• BMB Reports
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• v.54 no.5
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• pp.278-283
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• 2021

Our understanding of the differential effects between specific omega-3 fatty acids is incomplete. Here, we aimed to evaluate the effects of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on T-helper type 1 (Th1) cell responses and identify the pathways associated with these responses. Naïve CD4⁺ T cells were co-cultured with bone marrow-derived dendritic cells (DCs) in the presence or absence of palmitate (PA), DHA, or EPA. DHA or EPA treatment lowered the number of differentiated IFN-γ-positive cells and inhibited the secretion of IFN-γ, whereas only DHA increased IL-2 and reduced TNF-α secretion. There was reduced expression of MHC II on DCs after DHA or EPA treatment. In the DC-independent model, DHA and EPA reduced Th1 cell differentiation and lowered the cell number. DHA and EPA markedly inhibited IFN-γ secretion, while only EPA reduced TNF-α secretion. Microarray analysis identified pathways involved in inflammation, immunity, metabolism, and cell proliferation. Moreover, DHA and EPA inhibited Th1 cells through the regulation of diverse pathways and genes, including Igf1 and Cpt1a. Our results showed that DHA and EPA had largely comparable inhibitory effects on Th1 cell differentiation. However, each of the fatty acids also had distinct effects on specific cytokine secretion, particularly according to the presence of DCs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.14-19
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• 2001

This study was designed to compare content and composition of fatty acid in egg yolk oil among general eggs from chicken, quail, duck. We also compared those of general and functional chicken egg. Fatty acids were determined by GC method and the results were as follows: Palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and timnodonic acid were identified in egg of chicken, quail and duck. The major fatty acid was oleic acid and palmitic acid in three kinds of eggs. Arachidonic acid and docosahexaenoic acid (DHA) were analyzed in egg of quail , but no in chicken. Monounsaturaterd fatty acid (MUFA) was higher in egg yolk oil of chicken and quail. Polyunsaturated fatty acid (PUFA) was higher in duck egg. Ginseng egg had significantly higher palmitic acid and oleic acid lower than general chicken egg. Gamgoal egg had lower palmitic acid and oleic acid, and higher palmitoleic acid and stearic acid than general chiekcn egg. The content of oleic acid was lower in DHA egg than in general chiecken egg, but arachidonic acid was detected only in DHA egg. Ginseng egg had the highest content of saturated fatty acid among chicken eggs. The content of MUFA acid was the highest in gamgoal egg and general chicken egg. DHA egg had the most amount of PUFA among all chicken egg.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1224-1231
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• 2006

Sucrose esters were synthesized by transesterification of sucrose with docosahexaenoic acid ethylester mixture (DHAEE). Potassium carbonate as a base catalyst was used in the presence of dimethylsulfoxide (DMSO) for the reactions. The reactions were performed with the different reaction times and molar ratios of substrates in the presence of surfactant in vacuum. Among the reaction conditions in this study, SE#4～7 showed the relatively high conversion rate (>96%) of DHAEE, leading to the high yield of sucrose esters. In addition, the product composition was changed from sucrose mono ester to di/tri/polyesters after the prolonged reaction time while the increased molar ratio of DHAEE also resulted in the composition changes of sucrose mono ester to the sucrose di/tri/polyesters. From the reaction (SE#7), conversion ratio was 98.5% in which 87.3% mono ester and 13.7% di/tri/polyester were found, resulting in the highest content of mono ester. Therefore, the sucrose ester containing various rates of mono and di/tri/polyesters, which effects on hydrophilic lipophilic balance (HLB) values, can be manipulatively synthesized using the reaction conditions reported in this study.

• Journal of Nutrition and Health
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• v.23 no.6
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• pp.408-417
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• 1990

To compare the hypolipidemic effect of n6 linoleic acid n3 $\alpha$-linolenic acid and n3 eicosapentaenoic acid plus docosahexaenoic acid, male Sprague Dawley rats weighing about 450g were fed the experimental diets for 6 weeks which composed of fat at 15%(W/W) level and were different only in dietary PUFA. Dietary fat was corn oil, perilla oil, and fish oil concentrate as a source of n6 linoleic acid, n3 $\alpha$-linolenic acid, and n3 eicosapentaenoic acid+docosahexaenoic acid, respectively. Plasma total Chol and HDL-chol levels were significantly-lower in fish oil group than in corn oil and erilla oil groups. Plasma cholesterol lowering effect of PUFa was in the order of n3 EPA+DHA>n3 $\alpha$-linolenic acid>n6 linoleic acid. Plasma TG was significantly lower in both fish oil and perilla oil groups than in corn oil group. Plasma TG-lowering effect was greater by n3 PUFA (EPA+DHA, $\alpha$-linolenic acid) than by n6 PUFA(linoleic acid). However, there were no significant effects on lipoprotein pattern hemolysis, and the levels of tocopherol and malondialdehyde in plasma and RBC by difference dietary fat with sufficient tocopherol supplement. Liver superoxide dismutase activity was significantly increased in proportion to the degree of fat unsaturation, thereby resulted in the lower level of MDA in fish oil group. In conclusion, fish oil and perilla oil rich in n3 PUFA may have important nutritional applications in the prevention and treatment of atherosclerotic disease.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2000.12a
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• pp.54.1-54
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• 2000

한국 남해안 완도지역에 자생하는 미역 (Undaria pinnatifida)의 부위별 지방산조성 특성을 계통적으로 분석코자 미역의 부위별 지방질 및 지방산 조성을 silicic acid 컬럼과 기체-액체 크로마토그래피 분석하였다. 총지방질 함량을 비교해 볼 때 엽상부 3.37%, 포자엽 4.59% 및 줄기 2.50%였으나, 엽상부는 총 포리엔산과 linolenic acid(18:3, n-3), stearidonic acid(18:4, n-3), eicosapentaenoic acid(20:5, n-3) 및 docosahexaenoic acid(22:6, n-3)와 같은 n-3계열의 포리엔산의 조성비율이 높았다. 즉 총 포리엔산과 n-3계열의 포리엔산 조성비율을 볼 때 엽상부는 44.18% 및 29.69%였고, 포자엽은 23.63% 및 5.58% 줄기는 26.66% 및 7.37%였다. 한편 중성지방질, 당지방질 및 인지방질의 n-3 포리엔산의 함량을 볼 때 엽상부는 22.40%, 35.82% 및 3.53%로 다른 부위에 비하여 현저하게 높았으나, 줄기는 5.26%, 9.51% 및 2.37%였고 포자엽은 4.49%, 8.01% 및 2.14%로 가장 낮았다.

• 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.

• 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.

• Clean Technology
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• v.17 no.3
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• pp.266-272
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• 2011

Anchovy oil was extracted using supercritical carbon dioxide ($SCO_2$) and organic solvents. Extraction was carried out at temperature range from 40 to $60^{\circ}C$, and pressure range from 15 to 25 MPa. The flow rate of $CO_2$ (22 $gmin^{-1}$) was constant entire the extraction period of 1.5 h. The fatty acid composition of anchovy oil was analyzed by gas chromatography (GC). The main fatty acids of anchovy oil were myristic acid, palmitic acid, stearic acid, palmitoleic acid, EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid). In addition, the oil obtained by $SCO_2$ extraction contained a higher percentage of polyunsaturated fatty acids especially EPA and DHA comparing to the organic solvent extracted oil. The oxidative stability of oils extracted from Anchovy by $SCO_2$ extraction was compared to those extracted by organic solvents. Results showed that the storage periods of oils obtained by $SCO_2$ extraction were longer than those of organic solvents extraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.981-986
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• 2000

In the process of tuna for food, the unprocessed parts of the whole fish range from 30 to 35%, which are mostly used as animal feed stuff, and wasted. Thus, preliminary study on the recycling of the by-product was done to ultimately produce highly valuable products. The study was peformed on skin, skin flesh, tail flesh, dark flesh and abdominal flesh of the tuna. First, crude protein was the most abundant in the skin at 26.31%. About 21% of the crude protein were found in the other samples. Second, crude fat was greatly obtained in the skin at 15.58%. Interestingly, only 0.75% of crude fat was found in the dark flesh. Third, vitamin C and vitamin B group were highly measured in the abdominal flesh and the dark flesh, respectively. Importantly, docosahexaenoic acid (DHA, C22 : 6 $\omega$ -3) and eicosapentaenoic acid (EPA, C22 : 6 $\omega$ -3) which are highly unsaturated fatty acids, were abundant in the skin and skin flesh. To determine the effect of high temperature to the unprocessed parts, the samples were exposed to steam for 30 min. After this processing, 15-methylhexadecanoic acid (i-17 : 0) were in- creased in the skin flesh and the dark flesh. Furthermore, 3-hydroxytetradecanoic acid (3-OH 14 : 0), heptadecanoic acid (17 : 0), 2-hydroxyhexadecanoic acid (2-OH 16 : 0) and nonadecanoic acid (19 : 0) hat were not found before with steam were detected. The DHA and EPA in the dark flesh and the DHA in the skin were stable, respectively, even after the treatment.

• Nutritional Sciences
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• v.4 no.1
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• pp.3-12
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• 2001

Long chain polyunsaturated fatty acids (LCPUFA) are important components of brain phospholipds and play important role (s) in brain function. In rats, the maximum brain growth occurs during the period of lactation even though it happens during the third trimester of gestation in human. Since milk contained docosahexaenoic acid (DHA) even through the maternal diet had no DHA and/or a very small amount of its precursor, $\alpha$-linolenic acid ($\alpha$-LnA), an emphasis was given to maternal adipose tissue as a reservoir of this fatty acid. We, therefore, investigated the mesenteric and subcutaneous adipose tissues for their fatty acid composition in dams reared with different fat diets. Diets containing various amounts of $\omega$6 and $\omega$3 fatty acids were given to adult female rats (200-250g) throughout the pregnancy and lactation periods. Diets were composed of 10% (wt/wt) corn oil (CO), soybean oil (SO), perilla seed oil (PO) containing about 60% $\alpha$-LnA, or fish oil (FO) rich in eicosapentaenoic acid (EPA) and DHA. The fatty acid ompositions of mesenteric and subcutaneous fat were measured and evaluated at Day-2 and Day-15 after parturition. In general, major characteristics of dietary fatty acid composition was reflected on the fatty acid composition of adipose tissues. Dietary fatty acid composition was reflected more on mesenteric fat as compared to subcutaneous fat. Mesenteric fat was found to contain less arachidonic acid (AA) and mesenteric fats of CO, SO and PO groups contained less DHA than did the subcutaneous fat. The P/M/S ratios of adipose tissues were similar between experimental groups while dietary P/M/S ratios differed significantly. It was noticeable that a small proportion of DHA was found in the adipose tissues of animals of CO, SO and PO groups (Day-2) and in SO and PO groups (Day-15), the groups which do not contain DHA in their diets. The percentage of DHA in mesenteric fat o CO, SO and PO groups decreased as lactation continues, while the proportion of DHA in FO group increased. Adipose tissues of FO group had higher DHA/EPA ratio as compared to the diet. Considering the fact that the body contains a large amount of adipose tissues, our present finding suggests that the adipose tissue can serve as a reservoir of DHA for pregnant and lactating rats.