• Korean journal of food and cookery science
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• v.14 no.1
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• pp.84-90
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• 1998

A research was carried out to determine the formation, contents in foods, and antioxidative effects of conjugated linoleic acid (CLA). CLA was known as a mixture of positional isomer of linoleic acid (LA), that was included in milk, meat, and fish. The formation of CLA from methyl linoleate and soybean oil (SBO) storecd at 20${\pm}$1$^{\circ}C$ was higher than at 40${\pm}$1$^{\circ}C$, and CLA formation from methyl linoleate stored at 20${\pm}$1$^{\circ}C$ was over 13 times higher than early amounts(188 ppm) and was higher than that from SBO. In edible vegetable oils, the content of CLA were the highest in canola oil (CAO, 348 ppm) but were decreased during storage at 40${\pm}$1$^{\circ}C$, while the content of CLA in cotton seed oil (CSO) were 292 ppm, which increased dramatically (1322 ppm) during 28 days of storage at 40${\pm}$1$^{\circ}C$. Because the peroxide value (POV) of CSO at that time was very low (10.05 meq/kg $.$ oil), CLA occurrence of CSO was shown to be very available during storage at temperature. CLA content of milk from a market ranged 293∼2148 ppm, which depended on the manufacturing, companies. In meat, the CLA content was very high in pork (2379 ppm), and among fishes, that of spanish mackerel was the highest (1040 ppm, almost same as beef, which increased greatly (2039 ppm) during boiling with seasoning. Antioxidative effect of CLA on SBO was almost same as that of BHT until 7 days of storage at 40${\pm}$1$^{\circ}C$, but decreased greatly after that period. In case of com oil (CNO), antioxidative effects of CLA were higher than those or BHN and tocopherol, suggesting that the effect was different depending on the kinds of oils used as substrates. During heating at 180${\pm}$1$^{\circ}C$, antioxidative effect of CLA on SBO appeared almost same as those or BHT and tocopherol, and it was also shown greater effects in heating at high temperature (180${\pm}$1$^{\circ}C$) than at low temperature(40${\pm}$1$^{\circ}C$).

• Preventive Nutrition and Food Science
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• v.11 no.3
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• pp.253-256
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• 2006

The purpose of this study was to develop a gas chromatographic (GC) method to analyze fatty acids in milk fat with a single injection. The single-injection GC method we developed for analyzing fatty acid composition can separate a wide range of fatty acid methyl esters from butyric acid to docosahexaenoic acid. It separated 6 isomers of 18:1 (cis-6, cis-9, cis-11, trans-6, trans-9 and trans-11), 4 isomers of 18:2 (cis-9-cis-12, trans-9-trans-12, cis-9-trans-12 and trans-9-cis-12), and 4 isomers of conjugated 18:2 (cis-9- trans-11, trans-9-cis-11, cis-10-trans-12 and trans-10-cis-12).

• Journal of the Korean Chemical Society
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• v.21 no.1
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• pp.67-72
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• 1977

Author studied on the isolation technique and properties of the products obtained by the reaction of soybean oil with maleic anhydride. Before studying above purpose, oleic acid and linoleic acid contained in soybean oil were reacted with maleic anhydride. Thin-layer chromatography using silica coated plate and solvent system consisting of petroleum ether-diethyl ether = 7:3∼5:5 (v/v) resulted in good effects on the isolation of maleic anhydride adducts. Four fractions were separated and fraction No. 2 were analyzed by IR & UV spectrophotometer, obtaining the following conclusions. In the case of oleic acid adduct and linoleic acid adduct, it were conjectured that the succinic acid type adduct was formed. In the case of conjugated $C_{18}$ fatty acid adduct, cyclohexene type adduct was formed which differed from oleic acid and linoleic acid adduct.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1249-1255
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• 2011

This study examined the effect of CLA, flaxseed oil and fish oil and their combination forms on crude fat of liver and fatty acid profiles of liver, breast and thigh meat in broiler chicks. A total of 72, 1-day-old Cobb broilers were assigned to 6 groups, and fed an experimental diet supplemented with 5 different fat sources; conjugated linoleic acid (2% CLA), flaxseed oil (2% FXO), fish oil (2% FHO), CLA and flaxseed oil combination (1:1; 2% CXO), and CLA and fish oil combination (1:1; 2% CHO). Eight birds per treatment were processed, and liver, breast and thigh samples were investigated at 21 d of age. As a result of this study, most fatty acids of liver, breast and thigh meat were influenced by fat sources supplemented in the diet (p<0.05). CLA addition resulted in an increase of crude fat and saturated fatty acid (SFA) content but a concomitant decrease in n-3 to n-6 fatty acid ratio was observed in liver (p<0.05). Moreover, the same trends of SFA and n-3 to n-6 fatty acid ratio were also observed in breast and thigh meats of birds fed CLA alone. In the CXO-fed group or CHO-fed group, n-3 and n-3 to n-6 fatty acid ratio in both breast and thigh meat increased compared with CLA group, while SFA content decreased (p<0.05). FHO fed-groups had the lowest proportion of n-6 fatty acid in both breast and thigh meats compared to other fat source treatments (p<0.05). In conclusion, the increased levels of crude fat and SFA in liver and meats obtained by feeding CLA could be reduced by its combination with FXO or FHO. In addition, the combination of CLA and FXO or FHO fed to broiler chicks could increase the n-3 to n-6 fatty acid ratio of their meat along with the deposition of CLA.

• Journal of Nutrition and Health
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• v.25 no.5
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• pp.351-359
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• 1992

This study was conducted to compare the effects of perilla oil or corn oil on lipid peroxidation and eicosanoid productions which are associated with the promotion of carcinogenesis. in liver or blood in rats. Male Sprague-Dawley8 weaning rats were fed on semisynthetic diets containing 15%(w/w) beef fat(BF). corn oil(CO) or perilla oil(PO) Three weeks after the half of rats in each diet group were injected with a single dose of 50mg 2-acetylaminofluorene (AAF)/Kg BW hepatocarcinogen intraperitoneally 3 times at 2-day interval and all of the rats were sacrificed after 8 weeks from the first injection. The rats fed on different dietary fats without 2-AAF treatment had not different MDA produc-tion and conjugated diene content in liver microsome. CO+AAf group had significantly higher conjugated diene content than BF+AAF and PO+AAF groups. and lower glucose-6-phospha-tase activity than BF+AAF group But PO+AAF had similar conjugated diene content to BF+AAF group and significantly lower MDA production than BF+AAF and CO+AAF groups. The hepatic mocrosomal lipid peroxidation was slightly greater in CO group than in PO group though perilla oil(P/S=9.67) has much more polyunsaturated fatty acids than corn oil(P/S=2.92) PG E2 level in liver and TX B2 level in plasma were significantly higher in CO group than in BF and PO groups. TX B2 level was lowered in CO and BF groups by 2-AAF treatment. These results reach to the contclousion than the type of dietary fatty acid as well as the P/S ratio has effect on hepatic microsomal lipid peroxidation and eicosanoid production and perilla oil or linolenic acid(n3) might be less effective on lipid peroxidation or PG E2 and TX B2 mediated tumor promotion than corn oil or linoleic acid(n6).

• Journal of Animal Science and Technology
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• v.47 no.3
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• pp.429-438
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• 2005

This experiment was conducted to determine the effects of feeding CLA and coumarin on the changes of biochemical composition of velvet antler and blood serum in spotted deer (Cervus nippon). There were no significant differences between treatments in crude protein, crude fiber, and crude ash contents of velvet antler. The content of fatty acid did not differ between treatments, although there were significant differences (P<0.05) in C16:0 and C20:0. The content of collagen was significantly higher (P<0.05) in control than those in CLA and coumarin treatments. There were no significant differences between treatments in the contents of amino acids. Some constituents of blood showed much differences in comparison of pre and post-experiment for all treatments. Feeding of CLA and coumarin was not influential on the chemical composition of velvet antler and blood serum.

• Journal of Nutrition and Health
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• v.34 no.8
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• pp.850-857
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• 2001

The study was designed to observe whether the conjugated linoleic acid supplemented to diet could reduce plasma levels of glucose and lipids which were increased in 27-weeks old Otsuka Long Evans Tokushima Fatty(OLETF) rats. Twenty male OLETF rats of 7 weeks old were fed an experimental diet containing 4.5%(w/w) total fat including 1% CLA and six of twenty rats were sacrified at 6 weeks feeding. The rest of OLETF rats was divided into 2 groups, one group was continuously fed for 14 weeks more the same experimental diet containing 1% CLA and the other group was fed control diet which eliminated CLA. CLA did not significantly reduce food intake and body weight gain in OLETF obese rats. Plasma triglyceride and total cholesterol level were significantly increased at older age of OLETF obese rats, but CLA could significantly reduce plasma cholesterol and triglyceride increased in obese rats. However, CLA was not strong enough to reduce the increased plasma glucose level and hepatic lipogenic enzyme acitivies. CLA was mostly deposited in epididymal fat pad and could be incorporated into hepatic microsomal membrane and did interfere the conversion of C18 : 0 into C18 : 1 in liver. In conclusion, CLA could have anti-atherogenic effect by reducing plasma cholesterol and triglyceride which was increased in genetically obese rats, but CLA(1%) was not good source of dietary fatty acid to reduce body fatness and plasma glucose which was increased by obese gene in older rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1062-1068
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• 2009

Diacylglycerol (DAG) were synthesized by enzymatic esterification of glyceryl monooleate (GMO) and conjugated linoleic acid (CLA) in a shaking water bath. The reaction was catalyzed by Lipozyme TLIM (immobilized lipase from Thermomyces lanuginosa). Effects of reaction time, molar ratio, enzyme road and molecular sieves were studied. Results of normal-phase high performance liquid chromatography (NP-HPLC) analysis were performed. At 1:1, 2:1 and 3:1 (GMO : CLA) molar ratio and Lipozyme TLIM of 20% amount, DAG were produced in 42.6, 54.4 and 54.6 area% in 1 hr, respectively. When different Lipozyme TLIM amounts (2, 5, 10, 20%) were used with 2:1 (GMO : CLA) molar ratio, DAG were produced 21.4 (24 hr), 51.7 (12 hr), 56.2 (6 hr) and 54.4 (1 hr) area%, respectively. The reaction in the absence of molecular sieves increased DAG contents. The maximum DAG concentration conditions were obtained with molar ratio of 2:1 (GMO : CLA), lipase concentration of 10% (of substrate), 10% molecular sieves and reaction time of 6 hours at 55$^{\circ}C$. Under this reaction condition, produced DAG-rich oil was composed of 69 area% DAG, 7.9 area% TAG, 2 area% FFA, and 21.1 area% MAG.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.797-802
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• 2003

Structured lipids (SL) were synthesized by esterification of corn oil and conjugated linoleic acid (CLA) in a continuous packed-bed column reactor. The effects of flow rate, reaction temperature, and substrate molar ratios were studied. The reaction was catalyzed by TL IM (immobilized lipase from Thermomyces lanuginosa). Results of triacylglycerol (TAG) analysis by GC showed that the incorporated CLA isomers were mainly cis9, trans11- and trans 10, cis12-CLA. Slower flow rates yielded higher incorporation, and maximum incorporation of CLA was obtained with a molar ratio of 1:3 (corn oil: CLA) at a temperature of $55^{\circ}C$. The obtained SLs had iodine values ranging from 120 to 128. The SLs were composed of TAG $(98{\sim}99%)$, 1,2- and 1,3-diacylglycerol ($0.7{\sim}1.3%$), and a small amount of monoacylglycerol.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.31-37
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• 2008

The distributions and content of geometrical isomers of conjugated linoleic acids (CLA) in dairy foods such as milk, yogurt, and cheese, produced or being sold in the Quebec province of Canada, were investigated by gas chromatographic analysis. The mean contents of total CLA (mg/g fat) were $5.06{\pm}0.74$ in 4 low-fat milk samples, $14.14{\pm}4.95$ in 6 yogurt samples, and $18.22{\pm}7.89$ in 5 natural ripened cheeses. Among the yogurt samples, YY contained the highest content of total CLA ($20.68{\pm}5.17\;mg/g$ fat). Among the cheese samples, Gruyere contained the highest amount of total CLA ($29.86{\pm}0.62$) as well as c-9,t-11 ($22.03{\pm}0.36\;mg/g$ fat), followed by Jarlsberg ($22.76{\pm}0.14$), Provolone ($16.42{\pm}0.52$), Cheddar ($13.83{\pm}0.81$), and Swiss ($8.23{\pm}1.11$). Based on the distribution ratios of CLA isomers in these dairy foods, the c-9,t-11 isomer appeared to be the major CLA isomer in both the low-fat milk ($89.87{\pm}2.39%$) and yogurt ($90.98{\pm}4.42%$). In the cheeses, however, the ratio of c-9,t-11 ($54.86{\pm}13.06%$) was slightly higher than that of c-10,c-12 ($40.81{\pm}13.40%$).