• 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.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.505-508
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• 2000

In order to determine the position and the content of fatty acids attached to glycerides and the migration degree of fatty acids in the migration reaction, hydrolysis of fish oil was carried out with lipolase-100T derived from Aspergillus oryzae. The content of fatty acids in the glyceride mixture was analyzed and compared with that of fish oil. The amounts of fatty acid in 2-position and the migration degree of the fatty acid in 2,3-DG (diglyceride) and 2-MG (monoglyceride) were calculated. The results showed that approximately 95% (w/w) of DHA (docosahexaenoic acid) and 65% of EPA (eicosapentaenoic acid) was attached to the 2-position of glycerides in the fish oil. Approximately 87% (w/w) of DHA and 75% of EPA remained in 2,3-DG and 88% of DHA and 65% of EPA in 2-MG were not involved in the migration reaction.

• Journal of Nutrition and Health
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• v.26 no.6
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• pp.680-691
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• 1993

Rats were fed for an 8-week period a low riboflavin diet(5ug riboflavin/day) or a control diet(30ug/day) supplied either ad libitum or by pair feeding in order to study the effect of riboflavin on the metabolism of lipids and neurotransmitters. Erythrocyte glutathione reductase (EGR) and monomine oxidase(MAO) activity in the liver and brain were assayed. EGR activity coefficient in riboflavin deficient rats was significantly higher than in ad libitum controls whereas MAO activity was decreased in the deficient rats. Fatty acid composition showed a different trend in the serum, liver and brain. In the serum, the concentrations of essential fatty acids and $\omega$-3 fatty acids(eicosapentaenoic acid, docosahexaenoic acid)were decreased about 20-40% in the deficient and pair-fed than in the ad libitum controls. Brain serotonin and 5-HIAA(5-hydroxyindole acetic acid) concentrations were decreased in the riboflavin deficient rats. Learning ability measured by a water maze and exploratory activity using the open field test were not impaired in the deficient rats. These results indicate that brain lipid metabolism was protected in subclinical riboflavin deficiency, however, riboflavin deficiency affected brain serotonin content.

• Journal of the Korean Applied Science and Technology
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• v.7 no.2
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• pp.55-61
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• 1990

To investigate the influence of saturated fats, ${\alpha}-linolenic$ acid, EPA and DHA on the lipid hydroperoxide concentration and fatty acid composition in liver microsomes and in plasma lipid of rabbits, the animals were fed on the perilla oil rich ${\alpha}-linolenic$ acid or sardine oil rich EPA and DHA diet for four weeks Were examined. The fatty acid composition of plasma lipid and liver microsomes of rabbits fed on the perilla oil diet was an accumulation of arachidonic acid(AA) 20:4 n-6, eicosapentaenoic acid(EPA) 20:5 n-3, and docosahexaenoic acid(DHA) 22:6 n-3, The fatty acid composition of plasma lipid and liver microsomes of rabbits fed on the sardine oil was an accumulation of ${\alpha}-linolenic$ acid(LNA) 18:3 n-3, and arachidonic acid(AA) 20:4. The p/s ratio of rabbits fed on the perilla oil diet changed from 7.4 to 2.27 for plasma lipid and 2.47 for liver microsomes. The concentration of lipid hydroperoxide was 3.48 nmol MDA/ml and 4.35 nmol MDA/ml for plasma lipid and liver microsomes, respectively, in perilla oil diet. The lipid hydroperoxide liver was 4.22 nmol MDA/ml and 67 nmol MDA/ml for plasma lipid and liver microsornes in sardine oil diet.

• 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.

• Preventive Nutrition and Food Science
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• v.21 no.3
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• pp.171-180
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• 2016

Non-alcoholic fatty liver disease (NAFLD) is one of the most prevalent liver diseases associated with an altered lifestyle, besides genetic factors. The control and management of NAFLD mostly depend on lifestyle modifications, due to the lack of a specific therapeutic approach. In this context, we assessed the effect of carrot juice on the development of high fructose-induced hepatic steatosis. For this purpose, male weanling Wistar rats were divided into 4 groups, fed either a control (Con) or high fructose (HFr) diet of AIN93G composition, with or without carrot juice (CJ) for 8 weeks. At the end of the experimental period, plasma biochemical markers, such as triglycerides, alanine aminotransferase, and ${\beta}$-hydroxy butyrate levels were comparable among the 4 groups. Although, the liver injury marker, aspartate aminotransferase, levels in plasma showed a reduction, hepatic triglycerides levels were not significantly reduced by carrot juice ingestion in the HFr diet-fed rats (HFr-CJ). On the other hand, the key triglyceride synthesis pathway enzyme, hepatic stearoyl-CoA desaturase 1 (SCD1), expression at mRNA level was augmented by carrot juice ingestion, while their protein levels showed a significant reduction, which corroborated with decreased monounsaturated fatty acids (MUFA), particularly palmitoleic (C16:1) and oleic (C18:1) acids. Notably, it also improved the long chain n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA; C22:6) content of the liver in HFr-CJ. In conclusion, carrot juice ingestion decreased the SCD1-mediated production of MUFA and improved DHA levels in liver, under high fructose diet-fed conditions. However, these changes did not significantly lower the hepatic triglyceride levels.

• KSBB Journal
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• v.26 no.6
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• pp.557-560
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• 2011

It has been known that Δ-desaturase (TAD5) in the biosynthetic pathway of long chain polyunsaturated fatty acids of Thraustochytrium aureumis responsible for the conversion of di-homo-${\gamma}$-linolenic acid (C20：4) into arachidonic acid (C20：4). The genetic sequence analysis on TAD5 of Thraustochytrium aureum ATCC34304 used in this study showed that it has two amino acid changes when compared to that of Thraustochytrium aureum TAD5 first reported in 2003. Accordingly, Thraustochytrium aureum ATCC34304 TAD5 was named TAD5_1. TAD5_1-inserted methylotropic Pichia pastoris was prepared and then cultured with a precursor fatty acid, di-homo-${\gamma}$-linolenic acid. GC analysis confirmed that a certain amount of the precursor fatty acid was converted into arachidonic acid. In this study, not only a recombinant Pichia pastoris with the typical activity of ${\Delta}5$-desaturase which plays an essential role in the biosynthesis of LCPUFAs was successfully made but also the preparationpotential of a recombinant Pichia pastoris strain which may synthesize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that are important in maintaining and improving human's brain function was proposed.

• 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.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.547-557
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• 1993

This study was done to investigate whether dietary fats differing in their fatty acid compositions change hepatic mitochondrial lipid composition and thereby change adenine nucleotide translocase activity. Male Sprague-Dawley rats were fed 5 different wxperimental diets for 6 weeks, which were different in their fatty acid compositions. The dietary fats were beef tallow(BT), olive oil(OO), corn oil(CO), perilla oil(PO) and sardine oil(SO) as a source of saturated fatty acid, oleic acid, n-6 linoleic acid, n-3 $\alpha$-linolenic acid and n-3 eiocosapentaenoic acid+docosahexaenoic acid respectively. Body weight of PO group was significantly higher than that of either BT or SO group. This increase in body weight of PO group was due to the increase of food intake. Although there was no difference in liver weight, % liver weight per body weight of SO group was significantly higher than BT and OO groups. Analysis of mitochondrial lipid composition showed that dietary oils differing their fatty acid compositions altered mitochondrial fatty acid patterns, especially n-6/n-3 ratio, cholesterol/phospholipid ratio and phopsholipid composition. The n-6/n-3 ratio was highest in CO group but lowest in SO group whereas the ratio of Chol/PL was highest in SO group but lowest in CO group. Such changes in mitochondrial lipids did not lead to a significant alteration in the activities of adenine nucleotide translocase, which is embedded in mitochodrial inner membrane.