Quantitation of trans fatty acids in milk fat using spectroscopic and chromatographic methods

1994 ◽  
Vol 61 (4) ◽  
pp. 517-527 ◽  
Author(s):  
Franz Ulberth ◽  
Monika Henninger
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Milk Fat ◽  
Trans Fatty Acids ◽  
Methyl Esters ◽  
Oxidative Degradation ◽  
Subtraction Technique ◽  
Argentation Chromatography ◽  
Ruminant Animals ◽  
Octadecadienoic Acids

SummaryTrans fatty acids (TFA) formed during biohydrogenation by ruminant animals were quantified in cows' milk fat by means of Fourier transform i.r. (FTIR) spectroscopy. When samples were analysed as the derived methyl esters, a spectral subtraction technique resulted in TFA values that were not biased by the unspecific absorption of intact triacylglycerols or influenced by the shape of the trans band. Austrian milk fat samples contained 20–50 g TFA/kg. Results obtained by analysis of TFA as triacylglycerols compared favourably with those obtained by using methyl esters. The findings of the FTIR method were further substantiated by applying argentation chromatography in combination with capillary gas chromatography to the same set of samples. Besides trans monoenoic acids, non-methylene interrupted cis, trans octadecadienoic acids contributed significantly to the total trans content. Two novel TFA, trans-11, cis-15 octadecadienoic and cis-9, trans-13 octadecadienoic acids, were identified in milk fat by means of their retention behaviour on argentation chromatography and gas chromatography as well as by an oxidative degradation procedure.

Differential Characteristics of Fatty Acids in Cheese from Milk of Various Animal Species by Capillary Gas Chromatography

1989 ◽  
Vol 72 (3) ◽  
pp. 418-421 ◽  
Author(s):  
Manfred J Prager
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Milk Fat ◽  
Animal Species ◽  
Capillary Column ◽  
Methyl Esters ◽  
Capillary Column Gas Chromatography

Abstract The kind of milk used in the manufacture of cheese has been identified by analysis of the fatty acids. The milk fat is extracted from the cheese and saponified. The methyl esters of the fatty acids are prepared and determined by capillary column gas chromatography. Seven major fatty acids are separated and quantitated, namely, C8:0, C10:0, C12:0, C14:0, C16:0, C18:0, and C18:l. Many of the 21 simple ratios that can be formed from these 7 quantities are characteristic of the type of milk from which the fatty acids were obtained. The method allows the identification of cheese prepared with the milk of cows, buffalo, sheep, or goats. Substitution or adulteration of milk can also be detected.

Fatty acid profile of milk from Nordestina donkey breed raised on Caatinga pasture

2021 ◽  
pp. 1-5
Author(s):  
Tayanna Bernardo Oliveira Nunes Messias ◽  
Susana Paula Alves ◽  
Rui José Branquinho Bessa ◽  
Marta Suely Madruga ◽  
Maria Teresa Bertoldo Pacheco ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Milk Fat ◽  
Fat Content ◽  
Donkey Milk ◽  
Fat Percentage ◽  
Mid Infrared ◽  
Milk Samples ◽  
The Third ◽  
Commercial Viability

Abstract In this research communication we describe the composition of fatty acids (FA) present in the milk of the Nordestina donkey breed, and how they differ during lactation. Milk samples were taken from 24 multiparous lactating Nordestina donkeys that grazed the Caatinga, comprising 5 animals at each of around 30, 60 and 90 d in milk (DIM) and a further 9 animals ranging from 120 to 180 DIM. The milk fat content was analysed by mid infrared spectroscopy and the FA profile by gas chromatography. The milk fat percentage ranged from 0.45 to 0.61%. The main FA found in milk were 16:0 and 18:1c9. These did not differ among DIM classes and comprised 23% and 25% of total FA. Notably, the α-Linolenic acid (18:3 n-3) was the third most abundant FA and differed (P < 0.05) with DIM, being lowest in the 30 and 60 DIM samples (around 10.7% of total FA) and highest in the 60 and 90 DIM classes (around 14.6% of total FA). The low-fat content and the FA profile of the donkey milk gives it potential as a functional ingredient, which could help to preserve the commercial viability of the Nordestina donkey breed.

Persistency of milk trans-18:1 isomers and rumenic acid in Holstein cows over a full lactation

2011 ◽  
Vol 91 (1) ◽  
pp. 147-167 ◽  
Author(s):  
Riazuddin Mohammed ◽  
Reza Khorasani ◽  
Laksiri Goonewardene ◽  
John Kramer ◽  
John Kennelly
Keyword(s):  
Fatty Acids ◽  
Milk Fat ◽  
De Novo ◽  
Vaccenic Acid ◽  
Methyl Esters ◽  
Control Diet ◽  
Barley Grain ◽  
Holstein Cows ◽  
Test Diet ◽  
Barley Silage

Mohammed, R., Khorasani, R. G., Goonewardene, L. A., Kramer, J. K. G. and Kennelly, J. J. 2011. Persistency of milk trans-18:1 isomers and rumenic acid in Holstein cows over a full lactation. Can. J. Anim. Sci. 91: 147–167. A long-term lactation study was undertaken to determine whether the previously reported short-term persistency in vaccenic acid [VA; trans(t)11-18:1] and rumenic acid (RA) could be maintained. To test this hypothesis, 24 Holstein cows were allotted to two experimental diets (control and test) from 2 wk before calving until they were 270 d in milk (DIM). The test diet was similar to the control diet, but supplemented with sunflower seed (11.2% diet DM), fish oil (0.5%) and monensin (22 mg/kg DM) by replacing an equivalent amount of barley grain. The forage: concentrate ratio was 50:50 (DM basis) with 35% barley silage and 15% alfalfa hay. Milk was sampled every fortnight from the start of lactation until cows were 270 DIM. Data obtained were averaged into three equal periods of 90 d each, representing three stages of lactation (SOL): early-lactation (EL), mid-lactation (ML) and late-lactation (LL). Dry matter intakes were not different between treatments with greater intakes observed during ML than during EL or LL. Milk yield was not different between treatments and decreased with increasing DIM. Milk fat content and yield showed interaction between treatment and SOL with lower values observed for the test diet than control diet during EL and ML. De novo synthesized fatty acids (4:0–15:0), 16:0–16:1 and preformed fatty acids (17:0 and above) showed interaction between treatment and SOL with the former two being greater for control diet than test diet and the latter greater for the test diet than control diet within each SOL. Milk t10-18:1 (% fatty acid methyl esters, FAME) was greater for the test diet compared with control diet (4.38 vs. 1.32) and was greater during ML (3.79) than during EL (2.38) or LL (2.38). Milk VA and RA showed interactions between treatment and SOL with greater values observed for the test diet than the control diet within each SOL. When analyzed by treatment, milk VA was not different across SOL for both diets. Milk RA was not different across SOL for the test diet, but was different for the control diet; it was lower during EL than during ML. Step-wise regression analysis revealed that the variability in milk RA for the control diet (P<0.01; R2=0.97) was determined by VA (70%) and RA/VA (27%); and for the test diet (P<0.01; R2=0.987) by VA (88.7%), RA/VA (5%) and t10-18:1 (3.8%). Desaturase index based on RA/VA showed an interaction between treatment and SOL; it was greater for the control diet than the test diet within each SOL. Overall findings revealed that the differences in milk t10- and VA across SOL reflected possible differences in starch and PUFA intakes, respectively. Differences in milk RA across SOL for the control diet could be attributed to possible differences in mammary desaturase activity based on differences in RA/VA.

scholarly journals Comparison of fatty acid composition in milk fat of Czech Pied cattle andHolsteincattle

2011 ◽  
Vol 50 (No. 3) ◽  
pp. 122-128 ◽  
Author(s):  
M. Pešek ◽  
J. Špička ◽  
E. Samková
Keyword(s):  
Fatty Acids ◽  
Milk Fat ◽  
Methyl Esters ◽  
Capric Acid ◽  
Holstein Cows ◽  
The Czech Republic ◽  
Milk Samples ◽  
Daily Diet ◽  
Fat Composition ◽  
The Individual

In May 2003 differences in milk fat composition in two main dairy breeds in the Czech Republic, Czech Pied cattle and Holstein cattle, were studied in two uniform groups, each containing eight cows. The groups were housed together and received the same daily diet. Fatty acids were determined in mean milk samples from the individual cows as their methyl esters using a gas chromatography procedure. The groups of the fatty acids, namely saturated (SAFA), monounsaturated (MUFA) and polyunsaturated (PUFA) ones, were examined together with the individual acids. The milk fat of Czech Pied cattle was found to contain significantly less SAFAs than the fat of Holstein cows (60.78 and 63.62% of total acids; P &lt; 0.05). Determined mean MUFA contents (27.64 and 25.76%) and total levels (34.31 and 32.11%) of all the unsaturated acids (MUFAs and PUFAs) were insignificantly elevated in the milk fat of Czech Pied cattle. The contents of the most of the individual fatty acids did not differ considerably between the breeds. In Holstein cows, significantly higher contents (P &lt; 0.05) of capric acid (C<sub>10:0</sub>) and stearic acid (C<sub>18:0</sub>) 3.30 and 4.45%, respectively, as compared with 2.69 and 2.61% for Czech Pied cows, were observed. The milk fat of Czech Pied cows had significantly higher contents of oleic acid (C<sub>18:1</sub>) 23.60% (P &lt; 0.05) and of an isomer of octadecatrienic acid (C<sub>18:3n4</sub>) 0.16% (P &lt; 0.001) as compared with 21.68 and 0.10%, respectively, in the fat ofHolstein cows. &nbsp;

Effect of dietary fat supplements on levels of n-3 poly-unsaturated fatty acids,transacids and conjugated linoleic acid in bovine milk

1999 ◽  
Vol 69 (3) ◽  
pp. 613-625 ◽  
Author(s):  
N. W. Offer ◽  
M. Marsden ◽  
J. Dixon ◽  
B. K. Speake ◽  
F. E. Thacker
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Milk Yield ◽  
Milk Fat ◽  
Trans Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Linseed Oil ◽  
The Other ◽  
Fat Supplements

AbstractThe effects of three fat supplements on milk yield and composition were measured using 12 mid-lactation in-calf Hoistein-Friesian cows in a balanced incomplete change-over design over three periods each of 3 weeks. All cows received a basal diet consisting of 36 kg/day grass silage (dry matter (DM) 270 g/kg, metabolizable energy (ME) 11·6 MJ/kg DM) and 7 kg/day o f a concentrate mixture containing (g/kg) rolled barley (501), molassed sugar-beet pulp shreds (277), soya-bean meal (208) and a standard cow mineral supplement (14). Treatments were CON (control-no supplement); LIN and FISH (250 gl day of either linseed oil or marine oil, providing approximately 0·046 of ME intake) or TOA (95 glday of tuna orbital oil, providing 0·018 of total ME intake).There were no significant effects on silage DM intake or milk yield (means 9·25 and 17·2 kg/day respectively). The FISH and TOA treatments depressed (F < 0·05) milk fat concentration (45·4, 44·6, 34·5 and 41·6 (s.e.d. 1·08) g/kg for CON, LIN, FISH and TOA respectively; note — the same treatment order is used for all results quoted). Compared with values for CON, yield of f at (glday) was significantly (F < 0·05) greater for LIN and significantly lower for FISH (739, 808, 572 and 732, s.e.d. 28·7). All three oil supplements reduced (F < 0·05) milk protein content (33·6, 32·5, 30·6 and 32·4 (s.e.d. 0·43) g/kg) but, apart from a small increase for LIN, protein yield (glday) was unaffected (545, 586, 510 and 574, s.e.d. 20·2).The concentrations (g/100 g) of short-chain fatty acids (< C14) and C16 : 0 in milk f at were lower (F < 0·05) for LIN than for the other treatments. All supplements increased the concentrations ofC18:1 (F < 0·05), the value for LIN being greater (F < 0·05) than for the other treatments (21·0, 27·2, 25·3 and 23·7, s.e.d. 0·74). The FISH and TOA treatments increased (F < 0·05) the concentrations of long chain (< C2O) (n-3) poly-unsaturated fatty acids (PUFA), (0·19, 0·17, 0·49 and 0·27, s.e.d. 0·026) but less than proportionately 0·03 of dietary intake of these acids was transferred to milk, probably because they were found to be mostly in the phospholipid and cholesterol ester fractions of plasma. The FISH and TOA treatments increased (F < 0·05) the percentages of total trans fatty acids in milk fat (1·13, 2·19, 10·26 and 3·62, s.e.d. 0·728) whilst a significant (F < 0·05) increase in conjugated linoleic acid (CLA) was observed only for FISH (0·16, 0·28, 1·55, and 0·52, s.e.d. 0·154). Concentrations of CLA and total trans acids in milk were highly correlated (r = 0·91, no. =36, F < 0·001) whilst trans acids in milk were inversely correlated with milk fat content (r = -0·63, no. = 36, F < 0·001) supporting the theory that milk fat depression may be caused by increased supply of trans fatty acids to the mammary gland. The health implications of these changes in milk fat composition are discussed.

scholarly journals Comparison of Two Derivatization Methods for the Analysis of Fatty Acids andTransFatty Acids in Bakery Products Using Gas Chromatography

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jumat Salimon ◽  
Talal A. Omar ◽  
Nadia Salih
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Methyl Esters ◽  
Correlation Coefficients ◽  
Bakery Products ◽  
Trimethylsilyl Diazomethane ◽  
Acid Catalyzed ◽  
High Level ◽  
Level Of Agreement

Two different procedures for the methylation of fatty acids (FAs) andtransfatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS–DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination ofcis/transFAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P=0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higherRvalues, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of richcis/transUFA samples.

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