IUPAC Gas Chromatographic Method for Determination of Fatty Acid Composition: Collaborative Study

1979 ◽  
Vol 62 (4) ◽  
pp. 709-721
Author(s):  
David Firestone ◽  
William Horwitz
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Butyric Acid ◽  
Vegetable Oils ◽  
Milk Fat ◽  
Methyl Esters ◽  
Collaborative Study ◽  
Fats And Oils ◽  
Check Sample ◽  
Coefficients Of Variation

Abstract An international collaborative study of IUPAC methods II.D.19 and II.D.25 for preparation and GLC analysis of fatty acid methyl esters was begun in 1976. The IUPAC methodology, applicable to animal and vegetable oils and fats and fatty acids from all sources, contains special instructions for preparation and analysis of methyl esters of fatty acids containing 4 or more carbon atoms (analysis of milk fat). Twenty-three collaborators participated in the analysis of 5 known mixtures, 4 vegetable oils, 1 fish oil, and 2 butterfats. Several blind duplicate samples were included. The experimental data were subjected to statistical analysis to examine intra- and interlaboratory variation. Reproducibility and accuracy data for the higher fatty acid (14:0–22:1) mixtures and fish and vegetable oils were satisfactory and were in good agreement with results from an AOCS Smalley Committee check sample program involving analysis of the same samples. Typical coefficients of variation (%) at various concentrations were 15 (2% level), 8.5 (5% level), 7 (10% level), and 3 (50% level). Low recoveries and poor reproducibility were characteristic of results obtained for butyric acid in the butterfat and related known mixtures. A coefficient of variation of about 19% was found for analysis of butyric acid in butterfat, vs. coefficients of variation in the range of 4–13% for similar levels of other components in butterfat and other samples. The IUPAC methodology for GLC analysis .of fats and oils other than milk fats has been adopted by the AOAC as official first action to replace the current GLC method, 28.063-28.067.

Recent advances in the field of selective epoxidation of vegetable oils and their derivatives: a review and perspective

2017 ◽  
Vol 7 (17) ◽  
pp. 3659-3675 ◽  
Author(s):  
S. M. Danov ◽  
O. A. Kazantsev ◽  
A. L. Esipovich ◽  
A. S. Belousov ◽  
A. E. Rogozhin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Vegetable Oils ◽  
Critical Review ◽  
Fatty Acid Methyl Esters ◽  
Recent Progress ◽  
Unsaturated Fatty Acids ◽  
Methyl Esters ◽  
Acid Methyl ◽  
Review Reports

The present critical review reports the recent progress of the last 15 years in the selective epoxidation of vegetable oils and their derivatives, in particular unsaturated fatty acids (UFAs) and fatty acid methyl esters (FAMEs).

scholarly journals Performance and emission characteristics of a diesel engine employing straight vegetable oils from Vanuatu as fuels

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402096235
Author(s):  
Misel J Sisi ◽  
M Rafiuddin Ahmed ◽  
David Rohindra
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Diesel Engine ◽  
Vegetable Oils ◽  
Methyl Esters ◽  
Cocos Nucifera ◽  
Capric Acid ◽  
Performance And Emission ◽  
Development Goals

The performance characteristics of the engine and the emission levels with Copra Oil (CPO), Virgin Coconut (cocos nucifera) Oil (VCO), Tamanu (calaphyllum inopyllum) Oil (TMO), and Nangae (canarium indicum) Oil (NGO) are presented. The oils, obtained from naturally grown trees in Vanuatu, were tested as straight vegetable oils (SVOs) in a Diesel engine and the results are compared with those of neat diesel. The oils were converted to their fatty-acid-methyl-esters (FAMEs) using gas chromatography to determine their fatty acid compositions. The brake thermal efficiency with SVOs was found to be comparable to diesel. The structure of the alkyl chain and the carbon-to-hydrogen ratio were also studied. All the oils have Palmitic acid, Capric acid, Caprylic acid, and Oleic acid as the major fatty acids. The CPO and VCO have higher amounts of Oleic acid, which acts as an additive and breaks up the interaction between the major fatty acids at higher temperatures, reducing the viscosity. Emissions of CO2 were lower while those of CO, NOx, and SO2 were higher with SVOs compared to diesel. The results indicate that the local SVOs are good and inexpensive substitute fuels for Vanuatu that can help the country meet the UN’s sustainable development goals.

Tutorial for the Characterization of Fatty Acid Methyl Esters by Gas Chromatography with Highly Polar Capillary Columns

2020 ◽  
Author(s):  
Pierluigi Delmonte ◽  
Andrea Milani ◽  
John K G Kramer
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Fatty Acid ◽  
Vegetable Oils ◽  
Fatty Acid Methyl Esters ◽  
Methyl Esters ◽  
Capillary Columns ◽  
Marine Oils ◽  
Optimal Separation ◽  
Acid Methyl

Abstract The fatty acid composition of fats and oils is commonly determined by gas chromatography after preparing fatty acid methyl esters (FAME). Capillary columns coated with polyethylene glycol emerged as the preferred separation tool for the quantification of the polyunsaturated fatty acids contained primarily in marine oils. However, their selectivity is inadequate for measuring the trans fatty acids (TFA) contained in refined vegetable oils, dairy fats, and marine oils. Highly polar 100% poly(biscyanopropyl siloxane) capillary columns provide the necessary selectivity, but small differences in the phase polarity caused by column age, conditioning, or manufacturing variations affect the reproducibility of their separations of these complex samples. In this study, a simple procedure is described to compensate for small variations in column selectivity by adjusting the elution temperature. The balance between the dipole-induced dipole interactions and dispersive interactions was determined by measuring selectivity factors [SF(i)] corresponding to the elution of an unsaturated FAME such as 18:3n-3 relative to two saturated FAME such as 20:0 and 22:0. Knowing the SF(i) provided by the installed capillary column at a given elution temperature, and the SF(i) of the target separation, we propose a simple calculation to determine the necessary elution temperature adjustment to achieve (or restore) the desired separation. After determining the SF(i) which provides the optimal separation of TFA, the novel methodology was applied to the separation of refined vegetable oils, butter fats, and marine oils.

scholarly journals Dairy proteins, dairy lipids, and postprandial lipemia in persons with abdominal obesity (DairyHealth): a 12-wk, randomized, parallel-controlled, double-blinded, diet intervention study

2015 ◽  
Vol 101 (4) ◽  
pp. 870-878 ◽  
Author(s):  
Mette Bohl ◽  
Ann Bjørnshave ◽  
Kia V Rasmussen ◽  
Anne Grethe Schioldan ◽  
Bashar Amer ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Abdominal Obesity ◽  
Milk Fat ◽  
Milk Protein ◽  
Intervention Study ◽  
Postprandial Lipemia ◽  
Double Blinded ◽  
Postprandial Triacylglycerol

ABSTRACT Background: Abdominal obesity and exaggerated postprandial lipemia are independent risk factors for cardiovascular disease (CVD) and mortality, and both are affected by dietary behavior. Objective: We investigated whether dietary supplementation with whey protein and medium-chain saturated fatty acids (MC-SFAs) improved postprandial lipid metabolism in humans with abdominal obesity. Design: We conducted a 12-wk, randomized, double-blinded, diet intervention study. Sixty-three adults were randomly allocated to one of 4 diets in a 2 × 2 factorial design. Participants consumed 60 g milk protein (whey or casein) and 63 g milk fat (with high or low MC-SFA content) daily. Before and after the intervention, a high-fat meal test was performed. We measured changes from baseline in fasting and postprandial triacylglycerol, apolipoprotein B-48 (apoB-48; reflecting chylomicrons of intestinal origin), free fatty acids (FFAs), insulin, glucose, glucagon, glucagon-like peptide 1 (GLP-1), and gastric inhibitory polypeptide (GIP). Furthermore, changes in the expression of adipose tissue genes involved in lipid metabolism were investigated. Two-factor ANOVA was used to examine the difference between protein types and fatty acid compositions, as well as any interaction between the two. Results: Fifty-two participants completed the study. We found that the postprandial apoB-48 response decreased significantly after whey compared with casein (P = 0.025) independently of fatty acid composition. Furthermore, supplementation with casein resulted in a significant increase in the postprandial GLP-1 response compared with whey (P = 0.003). We found no difference in postprandial triacylglycerol, FFA, insulin, glucose, glucagon, or GIP related to protein type or MC-SFA content. We observed no interaction between milk protein and milk fat on postprandial lipemia. Conclusion: We found that a whey protein supplement decreased the postprandial chylomicron response compared with casein in persons with abdominal obesity, thereby indicating a beneficial impact on CVD risk. This trial was registered at clinicaltrials.gov as NCT01472666.

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 Effect of Chlorella Vulgaris and Japonochytrium sp. Microalgae Supplementation on Composition and Fatty Acid Profile of Goat Milk

2017 ◽  
Vol 65 (5) ◽  
pp. 1585-1593
Author(s):  
Klára Novotná ◽  
Milena Fantová ◽  
Lenka Nohejlová ◽  
Markéta Borková ◽  
Luděk Stádník ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Milk Yield ◽  
Chlorella Vulgaris ◽  
Milk Fat ◽  
Goat Milk ◽  
Control Group ◽  
Basic Composition ◽  
Experimental Group

The aim of this study was to investigate the effect of two species of the microalgae on the milk yield, the basic composition and the fatty acid profile of goat milk, with focus on n‑3 fatty acids. Forty‑five White short‑haired goats were randomly allocated to three groups; the control group (C) with no supplementation microalgae to the diet. The first experimental group (Ch) was supplemented with Chlorella vulgaris and second experimental group (J) has been supplemented with Japonochytrium sp. The Japonochytrium supplementation negatively affected milk yield, but the amount of milk fat (+0.1 %; +0.45 %) and solids‑not‑fat (+0.27 %; +0.86 %) were higher than in group C and Ch. The amount of polyunsaturated (5.527 % ± 0.378) and saturated (71.560 % ± 0.861) fatty acids was also highest in group J. An increase of C20:4, C20:5 was detected in J and Ch, and the concentration of C22:6 was highest in group J (+0.019 %; P < 0.001).

scholarly journals Daytime Grazing in Mountainous Areas Increases Unsaturated Fatty Acids and Decreases Cortisol in the Milk of Holstein Dairy Cows

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3122
Author(s):  
Jalil Ghassemi Nejad ◽  
Bae-Hun Lee ◽  
Ji-Yung Kim ◽  
Kyung-Il Sung ◽  
Hong-Gu Lee
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Dairy Cows ◽  
Milk Fat ◽  
Unsaturated Fatty Acids ◽  
Control Group ◽  
Milk Fatty Acid ◽  
Omega 3 ◽  
Mountainous Areas ◽  
Lactating Cows

The effects of grazing lactating cows in mountainous areas for 12 and 24 h compared with the confined indoor system were evaluated by examining the overall milk fatty acid and cortisol. Twenty-one dairy cows were allocated to three treatment groups: (1) control (confined management system in a free-stall barn; TMR based), (2) grazing for 12 h (12hG; TMR plus grazing pasture), and (3) grazing for 24 h (24hG; pasture-based feeding system). Dry matter intake was higher in the control and 12hG groups than in the 24hG group. The yields of total milk and the 3.5% fat-corrected milk were the lowest in the 24hG group. Milk fat was the highest in the 24hG group and higher in 12hG compared with the control group. Milk protein and lactose levels were the highest in the 12hG group. The highest somatic cell count was observed in the 24hG group. The saturated fatty acid levels were higher in the control group compared with the 12hG and 24hG groups. There was no difference in overall mono-unsaturated fatty acids between 12hG and 24hG groups. Poly-unsaturated fatty acids were higher in the 12hG group compared with the control and 24hG groups. There was no difference in omega-6 (ω-6) fatty acids among the groups, and omega-3 fatty acids were higher in the 12hG group than in the control group. Milk cortisol was the highest in the 24hG group and higher in the control group compared with the 12hG group. Taken together, grazing for 12 h is advisable for farms that have access to mountainous areas to improve the milk fatty acid profile and decrease the stress levels in high-yielding Holstein lactating cows.

scholarly journals Fatty Acids Profiles of Stipe and Blade from the Norwegian Brown Macroalga Laminaria hyperborea, Using Off-Line SPE and GC-MS

2016 ◽  
Author(s):  
Lena Oksdøl Foseid ◽  
Hanne Devle ◽  
Yngve Stenstrøm ◽  
Carl Fredrik Naess-Andresen ◽  
Dag Ekeberg
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Neutral Lipids ◽  
Methyl Esters ◽  
Lipid Fraction ◽  
Environmental Benefits ◽  
Laminaria Hyperborea ◽  
Alpha Linolenic Acid ◽  
Lipid Fractions

A thorough analysis and comparison of the fatty acid profiles of stipe and blade from Laminaria hyperborea, a kelp species found in the northern Atlantic, is presented. Lipids were extracted and fractionated into neutral lipids, free fatty acids and polar lipids, then derivatized to fatty acid methyl esters prior to GC-MS analysis. A total of 42 fatty acids were identified and quantified, including the n-3 fatty acids &alpha;-linolenic acid, stearidonic acid and eicosapentaenoic acid. An n-6/n-3 ratio of 0.8:1 was found in blade and 3.5:1 in stipe, respectively. The ratios vary between the lipid fractions within stipe and blade, with the lowest ratio in the polar lipid fraction of blade. The fatty acid amounts are higher in blade than in stipe, and the highest amounts of n-3 fatty acids are found within the neutral lipid fractions. The amounts of polyunsaturated fatty acids are 3.4 times higher in blade than stipe. This study highlights the compositional differences between the lipid fractions of stipe and blade from L. hyperborea. The amount of polyunsaturated fatty acids, compared to saturated- and monounsaturated fatty acids, as well as the n-6/n-3-ratio, is known to influence human health. In the pharmaceutical, food, and feed industries this can be of importance for production and sale of different health products. Additionally, lipids are today among the unused by products of alginate production, exploiting this material for commercial interest should give both economical and environmental benefits.

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