• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.16-23
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• 2009

Lipids were extracted from marine rotifer, Brachionus rotundiformis in order to examine the functionality of lipid enzymatic modification. The fatty acids, palmitic, linoleic, oleic and stearic acids were the dominant forms accounting for approximately 35.8%, 21.5%, 15.9% and 7.7% of the total lipid content, respectively. Lipid fractions were categorized as neutral lipids (38.5%), glycolipids (45.9%) and phospholipids (17.6%), and after extraction from the rotifer were isolated by thin-layer chromatography (TLC) as free fatty acids (FFA), monoacylglycerol (MAG), diacylglycerol (DAG) and triacylglycerol (TAG). The production of polyunsaturated fatty acid (PUFA) concentrate from rotifer lipids was studied using lipase-catalyzed hydrolysis. In addition, rotifer lipids were modified by hydrolysis using lipases such as porcine pancreas, Candida rugosa and Rhizomucor miehei. The lipase from Rhizomucor miehei was effective in extracting linoleic acid (C 18:2), while the lipase from Candida rugosa was effective in palmitic acid (C16:0) extraction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.145-152
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• 1999

To explore the possibility of using freeze dried loach for instant choo o tang(Korean traditional loach soup), protein qualities and fatty acid composition were evaluated on boiled and steamed loach. Total lipid and ash content were lowered in both heated(boiled and steamed) loaches due to deboning and eviscerating during cooked meat preparation. Profiles of total amino acids were not changed seriously by the type of cooking, but the amount of essential amino acids were comparable in all samples. Two times more free amino acids were quantified in cooked samples compared to raw meat. Available lysine was marginally decreased by cooking, and that caused some measurable change in typsin indigestible substrate(TI) in streamed whole loach. In vitro protein digestibility of the heated loaches was not altered drastically and the protein quality determined as computed protein efficiency ratio(C PER) was similar for the raw, boiled and steamed loach. The ratios of unsaturated to saturated fatty acids changed measurably in heated whole loach. The results shows that heating caused apparent oxidative deterioration of the polyunsaturated fatty acids.

• Food Science of Animal Resources
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• v.18 no.3
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• pp.261-268
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• 1998

In beef, the composition of saturated and unsaturated fatty acids(UFA) were 41.1% and 56.7%, respectively. The rates of saturated fatty acid (SFA) was 36.3, 40.9, 39.2 and 48.1% in loin, picnic shoulder, ham and rib, respectively. However, UFA showed 62.3, 58.4, 56.8, 50.9% in loin, picnic shoulder, ham and rib, respectively. The rates of monounsaturated fatty acid (MUFA) were similar to those of unsaturated fatty acid in four portions. The content of SFA, UFA and polyunsaturated fatty acid(PUFA) were 40, 59 and 9.4%, respectively, in pork. In portional comparison, composition of unsaturated fatty acids in picnic shoulder, ham rib and loin were 64.2, 60.4, 54.6 and 55.3%, respectively. The UFA contents of rib and loin were lower than picnic shoulder and ham, but SFA levels were higher. Total UFA content of chicken was 62.9% showing higher level than other species, but low when compared to that of duck meat. SFA content resulted in lower level than other portions. In the skin of chicken, MUFA content was especially high showing no significant changes in UFA contents. Duck meat showed lower SFA content, but higher content in UFA compared to those of other species. Skin and thigh contained 31.8 and 31.5%, respectively, in SFA, which are lower level than those of breast and thigh meat. The UFA contents of skin and thigh were 67.4 and 67.7%, respectively, which are relatively high compared to those of other portions. Meanwhile, the ratio of UFA was not high in canis meat compared to other meat. PUFA was, however, 24.2% showed significantly different from other meats. The contents of SFA were 35.4% and 35.9%, respectively, in picnic shoulder and ham. They showed lower SFA but higher UFA content than those of rib and loin. In contrast, the ratio of picnic shoulder and ham were 61.6 and 61.4%, respectively. Interestingly, picnic shoulder showed higher UFA content, especially in arachidonic acid level than other portions.

• ALGAE
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• v.31 no.1
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• pp.61-72
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• 2016

Arctic microalgae thrive and support primary production in extremely cold environment. Three Arctic green microalgal strains collected from freshwater near Dasan Station in Ny-Alesund, Svalbard, Arctic, were analyzed to evaluate the optimal growth conditions and contents of fatty acids. The optimal growth temperature for KNF0022, KNF0024, and KNF0032 was between 4 and 8℃. Among the three microalgal strains, KNF0032 showed the maximal cell number of 1.6 × 107 cells mL^-1 at 4℃. The contents of fatty acids in microalgae biomass of KNF0022, KNF0024, and KNF0032 cultured for 75 days were 37.34, 73.25, and 144.35 mg g^-1 dry cell weight, respectively. The common fatty acid methyl esters (FAMEs) analyzed from Arctic green microalgae consisted of palmitic acid methyl ester (C16:0), 5,8,11-heptadecatrienoic acid methyl ester (C17:3), oleic acid methyl ester (C18:1), linoleic acid methyl ester (C18:2), and α-linolenic acid methyl ester (C18:3). KNF0022 had high levels of heptadecanoic acid methyl ester (26.58%) and heptadecatrienoic acid methyl ester (22.17% of the total FAMEs). In KNF0024 and KNF0032, more than 72.09% of the total FAMEs consisted of mono- and polyunsaturated fatty acids. Oleic acid methyl ester from KNF0032 was detected at a high level of 20.13% of the FAMEs. Arctic freshwater microalgae are able to increase the levels of polyunsaturated fatty acids under a wide range of growth temperatures and can also be used to produce valuable industrial materials.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.637-649
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• 2017

Lipid levels and fatty acid compositions of 20 species of subtropical fish caught off the coast of Jeju Island, Korea were determined. The fish were categorized according to total lipid (TL) content as follows; lean fish ($TL=1.19{\pm}0.32%$, n=10 species), low-fat fish ($TL=3.02{\pm}0.44%$, n=6 species) and medium-fat fish ($TL=6.87{\pm}1.23%$, n=4 species). The prominent fatty acids were saturated fatty acids (SFAs), at 16:0 and 18:0 monounsaturated fatty acids (MUFAs), at 18:1n-9 and 16:1n-7, and polyunsaturated fatty acids (PUFAs), at 22:6n-3, 20:5n-3 and/or 20:4n-6. Across all species, the percentages of PUFAs and SFAs were $38.0{\pm}7.89%$ and $34.3{\pm}3.08%$, respectively, with no significant difference between both groups (P<0.05), but showed higher proportions than that of MUFA group ($27.8{\pm}7.23%$) (P<0.05). The proportion of n-3 PUFAs was $27.1{\pm}8.68%$ across all fish species, similar to levels in other fishes from Korea. These results suggest that subtropical fish from Jeju Island are a good source of n-3 PUFAs for humans.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.919-923
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• 1999

The edible portions of saury were cooked by pan frying, deep fat frying, steaming and microwave cooking to compare the compositions of fatty acids in cooked fish with those in raw fish. The total lipid in saury studied varied by each fish but ranged from 21.87% to 30.63%. The distribution of each fatty acid (average) was in order; $C_{22:1}\;(21.75%)>C_{20:1}\;(15.81%)>C_{16:0}\;(11.75%)>C_{22:6}\;(DHA,\;10.61%)>C_{14:0}\;(7.04%)>C_{20:5}\;(EPA,\;5.13%)$. The average ratio of PUFA (polyunsaturated fatty acids)/SFA (saturated fatty acids) in saury fillet was 1.07 and that of n-3/n-6 was 9.15, which showed saury might be a good source for PUFA including n-3 fatty acids. Comparing the effects of cooking on EPA and DHA, two of the most important n-3 PUFA, the decreasing rate of EPA were 6.98% (pan frying), 26.93% (deep fat frying), 1.16% (steaming) and 15.12% (microwave cooking), respectively. The decreasing rate of DHA ware 4.30% (pan frying), 15.99% (deep fat frying), 3.26% (steaming) and 9.56% (microwave cooking). This study showed that both EPA and DHA were reduced by steaming least, and pan frying, microwave cooking, deep fat frying most, in order.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.2
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• pp.95-98
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• 1985

This study was carried out to investigate changes in the compositions of fatty acids according to the different drying methods of raw mugwort. Raw mugwort from Kang-wha was dried with four methods such as sun-drying, shady sun-drying, heated oven-drying and freeze-drying. Total contents and fatty acid compositions of the ethyl ether extracts from the dried mugworts were examined. Total contents of the ethyl ether extracts showed remarkable differences with drying methods; freeze-dried mugwort had the highest content (5.60%), while oven dried mugwort revealed the lowest content (2.45%). Eleven fatty acids and four unknown peaks were identified by gas-liquid chromatography; major fatty acids were linoleic acid, linolenic acid and palmitic acid. Fatty acids of mugworts dried by 4 different methods were the same in kinds, but different in their compositions. The content of polyunsaturated fatty acids $(C_{18:2}+C_{18:3})$ was the highest and the loss of low volatile fatty acids was the least in mugwort dried by the freeze-drying method. The volatile fatty acids considerably decreased in oven-dried mugwort. However, the contents of polyunsaturated fatty acids were a little higher in oven-dried mugwort than in sun-dried and shady sun-dried mugwort, and the lowest in sun-dried mugwort.

• Development and Reproduction
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• v.21 no.3
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• pp.275-286
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• 2017

The purpose of this study is to investigate the differences fatty acids and hormonal parameters in the spawning and non-spawning season between the diploid and induced triploid Far Eastern catfish, Silurus asotus. The measured triploids were produced by cold shock for 50 min at $4^{\circ}C$ in May 2014, the spawning season of diploid was in May, and the non-spawning season was designated in January. Estradiol and testosterone and gonadosomatic index of diploid were higher than those of induced triploid in spawning season (P<0.05), and those of diploid in spawning season were higher than non-spawning season. On the other hand, thyroid stimulating hormone and thyroxine of induced triploid were higher than those of diploid in spawning season (P<0.05). Erythrocyte count of diploid was higher than that of induced triploid in spawning season and non-spawning seasons. Mean corpuscular volume and mean corpuscular hemoglobin of induced triploid were higher than those of diploid in both seasons (P<0.05). Percentages of total saturated fatty acids and n-3 polyunsaturated fatty acids of induced triploid were higher than those of diploid in spawning season, but those of diploid were higher in non-spawning season (P<0.05). Percentages of total mono unsaturated fatty acids and total n-6 polyunsaturated fatty acids of diploid were higher than those of induced triploids in spawning season, while those of induced triploid in non-spawning season were higher (P<0.05). Therefore, induced triploids in the spawning season tend to concentrate on growth and lipid-synthesization, whereas, diploids concentrate on reproduction and gonadal maturation rather than on growth. In non-spawning season, growth and lipid-synthesization were not significantly different between diploid and induced triploid.

• Nutritional Sciences
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• v.6 no.2
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• pp.78-84
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• 2003

The objective of this study was to examine the effects of seven dietary oils on the serum lipid patterns of rats. Seventy weanling Wistar Kyoto rats were divided into seven groups of ten rats each. Walnut oil (rich in PUFA), wheat germ oil (rich in PUFA), corn oil (rich in PUFA), canola oil (rich in monounsaturated fatty acids), fish oil (rich in PUFA), primrose oil (rich in PUFA), and palm oil (rich in saturated fatty acids) were employed for 21 days. Serum total cholesterol concentrations for rats fed palm oil, walnut oil, and wheat germ oil were significantly higher than were concentrations for rats receiving corn oil. fish oil, and primrose oil. The mean serum LDL cholesterol values for rats fed fish oil, primrose oil, and corn oil were significantly lower than those for rats fed walnut oil, wheat germ oil, canola oil, and palm oil. HDL cholesterol concentrations were the highest when wheat germ oil was fed and the lowest when fish oil was fed. The feeding of wheat germ oil and palm oil to rats resulted in considerably higher serum triglyceride levels than did all other treatments. The feeding of wheat germ oil to rats resulted in considerably higher serum phospholipid levels. Serum phospholipid concentrations were significantly lower in rats fed the canola oil, fish oil, ,and primrose oil diets, when compared to concentrations achieved with the feeding of walnut oil, wheat germ oil, corn oil, and palm oil. Palm oil, which has a high ratio of saturated to polyunsaturated fatty acids, resulted in the highest serum total cholesterol and highest LDL cholesterol levels, while fish oil, primrose oil, and corn oil produced the lowest total cholesterol and LDL cholesterol. Wheat germ oil produced the highest values for HDL cholesterol, triglycerides, and phospholipids. In general, feeding oils rich in polyunsaturated fatty acids produced more favorable responses than feeding oils containing large amounts of monounsaturated or saturated fatty acids.

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