.163-175
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• 2019

To compare the nutritional quality of TPG (Teleaulax / Plagioselmis / Geminigera) clade species of cryptomonads with that of RHO (Rhodomonas / Rhinomonas / Storeatula) clade species 6 Teleaulax amphioxeia (TA) and 1 Rhinomonas sp. strains were mass-cultured in newly designed 500-L photobioreactors to the end of exponential growth phase. Intraspecific variations (IVs) in terms of one standard deviation among the 6 TA strains in the compositions of the three macronutrients were 41.5 (protein), 89.8 (lipid), and 15.6% (carbohydrate) of the mean. When harvested from stationary growth phase mean compositions of essential amino acids (EAAs, 47.3%) and non-EAAs (52.7%) of the 2 TA strains, CR-MAL07 and CR-MAL08-2, were similar to those of a Chroomonas strain. The IVs between the 2 TA strains in the composition of EAAs (10.3 and 2.4) and non-EAAs (8.5 and 2.1% of the mean) were rather smaller than those of saturated fatty acids (30.3 and 26.1) and unsaturated fatty acids (UFAs, 12.0 and 12.5% of the mean) in f/2-Si and urea-based compound fertilizer (UCF) culture media, respectively. Mean compositions of eicosapentaenoic acid (EPA, 17.9%) and docosahexaenoic acid (DHA, 12.7%) of total fatty acids of the 2 TA strains were higher than those that of a Chroomonas strain. EPA and DHA compositions exhibited similar level of IVs between the 2 TA strains in f/2-Si (14.6 and 11.0) and UCF media (12.6 and 13.5% of the mean). Thus, the nutritional quality in terms of amino acids, UFAs, EPA, and DHA in a TPG clade species, T. amphioxeia was comparable to those of RHO clade species with notable IVs. Practically, biotechnological targets for TPG clade cryptomonad strains might be subspecies or clone level.

• Clean Technology
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• v.25 no.4
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• pp.275-282
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• 2019

In this study, the extraction of Conger myriaster oil by using supercritical carbon dioxide (SC-CO₂) and organic solvent was investigated. The extraction conditions conducted for SC-CO₂ varied for pressure (25, 30 MPa) and temperature (45, 55 ℃), while the SC-CO₂ flow rate was kept constant during the experiment (27 g min^-1) and hexane was used as a conventional organic solvent. The extraction yield indicated that the best extraction condition would be SC-CO₂ at 55 ℃ and 30 MPa, resulting in the highest yield of 37.73 ± 0.14%. The oils were characterized for their fatty acid (FAs) composition using gas chromatography, while it was revealed that the major FAs were mystric acid, palmitoleic acid, oleic acid, electroosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The oxidation stability of the extracted C. myriaster oil was evaluated by measuring the acid value, peroxide value, and free fatty acid. The best oxidative stability was obtained from SC-CO₂ extracted oil at 30 MPa and 55 ℃. There was a significant difference in the color properties of the SC-CO₂ and hexane extracted oils, with the SC-CO₂ extracted oil showing better chromaticity than the oil extracted using hexane. Extracting oils from C. myriaster with SC-CO₂ could bring better economic benefits than using organic solvents. When supercritical carbon dioxide was used, there was no post-treatment process; thus, it was confirmed that this is a more environmentally friendly oil extraction method.

• Journal of Animal Science and Technology
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• v.49 no.1
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• pp.51-58
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• 2007

Twenty Hanwoo steers (average body weight=440.8±32.4kg) were used to investigate the effects of fish oil supplementation on growth performance, fatty acid composition of longissimus muscle and carcass characteristics. The experiment was done with two treatment groups; FO-0, without fish oil and FO-3, supplemented with 3% fish oil. Total gain and average daily gain (ADG) of steers were similar between two groups. Fish oil supplementation had no effects on contents of protein, ether extract and ash in longissimus muscle. Contents of isoleucine and glycine in longissimus muscle were decreased by fish oil supplementation (p<0.05), but content of cystein was increased by fish oil supplementation (p<0.05). Fish oil supplementation decreased contents of myristic acid and eicosenoic acid in longissimus muscle (p<0.05), but increased contents of oleic acid and arachidonic acid in longissimus muscle (p<0.05). Contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in longissimus muscle were increased by fish oil supplementation p<0.05). Carcass weight, back fat thickness, rib-eye area, yield index and yield grade were similar between two groups. Meat color was improved by fish oil supplementation (p<0.05), Ratio of quality grade ‘1 or over’ increased by fish oil supplementation. Therefore, the present study indicating that fish oil supplementation had positive effects on content of oleic acids in relation to flavor of beef, contents of EPA and DHA in relation to human health and ratio of quality grade ‘1 or over’.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.617-626
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• 1992

This study was designed to observe the effects of the feeding mixed oils of the sardine oil containing n-3 EPA(eicosapentaenoic acid) and DHA (docosahexaenoic acid) and the safflower oil in which were plenty of n-6 linoleic acid, on the fatty acid metabolism of serum and liver in the dietary hyperlipidemic rats. Experimental oils mixed with 16% butter(control group), 8% butter + 8% olive oil and 8% butter with various level of sardine and safflower oils were administered to the male rats of the Sprague Dawley for 4 weeks. In the fatty acid compositions of serum phospholipid, triglyceride and cholesteryl ester, according as the contents of mixed safflower oil increased, n-3 PUFA(polyunsaturated fatty acid) contents and ratio of EPA/AA(arachidonic acid) tended to be decreased, but n-6 PUFA contents and ratio of AA/PUFA tended to be increased. In the fatty acid composition of triglyceride component in liver lipid, DHA contents were most in the liver lipid. And components of cholesteryl ester, n-6 linoleic acid contents were high percentage. Fatty acid compositions of serum and liver lipids were influenced from the fatty acid composition of the test lipids.