• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.210-216
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• 1998

Relationship between population group properties and docosahexaenoic acid (DHA) content of the Pacific oyster had been carried out at the Bukman oyster farm near Tongyeong based on the regular monthly sampling from November 1994 through April 1996. DHA content in lipids was least abundant in June and most abundant in November. Minimum DHA content close to 'zero' in lune suggests that much of DHA are being used for maturing and discharging of eggs and sperms, in consideration of the fact that lure is the spawning periods of the oyster. The corelationships among DHA content, mortality, and growth coefficient, have not been recognized. The approximate positive relations have been acknowledged between DHA content and the individual density in times of harvest, and also the individual weight. But it seems that the relaltions between DHA content and the individual weight are not directly related, rather it seems that it is the result from the population density effects caused by the relations between DHA and the number of individuls. But the meaning of the above mentioned relations can not be clearly defined yet.

• Journal of Nutrition and Health
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• v.24 no.4
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• pp.314-325
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• 1991

To compare the hypolipidemic effects of n6 and n3 PUFA at different fat levels, male Sprague Dawley rats were fed either low fat (LF, 10% Cal) or high fat (HF, 40% Cal) diet which was different only in fatty acid composition for 6 weeks. Dietary fats were beef tallow, corn oil, perilla oil, and fish oil concentrate as a source of saturated fatty acid, n6 linoleic acid(LA). n3 ${\alpha}-linolenic$ acid(LL) and n3 eicosapentaenoic acid(EPA)+docosahexaenoic acid(DHA), respectively. VLDL fraction was separated by ultracentrifugation and chemical composition was determined by thin layer chromatography. Plasma cholesterol level was increased by n6 LA but decreased by n3 LL and n3 EPA in LF and HF diets, and the hypocholesterolemic effect of n3 EPA was most significant in HF diet. HDL-Chol level was raised by n6 LA in LF and HF diets, but significantly reduced by n3 EPA in HF. Plasma TG level was reduced by n6 LA n3 LL and EPA in LF and HF with the reduction of lipogenic enzyme activity only by n3 PUFAs. The proportion of TG in VLDL fraction was significantly lowered by n3 EPA in LF and HF. The proportion of apo-B in VLDL fraction was not changed in LF, but was significantly decreased in HF by n3 EPA. Therefore, the hypotriglyceridemic effect of n3 PUFA could be from the reduced lipogenesis in liver and resulted in the depressed secretion of TG as VLDL in LF and HF with significant lower production of apoB in HF diet.

• Journal of Nutrition and Health
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• v.31 no.5
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• pp.897-905
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• 1998

Docosahexaenoic acid(DHA), a $\omega$3 series fatty acid and arachidonic acid(AA). a $\omega$6 series fatty acid were found in relatively high concentrations in the phospholipids(PLs) of cell membranes of nerve tissues, and they can be affected by various factors. The present study examined the effects of dietary $\omega$6 and $\omega$3 fatty acid composition on P/M/S and on $\omega$3/$\omega$6 fatty acid ratios in brain PLs of 2nd generation rats. The expeimental diets consisted of 10% fat(by wt), which were computer- searched mixed oil('M') with P/M/S ratio, 1 : 1.4 : 1 and $\omega$6/$\omega$3 ratio, 6 : 1 and safflower oil('S') poor in $\omega$3 fatty acids. The experimental diets were started 3-4 wks prior to conception. During the lactation period, the feeding mothers were switched 1 wk after birth and provided the pups for 2 wks with milk which had compositions different from that of their natural mother. The same diet as their mothers was provided from weaning to 9 wks of age. The 'M'and 'S' rats were again subdivided into MM, MS, SS, SM rats according to diet which their lactating mothers were fed from the begining of the experiment. The relative percentage of P/M/S fatty acids in brain PLs in all experimental groups converged to a very similar value at 9 wks of age, indicating the existence of a control mechanism for the degree of fatty acids, unsaturation. The $\omega$3/$\omega$6 fatty acid ratios of brain PLs converged to about 1.0 in MM & SM groups and to 0.7 in SS & MS groups, suggesting also the existence of some balance between $\omega$3 and $\omega$6 fatty acids in developing rat brain. The concentrations of $\omega$3 fatty acids, especially DHA, in the SM group were increased and became similar to those in MM group at 9 wks of age. The increase in DHA of brain PLs was counterbalanced b)r a decrease in 22 5$\omega$6. Therefore, the ratios of 22 : 6$\omega$6/22 : 5$\omega$6 were higher in both MM & SM groups than those of SS & MS groups at 9 wak of age. Although dietary $\omega$3 and $\omega$6 fatty acids affected 22 : 6$\omega$S and 22 : 5$\omega$6 contained in rat brain PLs reciprocally, the relative percentage of AA did not appear to be significantly influenced by the diet in all groups at 9 wks of age, suggesting that a mechanism for the maintenance of a certain level of AA in brain PLs exists. In conclusion, the $\omega$3/$\omega$6 fatty acid and 22 : 6$\omega$3/22 : 5$\omega$6 ratios, but not P/M/S ratio, of rat brain PLs were affected by the postnatal dietary changes. Futher studies are required to clarify the mechanism(S) of ensuring a certain level of DHA and of maintaining a similar level of AA in rat brain PLs after. weaning(9 wk) regardless of prenatal and postnatal dietary changes. (Korean J Nutrition 31(5) : 897-905, 1998)

• Journal of Environmental Science International
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• v.23 no.1
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• pp.47-52
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• 2014

Antarctic krill (Euphausia superba) is typical of a enormous biomass of marine zooplankton that could provide good nutrition in human body. This study was conducted to identify the nutrition of krill, a live in Antarctic Ocean. The analysis result of fatty acids of krill meal was as follow. The compositions of fatty acid were saturated fatty (SFA) acid 41.41%, monounsaturated fatty acid (MUFA) 21.69%, polyunsaturated fatty acid (PUFA) 36.89%, and p/s ratio was 0.89. The major fatty acids in all parts were eicosapentaenoic acid (EPA, 21.54%), palmitic acid (27.51%), oleic acid (13.35%) and docosahexaenoic acid (DHA, 12.42%). Especially, EPA and DHA were occupied 33.96% of polyunsaturated fatty acid. The mineral contents of krill meal were calcium 24477.21 mg $kg^{-1}$, sodium 14728.69 mg $kg^{-1}$, magnesium 6973.49 mg $kg^{-1}$, potassium 3981.67 mg $kg^{-1}$, iron 395.33 mg $kg^{-1}$ and manganese 5.74 mg $kg^{-1}$. The contents of major vitamin were retinol 86717.37 ${\mu}g$ RE, ${\beta}$-carotene 44.87 ${\mu}g$ RE, tocopherol 2.60 mg, pantothenic acid 1.61 mg, indicating that krill meal contains large amount of retinol and ${\beta}$-carotene.

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.255-265
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• 2008

The objective of this study was to evaluate the docosahexaenoic acid(DHA) levels of meats and eggs from chickens which were fed fermented soybean meal(FSM) by marine microalgae(Schizochytrium mangrovei MM103). The diets contained different amounts of FSM at 0, 3, 5 and 10%. DHA content of carcass was increased with dietary FSM. DHA amounts in the breast meat were higher in the 10% FSM diet(2.21%) than the 5%(1.65%) and 3%(1.18%) FSM, and similar results were observed in the leg meat(10% FSM: 2.21%; 5% FSM: 1.65%; and 3% FSM: 1.18%, respectively) and in eggs(10% FSM: 2.02%; 5% FSM: 1.22%; and 3% FSM: 0.73%). The level of n-3 polyunsaturated fatty acids such as DHA(22:6n-3) in the FSM treatment was significantly higher than those of the other groups(P<0.05). The results demonstrated that FSM by marine microalgae could be used to enhance DHA amounts in chicken meats and eggs.

• Journal of Nutrition and Health
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• v.24 no.5
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• pp.420-430
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• 1991

To compare the hypolipidemic effects of n6 linoleic acid. n3 $\alpha$-linolenic acid and n3 eicosapentaenoic acid in rats fed high carbohydrate(70% Cal) diet. male Sprague Dawley rats were fed different experimental diets for 6 weeks. which were different only in fatty acid composition. The dietary fats were beer tallow(BT) as a source of saturated fatty acid (SFA), corn oil(CO) for n6 linoleic acid(LA), perilla oil(PO) for n3 $\alpha$-linolenic acid(LL) and fish oil(FO) for n3 eicosapentaenoic acid(EPA) and docosahexaenoic acid (DHA) Plasma total cholesterol(Chol) level was increased by n6 LA but decreased by n3 LL and n3 EPA and most effectively reduced by n3 EPA. HDL-Chol level was raised by n6 LA, but there was no significant change in HDL-Chol levels by n3 LL and was lowered by n3 EPA. Plasma TG level was reduced by n6 LA, but lipogenesis in liver was not affected by n6 LA. However, plasma TG level was lowered by n3 LL and EPA. Both lipogenic enzyme activity and liver TC level were also decreased by n3 PUFA. The relative proportions of TG in VLDL was significantly lowered by n3 EPA. but the proportions of Apo B in VLDL was not changed by n3 EPA. Overall. the hypolipidemic effect was in the order of EPA+ DHA(n3) >LL(n3) >LA(n6) and fish oil and perilla oil rich in n3 PUFA may have important nutritional applications in the prevention and treatment of hypertriglyceridemia.

• Journal of Environmental Science International
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• v.17 no.5
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• pp.537-546
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• 2008

The experiment was conducted to determine the effect of the mixed herbal medicine for the substitution of antibiotics on the performance of laying hens. Day old hyline 1,500 layer chicks were randomly assigned to 4 treatments. Control were 600 and three each treatment was 300. Eggs were collected at every weeks for measuring egg production and week 26, 27, 28 for chemical analyses. Chemical analyses were done for fatty acid profile of egg yolks, amino acid, antibiotics residue in eggs(collect eggs after supplying OTC 21ppm/bird/day to control for four day at 26, 27, 28) during the laying period($19{\sim}77wk$). On $0{\sim}4$ week, T-3 showed higher feed intake than those fed the other diets and on $5{\sim}13$ week, T-2 showed highest feed intake among treatments. After birds were moved ($14{\sim}18$ wk) CT-3 showed highest, but for overall rearing period, there was not significantly different among treatments. In conclusion the mixed herbal medicine did not tended to influence palatability to rearing birds. Egg quality(egg yolk color, haugh unit, eggshell breaking strength) showed no difference among treatments. Ratio of unsaturated fatty acid (mg/100g)/saturated fatty acid (mg/100g) was not difference among treatments, but linolenic acid and docosahexaenoic acid(DHA) of the mixed herbal medicine treatments showed higher then control. The antibiotics residue of CT, T treatments egg was not detected and control was not detected or below allowance. In conclusion the mixed herbal medicine can be possible to feed laying hen without antibiotics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.49-58
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• 2019

This study was conducted to investigate the effects of different dietary lipid sources on the growth, feed utilization, body composition and tissue fatty acid profile of olive flounder Paralichthys olivaceus. Five isonitrogenous and isocaloric diets were formulated by adding various lipid sources including soybean oil (SO), eicosapentaenoic acid triglyceride (EPATG) and ethyl ester (EPAEE) forms, docosahexaenoic acid triglycerides (DHATG) and a 1:1 blend of soybean oil and DHATG. Triplicate groups of fish ($6.8{\pm}0.01g$) were fed one of the experimental diets to apparent satiation twice daily for 8 weeks. Fish fed the DHATG diet had the highest growth, protein efficiency ratio and feed efficiency values which were significantly higher than those fed the SO and EPAEE diets. Whole body proximate composition and somatic parameters were not influenced by the dietary treatments. Muscle of fish fed with SO diets were rich in 18:1n-9, 18:2n-6 and 18:3n-3, whereas those of fish fed with EPATG, EPAEE and DHATG diets were rich in n-3 highly unsaturated fatty acids (HUFA). These findings indicated that the inclusion of n-3HUFA oils in olive flounder feed could be beneficial for the fish while simultaneously increasing the concentration of beneficial n-3HUFA in fish fillets destined for the human consumer.

• Journal of Life Science
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• v.26 no.9
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• pp.1049-1055
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• 2016

This study aimed to investigate an effective method of purifying oil from hydrolysates of mackerel by-products. A hydrolyzed sample was separated into lipids and other material. After degumming of crude lipids with 6% citric acid solution, the phosphorous content (45 mg/kg) decreased to 5.8 mg/kg, and the acid value (18.03 mg /g) decreased to 1.19 mg KOH/g. Following the addition of 8% sodium hydroxide solution, the peroxide value (30.25 meq/kg) dropped to 3.18 meq/kg, and the chromaticity decreased from 0.488 nm to 0.057 nm. Bleaching was performed by adding 5% activated charcoal for 60℃ for 20 min under vacuum conditions. After bleaching, the acid value was 0.17 mg KOH/g, and the peroxide value was 1.21 meq/kg, but the chromaticity was not changed remarkably (0.062 nm). Crystallization was conducted to increase the amount of unsaturated fatty acids. After crystallization, the total amount of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) was 228.83 mg/g. The results suggest that the product can be used as an omega-3 fatty acid resource for functional food.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.319-328
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• 1997

To develop a beneficial microbial feed for the cultivation of rotifer, Brachionus plicatilis, an aerobic photosynthetic bacterium, Erythrobacter sp. $S\;\pi-I$ was isolated from marine structure at Haeundae beach in Pusan, Korea. Feeding effects of Erythrobacter sp. $S\;\pi-I$ on the growth of rotifer were analyzed comparing to other feeds such as PSB (purple nonsulfur bacteria), Chlorella sp. and baker's yeast. Erythrobacter sp. $S\;\pi-I$ contained more linoleic acid $(C_{18:3\omega3})$ and oleic acid $(C_{18:1\omega9})$ and amino acids than PSB (purple nonsulfur bacteria), Chlorella sp. and baker's yeast. The rotifer fed on Erythrobacter sp. $S\;\pi-I$ showed better effects than those fed on other feeds in the individual growth, size and weight. Also, the rotifer especially contained more eicosapentaenoic acid $(C_{20:5\omega3})$ and docosahexaenoic acid $(C_{22:6\omega3})$ in case of Erythrobacter sp. $S\;\pi-I$ feeding than the other feeds. In case of the feed of PSB and baker's yeast docosahexaenoic acid $(C_{22:6\omega3})$ did not show. In amino acid analysis, the rotifer fed on Erthrobacter sp, $S\;\pi-I$ showed more amino acid content comparing to those fed on other diets. Especially, arginine, isoleucine, histidine, lysine, methionine, phenylalanine, threonine, which are essential amino acid for fish growth, showed high contents. These results suggested that the aerobic photosynthetic bacterium, Erythrobacter sp. $S\;\pi-I$ would be a beneficial microbial teed for the cultivation of rotifer.