• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.141.2-141
• /
• 2003

고도불포화지방산 중 EPA(eicosapentaenoic acid)와 DHA(docosahexaenoic acid)는 여러 가지 생리활성 효과를 나타내는 것으로 알려져 있으며, 최근 관심이 주목되고 있다. 본 실험에서는 특히 DHA의 함량이 높은 해양미생물, 즉 조류(microalgae)인 Schizochytrium sp.에서 얻어진 DHA powder로부터 두 가지 방법으로 유지를 추출한 뒤 그 성질을 비교.분석하였다. 먼저, 8$0^{\circ}C$, soxhlet extractor로부터 6시간 동안 추출하고, 55$^{\circ}C$, shaking water bath로부터 같은 시간 동안 추출한 결과, 각각 25.5, 24.0%의 수율을 나타내었다. GC에 의한 지방산 조성 분석 결과, soxhlet extractor에서 추출한 경우, palmitic acid, DHA가 각각 30.98, 30.04 mol%로 주요 지방산인 것으로 나타났으며, shaking water bath에서 추출된 유지는 그 함량이 각각 31.44, 34.78 mol%를 나타내었다. 또한 pancreatic lipase에 의한 가수분해를 통해 sn-2 위치의 지방산 조성 분석 결과, DHA가 sn-2 위치에 주로 함유되어있는 것으로 조사되었다. 한편, HPLC-ELSD system을 이용하여 중성지방의 구성 성분을 분석 결과, 유지의 99%이상이 TAG(triacylglycerol) 형태로 이루어져 있었으며, 소량의 MAG(monoacylglycerol) 존재를 확인할 수 있었다.

• Journal of Medicine and Life Science
• /
• v.18 no.1
• /
• pp.1-10
• /
• 2021

Omega-3 fatty acids (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) may be beneficial for the primary and secondary prevention of cardiovascular events (CVEs), especially in patients with myocardial infarction or heart failure with reduced ejection fraction. For this purpose, one to two seafood meals per week is preferentially recommended. Omega-3 fatty acids with a high-dose EPA formula (4 g/day) may be more effective than EPA+DHA mixed supplements for the secondary prevention of CVE. Krill oil also contains omega-3 fatty acids, but at a much lower dose compared to fish oil. Supplemental vitamins and minerals have not shown the preventive effects on CVE in prospective, and randomized clinical trials, except for one Chinese study showing the stroke prevention effects of folic acid. The clinical benefit of chelation therapy in reducing CVEs is uncertain.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.4
• /
• pp.315-321
• /
• 2005

Supercritical carbon dioxide extraction was investigated as a method for removing lipids and bad flavor from tuna viscera. To find the optimum conditions, different experimental variables, such as pressure, temperature, flow rate of solvent and sample size, were evaluated for the effective removal of lipids and the undesirable smell. Ethanol was used as the entrainer, with a $3\%$ by vol $CO_2$ flow rate. By increasing the pressure at constant temperature, the efficiency of the lipid removal was improved and the protein was concentrated without denaturalization. The main fatty acids extracted from the tuna viscera were palmitic acid (16:0), heptadecanoic acid (17:1), oleic acid (18:1) and docosahexaenoic acid (22:6). The major amino acids in the tuna viscera treated by supercritical carbon dioxide were glutamic acid, leucine and lysine, and the free amino acids were L-proline, taurine and L-$\alpha$-aminoadipic acid.

• Journal of Nutrition and Health
• /
• v.29 no.1
• /
• pp.32-40
• /
• 1996

To investigate the effect of dietary docosahexaenoic acid(DHA) and environmental enrichment on brain fatty acid composition and acetylcholinesterase(AChE) activity, two groups of was fed isocaloric diets containing 10 or 12% dietary lipids for 7 weeks. A third group was fed 10% (w/w) dietary lipids with supplemented 2% DHA-rich fish oil. Each diet group was housed either in a stainless steel cage individually or in a large enriched cage with toys where 7 rats were kept together. The fatty acid composition of plasma and brain was significantly affected by dietary lipid composition but not by environmental enrichment. Fish oil supplementation significanlty decreased plasma levels of monounsaturated fatty acids(MUFA) and increased polyunsaturated fatty acids(PUFA). Fish oil supplemented groups also maintained lower plasma n-6 fatty acids and higher n-3 fatty acids levels than unsupplemented groups. The fish oil supplementation significantly decreased arachidonic acid and increased eicosapentaenic, docosapentaenoic acids, and DHA in brain fatty acid composition. In addition, brain DHA level in supplemented groups tended higher than the unsupplemented. Brain, AChE activity significantly increased by the environmental enrichment but not by the fish oil supplementation. These finding suggest that the 2% fish oil (0.57% DHA & 0.31% EPA, per diet weigth) supplementation is enough to accumulate n-3 fatty acids and to change the n-6 n-3 ratio in brain and environmental enrichment might promote the learning ability.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.10
• /
• pp.1413-1421
• /
• 2013

The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, $C20:5{\omega}-3$) and docosahexaenoic acid (DHA, $C22:6{\omega}-3$) that are important to human health. Here, we report a functional characterization of a ${\Delta}4$-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.

• Journal of Nutrition and Health
• /
• v.27 no.9
• /
• pp.901-909
• /
• 1994

The effects of sardine oil(high in eicosapentaenoic acid : EPA) and tuna oil(high in docosahexaenoic acid : DHA, also high in EPA) on fatty acid composition of brain and learning ability were evaluated in male weanling Sprague-Dawley rats and compared with the effects of corn oil and beef tallow. Animals assigned by randomized block design to one of the four experimental diet groups containing dietary lipid at 15%(w/w) level were given ad libitum for 7 weeks. Food intake and body weight gain of the fish oil groups were significantly lower than those of the corn oil and beef tallow groups. However, brain weights of the groups were not significantly different. In the brain fatty acid composition, the corn oil group showed high concentrations of n-6 fatty acids, the fish oil groups of n-3 fatty acids, and the beef tallow group of saturated fatty acids. Brain EPA and DHA contents of the fish oil groups showed significantly higher than the other groups while the brain ratio of saturated/monounsaturated/polyunsaturated fatty acid was controlled in a narrow range. In a maze test, the fish oil groups appeared to arrive at the goal faster than the corn oil and beef tallow groups. It explained that EPA in diets might efficiently convert to DHA resulting in DHA accumulation in brain tissue and might increase the learning performance as DHA did.

• Food Science and Preservation
• /
• v.15 no.3
• /
• pp.437-444
• /
• 2008

Structured lipids(SLs) were synthesized by enzymatic interesterification with DHA-enriched fish oil(containing 27% docosahexaenoic acid) and soybean oil in the hatch-type reactor. The interesterification was performed for 24 hr at $55^{\circ}C$ and TLIM(immobilized lipase from Thermonyces lanuginosa, 10% by weight of total substrates) was mixed with 180 rpm of shaking. The fish oil and soybean oil were interesterifed with several weight ratio(fish oil : soybean oil, 2:8, 3:7, 4:6, 5:5, w:w), Reverse-phase high performance liquid chromatography with an evaporative light-scattering detector separated the triglyceride species of SLs. The products contained the newly synthesized peaks. Especially, one of peaks was distinctively increased with the increasing weight ratio from 2:8 to 5:5 while the peak of trilinolein (LLL) decreased vice versa. The effect of antioxidants such as catechin, BHT(Butylated hydroxytoluene), and their combinations on the oxidative stability in SL were investigated. Oxidative stability was carried out under oven test at $60^{\circ}C$ over 72 hr thereafter SLs were analyzed for total fatty acid content, rancimat, peroxide value, electronic nose and TBARS value. Among all combinations of antioxidant, the highest stability was obtained from 200 ppm of catechin. Besides, total tocopherol ($\alpha$, $\gamma$, and $\delta$-tocopherol), iodine and saponification value were analyzed in which iodine and saponification value of SLs were 151.19 and 182.35.

• The Korean Journal of Food And Nutrition
• /
• v.24 no.4
• /
• pp.501-508
• /
• 2011

Previous studies suggest that polyunsaturated fatty acids with long carbon chains such as eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) have several health benefits. However metabolic consequences of these fatty acids themselves and their regulation of transcriptional activity involving glucose utilization are not well established. Thus, the purpose of this study was to investigate how EPA influx affects cellular lipid accumulation and gene expressions involving $de$ $novo$ lipogenesis in hepatocyte cultures. Compared to oleic acid treatment, EPA treatment showed remarkably decreased cellular TG conversion and accumulation, along with phospholipids at a lower extent. As expected, EPA increased mRNA expression involving fatty acid influx and lipid droplet formation, but did not affect mRNA expression involving glucose utilization. EPA increased transcriptional activity of PPAR-${\alpha}$ and glucose responsive transcription factor when transcription factor binding protein was activated. Taken together, these data suggest that EPA decreases lipid accumulation through increases of the ${\beta}$-oxidation pathway without interruption of glucose utilization.

• YAKHAK HOEJI
• /
• v.52 no.4
• /
• pp.264-273
• /
• 2008

The inhibitory effect of omega-3 such as linolenic acid (LNA), docosahexaenoic acid (DNA) and eicosapentaenoic acid(EPA) on the growth of normal cell lines and cancer cell lines was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyItetrazolium bromide (MTT) and 2,3-bis-2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-caboxanilide (XTT) methods. LNA was found to decrease the cell viability of human oral epithelioid carcinoma cells (KB) in the MTT assay, whereas EPA appeared to inhibit the cell adhesion activity of human skin melanoma cells (SK-MEL-3) in the XTT assay analysis. DPPH radical scavenging activity was examined on LNA, DHA and EPA at the concentration of 100 ${\mu}M$, where they showed about 53% scavenging activity. These results suggest that omega-3 unsaturated fatty acid has a potential anticancer activity.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.1
• /
• pp.66-71
• /
• 2002

We investigated the effect of fish oil (FOS) on growth performance, ruminal metabolism and fatty acid composition and physical characteristics of longissimus muscle in 10 steers and 10 bulls of Korean cattle. Concentrates diet was supplemented with FOS at 5% of the diet. FOS contained 3.34% eicosapentaenoic acid (EPA) and 24.87% docosahexaenoic acid (DHA) of total fatty acids by weight. Average daily weight gain and feed efficiency were not affected (p>0.871) by FOS, but feed intake was decreased. FOS had lower (p<0.003) pH and higher (p<0.001) $NH_3$-N than that of control. There was a treatment effect (p<0.001) for serum cholesterol concentrations. FOS increased (p<0.009) concentrations of n-3 fatty acids, including linolenic, EPA and DHA in longissimus muscle. Physical traits were significantly (p<0.015) changed by feeding FOS except for pH and lightness (L). We concluded that the fatty acid composition and physical properties of the muscle in fattening Korean cattle can be altered by feeding 5% FOS.