scholarly journals Investigation of Some Preparation Procedures of Fatty Acid Methyl Esters for Capillary Gas-Liquid Chromatographic Analysis of Conjugated Linoleic Acid in Meat

1999 ◽  
Vol 70 (5) ◽  
pp. 336-342 ◽  
Author(s):  
Shin-ichi TAKENOYAMA ◽  
Satoshi KAWAHARA ◽  
Hisashi MURATA ◽  
Kiyoshi YAMAUCHI
Keyword(s):  
Fatty Acid ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Chromatographic Analysis ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Acid Methyl ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

scholarly journals Isomerisation of cis-9 trans-11 conjugated linoleic acid (CLA) to trans-9 trans-11 CLA during acidic methylation can be avoided by a rapid base catalysed methylation of milk fat

2008 ◽  
Vol 75 (3) ◽  
pp. 354-356 ◽  
Author(s):  
Michael R F Lee ◽  
John K S Tweed
Keyword(s):  
Fatty Acid ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Milk Fat ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
The Other ◽  
Gas Liquid Chromatography ◽  
Freeze Dried ◽  
Acidic Conditions

This study investigated the evolution of trans-9 trans-11 conjugated linoleic acid (CLA) from cis-9 trans-11 CLA during methylation and its avoidance through a rapid base methylation of milk fat. The study examined three conditions shown to result in loss of cis-9 trans-11 CLA during methylation namely: temperature, methylation time, water contamination in old reagents and acidic conditions. Three techniques currently used for the conversion of milk fat into fatty acid methyl esters for analysis of CLA content by gas liquid chromatography and a fourth procedure designed to eliminate acidic conditions and to limit methylation temperature and time were used. The four methods were: (i) acidic methylation (AM); (ii) acidic and basic bimethylation with fresh reagents (FBM); (iii) acidic and basic bimethylation with pre-prepared reagents (PBM) and (iv) basic methylation (BM). Each regime was carried out on six milk samples over two periods and methylated 1 ml freeze-dried milk (n=12 per regime). Total CLA was not different across methylation regimes (0·30 mg/ml). Isomer cis-9 trans-11 was higher (P<0·01) with BM than the other regimes and lowest with AM: 21·2, 17·8, 18·8 and 14·7 mg/100 ml for BM, FBM, PBM and AM, respectively. The inverse relationship was shown for trans-9 trans-11 with higher (P<0·001) amounts with AM than the other regimes and lowest with BM: 0·57, 2·55, 2·36 and 3·69 mg/100 ml for BM, FBM, PBM and AM, respectively. The trans-10 cis-12 isomer was also shown to alter with methylation procedure being higher (P<0·001) with AM than the other regimes: 0·43, 0·47, 0·29 and 1·20 mg/100 ml for BM, FBM, PBM and AM, respectively. Validation with known CLA free fatty acid and triacylglycerol standards confirmed that AM resulted in conversion of cis-9 trans-11 to trans-9 trans-11, and also elevated trans-10 cis-12 whilst BM of triacylglycerol CLA did not isomerise cis-9 trans-11 and was comparable to FBM.

scholarly journals Identification of Bacillus anthracis from Culture Using Gas Chromatographic Analysis of Fatty Acid Methyl Esters

2005 ◽  
Vol 88 (1) ◽  
pp. 178-181 ◽  
Author(s):  
Myron Sasser ◽  
Craig Kunitsky ◽  
Gary Jackoway ◽  
John W Ezzell ◽  
Jeffrey D Teska ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Bacillus Anthracis ◽  
Chromatographic Analysis ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Gas Chromatographic Analysis ◽  
Acid Methyl

scholarly journals Conjugated linoleic acid (CLA)-enriched milk fat inhibits growth and modulates CLA-responsive biomarkers in MCF-7 and SW480 human cancer cell lines

2003 ◽  
Vol 90 (5) ◽  
pp. 877-885 ◽  
Author(s):  
Áine Miller ◽  
Catherine Stanton ◽  
John Murphy ◽  
Rosaleen Devery
Keyword(s):  
Fatty Acid ◽  
Linoleic Acid ◽  
Cell Lines ◽  
Milk Fat ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Acid Methyl ◽  
Sw480 Cells ◽  
Enriched Milk ◽  
Mcf 7

Milk enriched in conjugated linoleic acid (CLA) was obtained from cows on pasture supplemented with full-fat rapeseeds (FFR; 2·26g cis 9, trans 11 (c9, t11)-CLA/100g fatty acid methyl esters) and full-fat soyabeans (1·83g c9, t11-CLA/100g fatty acid methyl esters). A control milk fat (1·69g c9, t11-CLA/100g fatty acid methyl esters) was obtained from cows fed on pasture only. The present study assessed the potency of the CLA-enriched milk fats to modulate biomarkers that had previously been observed to respond to c9, t11-CLA in the MCF-7 and SW480 cell lines. Cell numbers decreased (P<0·05) by up to 61 and 58% following the incubation of MCF-7 and SW480 cells, respectively, for 4d with milk fats (yielding CLA concentrations between 60·2 and 80·6μM). The FFR milk fat, containing the highest CLA content, increased (P<0·05) [14C]arachidonic acid (AA) uptake into the monoacylglycerol fraction of MCF-7 and SW480 cells while it decreased (P<0·05) uptake into the phospholipid fraction of the latter. This milk fat also decreased (P<0·05) [14C]AA conversion to prostaglandin (PG) E2 while increasing conversion to PGF2α in both cell lines. All milk-fat samples increased (P<0·05) lipid peroxidation as measured by 8-epi-PGF2α in both cell lines. In SW480 cells the milk-fat samples decreased (P<0·05) bcl-2 and cytosolic glutathione levels while increasing (P<0·05) membrane-associated annexin V levels. All milk-fat samples decreased (P<0·05) the expression of ras in SW480 cells. These data suggest that milk-fat CLA was effective at modulating synthetic CLA-responsive biomarkers.

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