• Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.206-209
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• 2010

Chum salmon (Oncorhynchus keta) meat oil contained high amounts of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) compared to oils extracted from other tissues of the fish. EPA and DHA occupied more than 25% of the total fatty acids in chum salmon meat oil. The main lipid classes in the meat oil were triacylglycerides and phospholipids. The major fatty acids of the molecular species composition of phosphatidylcholine isolated from the meat oil were DHA and EPA. DHA and EPA were the major molecular species in the phosphatidylcholine of chum salmon meat oil, representing 44% and 17%, respectively.

• Preventive Nutrition and Food Science
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• v.6 no.3
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• pp.170-175
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• 2001

This study was designed to investigate the effect of different sources of $\omega$3 fatty acid in the diet with a similar polyunsaturated/saturated (P/S) fatty acid ratio and $\omega$6/$\omega$3 fatty acid ratio as well as excess DHA on the plasma fatty acid composition and cholesterol level of rats. Three experimental diets contained 10% (w/w) dietary lipids. The control diet and one treatment diet were corn oil-based diets with different $\omega$-3 fatty acid sources: perilla (CO) or fish oil (CF), respectively. In order to examine the effect of excess DHA, the other treatment diet (FO) was a fish oil-based diet with corn oil to supply essential fatty acids at the level of 1.8% (w/w) of the diet. Female Sprague Dawley rats were fed the experimental diets for 2 weeks prior to mating and throughout gestation and lactation. Pups were weaned to the same diet of dams at 21 days of age. Plasma fatty acid compositions and cholesterol contents were analyzed for pups at 3th, 7th and 10th week after birth. Plasma DHA concentrations increased significantly as the level of fish oil supplementation increased. Three-, seven- and ten-week old rats fed on CO diet which contained only $\alpha$-lino1enic acid as a $\omega$-3 fatty acid Source had Plasma DHA levels of 4.85%, 3.15% ana 2.47%, respectively, suggesting that rats at this period of development can convert $\alpha$-linolenic acid to DHA. But the ability to form DHA might be limited, since dietary DHA showed to be more effective in raising the plasma level of DHA. There was a significant negative correlation between DHA and cholesterol concentration of the rat plasma at 7th week (r=0.34, p<0.05) and l0th week after birth (r=036, p<0.05), proving the hypocholesterolemic effect of DHA.

• Journal of Nutrition and Health
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• v.29 no.3
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• pp.267-277
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• 1996

Effect of DHA-rich fish oil on brain development and learning ability has been studied in Sprague Dawley rats. Female rats were fed experimental diets containing either corn oil fish oil at 10%(w/w) level throughout the gestation and lactation. Corn oil was added in fish oil diet to supply essential fatty acid at 2.3% of the calories. All male pups were weaned to the same diets of dams at 21-days after birth. Plasma fatty acid composition was analyzed for dams and pups at 21-days, 28-days and 22-weeks after birth. The analysis of DNA and fatty acid profile in the brain were undertaken at birth, 3, 7, 14, 21, 28 days and 22 weeks after birth and learning ability was tested at 18-20 weeks of age. Regardless of dietary fats, arachidonic acid(AA) and docosahexaenoic acid(DHA) were the principal polyunsaturated fatty acids in the brain. Rats fed CO diet showed a continouus increase of AA content in the brain from 10.9%(at birth) to maximum 15.3% level (14-days old), while the rars fed FO diet showed 78-79% of CO group throughout the period. Rats fed FO diet showed higher incorparation of DHA from 15.2% at birth to a maximum level of 18.5% at 140days, while the rats fed CO diet showed only 7.0% incorporation of DHA at birth and a maximum level of 11.1% at 21-days. Compared to CO group, FO group showed lower ratio of chol/PL and higher content of DHA in brain microsomal membrane, resulting in better membrane fluidity. Total amount of DNA per gram of brain was reached maximum level at 21 days in both groups. This would be a period of the cell proliferation during brain development. Overall, the rats fed fish oil diet showed a higher incorporation of DHA and membrane fluidity in the brain and better learning performances (p<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.2
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• pp.181-190
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• 2020

This study was conducted to estimate the optimum dietary DHA oil level and replacement level of enzyme treated fish meal (EFM) with sardine fish meal for juvenile Atlantic bluefin tuna Thunnus thynnus. Four diets were used: 1) EFM75 in which 75% EFM and 4% DHA oil were applied, 2) EFM60, with 60% EFM and 15% sardine fish meal, 3) DHA2 with 2% of DHA oil, and 4) SL as a raw fish feed. In a feeding trial, juvenile bluefin tuna (body weight 30.1 g) were randomly stocked into four experimental tanks (69 tones) and fed the experimental diets for 13 days. Fish weight gain was higher in the EFM75 and SL groups than in the DHA2 and EFM60 groups. The feed conversion ratio was lower in the EFM75 and DHA2 groups than in the EFM60 and SL groups. Survival was higher in fish fed the formulated diet groups (EFM75, EFM60 and DHA2) than in fish fed SL. This study clearly indicates that up to 10% dietary sardine fish meal can be used in juvenile T. thynnus diets, with an optimum dietary DHA oil level of approximately 3%.

• Journal of Nutrition and Health
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• v.29 no.2
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• pp.213-222
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• 1996

The most abundant long-chain polyunsaturated fatty acid in brain lipids is docosahexaenoic acid(C22 : 6 N-3, DHA). It is incorporated into nerve tissues mostly in utero and during the first year of life. DHA in brain is derived from either pre-formed DHA in human milk or by infant hepatic synthesis from linolenic acid in milk. This study was designed to investigate the effects of DHA supplementation on fatty acid profiles in maternal plasma lipid and breast milk. Twenty lactating women participated in the study. Seven women took 3g of fish oil per day and vitamin E for 28 days starting from the day of giving birth. Five women consumed 1.5g of fish oil as well as tivamin E, and the rest took vitamin E supplements for the same period of time. Dietary questionnaires and 3 consecutive 24-h recalls were collected to evaluate theri nutritional status and food habits. Finding that DHA intake from fish was not significantly different among three experimental groups, the partcipants were instructed to continue eating their usual home diets. Milk samples were taken on the day of giving birth, as well as the 7th, 14th and 28th day being the supplement phase, and finally 2 weeks after the cessating of DHA supplements. The amounts of the fish oil supplements produced significant dose-dependent increased in the DHA content of milk and plasma, but to a lesser degree. Base-line for 28 days raised the level to 2.05$\pm$0.43% and 1.5g/day supplement produced DHA levels of 1.02$\pm$0.19%. The results of this study indicated that relatively small amount of dietary DHA supplementation significantly elevats DHA content in milk. This would clearly elevate the infant's DHA intake which in turn may have implications for the infant's brain development.

• Journal of Nutrition and Health
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• v.31 no.7
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• pp.1100-1111
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• 1998

The incorporation of docosahexaenoic acid(DHA) and arachidonic acid(AA) into brain and liver lipid has been compared in male pups from binth to 10 weeks old by feeding DHA-rich experimental diets or chow diets to dams from pregnancy in rats. The experimental DHA-rich diets contained 7g fish oil and 3g corn oil per 100g diet. There were three experimental groups, FO-I : Dams were fed DHA-rich diet during pregnancy and lactation, and their it pups fed the same diet until 10 weeks old. FO-II Dams fed chow diet during pregnancy and DHA-diet during lactation, and their pups fed the same DHA-diet until 10 weeks. FO-III : Dams fed chow diet during gestation and lactation, and then the pups fed DHA-diet after weaning. The relative % of DHA in hepatic lipid was about 12% with chow diets, but increased rapidly to 20-25% level when DHA-rich diets were supplied after weaning. The AA(%) of FO-III group was relatively high when a chow diet containing higher amount of linoleic acid was given, but there was no significant difference between the groups after feeding on a DHA-rich diet. When the DHA-rich diet was supplied from pregnancy(FO-I), the relative % of DHA in brain lipid was 13.7% at birth and continuously increased to a maximum level(17.2%) at 3-weeks and then was sustained until 5 weeks old. Similar levels of DHA incorporation were observed when DHA-rich diet was supplied from lactation(FO-II). However, the pups of FO-III group showed significantly lower levels of DHA incorporation(72%) at birth. These livels slowly increased and reached an 87% level of FO-I at 10 weeks when the pups ate DHA-rich diets after weaning. The relative % of AA in brain lipid was 10.4% in the FO-I group at birth, which was significantly lower than those of other groups, but there was no significant difference between groups after feeding DHA-rich diets in all groups. The Ah(%) level increased to maximum(11-12%) at 3-weeks and then was slightly reduced and was sustained at about 10% after S-weeks. Total amounts of DNA in the whole brain rapidly reached maximum level at 3-weeks and then was sustained at a constant level after S-weeks. DNA content was not significantly different between groups at birth, but it was significantly higher in FO-I and FO-II groups than in FO-III group at 3-weeks. However, DNA content in FO-III group was continuously increased to 80% level of FO-I at 10-weeks after feeding DHA-rich diet since weaning. In conclusion, the DHA(%) in whole brain was most effectively deposited when DHA-rich diet had been supplied during pregnancy and lactation in rats. However, DHA supplementation after weaning also improved the incorporaton of DHA into brain and content of DNA even though brain development was almost completed, which suggests that DHA supplementation might be necessary to improve brain development in humans during infancy as well as pregnancy and lactation. (Korean J Nutrition 31(7) 1100-1111, 1998)

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.692-701
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• 1993

This study was designed to examine effects of the various levels of sardine and safflower oil mix on lipid contents of serveral tissues in dietary hyperlipidemic rats. Experimental oils were 16% butter(control group), 8% butter+8% olive oil(group 2), 8% butter+8% sardine oil(group 3), 8% butter+6% sardine oil+2% safflower oil(group 4), 8% butter+4% sardine oil+4% safflower oil(group 5), 8% butter+2% sardine oil+6% safflower oil(group 6) and 8% butter+8% safflower oil(group 7). The diet administered to the male rats of Sprague-Dawley were fed for 4 weeks. In the fatty aicd composition of brain phospholipid, n-3 EPA and DHA contents were increased, and DHA content was remarkably high in the phosphatidylethanolamine(PE) component. Arachidonic acid content were high in the cardiolipin component. In the fatty acid composition of heart phospholipid, PUFA contents were highest in the group 5 and DHA content was higher in the groups 4 and 5, particularly. Fatty acid composition of spleen lipid showed that n-3 EPA and DHA contents were higher in the group 3 than in the other groups.

• Journal of Nutrition and Health
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• v.34 no.2
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• pp.132-140
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• 2001

The effects of various dietary docosahexaenoix acid(DHA) levels on the brain phospholipids and serum and liver lipid compositions were studied in rats using DHA concentrated oil and corn oil as a control for 4 weeks. Serum total cholesterol and HDL cholesterol levels tended to be the lowest by adding 20% DHA to corn oil. Serum triglyceride levels significantly decreased by adding 30% DHA. Liver cholesterol and triglyceride levels were apparently decreased in the groups added above 20% DHA, especially, the lowest at adding 30% DHA. Brain weight and phospholipid content were not different among groups. The ratios of arachidonic to linoleic acids in serum and liver phosphatidylcholine(PC) were significantly decreased by adding dietary DHA and showed a flat form above 20% of dietary DHA. DHA levels of serum PC were gradually increased according to dietary DHA level. The fatty acid compositions of the brain PC and phosphatidylethanolamine(PE) did not appear any changes with accordance of the dietary DHA levels. However, compared with those of serum and liver in general, linoleic and arachidonic acid levels were very low. Oleic acids were apparently higher than those in the other tissues. DHA were higher than those in the other tissues rigardless of the dietary DHA, especially in brain PE. The ratios of arachidonic to linoleic acid were not apparent tendency in brain PC and PE. However, the ratios of brain PE were above 2 times higher than those of brain PC. As the results, the hypolipidemic effects of dietary DNA were remarkable in liver. Especially in regard to tendency of liver lipid levels and desaturation indices in serum and liver PC, the effects indicated significantly higher by adding 20-30% DHA to diet(n-6/n-3 ratio, about 4-7). Thus, in this study, these dietary DHA levels seemed to be appropriate, at least in these lipid paramenters.(Korean J Nutrition 34(2) : 132∼140, 2001)

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.2
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• pp.231-235
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• 2006

The objectives of this study were to investigate the effects of dietary fish oil inclusion on the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents and organoleptic characteristics of breast meat in mule ducks. Three hundred mule ducks at four weeks of age were randomly assigned to three dietary treatments with five replicate pens in each. One replicate pen had ten males and females each with a total of 100 ducks in each treatment. The diet in the three treatments contained 0, 1.5, and 3.0% fish oil, respectively. Body weights at 4, 6, 8, and 10 weeks of age, and feed efficiency at 4 to 6, 6 to 8, and 8 to 10 weeks of age were recorded. At 10 weeks of age, one male and one female from each replicate were sacrificed for oxidative stability of breast meat and the sacrificed males were employed for the analysis of fatty acids in breast meat and skin. Sensory evaluation of breast meat was also performed. A level of 3.0% fish oil in the diet significantly deteriorated feed efficiency and body weight gain. Dietary fish oil inclusion had a trend of increasing abdominal fat deposition and decreasing the flavor of breast meat. The EPA and DHA contents in the breast meat were higher than those in the breast skin irrespective of oil sources. The EPA and DHA contents in breast meat and breast skin was significantly increased in the 3.0% fish oil group. Although EPA and DHA were not efficiently deposited in the duck meat through dietary fish oil inclusion, this method can still provide a partial supplementation of EPA and DHA.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.254-267
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• 1993

Fatty acid contents of 59 food items which are major fat sources in Korean diet were analyzed. The contents of EPA and DHA in fish were 0.02-2.66g and 0.02-3.01g per 100g edible portion, respectively. Items with high amount of EPA and DHA were canned Sardine, Mackerel, Mackrel pike, Atka-fish, Hair tail, Conger eel and Herring. But white fish such as Croaker, Gindaro, Flounder and frozen Alaskan pollack contained less than 0.1g of EPA and DHA per 100g edible portion. Other sources of n-3 fatty acid were perilla oil, rapeseed oil, soybean oil and walnuts all of which contained relatively high amounts of linolenic acid.