• 한국수산과학회지
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• 제31권2호
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• pp.210-216
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• 1998

(1) 통영시 관내 북만해역의 굴양식장군의 8개 조사양식장에서 $1994\~1996$년까지 매월 1회씩 굴 시료를 채취하여 양식굴의 집단생태학적 특성치를 조사하고, 굴 육질의 지방산조성을 분석하여 얻은 자료를 토대로, DHA 함량조성과 굴의 집단생태학적인 몇가지 특성간의 관련성을 검토하였다. (2) 굴의 지질중 DHA 함량조성은 연중 $0\~25\%$ 범위로 변동하였으며, 6월에 최저치를 나타내었고, 11월에 최고치를 나타내었다. (3) DHA함량조성과 굴의 사망계수 및 성장계수와의 사이에는 관련성이 나타나지 않았다. (4) 11월의 DHA 함량조성과 수확시 개체군의 크기사이에는 강한 (+)상관성이 인정되었고, 수확시 개체육 중량과의 사이에는 (-)상관성이 인정되었다. (5) 굴에 있어서 DHA는 산란기에 생식소의 성숙과 방출에 에너지원으로 다량 소모되는 것으로 보이며, 북만해역에서 11월의 DHA 함량조성은 수확시의 집단크기의 선행지수로 사용해 봄직하고, 체중과의 역 관련성을 잘해 석 하면 밀도효과를 유추할 수 있을 것으로 고찰되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권1호
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• pp.10-15
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• 2002

Environmental and medium factors were investigated as basic data for optimizing DHA production when using Thraustochytrium aureum. To study the effect of environmental conditions, the rotation speed and culture temperature were changed. Plus the trend of the growth characteristics, lipid content in the biomass, and DHA content in lipids were evaluated according to various initial glucose concentrations. The biomass, lipid, and DHA analyses showed that the physiological characteristics of T. aureum were closely related with the environmental and medium conditions, as in the case of other marine microorganisms. For example, a low rotation speed of 50 rpm lowered the cell growth rate as well as the DHA content in the lipids. A low temperature had a negative effect on the cell growth, yet a positive effect on the lipid content in the biomass. Different initial glucose concentrations had no effect on the lipid content in the biomass or DHA content in the lipids, yet did affect the cell growth. Accordingly, these results show that environmental and medium factors must be synthetically considered in order to optimize DHA production when using T. aureum.

• Journal of Nutrition and Health
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• 제32권5호
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• pp.526-532
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• 1999

The aim of this study was to observe whether the dietary supplementation of docosahexaenoic acid(DHA). In growing rats requires extra supplementation of arachidonic acid(AA) for brain development. Sprague-Dawley rats were divided into three groups, each fed a different diet. In the FO group, dams were fed a DHA-rich FO diet during pregnancy and lactation and pups were fed the same diet until 10 weeks old. In the AO group dams and pups were similarly fed a FO diet after weaning. DHA and AA were most effetively deposited in the developing brain during pregnancy and lactation in rats. However, FO-W pups showed significantly lower level of DHA at 0-3 weeks compared with the FO and AO groups and than slowly increased DHA levels to about 87% of other groups at 10 weeks with the introduction of the FO diet after weaning. The total amount of DNA in whole brain rapidly reached a maximum level at 3 weeks and then was sustained at a constant level after 5 weeks of age. The DNA content was positively correlated with DHA level but not with AA level in the developing brain. DNA content was significantly lower in the FO-W group compared to the FO and AO group at 3 weeks of age. However, the DNA content of brain in FO-W pups increased to 80% of the FO group level at 10 weeks after feeding the FO diet after weaning. The relative percentage of AA in brain lipids was significantly reduced in the early stage of brain development when only DHA was supplemented. However, DHA supplementation had no significant effect on the incorporation of AA when the approximately 35% of LA in the FO diet was substituted by preformed AA. These results suggest that large quantities of DHA could interfere with the normal conversion of LA to AA if LA is not supplemented enough together with DHA. Therefore, high DHA supplementation may require preformed AA in the diet even though AA has no significant correlation with the DNA content in brain. DHA supplementation after weaning also improved the incorporation of DHA into brain and content of DNA even though brain development was almost completed, suggesting that a low level of DHA supplementation without AA addition might be necessary to improve brain development during infancy as well as during pregnancy and lactation.

• Journal of Nutrition and Health
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• 제31권7호
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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)

• 한국식품위생안전성학회지
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• 제26권4호
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• pp.349-354
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• 2011

시중에서 판매된 일반우유와 포름알데히드를 처리한 참치어유 배합사료를 먹여 DHA를 강화한 DHA 강화우유내의 포름알데히드 함량을 분석함으로써 포름알데히드를 처리한 사료를 먹여 DHA를 강화한 우유의 안전성을 평가하고자 하였다. 시중에서 판매된 일반우유와 DHA 강화우유를 CM, DHA-K, DHA-B로 구분하였다. 이화학 검사를 통해 세 제품이 모두 기준치 이내의 정상 수준을 나타내는 신선한 제품임을 확인하였고, 전반적인 시료간의 유의적 차이는 거의 없었으나, DHA-K를 다른 두 시료와 비교하면 지방함량은 두 시료의 지방함량의 절반 정도인 1.85%이었으며, 단백질은 약 1% 높게 나타났다. DHA 강화우유에 함유된 DHA의 함량을 분석해본 결과 DHA-B가 DHA-K보다 약 2배이상 높게 나타났으며, 이러한 차이는 연령별 섭취량 기준과 비슷한 양상을 나타내는 것으로 보인다. HPLC를 이용하여 우유 내 포름알데히드를 분석한 결과, 일반우유와 포름알데히드를 처리한 참치어유배합사료를 먹인 DHA 강화우유 모두 WHO에서 정한 신선유 중 포름알데히드 함량 기준치인 0.013~0.057 ppm사이에 존재했으며, 또한 세 시료간에 유의적 차이가 없는 것으로 보아 DHA를 강화하기 위해 포름알데히드를 첨가한 참치어유 배합사료를 소에게 먹이더라도 포름알데히드가 우유로 전이되지는 않는 것으로 보이며, 포름알데히드를 처리한 사료를 먹인 DHA 강화우유의 포름알데히드에 대한 안전성은 일반우유 수준이라고 판단된다.

• 한국식품과학회지
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• 제22권5호
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• pp.520-525
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• 1990

포화지방산 또는 불포화지방산의 분리방법인 요소부 가법이 지닌 가메탄올 분해(methanolysis)와 농축물 회수의 곤란함 등의 문제를 해결하기 위하여 지방산과 요소의 부가화합물 형성의 반응매질로 유기용매를 사용하고 요소의 습윤제로 물을 사용한 새로운 요소부가법을 제시하였다. 어유를 원료로 제조한 지방산을 헵탄, 헥산, 이소옥탄같은 비극성 유기용매에 용해키시고 요소와 요소의 습윤제인 물을 첨가하여 부가화합물 형성을 유도한 후 요소와 부가화합물을 잘 형성하지 않는 불포화지방산 분획을 회수하여 지방산 조성을 분석한 결과 EPA, DHA 및 이들의 전구물질을 포함한 고도불포화지방산이 80%이상인 것으로 나타났다. 이 고도불포화지방산 농축물내에 EPA와 DHA 함량은 사용하는 유기용매으 종류에 따라서 변화되었는데, 헵탄과 에틸 에테르 등을 사용할 경우에는 EPA의 농축에 효과가 높았다. 이러한 특성을 이용하여 우선 펜탄을 사용하여 DHA를 농축하고 다시 헵탄을 사용하여 EPA의 농축을 시도한 바 어유 지방산으로부터 DHA가 50%인 농축물과 EPA가 53%인 분획을 각각 얻을 수 있었다.

• ALGAE
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• 제35권3호
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• pp.277-292
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• 2020

Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are polyunsaturated fatty acids beneficial to human health. A limited number of microalgae have been used for commercial omega-3 production, which necessitates the identification of new microalgae with high omega-3 contents. We explored the fatty acid composition and EPA and DHA contents of the mixotrophic dinoflagellate Gymnodinium smaydae fed with the optimal algal prey species Heterocapsa rotundata. Cells of G. smaydae were found to be rich in omega-3 fatty acids. In particular, the DHA content of G. smaydae was 21 mg g^-1 dry weight, accounting for 43% of the total fatty acid content. The percentage of DHA in the total fatty acid content of G. smaydae was the highest among the reported microalgae except for Crypthecodinium cohnii. Moreover, to determine if the prey supply interval affected the growth rate of G. smaydae and its fatty acid content, three different prey supply intervals (daily, once every 2 d, and once for 4 d) were tested. Daily prey supply yielded the highest total fatty acid and DHA contents in G. smaydae. Furthermore, we successfully produced high-density G. smaydae cultures semi-continuously for 43 d with daily prey supply. During the semi-continuous cultivation period, the highest density of G. smaydae was 57,000 cells mL^-1, with an average growth rate of 0.7 d^-1. Taken together, the percentage of EPA and DHA in the total fatty acid content was maintained in the range of 54.2-56.9%. The results of this study support G. smaydae as a promising microalgal candidate for commercial DHA production and demonstrate that daily supply of prey can efficiently produce high-density G. smaydae cultures for more than a month.

• Journal of Nutrition and Health
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• 제29권2호
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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.

• 생명과학회지
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• 제9권4호
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• pp.493-495
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• 1999

Eicosapentaenoic (EPA, 20:5) and docosahexaenoic (DHA, 22:6) acids of gull eggs were analyzed and the results are summarized as follows: 1. EPA and DHA were 2.25% and 4.35% in the total fatty acid of gull eggs. 2. Triglyceride fractions in the fatty acids had 0.56% in EPA and 1.59% DHA. 3. Diglyceride fractions contained 1.10% EPA and 1.97% DHA. 4. Phospholipid fractions had the most abundant amounts of 4.26% EPA and 8.13% DHA.

• Asian-Australasian Journal of Animal Sciences
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• 제19권7호
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• pp.1047-1053
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• 2006

The current study was designed to determine the effects of dietary docosahexaenoic acid (DHA) on fatty acid deposition in egg yolk and various tissues of laying Tsaiya ducks, and on the mRNA concentrations of hepatic lipogenesis-related transcription factors. Thirty laying ducks were randomly assigned to three treatments with diets based on corn-soybean meal (ME: 2803 kcal/kg; CP: 17.1%; Ca: 3.4%) supplemented with 0% (control diet), 0.5% or 2% algal DHA oil. The DHA content in egg yolks of the ducks was elevated significantly (p<0.01) with the supplementation of dietary DHA. The DHA percentage of the total fatty acids in the egg yolk of laying ducks was 0.5%, 1.3% and 3.4% for 0%, 0.5% and 2% algal DHA oil treatments, respectively, for the $1^{st}$ week, and 0.5%, 1.5% and 3.3% for the $2^{nd}$ week. Therefore, algal DHA oil can be utilized by laying Tsaiya ducks to enhance the egg-yolk DHA content. The concentrations of triacylglycerol (TG) and cholesterol in plasma of laying Tsaiya ducks were not affected by dietary DHA treatments (p>0.05). The DHA concentration in plasma, liver, and skeletal muscle was increased with the addition of dietary algal DHA oil (p<0.05). The mRNA abundance of sterol regulatory element binding protein 1 (SREBP1) and SREBP2 in the livers of laying Tsaiya ducks was not affected by dietary DHA, suggesting that the expression of these transcription factors is tightly controlled and not sensitive to DHA treatments.