• Journal of Nutrition and Health
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• 제30권4호
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• pp.442-450
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• 1997

Conjugated dienoic derivatives of linoleic acid(CLA) are a mixture of positional and geometric isomers of linoleic acid(LA). We previously found that CLA changes the fatty acid profile in chicken eggs and serum by decreasing monounsaturated fatty acids. Studies were conducted to explore the effects of CLA on fatty acid composition. Rabbits were fed a semisynthetic diet with or without CLA(0.5g CLA/rabbit/day) for 22 weeks. Compared to the control, rabbits fed CLA had significantly lower monounsaturated fatty acid levels(palmitoleic acid Cl6 : 1 by 50% and oleic acid Cl8 : 1, by 20%) in plasma lipids. We found similar differences in fatty acid composition in the liver and the aorta. The inhibitory effect of CLA on $\Delta$9 desaturation was confirmed in a human hepatoma cell line, Hep G2. CLA significantly decreased $\Delta$9 desaturation in 4-5 hours as shown by an increase in the ratio of Cl6 : 0 to C 16 1, This is apparently due to a decrease in $\Delta$9 desaturase(stearoyl-CoA desaturase, SCD) activity ; it was decreased more than 50%. These results, along with our previous findings, indicate that CLA is an inhibitor of $\Delta$9 desaturase in the liver.

• 한국식품과학회지
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• 제30권5호
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• pp.1243-1246
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• 1998

시판되는 우유 15종, 요쿠르트 16종, 치즈 5종에 대하여 항암성분으로 알려진 CLA 함량을 분석하였다. 우유와 치즈 중 CLA 함량은 지방질 g 당 각각 $4.10{\sim}2.24\;mg$ 및 $5.78{\sim}3.69\;mg$ 였으며, 제품간에 큰 차이가 없었다. 요쿠르트 중의 CLA 함량은 지방질 g 당 $4.54{\sim}0.13\;mg$ 이었으며, 탈지유로 제조한 것은 원유로 제조한 것에 비해 그 함량이 낮았다. 낙농제품 중 CLA함량과 특정 지방산 함량과의 상관관계를 알아보기 위하여 다중회귀분석을 하였다. 3가지 낙농제품에서 CLA 함량은 oleic acid 함량과는 정의 상관관계가, linoleic acid 함량과는 부의 상관관계가 각각 있었다. 우유 중의 CLA 함량은 linolenic acid 함량과 정의 상관관계가 있었으나 치즈와 요쿠르트 중의 CLA 함량은 linolenic acid 함량과는 서로 상관관계가 없었다.

• 한국식품영양과학회지
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• 제40권12호
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• pp.1734-1742
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• 2011

본 실험에서는 들기름에 약 60%로 존재하는 ${\alpha}$-linolenic acid를 알칼리 이성질화 반응을 이용하여 CLnA(conjugated linolenic acid)와 CLA(conjugated linoleic acid)를 생산하고자 하였다. 들기름을 가수분해한 뒤에 10분에서 6시간까지의 반응시간과 5%에서 60%까지의 NaOH 농도에서 CLnA와 CLA의 생성을 표준물질과 함께 GC와 spectrophotometer를 이용하여 확인하였다. 시간에 따른 CLnA와 CLA 함량 변화는 나타나지 않았으나, NaOH 농도가 증가함에 따라서 CLnA와 CLA가 유의적으로 증가하는 경향을 보였다. 반응조건 중, 20% KOH, $180^{\circ}C$, 1시간 반응에서 14.5%와 14%의 CLnA와 CLA의 함량을 나타냈으며, 42.2%의 C18:3 conjugated 이성질체가 생성되었다. 이성질체를 확인하기 위해 GC-MS 그리고 FT-IR을 이용한 실험을 수행하였다. GC-MS의 ion peak 분석 결과, conjugated 형태에서만 특징적으로 나타나는 m/z=91 ion peak를 확인할 수 있었고, CLA와 CLnA의 분자량이 C18:2와 C18:3과 일치하는 것을 확인할 수 있었다. 그리고 NIST Library에서 검색된 methyl 9c, 11t-CLA, methyl 10t, 12c-CLA와 methyl 9cis, 11trans, 13trans-octadecatrienoate의 결과와 일치하는 ion peak를 형성하였다. 이 외의 이성질체는 FT-IR 분석 결과, 높은 trans fatty acid 함량을 보여 알칼리 이성질화 반응 시, $180^{\circ}C$의 높은 열에 반응을 하여 trans 형태의 conjugated form이 다량 생성된 것으로 사료된다. conjugated 이성질체의 생성 양을 높이기 위해 들기름 가수분해물을 우레아 분별을 한 뒤에, ${\alpha}$-linolenic acid의 함량을 70%까지 높인 뒤에 알칼리 이성질화 반응을 수행한 결과 CLnA의 생성 양이 16.6%까지 증가한 것을 확인할 수 있었다. 그러나 CLnA 이외의 conjugated 지방산 함량의 변화는 없었다.

• 한국축산식품학회지
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• 제18권4호
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• pp.339-347
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• 1998

The effects of conjugated linoleic acid (CLA) in egg yolk on fatty acid composition and lipid oxidation during chilled storage (4$^{\circ}C$) were investigated. CLA was synthesized according to the method of alkali isomerization using safflower seed oil (SSO). A total of 250 hens (200 days of age) were fed control diet (commercial formula feed for han) or CLA-supplemented diet (1%, 2.5% and 5% CLA) or 5% SSO supplemented diet for 6 weeks, and eggs were collected for analysis of CLA, fatty acid compositons and lipid oxidation. Eggs from CLA-supplemented diets groups showed significantly (p＜0.05) higher CLA content compared to those of control group. The contents of linoleic, palmitic, and myristic acid were increased as well as CLA content by feeding a CLA-supplemented diet. However, the contents of oleic and arachidonic acids in egg yolks were decreased by dietary CLA supplementation. The pH of egg yolk increased by the levels of CLA during storage. The contents of CLA were not significantly (p＜0.05) changed during chilled storage for 28 days, whereas TBARS were significantly (p＜0.05) increased. It is suggested that lipid oxidation of egg yolk might be affected by the levels of CLA in egg yolk due to changes in fatty acid compositions.

• Preventive Nutrition and Food Science
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• 제5권2호
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• pp.70-74
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• 2000

Most fatty acids in food matrices are triglyceride(TG) forms. Conjugated linoleic acid(CLA) produced from linoleic acid by microorganisms or chemicals is a free form. To apply the CLA to food systems, the TG containing CLA(designate CLA-TG) was synthesized by Lipozyme-catalyzed esterification method. An optimum reaction con-dition for the esterification of free CLA(FCLA) to glycerol by Lipozyme was determined as follows; Lipozyme(50mg) effectively catalyzed the esterification of CLA(500mg) to glycerol(1150mg) dissolved in isooctane (3ml) in a shaking incubator (200 rpm, 5$0^{\circ}C$) for 48 hr. Under the reaction condition, the resultant contained 52.4% CLA-TG as well as 31.1% Di-CLA-glycerol(CLA-DG), 7.6% mono-CLA-glycerol(CLA-MG), and 9.0% other CLA(un-reacted FCLA plus CLA dimer). These results suggest that the Lipozyme could be a useful enzyme for the production of CLA-TG to be employed in foods.

• 한국임상수의학회지
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• 제20권1호
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• pp.59-65
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• 2003

This study was performed to investigate the immunopotentiative effects of conjugated linoleic acid on mice immunosuppressed by administratin corticoids. Mice were divided into four groups of 8 mice. Two groups (C, CP) were given diet supplemented with 1% linoleic acid (CLA) and the other two groups (L, LP) were given diet supplemented with 1% linoleic acid (LA) instead of CLA. Prednison was administered to two groups (CP, LP) for immune depression. After feeding diets for 3 weeks containing PDS injection for last 1 week. Serum and gut lumen lavage were taken. Measurement of total Ig were executed using sandwich ELISA. Serum levels of IgA, IgG, and IgM showed some trend which groups fed with CLA were higher than groups fed with LA while IgE was reduced in those fed the CLA intake, and groups administered with PDS were lower than groups administered with saline. However, no significant differences were seen in the proportion of total immunoglobulin in serum. In case of secretory IgA, Group C and CP were significantly higher than group L and LP. Especially between CP and LP, it can be seen effects of CLA. In addition that the CLA treated group weighted a significantly lower level than the one's that have not been treated with CLA. These result support the view that CLA potentiate the immune response and prevent immune depression caused by administrating of corticoids. In conclusion, CLA produced a situation favorable for immunopotentiative effects. Thus, the clinical application of CLA is warranted.

• 한국식품영양과학회지
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• 제33권8호
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• pp.1343-1347
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• 2004

국내에서 시판 중인 요구르트의 CLA 함량과 상업용 dairy starter 유산균의 CLA 생산능을 조사하였다. 시판 요구르트 중의 CLA 함량은 4.1∼14.8 mg/100 g이었으며, 원료 우유사용비율이 낮아질수록 제품에 함유된 CLA 함량도 낮아지는 경향을 보였다. CLA 함량과 stearic acid, oleic acid, linoleic acid 및 linolenic acid의 함량, CLA 함량과 지방함량간에는 정의 상관관계를 보였다. 상업용 dairy starter 유산균 67균주 중 L. acidophilus 1종, L. casei 1종 및 Streptococcus thermophilus 3종 등 모두 5 균주가 기질로 첨가한 linoleic acid로부터 CLA를 생성하였다 또한 생성된 CLA는 cis-9, trans-11 이성체가 70% 이상으로 대부분을 차지하였다. 이들을 이용한 발효유는 대조구에 비해서 1.7∼2.6 mg/100 g의 CLA 함량의 증가를 보였으며, CLA 전환율은 6.1∼8.6%였다.

• Journal of Nutrition and Health
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• 제37권3호
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• pp.182-192
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• 2004

Conjugated linoleic acid (CLA) is the mixture of positional and geometric isomers of linoleic acid (LA), which is found abundantly in dairy products and meats. This study was performed to investigate the anticarcinogenic effect of CLA in HepG2 hepatoma cells. HepG2 cell were treated with LA and CLA at the various concentrations of 10, 20, 40, 80 uM each at different incubation times. After each incubation times, cell proliferation, fatty acids incorporation into cell, peroxidation and postaglandin E$_2$ (PGE$_2$) and thromboxane $A_2$ (TXA$_2$) for the eicosanoid metabolism were measured. LA treated HepG2 cells were increased cell growth 6 - 70％ of control whereas CLA increased cell death the half of those in LA group (p 〈 0.001). LA and CLA were incorporated very well into the cellular membranes four times higher than in control according to concentration and longer incubation times. Moreover, LA synthesized significantly arachidonic acids corresponding with LA concentration compared to CLA supplementation. The supplementation with LA increased intracellular lipid peroxides concentration corresponding with LA concentration and five times higher than those in CLA significantly at any incubation times (p 〈 0.001). PGE$_2$ and TXA$_2$ levels were three to twenty times lower in condition of CLA treatments than LA, respectively. Overall, the dietary CLA might change the HepG2 cell growth by the changes of cell composition, production of lipid peroxide. Since CLA have not changed the levels of arachidonic acid of cell membrane, which was sources of eicosanoids, eicosanoid synthesis was not increased in CLA compared to LA. Our results was suggest CLA has a possibility to protect the progress of atherosclerosis because CLA does not produce lipid production and endothelial contraction factors in liver.

• Journal of Nutrition and Health
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• 제34권4호
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• pp.367-374
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• 2001

Conjugated linoleic acid(CLA) is a naturally occuring group of derivatives of linoleic acid found in beef and dairy products. CLA has reported to reduce body fat. This study was designed to observe the effect of CLA supplementation on fat accumulation and degradation in male Sprague Dawley rats. Seventy two rats, weighing 150-180g, were divided into 2 groups according to the types of dietary fat(beef tallow or fish oil) and then each group was divided into 2 groups depending on CLA supplementation, i.e., BT, BT-CLA, FO, FO-CLA. All rats were fed experimental diet containing total fat at 12%(w/w) including CLA at 1% for 30 weeks. At 30 weeks, rats were sacrificed to measure TG, free fatty acid level in plasma, TG, lipogenic enzymes in lever and fat cell size, LPL and HSL activities in epididymal fat fad. Fish oil supplemented with CLA diet showed significant reduction in the food efficiency and weight in 30 weeks-fed rats. CLA supplement did not effect on plasma TG, hepatic TG levels and lipogenic enzymes activities in rats, but, fish oil significantly reduced, The LPL and HSL activities did not affected by CLA supplement and n-3 fatty acid rich fish oil. In conclusion, the results suggest that CLA supplement was not a proper way to reduce the fat accumulation in Sprague Dawley rats. Fish oil supplemented with CLA might better way to reduce the body fatness than fish oil itself. Therefore, It is recommended that further study be performed related to physiological and biochemical effects of CLA supplementation and n-3 fatty acid in rats for the reduction of body fatness.(Korean J Nutrition 34(4) : 367∼374, 2001)

• 한국축산식품학회지
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• 제38권4호
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• pp.693-702
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• 2018

The purpose of this study was to develop a commercially viable method for synthesis of conjugated linoleic acid (CLA) using the linoleic acid fraction obtained from six pork by-products (liver, lung, heart, stomach, small intestine, and large intestine). The workflow of CLA synthesis from each by-product was as follows: washing${\rightarrow}$crude fat extraction${\rightarrow}$fractionation into saturated and unsaturated fatty acids${\rightarrow}$repeat unsaturated fatty acid fractionation${\rightarrow}$CLA synthesis. Cis-9, trans-11, and trans-10, cis-12 CLA was synthesized from pork by-products. The yield of CLA synthesis of pork by-products ranged from 1.55 to 11.18 g per 100 g of by-products. The amount of synthesized CLA was the highest in the small intestine and large intestine by-products. Fractionation of pork by-products nearly doubled the yield of CLA. We suggest that commercial fractionation methods could increase the yield of CLA at low cost, reduce waste, and improve the efficiency of by-product utilization.