• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.624-630
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• 1999

In order to investigate the position of various fatty acids attached to glycerol and the specificity of Lipolase-100T, hydrolysis of fish oil was carried out with Lipolase-100T derived from Aspergillus oryzae. The amounts of free fatty acids produced from triglyceride, 1,2(2,3)-diglyceride, 1,3-diglyceride, and 2-monoglyceride and conversion rates of 1,2(2,3)-diglyceride to 1,3-diglyceride and 2-monoglyceride to 1(3)-monoglyceride were also calculated. The ratio of 1,2-diglyceride content to 1,3-diglyceride was higher than 70 in the early period of hydrolysis. The fatty acid content of the glyceride mixture after 72 h of hydrolysis was compared with that of fish oil, and it was found that polyunsaturated fatty acids such as C16:4, C20:4 n-3, C20:5 n-3, C21:5 n-3, C22:5 n-3 and C22:6 n-3 were located in the 2-position of glycerol. Material balance of each component in the hydrolysis system was written to obtain a set of simultaneous linear equations. The theoretical quantity of free fatty acids produced from triglyceride, 1,2-diglyceride, 1,3-diglyceride, and monoglyceride, respectively, were calculated by solving the linear equation system. The conversion rate of 1,2(2,3)-diglyceride to 1,3-diglyceride and that of 2-monoglyceride to 1(3)-monoglyceride were also obtained. The results showed that the migration rate of 1,2(2,3)-diglyceride to 1,3-diglyceride was higher than the hydrolysis rate of 1,2(2,3)-diglyceride to 2-monoglyceride and the conversion rate of 2-monoglyceride to 1(3)-monoglyceride was extremely low.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.144-153
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• 2014

Both docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) have attracted increasing attention since the first epidemiological report on the importance of n-3 essential fatty acids. Lipids in microbial cells play various biological roles and, consequently, much research has been carried out on their role in cell physiology. The lipid composition of microorganisms can exhibit considerable variations depending on environment. The effects of culture conditions, temperature (15, 20, 24, 28, 32 and $36^{\circ}C$), salinity (10, 20, 30, 40 and 50 psu), pH (pH5, 6, 7, 8 and 9), rotation speeds (50, 100, 150 and 200 rpm), carbon sources, nitrogen sources and C/N ratio on the production of docosahexaenoic acid, fatty-acid profiles, and acids secreted to the broth culture by the oleaginous microorganism, Schizochytrium mangrovei (KCTC 11117BP), were studied. Temperature (initially $28^{\circ}C$), salinity (20 psu), pH (pH7), rotation speeds (100 rpm), organism fatty acids, and secreted acids in the broth were varied during cultivation of S. mangrovei. At pH 7.0, S. mangrovei was able to accumulate lipids up to 40% of its biomass, with 13% (w/w) DHA content. The monosaccharides glucose and fructose, and yeast extract were suitable carbon and nitrogen sources, respectively. The primary omega-3 polyunsaturated fatty acid produced was docosahexaenoic acid.

• Journal of Applied Biological Chemistry
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• v.42 no.2
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• pp.75-80
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• 1999

The effects of dietary n-3 fatty acids, ${\alpha}$-linolenic acid (18:3), eicosapentaenoic acid (EPA, 20:5), and docosahexaenoic acid (DHA, 22:6), on brain phospholipid content and fatty acid composition were compared in rats fed with a diet containing constant ratios of saturated fatty acid/monounsaturated fatty acid/polyunsaturated fatty acid (PUFA) and n-3/n-6. The dietary fat in each diet was added at the level of 10%. In each diet, n-3 PUFA comprised two-thirds of the PUFA and the remaining one-third was linoleic acid (18:2). Dietary fat containing linoleic acid as the sole source of PUFA was also given to the control group. The content of brain phospholipid in the three n-3 PUFA groups was significantly lower than that of the linoleic acid group. This reduction was greater in the EPA and DHA groups than in the ${\alpha}$-linolenic acid group. The decrease in phospholipid content in rats fed n-3 fatty acid-rich diets was largely due to the decrease in the phosphatidylethanolamine fraction. Each dietary n-3 PUFA was found to affect the fatty acid composition of brain phospholipids; the most pronounced alteration was observed in phosphatidylethanolamine fraction. Furthermore, the proportion of DHA in the phosphatidylethanolamine fraction tended to be higher in the DHA group than in other PUFA groups. In conclusion, dietary ${\alpha}$-linolenic acid, EPA and DHA can influence the phospholipid content, phospholipid subclass, and fatty acid composition in rat brain.

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.118-125
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• 2000

Lipid classes and fatty acid compositions of eight species of wild and cultured seawater fish in Korea were investigated. Total lipid (TL) contents of wild and cultured fish were $2.64\pm1.88\%$ and $5.42\pm1.76\%$, respectively, except for rockfish and striped beakperch. Non-polar lipids (NL) in all fish samples comprised approximately $84\%$ of the TL content. The proportion equation of NL content to TL content was y=0.9296x-0.4468 $(R^2=0.98l2, p<0.001)$. The most abundant NL class was triglyceride. The prominent fatty acids in all fish samples were 16: 0, 18: 1(n-9), 22 : 6(n-3) (docosahexaenoic acid, DHA), 16: 1(n-7), 20 : 5 (n-3) (eicosapentaenoic acid, EPA), 18 : 0 and 18 : 1(n-7). The polyunsaturated fatty acid (PUFA) group was the richest among the total fatty acids (TFA). DHA and EPA were comprised of approximately $85\%$ of n-3 PUFA. There was a positive correlation between TFA content and n-3 PUFA content; y=0.292x-0.0055 $(R^2=0.9349, p<0.001)$. The n-3 PUFA content of the cultured fish was approximately twice as much as that of the wild fish. Therefore, cultured fish were proven to provide better sources of n-3 PUFA if compared to wild fish.

• Journal of the Korean Applied Science and Technology
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• v.12 no.1
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• pp.55-58
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• 1995

To investigate of the content of fatty acids and cholesterol level in Raja Skates, the skate was purchesed from Yangdong Fisheries market in Kwangju, Korea. The experimental skate contained moisture 77.1%, crude protein 20.5%, crude lipid 0.68% and ash 1.72% as the general components. The fatty acids composition of skate are 28 kinds, such as 10 kinds of saturated fatty acid and 18 kinds of unsaturated fatty acid. There are 5 kinds of odd numbered fatty acid, such as C15:0, C17:0, C19:0, C25:0. Lignoceric acid shows 11% content. As an unsaturated fatty acid, getoleic acid, C22:1: selecholeic acid, C24:1:9, 12-hexadecadienic acid, C16:2: trans-linolelaidic acid, C18:2:13, 16-docosadienoic acid, C22:2: are analyzed as the particular one. The p/s ratio of skates is 1.02 and n-3/n-6 ratio of Skates is 0.82, respectively. The content of cholesterol level of Skates muscle is less than 20mg%, and liver contains 300-500 mg% and Nechang-tang contains 100mg% each.

• Journal of the Korean Data and Information Science Society
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• v.26 no.3
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• pp.669-675
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• 2015

This study was carried out to elucidate the effect of different rearing system on cortisol level, stress hormone, and fatty acid composition in the edible muscle tissues. These steers were reared in two different systems including antibiotic-free (ARS) and conservative system (CRS). In the M-Longissimus tissue, cortisol level was significantly lower in ARS than CRS, (p=0.0176). But, the levels of total saturated and unsaturated-fatty acids does not differ in ARS as CRS (p >0.05). However, the total saturated fatty acid levels tended to be greater in CRS and the total unsaturated fatty acid levels tended to be greater in ARS. However, the level of n-6 unsaturated fatty acid was higher in ARS than CRS (p=0.004). Especially, levels of linoleic acid (LA) and ${\gamma}$-linolenic acid (GLA) were significantly higher in ARS (p <0.01). Cortisol level and the n-6 fatty acid content in muscle tissue were negatively correlated (at p=0.00140.) In conclusion, ARS may produce beef with higher quality which contains lower cortisol and greater n-6 fatty acids, such as ALA and GLA.

• Journal of the Korean Applied Science and Technology
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• v.25 no.4
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• pp.446-458
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• 2008

Essential fatty acids (EFA) are fatty acids that must be obtained from the diet because they can not be biosynthesized by human or animals. Gamma fatty acids contain gamma-linolenic acid (GLA, 18:3n-6) and dihomo-gamma-linolenic acid (DHGLA, 20:3n-6) as intermediate metabolites of linoleic acid (LA, 18:2n-6), which is an EFA found in vegetable oils. GLA is an important essential fatty acid that is required by human and animals to function normally. Recently, studies have indicated that GLA may be an essential component of the cell membrane, as well as an active component of dietary supplements and medicine. GLA must beadministered through the diet because it is converted into DHGLA in the body quickly and completely. DHGLA is a key material involved in the metabolism of LA. GLA is biosysthesized by the rate limiting step of ${\Deltac}^6$-desaturase, which is an enzyme that desaturates LA, there by allowing it to be converted into DHGLA via chain elongation. In addition, DHGLA exerts bioactive effects via action as a precursor of eicosanoid series 1. Breast milk contains an abundant amount of GLA; however, GLA is also available directly in evening primrose oil, black currant seed oil, borage oil and hemp seed oil. In addition, GLA enriched animal and plant can be produced using biotechnology, and highly pure GLA can be extracted using supercritical fluids, such as supercritical carbon dioxide, which will allow economically feasible production of GLA for use in medicines.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.427-431
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• 2002

Alkali treatment following acidic hydrolysis (ATAH) is a commonly used practice for reducing the levels of monochloropropanediol in commercial Korean soy sauce. This study investigated the chemical compounds produced in commercial Korean soy sauce made by ATAB. The levels of amino-N, total acidity, pH, salinity and Brix of the soy sauce were 6.66%, 2.52%, 19.81%, 4.57 and 35.01, respectively. The major fatty acids were C18:2n-6, C16:0, Cl8:ln-9 and C18:3n-6. The concentration of polyunsaturated fatty acids were especially high, with of C18:2n-6 (49.8%) being the highest followed by C18:3n-6 (3.8%) and C18:3n-3 (2.4%) in that order. Among the non-volatile organic acids, the concentration of levulinic acid (1,206.28 mg/100 g) was the highest, while the taste value of citric acid was the highest. Among the ATP related compounds, IMP concentration (31.19 mg/100 g) was highest followed by AMP, hypoxanthine and GMP in that order. The concentrations of free and total amino acids in soy sauce were 6,136.94 mg/100 g and 8,702.76 mg/100 g, respectively. On the other hand, the taste value of glutamic acid, a major amino acid flavor determinant in soy sauce, was highest of all the amino acids, which is desirable since most free amino acids such as methionine, histidine and phenylalanine have a bitter taste that detracts from the flavor of soy sauce.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1320-1325
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• 2003

The purpose of present study was to assess the effect of polyunsaturated fatty acids (PUFA) on the immune responses of laying hens. Three hundred and sixty hens at the age of 60 weeks were randomly assigned to ten diets, which contained no oil (CK), 1%, 3%, 5% fish oil (FO); 2%, 4%, 6% linseed oil (LO) and 2%, 4%, 6% corn oil (CO). After 5 weeks of feeding experimental diets, humoral and cellular immune responses were assayed. Laying hens were injected with Sheep Red Blood Cell (SRBC) and Bovine Serum Albumin (BSA) and antibody titers, which were measured on d6, d10, d14 after primary challenge and on d5, d9, d13 after secondary challenge. Concanavalin (ConA) and lipopolysaccharide (LPS) -stimulated proliferation of peripheral blood and spleen lymphocytes were assessed by [$^3$H] thymidine incorporation at the week age of 5 and 10, respectively. The results showed that antibody titers in FO-fed and LO-fed laying hens were higher than that in laying hens fed CO. The proliferation response to ConA was lower in laying hens that fed oils rich in n-3 fatty acids than that in laying hens fed CO. Higher level n-3 fatty acids can improve immune functions of laying hens. In conclusion, dietary fat source and level had a significant impact on immune responses of laying hens.

• Korean Journal of Poultry Science
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• v.24 no.2
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• pp.73-83
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• 1997

This study was conducted to investigate the influence of dietary $\omega$-fatty acids on fatty acids composition and storage characteristics in meat samples of spent hens. Spent hens were randomly assigned to one of the four dietary treatments : 1) Control (commercial feed), 2) T1 (commercial feed supplemented with 10% olive oil, 3) T2 (commercial feed with 10% canola oil), and 4) T3 (commercial feed with 10% sardine oil). They were fed one of the experimental diets for three weeks and slaughtered. The meat samples were stored at 4 ${\pm}$ 1 ˚C The storage characteristics and fatty acid contents were analyzed for meat samples stored over a period of 1, 3, 5, 7 and 9 days. The pH of all treatments significantly increased during the storage periods(P<0.05). The per-oxide values (POV) of all treatments were significantly increased up to 5 days ; after that the POV decreased significantly (P<0.05). The POV of treated groups were significantly higher than those of the Control in the thigh meat(P<0.05). The TBARS showed the highest POV among all treatments. Although the breast meat tended to he lower in POV than the thigh meat, no significant difference was detected between the two meats. The TBARS(thiobarbituric acid reactive substances) of all treatments were significantly increased as the storage period extended(P<0.05). After 3 days, the TB ARS of oil-treated groups were aignificantly higher than that of the Control (P<0.05). The T3 showed the highest TBARS among all treatments (P<0.05). The TBARS of the breast meat was lower than that of the thigh, but no statistical difference was found be- tween them. The unsaturated fatty acid content of the breast and thigh meats in all treatments were slightly decreased as the storage period extended. The oleic acid was higher in Ti, and the linoleic acid and linolenic acid were higher in T2 than the other treatments. The eicosapentaenoic acid and docosahexaenoic acid were higher in T3 than the other treatments. The unsaturated fatty acid contents of the breast meat were slightly lower than those of the thigh meat. The n-6 fatty acid contents of the breast and thigh meats were slightly increased as the storage periods ex-tended. The n-3 fatty acid content of T3 was the highest among all treatments. The n-6 fatty acid content of breast meat was lower than that of thigh meat. The n-6 fatty acid content of the breast meat was slightly lower than that of the thigh meat.