• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.179-183
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• 1996

The objective of this study was to investigate the difference of oxidative stability between DHA (docosahexaenoic acid) added and not added commercial mayonnaise, and then to find out stable condition for maintaining the quality of DHA added mayonnaise. During the storage at room temperature $(25^{\circ}C{\pm}1^{\circ}C)$, it showed that DHA added commercial mayonnaise was more sensitive to oxidation than DHA not added commercial mayonnaise. And sensory quality of DHA added commercial mayonnaise decreased drastically after 5 months from the production date of mayonnaise. During the storage at low temperature $(4^{\circ}C{\pm}1^{\circ}C)$, DHA added mayonnaise was also more sensitive to oxidation than DHA not added mayonnaise, but it showed no apparent and sensory problem with both samples during 8 months of cold storage test periods. In considering the distribution condition of mayonnaise in the country, it was suggested that shelf-life of the DHA added commercial mayonnaise should be shortened 2 or 3 months than that of the DHA not added commercial mayonnaise.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.712-726
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• 1994

Feeding trials were conducted to determine the essentiality of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and to compare the efficiency between EPA and DHA for juvenile Korean rockfish. Fish averaging 2.1 g were fed experimental diets containing different levels of EPA or DHA, and different combinations of EPA and DHA in two separate experiments. Graded levels ($0.0{\sim}l.75\%$) of dietary EPA or DHA as ethyl esters were substituted for a part of the $8\%$ beef tallow in the basal diet. After 5 weeks of the experimental period, weight gain, chemical composition of whole body, protein and lipid retention efficiency, hepatosomatic index, and fatty acid composition of liver were measured. Daily growth rate and feed efficiency were the lowest in fish fed the diets without EPA arid DHA. These responses were effectively improved by increasing EPA or DHA in the diets up to $1.0\%$ levels, and then reached a plateau between 1.0 and $1.75\%$ levels of either EPA or DHA. Protein and lipid retention efficiency were also improved with the high levels of dietary EPA or DHA. DHA was superior to EPA at the same level of each in weight gain, feed efficiency, and protein and lipid retention efficiency. Hepatosomatic index tended to decrease with increase of the dietary EPA or DHA levels. Lipid contents of whole body were increased with levels of EPA or DHA in the diets. Dietary EPA and/or DHA levels affected directly the fatty acid composition of liver polar lipid. EPA or DHA in the liver polar lipid were increased with levels of dietary EPA or DHA, respectively, whereas those in nonpolar lipid were not affected by the dietary levels of EPA and/or DHA. These finding indicate that either of the EPA or DHA is essential for normal growth of Korean rockfish, and the essential fatty acid requirement is $1.0\%$ of EPA and/or DHA in the diet. DHA is superior to EPA as essential fatty acid, and the dietary EPA/DHA ratio of less than 1.0 may be adequate for normal growth of Korean rockfish fed a diet enough n-3HUFA (EPA and DHA).

• 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 Life Science
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• v.19 no.10
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• pp.1417-1423
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• 2009

Previous studies have suggested that docosahexaenoic acid (DHA) supplementation into n-3 fatty acid deficient diet improved spatial learning performance, but there was no significant difference in brain related function when DHA was added into a n-3 fatty acid adequate diet. Here, we investigated the effect of adding DHA into an n-3 fatty acid deficient or adequate diet on brain and liver fatty acid composition. On the second day after conception, Sprague Dawley strain dams were divided into four groups as follows; n-3 fatty acid deficient (Def), n-3 fatty acid deficient plus DHA (Def+DHA, 10.2% DHA), n-3 fatty acid adequate (Adq, 3.4% linolenic acid), and n-3 fatty acid adequate plus DHA (Adq+DHA, 3.31% linolenic acid plus 9.65% DHA). After weaning, male pups were fed on the same diets of their respective dams until adulthood. In brain fatty acid composition, the Def group showed a lower brain DHA (64% decrease), which was largely compensated for by an increase in docosapentaenoic acid (22:5n-6). Brain DHA in the Def+DHA group was increased to almost the same extent as in the Adq and Adq+DHA groups and there were no significant differences among them. Liver fatty acid composition showed a similar pattern to that of the brain, but liver DHA in the Def+DHA showed the highest percentage among the diet groups. In conclusion, n-3 fatty acid deficiency from gestation to adulthood leads to decreased brain DHA, which has been shown to be highly associated with poor spatial leaning performance. Thus, adequate brain DHA levels are required for optimal nervous function.

• KSBB Journal
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• v.18 no.3
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• pp.229-233
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• 2003

Antioxidant effect of reconstituted liposome was studied for application to food and cosmetic industry. Vitamin-C/alginate alginate gel-entrapped DHA-PC liposome (AVDL) was prepared and studied with respect to morphology (TEM), loading efficiency (TLC) and antioxidant effect (TBARS assay). AVDL has spherical structure and 80 ∼ 250 ㎚ size. As DHA content increased, DHA and PC loading efficiency and antioxidant effect was increased. At addition of 0.2 % vitamin C in AVDL, DHA auto-oxidation was minimized and sustained about 3 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.529-537
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• 1993

Several methods were examined for purification of docosahexaenoic acid (DHA, 22:6n-3) from skipjack Euthynnus pelamis orbital tissue oil, a marine by-product, and a modified method for isolation of a high purity DHA was proposed. Skipjack orbital tissue contained $55.4\%$ of total lipid(TL), and DHA accounted for $23.7\%$ of the TL. Application of low-temperature crystallization and urea inclusion compound methods to the orbital fatty acid mixture resulted in increases of DHA concentrations to approximately $46\%\;and\;61\%$, respectively. These methods were suitable for large production of DHA with relative low purity because of the simple purification procedure. DHA of approximately $74\%$ in purity was obtained by silver nitrate aqueous solution method, but the method gave a very low recovery($<10\%$). Silver nitrate-impregnated silica column chromatography was suitable for purification of a high purity DHA(purity, $>98\%$ and recovery, $>90\%$) A modified method, silver nitrate-impregnated silica column chromatography combined with low-temperature crystallization(two step purication method) was proposed as the most effective method to obtain DHA with high purity($99.9\%$) from the skipjack orbital oil.

• Biomolecules & Therapeutics
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• v.20 no.2
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• pp.152-157
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• 2012

Docosahexaenoic acid (DHA) is the major polyunsaturated fatty acid (PUFA) in the brain and a structural component of neuronal membranes. Changes in DHA content of neuronal membranes lead to functional changes in the activity of receptors and other proteins which might be associated with synaptic function. Accumulating evidence suggests the beneficial effects of dietary DHA supplementation on neurotransmission. This article reviews the beneficial effects of DHA on the brain; uptake, incorporation and release of DHA at synapses, effects of DHA on synapses, effects of DHA on neurotransmitters, DHA metabolites, and changes in DHA with age. Further studies to better understand the metabolome of DHA could result in more effective use of this molecule for treatment of neurodegenerative or neuropsychiatric diseases.

• KSBB Journal
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• v.14 no.6
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• pp.655-660
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• 1999

Supercritical fractional extraction of DHA and EPA from the mixture of fatty acids composing the fish oil was performed. The compositions, extracted quantities, and cumulative extracted quantities of fatty acids in the extract and the raffinate were investigated according to the fractional steps. The temperature and pressure for the miximum concentration of DHA and EPA in the extract or the raffinate were 60$^{\circ}C$ and 101 bar respectively among the extraction conditions considered in this study. In this case, the weight percent of EPA in the extract was 50% and that of DHA in the raffinate was 40%. These values were two times higher than those in fish oil. THe same temperature and pressure were used to extract DHA and EPA from the mixture of fatty acids whose the initial weight percent of DHA was 34%. The weight percent of DHA in the raffinate after the fourth fractionation was 7-%. And the remaining weight of DHA in the raffinate was 80% of DHA initially loaded in the extraction vessel.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.268-281
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• 1995

This study was undertaken to elucidate the effect of DHA-rich fish oil (DHA-rich oil) added to different dietary fats on lipid metabolism. Rats were fed perilla oil, sesame oil and beef tallow with or without DHA-rich oil for 12 weeks. The weight gain was higher in groups with DHA-rich oil than that of groups without DHA-rich oil, with DHA-rich oil, while weight of epididymal fat pad was lower in perilla oil and beef tallow groups with DHA-rich oil. The contents of total lipid and triglyceride in plasma were not affected by dietary fat types, but that of total and HDL cholesterol in plasma were higher in sesame oil group than perilla oil and beef tallow groups without DHA-rich oil. The contents of total lipid, triglyceride, total cholesterol, HDL cholestrol and LDL cholesterol in plasma were decreased by DHL-rich oil addition. The contents of total lipid, total cholesterol and triglyceride in the liver were not affected by dietary fat type. The contents of total cholesterol and triglyceride in the liver were not affected by dietary fat type. The contents of total lipid and TG in liver were not affected by DHA-rich oil addition while hepatic cholesterol increased by DHA-rich oil addition. The activities of glucose 6-phosphate dehydrogenase and malic enzyme were highest in beef tallow group without DHA-rich oil and decreased by DHA-rich oil addition. Peroxisomal ${\beta}$-oxidation had an inverse relationship against the activities of lipogenic enzymes. In conclusion, dietary DHA-rich oil decreased fat accumulation and had hypolipidemic effect, especially in beef tallow group. Also groups with DHA-rich oil showed more hypolipidemic effect than perilla oil group. And DHA-rich oil addition to diets resulted in increasing dietary n-3/n-6 ratio. Therefore increase in n-3/n-6 ratio as well as dietary DHA were considered to be responsible for the hypolipidemic effect resulted from DHA-rich oil addition.

• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1295-1306
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• 1998

Recent research indicates that the n-3 fatty acid , docosahexaenoic acid(22 : 6n 3, DHA) plays an essential role in infant brain development . DHA is highly concentrated in brain and retinal tissues and accumulates during late fetal and early neonatal life. Diets deficient in DHA are associated with reduced levels of DHA in brain and retinal tissues. The purpose of this study is to investigate the long term effects of DHA supplementation on the growth and mental development of full-term infants. THirty four healty infants were recruited from those who were delivered at Kyung Hee Medical Center. The experimental groups were the breast milk+DHA(-) group who were fed human milk for 20 weeks after birth and thereafter were fed placebo formula for 28 weeks, the breast milk+DHA(+) group who were fed human milk for 20 weeks after birth and thereafter were fed DHA supplemented formula for 28 weeks, DHA(-) group who were fed placebo formula for 48 weeks, and DHA(+) group who were fed DHA supplemented formula for 48 weeks. The daily average intake of DHA for the breast milk+DHA(-) , breast milk+DHA(+), DHA(-) and DHA(+) groups were 39.1mg, 89.9mg, 17.7mg, and 160.224mg, respectively. The results showed that measurements of infant weight, length, head, and chest circumferncewere all in normal range and they were not influenced by the DHA supplements in their diets. There was a significant correlation between dietary DHA intake and erythrocyte DHA level. The results of flash visual evoke potential (VEP) test were not correlated with eerythrocyte DHA and dietary DHA levels at 48 weeks of age. No differences were found in Bayley mental and Psychomotor Development lndex scores among the four experimental groups at 48 weeks of age. Unlike the short-term effects there was no long-term effect of relatively small amounts of dietary DHA supplements on the scores for flash VEP and Bayley test, even thour호 there was an elevated DHA supplements on the scores for flash VEP and Bayley test, even through there was an elevated DHA content in the infants erythrocytes.