51
|
Eibler D, Hammerschick T, Buck L, Vetter W. Up to 21 Different Sulfur-Heterocyclic Fatty Acids in Rapeseed and Mustard Oil. J AM OIL CHEM SOC 2017. [DOI: 10.1007/s11746-017-3007-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
52
|
Raczyk M, Kmiecik D, Przybylski R, Rudzińska M. Effect of Fatty Acid Unsaturation on Phytosteryl Ester Degradation. J AM OIL CHEM SOC 2017; 94:701-711. [PMID: 28479606 PMCID: PMC5397657 DOI: 10.1007/s11746-017-2979-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 03/18/2017] [Accepted: 03/20/2017] [Indexed: 12/22/2022]
Abstract
This study examined the thermo-oxidative degradation of stigmasterol fatty acids esters. Stigmasterol stearate, oleate, linoleate and linolenate were synthesized by chemical esterification and their purity evaluated by 1H-NMR and GC-MS. The degradation of stigmasterol esters was examined after heating them at 60 and 180 °C for 1, 2, 4, 8 and 12 h. It was established that stigmasterol esters were prone to thermo-oxidative degradation, with time and temperature affecting the degree of degradation. The unsaturation of fatty acids affected the rate of stigmasteryl ester degradation. The kinetics of StS and StO degradation were similar and the additional double bonds in StL and StLn resulted in their faster decomposition. The esters degraded faster at 180 than at 60 °C. The sterol and fatty acid molecules degraded at different rates, such that the fatty acid moiety deteriorated faster than the sterol at both temperatures, independent of the time of heating and the level of unsaturation.
Collapse
Affiliation(s)
- Marianna Raczyk
- Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland
| | - Dominik Kmiecik
- Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland
| | - Roman Przybylski
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Canada
| | - Magdalena Rudzińska
- Faculty of Food Science and Nutrition, Poznań University of Life Sciences, Wojska Polskiego 31, 60-624 Poznań, Poland
| |
Collapse
|
53
|
Truzzi C, Illuminati S, Annibaldi A, Antonucci M, Scarponi G. Quantification of fatty acids in the muscle of Antarctic fish Trematomus bernacchii by gas chromatography-mass spectrometry: Optimization of the analytical methodology. CHEMOSPHERE 2017; 173:116-123. [PMID: 28107709 DOI: 10.1016/j.chemosphere.2016.12.140] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/23/2016] [Accepted: 12/28/2016] [Indexed: 06/06/2023]
Abstract
This work presents data on the quantification of fatty acids (FAs, in terms of mass unit per tissue weight) in the muscle of Trematomus bernacchii, a key species in Antarctica, often used as bioindicator for contamination studies. Modifications in fatty acids content should be considered a useful biomarker to study how contaminants affect Antarctic biota. Until now, very few studies quantified fatty acids of muscle of T. bernacchii, and only as percentage of a single fatty acid on total lipids. To perform the quantification of fatty acids, we used an analytical method based on a fast microwave-assisted extraction of lipids from a lyophilized sample, a base-catalyzed trans-esterification of lipid extract to obtain Fatty Acids Methyl Esters (FAMEs), and a separation and identification of FAMEs by gas chromatography-mass spectrometry. With the optimized and validated method, a fast and accurate separation of Fatty Acids Methyl Esters was performed in 43 min. The linearity was checked up to about 320 μg mL-1; limit of detection and limit of quantification are in the range 4-22 μg mL-1 and 13-66 μg mL-1, respectively. The optimized method showed a good accuracy and precision. Major fatty acids were 14:0, 16:0, 16:1n7, 18:1n9, 18:1n7, 20:1n9, 20:5n3 and 22:6n3. Quantified FAs compute for about 47 mg g-1 tissue dry weight (dw), with 9.1 ± 0.1 mg g-1 dw of saturated FAs, 25.5 ± 0.1 mg g-1 dw of mono-unsaturated FAs, and 12.2 ± 0.1 mg g-1 dw of poly-unsaturated FAs.
Collapse
Affiliation(s)
- C Truzzi
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
| | - S Illuminati
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - A Annibaldi
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - M Antonucci
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - G Scarponi
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| |
Collapse
|
54
|
Biohydrogenation patterns in digestive contents and plasma of lambs fed increasing levels of a tanniferous bush ( Cistus ladanifer L.) and vegetable oils. Anim Feed Sci Technol 2017. [DOI: 10.1016/j.anifeedsci.2017.01.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
55
|
Eibler D, Abdurahman H, Ruoff T, Kaffarnik S, Steingass H, Vetter W. Unexpected Formation of Low Amounts of (R)-Configurated anteiso-Fatty Acids in Rumen Fluid Experiments. PLoS One 2017; 12:e0170788. [PMID: 28129363 PMCID: PMC5271357 DOI: 10.1371/journal.pone.0170788] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 01/11/2017] [Indexed: 01/26/2023] Open
Abstract
Anteiso-fatty acids (aFA) with odd carbon number are a class of branched-chain fatty acids (BCFA) mainly produced by bacteria. Bacterial sources are also made responsible for their occurrence in the low percent-range in lipids of ruminants (meat and milk) and fish. aFAs are chiral molecules and typically occur predominantly in form of (S)-enantiomers, and their primary precursor has been noted to be isoleucine. Yet, low proportions of (R)-aFAs were also detected in fish and cheese samples. Here we investigated the potential formation of (R)-aFAs by means of incubation experiments with rumen fluid from fistulated cows. Supplementation of rumen fluid with both L- and DL-isoleucine, resulted in a significant (α <0.05) increase of the aFA concentrations but in both cases enantiopure (S)-aFAs were observed. By contrast, incubations without addition of any isoleucine lead to a significant (α <0.05) formation of small proportions of (R)-aFAs similarly to those previously observed in fish and cheese. These results were consistently reproduced in three different years with rumen fluid from different cows fed different diets. All findings point to the existence of a further biosynthesis pathway of aFAs with different stereospecificity than the classic one using isoleucine as primer.
Collapse
Affiliation(s)
- Dorothee Eibler
- University of Hohenheim, Institute of Food Chemistry (170b), Stuttgart, Germany
| | - Halima Abdurahman
- University of Hohenheim, Institute of Food Chemistry (170b), Stuttgart, Germany
| | - Tanja Ruoff
- University of Hohenheim, Institute of Food Chemistry (170b), Stuttgart, Germany
| | - Stefanie Kaffarnik
- University of Hohenheim, Institute of Food Chemistry (170b), Stuttgart, Germany
| | - Herbert Steingass
- University of Hohenheim, Institute of Animal Science (460a), Stuttgart, Germany
| | - Walter Vetter
- University of Hohenheim, Institute of Food Chemistry (170b), Stuttgart, Germany
- * E-mail:
| |
Collapse
|
56
|
Yousfi I, Ben Salem H, Aouadi D, Abidi S. Effect of sodium chloride, sodium sulfate or sodium nitrite in drinking water on intake, digestion, growth rate, carcass traits and meat quality of Barbarine lamb. Small Rumin Res 2016. [DOI: 10.1016/j.smallrumres.2016.08.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
57
|
Alves SP, Fernandes MJ, Fernandes MH, Bessa RJ, Laranjo M, A.-Santos AC, Elias M, Fraqueza MJ. Quality and Acceptability of Dry Fermented Sausages Prepared with Low Value Pork Raw Material. J FOOD PROCESS PRES 2016. [DOI: 10.1111/jfpp.12823] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Susana P. Alves
- CIISA, Faculty of Veterinary Medicine; University of Lisbon; Lisbon Portugal
| | - Maria J. Fernandes
- CIISA, Faculty of Veterinary Medicine; University of Lisbon; Lisbon Portugal
| | - Maria H. Fernandes
- CIISA, Faculty of Veterinary Medicine; University of Lisbon; Lisbon Portugal
| | - Rui J.B. Bessa
- CIISA, Faculty of Veterinary Medicine; University of Lisbon; Lisbon Portugal
| | - Marta Laranjo
- ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Instituto de Investigação e Formação Avançada (IIFA), Departamento de Fitotecnia, Escola de Ciências e Tecnologia; Universidade de Évora; Évora Portugal
| | - Ana Cristina A.-Santos
- ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Instituto de Investigação e Formação Avançada (IIFA), Departamento de Fitotecnia, Escola de Ciências e Tecnologia; Universidade de Évora; Évora Portugal
| | - Miguel Elias
- ICAAM-Instituto de Ciências Agrárias e Ambientais Mediterrânicas, Instituto de Investigação e Formação Avançada (IIFA), Departamento de Fitotecnia, Escola de Ciências e Tecnologia; Universidade de Évora; Évora Portugal
| | - Maria J. Fraqueza
- CIISA, Faculty of Veterinary Medicine; University of Lisbon; Lisbon Portugal
| |
Collapse
|
58
|
Rao G, Sui J, Zhang J. Metabolomics reveals significant variations in metabolites and correlations regarding the maturation of walnuts (Juglans regia L.). Biol Open 2016; 5:829-36. [PMID: 27215321 PMCID: PMC4920193 DOI: 10.1242/bio.017863] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The content of walnut metabolites is related to its nutritive value and physiological characteristics, however, comprehensive information concerning the metabolome of walnut kernels is limited. In this study we analyzed the metabolites of walnut kernels at five developmental stages from filling to ripening using GC-MS-based untargeted metabolomics; of a total 252 peaks identified, 85 metabolites were positively identified. Further statistical analysis revealed that these 85 metabolites covered different types of metabolism pathways. PCA scores revealed that the metabolic compositions of the embryo are different at each stage, while the metabolic composition of the endotesta could not be significantly separated into distinct groups. Additionally, 7225 metabolite-metabolite correlations were detected in walnut kernel by a Pearson correlation coefficient approach; during screening of the calculated correlations, 463 and 1047 were determined to be significant with r2≥0.49 and had a false discovery rate (FDR) ≤0.05 in endotesta and embryo, respectively. This work provides the first comprehensive metabolomic study of walnut kernels and reveals that most of the carbohydrate and protein-derived carbon was transferred into other compounds, such as fatty acids, during the maturation of walnuts, which may potentially provide the basis for further studies on walnut kernel metabolism. Summary: This work provides a comprehensive metabolomic study of walnut kernels and reveals most of the carbohydrate and protein-derived carbons were transferred into other compounds during the maturation of walnuts.
Collapse
Affiliation(s)
- Guodong Rao
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Republic of China Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China
| | - Jinkai Sui
- Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Republic of China
| | - Jianguo Zhang
- State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China Collaborative Innovation Center of Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, Republic of China Key Laboratory of Tree Breeding and Cultivation, State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Republic of China
| |
Collapse
|
59
|
Eibler D, Seyfried C, Kaffarnik S, Vetter W. anteiso-Fatty Acids in Brussels Sprouts (Brassica oleracea var. gemmifera L.): Quantities, Enantioselectivities, and Stable Carbon Isotope Ratios. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:8921-8929. [PMID: 26390192 DOI: 10.1021/acs.jafc.5b03877] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
anteiso-Fatty acids (aFAs) are a class of branched-chain fatty acids that are characterized by one methyl branch on the antepenultimate carbon of the straight acyl chain. aFAs are mainly produced by bacteria, and sources in vegetables are scarce. This study reports the concentrations of odd-numbered aFAs (a15:0-a21:0) in Brussels sprout buds. Selective enrichment followed by enantioselective gas chromatography with mass spectrometry in the selected ion monitoring mode revealed that both a15:0 and a17:0 were (S)-enantiopure in Brussels sprout samples. δ(13)C values (‰) of a17:0 in Brussels sprouts were comparable with those of palmitic acid, indicating no different source for both fatty acids.
Collapse
Affiliation(s)
- Dorothee Eibler
- Institute of Food Chemistry (170b), University of Hohenheim , Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Carolin Seyfried
- Institute of Food Chemistry (170b), University of Hohenheim , Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Stefanie Kaffarnik
- Institute of Food Chemistry (170b), University of Hohenheim , Garbenstrasse 28, 70599 Stuttgart, Germany
| | - Walter Vetter
- Institute of Food Chemistry (170b), University of Hohenheim , Garbenstrasse 28, 70599 Stuttgart, Germany
| |
Collapse
|
60
|
Brauch JE, Buchweitz M, Schweiggert RM, Carle R. Detailed analyses of fresh and dried maqui (Aristotelia chilensis (Mol.) Stuntz) berries and juice. Food Chem 2015. [PMID: 26212975 DOI: 10.1016/j.foodchem.2015.05.097] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, a detailed chemical characterization of nutritionally-relevant, quality-determining constituents in dried and fresh fruits as well as juices of maqui (Aristotelia chilensis (Mol.) Stuntz) is provided. A total of 8 glycosylated anthocyanins was characterized in maqui fruits, being composed of differently substituted cyanidin and delphinidin derivatives. During processing into juice, a substantial loss in total anthocyanin contents (TAC) was observed. TAC values were also reduced after drying of maqui berries. Likewise, the browning index (BI) of fresh fruits increased during processing. Being composed of flavonol glycosides and ellagic acids, 17 non-anthocyanin phenolics were characterized in all maqui samples. Besides characterizing phenolic compounds, antioxidant activities, total phenolics, major sugars, non-volatile organic acids, minerals and trace elements were quantitated. Moreover, total lipid contents and the fruits' mainly unsaturated fatty acid profiles are reported. The presented results indicate the high potential of maqui as so far under-utilized but extremely pigment-rich "superfruit".
Collapse
Affiliation(s)
- J E Brauch
- University of Hohenheim, Institute of Food Science and Biotechnology, Chair Plant Foodstuff Technology and Analysis, Garbenstrasse 25, D-70599 Stuttgart, Germany
| | - M Buchweitz
- University of Stuttgart, Faculty of Chemistry, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
| | - R M Schweiggert
- University of Hohenheim, Institute of Food Science and Biotechnology, Chair Plant Foodstuff Technology and Analysis, Garbenstrasse 25, D-70599 Stuttgart, Germany.
| | - R Carle
- University of Hohenheim, Institute of Food Science and Biotechnology, Chair Plant Foodstuff Technology and Analysis, Garbenstrasse 25, D-70599 Stuttgart, Germany; King Abdulaziz University, Biological Science Department, P.O. Box 80257, Jeddah 21589, Saudi Arabia
| |
Collapse
|
61
|
Profiling of fatty acids composition in suet oil based on GC-EI-qMS and chemometrics analysis. Int J Mol Sci 2015; 16:2864-78. [PMID: 25636032 PMCID: PMC4346870 DOI: 10.3390/ijms16022864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 12/18/2014] [Accepted: 01/20/2015] [Indexed: 12/27/2022] Open
Abstract
Fatty acid (FA) composition of suet oil (SO) was measured by precolumn methylesterification (PME) optimized using a Box-Behnken design (BBD) and gas chromatography/electron ionization-quadrupole mass spectrometry (GC-EI-qMS). A spectral library (NIST 08) and standard compounds were used to identify FAs in SO representing 90.89% of the total peak area. The ten most abundant FAs were derivatized into FA methyl esters (FAMEs) and quantified by GC-EI-qMS; the correlation coefficient of each FAME was 0.999 and the lowest concentration quantified was 0.01 μg/mL. The range of recovery of the FAMEs was 82.1%-98.7% (relative standard deviation 2.2%-6.8%). The limits of quantification (LOQ) were 1.25-5.95 μg/L. The number of carbon atoms in the FAs identified ranged from 12 to 20; hexadecanoic and octadecanoic acids were the most abundant. Eighteen samples of SO purchased from Qinghai, Anhui and Jiangsu provinces of China were categorized into three groups by principal component analysis (PCA) according to the contents of the most abundant FAs. The results showed SOs samples were rich in FAs with significantly different profiles from different origins. The method described here can be used for quality control and SO differentiation on the basis of the FA profile.
Collapse
|
62
|
|
63
|
Kaffarnik S, Preuß S, Vetter W. Direct determination of flavor relevant and further branched-chain fatty acids from sheep subcutaneous adipose tissue by gas chromatography with mass spectrometry. J Chromatogr A 2014; 1350:92-101. [DOI: 10.1016/j.chroma.2014.05.034] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 05/09/2014] [Accepted: 05/13/2014] [Indexed: 10/25/2022]
|
64
|
Schröder M, Lehnert K, Hammann S, Vetter W. Dihydrophytol and phytol isomers as marker substances for hydrogenated and refined vegetable oils. EUR J LIPID SCI TECH 2014. [DOI: 10.1002/ejlt.201400095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Markus Schröder
- University of HohenheimInstitute of Food Chemistry (170b)Garbenstrasse 28D‐70599StuttgartGermany
| | - Katja Lehnert
- University of HohenheimInstitute of Food Chemistry (170b)Garbenstrasse 28D‐70599StuttgartGermany
| | - Simon Hammann
- University of HohenheimInstitute of Food Chemistry (170b)Garbenstrasse 28D‐70599StuttgartGermany
| | - Walter Vetter
- University of HohenheimInstitute of Food Chemistry (170b)Garbenstrasse 28D‐70599StuttgartGermany
| |
Collapse
|
65
|
Reich M, Kümmerer K, Al-Ahmad A, Hannig C. Fatty Acid Profile of the Initial Oral Biofilm (Pellicle): an In-Situ Study. Lipids 2013; 48:929-37. [DOI: 10.1007/s11745-013-3822-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 07/15/2013] [Indexed: 10/26/2022]
|
66
|
Maskrey BH, Megson IL, Rossi AG, Whitfield PD. Emerging importance of omega-3 fatty acids in the innate immune response: molecular mechanisms and lipidomic strategies for their analysis. Mol Nutr Food Res 2013; 57:1390-400. [PMID: 23417926 DOI: 10.1002/mnfr.201200723] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 12/12/2012] [Accepted: 12/12/2012] [Indexed: 12/22/2022]
Abstract
The beneficial health properties of dietary omega-3 polyunsaturated fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have long been known and their metabolic dysfunction has been linked to a range of diseases including various inflammatory disorders, cardiovascular diseases, and cancer. However, the molecular mechanisms underlying their health benefits have remained unclear. Recent technological advances in lipidomic analytical strategies have resulted in the discovery of a range of bioactive mediators derived from EPA and DHA that possess potent anti-inflammatory and pro-resolving properties and that may be responsible, at least in part, for the beneficial effects observed. These mediators include resolvins, protectins and maresins, as well as EPA derivatives of classical arachidonic acid derived eicosanoids, such as prostaglandin E3 . The aim of this review is to provide an overview of the biosynthetic pathways and biological properties of these omega-3 mediators, with a particular focus on the emerging importance of the counter-regulatory role of omega-3 and -6 fatty acids in the spatial and temporal regulation of the inflammatory response. It will also provide an insight into a range of lipidomic approaches, which are currently available to analyse these fatty acids and their metabolites in biological matrices.
Collapse
Affiliation(s)
- Benjamin H Maskrey
- Lipidomics Research Facility, Department of Diabetes and Cardiovascular Science, University of the Highlands and Islands, Inverness, UK.
| | | | | | | |
Collapse
|
67
|
Ren J, Mozurkewich EL, Sen A, Vahratian AM, Ferreri TG, Morse AN, Djuric Z. Total Serum Fatty Acid Analysis by GC-MS: Assay Validation and Serum Sample Stability. CURR PHARM ANAL 2013; 9:331-339. [PMID: 25110470 DOI: 10.2174/1573412911309040002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Analysis of n3 fatty acids in serum samples has clinical applications in supplementation trials, but the analysis can be challenging due to low levels, stability issues and intra-individual variation. This study presents the single laboratory validation of a gas chromatographic-mass spectral (GC-MS) assay for analysis of fatty acid methyl esters (FAME) using sensitive single ion monitoring and provides data on fatty acid stability under different sample handling conditions. Recovery of total fatty acids from serum with Folch extraction was optimized and parallelism tests with spiked samples indicated that the serum matrix did not interfere with mass spectral quantitation. Precision and accuracy of the assay at the lowest limit of quantitation and at low, medium and high levels met with accepted guidelines for single laboratory validation. Several storage conditions that can be encountered with clinical samples also were evaluated for impact on fatty acid levels in serum. Serum from blood that was stored refrigerated for 3 days yielded similar results as serum that was prepared and frozen at -80°C immediately. Serum storage at room temperature for 3-24 hours and serum subjected to one freeze/thaw cycle had minimal effects on fatty acid levels. The intra-individual variability in pregnant women was reasonably small, with significant correlation coefficients ranging from 0.35 to 0.76 for blood drawn between 12-20 weeks versus 34-36 weeks of gestation. These results indicate that GC-MS with single ion monitoring is valid for the analysis of total fatty acids in clinical samples, even when blood processing cannot be performed in a timely manner.
Collapse
Affiliation(s)
- Jianwei Ren
- Department of Family Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Ellen L Mozurkewich
- Department of Obstetrics and Gynecology, School of Medicine, University of New Mexico, Albuquerque, NM, USA ; Department of Obstetrics and Gynecology, School of Medicine, University of Michigan, Ann Arbor, MI
| | - Ananda Sen
- Department of Family Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA ; Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Anjel M Vahratian
- Department of Obstetrics and Gynecology, School of Medicine, University of Michigan, Ann Arbor, MI
| | - Thomas G Ferreri
- Department of Family Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Alexander N Morse
- Department of Family Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Zora Djuric
- Department of Family Medicine, School of Medicine, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
68
|
Bendig P, Maier L, Lehnert K, Knapp H, Vetter W. Mass spectra of methyl esters of brominated fatty acids and their presence in soft drinks and cocktail syrups. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:1083-1089. [PMID: 23592212 DOI: 10.1002/rcm.6543] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 02/08/2013] [Accepted: 02/10/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE Brominated vegetable oil (BVO) is frequently used as a solubility transmitter in soft drinks. Being banned in Europe and Japan but permitted in the United States and Canada, there is a need for analytical methods suitable for use in food control. Brominated fatty acids in BVO are usually determined by gas chromatography (GC) after their conversion into the corresponding methyl esters. METHODS GC with mass spectrometry (MS) was used to record the electron ionization (EI) and negative ion chemical ionization (NICI) mass spectra of relevant brominated fatty acid methyl esters synthesized for this purpose. Brominated fatty acids obtained from transesterified BVO from soft drink and syrup samples were also analyzed. RESULTS GC/NICI-MS was the most sensitive method for the detection of brominated fatty acids but GC/EI-MS was found to be more suited for quantification due to the formation of more selective fragment ions in the higher mass range. Suitable ions were selected for determination of the methyl esters of brominated fatty acids in the selected ion monitoring (SIM) mode. Artifacts produced by the transesterification of BVO with boron trifluoride were observed and discussed. BVO was also quantified in three syrup samples commercially produced for use in cocktails/long drinks. In one of the syrup samples that tested positive, BVO was not labelled in the ingredient list. Bromination experiments produced evidence that one or more Br2 -18:0 isomers identified as a shoulder peak of threo-9,10-dibromooctadecanoic acid in several soft drink and syrup samples originated from the bromination of partly hydrogenated plant oil. CONCLUSIONS BVO was determined for the first time in syrup samples. Attention should be paid to the problem of BVO occurring unlabeled in soft drinks and cocktail syrups imported from North America.
Collapse
Affiliation(s)
- Paul Bendig
- University of Hohenheim, Institute of Food Chemistry, Stuttgart, Germany
| | | | | | | | | |
Collapse
|
69
|
Schröder M, Vetter W. Detection of 430 Fatty Acid Methyl Esters from a Transesterified Butter Sample. J AM OIL CHEM SOC 2013. [DOI: 10.1007/s11746-013-2218-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
70
|
Bendig P, Maier L, Vetter W. Brominated vegetable oil in soft drinks – an underrated source of human organobromine intake. Food Chem 2012. [DOI: 10.1016/j.foodchem.2012.01.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
71
|
Reich M, Hannig C, Al-Ahmad A, Bolek R, Kümmerer K. A comprehensive method for determination of fatty acids in the initial oral biofilm (pellicle). J Lipid Res 2012; 53:2226-2230. [PMID: 22829652 DOI: 10.1194/jlr.d026260] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The acquired pellicle is a tenacious organic layer covering the surface of teeth, protecting the underlying dental hard tissues. Lipids account for about one quarter of the pellicle's dry weight and are assumed to be of considerable importance for their protective properties. Nevertheless, only preliminary information is available about the nature of lipids in the pellicle. Gas chromatography coupled with electron impact ionization mass spectrometry was used to establish a convenient analytical protocol in order to obtain a qualitative and quantitative characterization of a wide range of FAs (C(12)-C(22)). In situ biofilm formation was performed on bovine enamel slabs mounted on individual splints carried by 10 subjects. A modified Folch extraction procedure was adopted to extract the lipids from the detached pellicle, followed by transesterification to fatty acid methyl esters using methanol and concentrated hydrochloric acid. Tridecanoic and nonadecanoic acid were used as internal standards suitable and reliable for robust, precise and accurate measurements. The present study demonstrates, for the first time, a procedure based on a combination of innovative specimen generation and convenient sample preparation with sensitive GC-MS analysis for the determination of the fatty acid profile of the initial oral biofilm.
Collapse
Affiliation(s)
- Marco Reich
- Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University Lüneburg, Lüneburg, Germany.
| | - Christian Hannig
- Clinic of Operative Dentistry, Faculty of Medicine Carl Gustav Carus, Technical University of Dresden, Dresden, Germany; and
| | - Ali Al-Ahmad
- Department of Operative Dentistry and Periodontology, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Richard Bolek
- Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University Lüneburg, Lüneburg, Germany
| | - Klaus Kümmerer
- Institute of Sustainable and Environmental Chemistry, Faculty of Sustainability, Leuphana University Lüneburg, Lüneburg, Germany
| |
Collapse
|
72
|
Nevigato T, Masci M, Orban E, Di Lena G, Casini I, Caproni R. Analysis of fatty acids in 12 Mediterranean fish species: advantages and limitations of a new GC-FID/GC-MS based technique. Lipids 2012; 47:741-53. [PMID: 22644810 DOI: 10.1007/s11745-012-3679-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 04/28/2012] [Indexed: 12/22/2022]
Abstract
When fatty acids in fish are analyzed, results in percentage form (profile analysis) are mostly reported. However, the much more useful results expressed as mg/100 g (absolute analysis) is the main information required. Absolute methods based on calibration curves are of good accuracy but with a high degree of complexity if applied to a great number of analytes. Procedures based on the sequence profile analysis-total FA determination-absolute analysis may be suitable for routine use, but suffer from a number of uncertainties that have never been really resolved. These uncertainties are mainly related to the profile analysis. In fact, most profile analyses reported in the literature disagree about the number and type of fatty acids monitored as well as about the total percentage to assign to their sum so leading to possible inaccuracies; in addition the instrumental response factor for all FAME (fatty acid methyl esters) is often considered as a constant, but this is not exactly true. In this work, a set of 24 fatty acids was selected and studied on 12 fish species in the Mediterranean area (variable in lipid content and month of sampling): in our results, and in these species, this set constitutes, on average, 90 ± 3 % of the total fatty acid content. Moreover the error derived from the assumption of a unique response factor was investigated. Two different detection techniques (GC-FID and GC-MS) together with two capillary columns (different in length and polarity) were used in order to acquire complementary data on the same sample. With the protocol here proposed absolute analyses on the 12 cited species are easily achievable by the total FA determination procedure. The accuracy of this approach is good in general, but in some cases (DHA for example) is lower than the accuracy of calibration-based methods. The differences were evaluated on a case by case basis.
Collapse
Affiliation(s)
- Teresina Nevigato
- National Research Institute for Food and Nutrition (INRAN), Via Ardeatina 546, 00178, Rome, Italy.
| | | | | | | | | | | |
Collapse
|
73
|
Schröder M, Lutz NL, Tangwan EC, Hajazimi E, Vetter W. Phytanic acid concentrations and diastereomer ratios in milk fat during changes in the cow’s feed from concentrate to hay and back. Eur Food Res Technol 2012. [DOI: 10.1007/s00217-012-1710-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
74
|
Vetter W, Laure S, Wendlinger C, Mattes A, Smith AWT, Knight DW. Determination of Furan Fatty Acids in Food Samples. J AM OIL CHEM SOC 2012. [DOI: 10.1007/s11746-012-2038-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
75
|
Villalobos-Gutiérrez M, Schweiggert R, Carle R, Esquivel P. Chemical characterization of Central American pitaya (Hylocereussp.) seeds and seed oil. CYTA - JOURNAL OF FOOD 2012. [DOI: 10.1080/19476337.2011.580063] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
|
76
|
Isolation of 6,9,12,15-Hexadecatetraenoic Fatty Acid (16:4n-1) Methyl Ester from Transesterified Fish Oil by HSCCC. Chromatographia 2011. [DOI: 10.1007/s10337-011-2155-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
77
|
Dreiucker J, Vetter W. Fatty acids patterns in camel, moose, cow and human milk as determined with GC/MS after silver ion solid phase extraction. Food Chem 2011. [DOI: 10.1016/j.foodchem.2010.11.061] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
78
|
Schlosser S, Vetter W. Fatty acids and polar lipid content of cheese and mould‐contaminated cheese. EUR J LIPID SCI TECH 2011. [DOI: 10.1002/ejlt.201000085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Sonja Schlosser
- Universität Hohenheim, Institut für Lebensmittelchemie, Stuttgart, Germany
| | - Walter Vetter
- Universität Hohenheim, Institut für Lebensmittelchemie, Stuttgart, Germany
| |
Collapse
|
79
|
Hauff S, Vetter W. Exploring the fatty acids of vernix caseosa in form of their methyl esters by off-line coupling of non-aqueous reversed phase high performance liquid chromatography and gas chromatography coupled to mass spectrometry. J Chromatogr A 2010; 1217:8270-8. [DOI: 10.1016/j.chroma.2010.10.088] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 09/29/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
|
80
|
GC/EI-MS Determination of the Diastereomer Distribution of Phytanic Acid in Food Samples. J AM OIL CHEM SOC 2010. [DOI: 10.1007/s11746-010-1682-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
81
|
Enantioselective Analysis of Chiral Anteiso Fatty Acids in the Polar and Neutral Lipids of Food. Lipids 2010; 45:357-65. [DOI: 10.1007/s11745-010-3400-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 02/18/2010] [Indexed: 10/19/2022]
|
82
|
Hauff S, Rilfors L, Hottinger G, Vetter W. Structure and absolute configuration of an unsaturated anteiso fatty acid from Bacillus megaterium. J Chromatogr A 2010; 1217:1683-7. [DOI: 10.1016/j.chroma.2010.01.036] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 01/03/2010] [Accepted: 01/08/2010] [Indexed: 11/26/2022]
|
83
|
Creation and evaluation of a two-dimensional contour plot of fatty acid methyl esters after off-line coupling of reversed-phase HPLC and GC/EI-MS. Anal Bioanal Chem 2010; 396:2695-707. [DOI: 10.1007/s00216-010-3502-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Revised: 01/20/2010] [Accepted: 01/20/2010] [Indexed: 11/26/2022]
|
84
|
Devle H, Rukke EO, Naess-Andresen CF, Ekeberg D. A GC â magnetic sector MS method for identification and quantification of fatty acids in ewe milk by different acquisition modes. J Sep Sci 2009; 32:3738-45. [DOI: 10.1002/jssc.200900455] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
85
|
Chin ST, Che Man YB, Tan CP, Hashim DM. Rapid Profiling of Animal-Derived Fatty Acids Using Fast GC × GC Coupled to Time-of-Flight Mass Spectrometry. J AM OIL CHEM SOC 2009. [DOI: 10.1007/s11746-009-1427-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
86
|
|
87
|
Vetter W, Wegner I. Quantitative Determination of Isostearic Acid Isomers in Skin Creams by GC-MS-SIM. Chromatographia 2009. [DOI: 10.1365/s10337-009-1134-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
88
|
Hauff S, Vetter W. Quantitation of cis- and trans-monounsaturated fatty acids in dairy products and cod liver oil by mass spectrometry in the selected ion monitoring mode. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2009; 57:3423-3430. [PMID: 19323583 DOI: 10.1021/jf803665u] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Monounsaturated fatty acids (MUFAs) are important constituents of dietary fats. While cis-configurated isomers belong to the classic fatty acids of food, trans-fatty acids are suspected to pose a risk to human health. In either case, a thorough assessment of both positional and geometrical isomers of MUFAs is an important task in food and life sciences. For this purpose, a method suitable for routine analysis was developed. After lipid extraction and conversion of fatty acids into corresponding fatty acid methyl esters, cis and trans isomers of MUFAs were separated on silver-ion-impregnated cartridges. Fractions containing either cis- or trans-MUFAs were determined by gas chromatography-electron ionization mass spectrometry in the selected ion monitoring (GC/EI-MS-SIM) mode using [M-32](+) as quantification ions and [M-74](+) as well as M(+) as qualifier ions. A total of 14 MUFAs were available as reference standards, but a total of 40 MUFAs (22 cis and 18 trans isomers) were identified with high selectivity in samples of cheese, goat fat, human milk, and cod liver oil. The 18:1 and 16:1 isomers contributed most to both the cis- and trans-MUFAs. Application of internal standards allowed for the quantification of MUFAs only in the food samples. The amount of trans-fatty acids was determined to be 0.9- 4.3 g/100 g, with the lowest levels in human milk fat and the highest levels in Roquefort cheese. After exclusion of oleic acid, the concentrations of trans- and cis-MUFAs were at the same level in samples from ruminants and human milk fat.
Collapse
Affiliation(s)
- Simone Hauff
- Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany
| | | |
Collapse
|
89
|
Quantification of fatty acids as methyl esters and phospholipids in cheese samples after separation of triacylglycerides and phospholipids. Anal Chim Acta 2009; 636:229-35. [DOI: 10.1016/j.aca.2009.01.056] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2008] [Revised: 01/23/2009] [Accepted: 01/26/2009] [Indexed: 11/21/2022]
|
90
|
Schütz K, Nagel P, Vetter W, Kandeler E, Ruess L. Flooding forested groundwater recharge areas modifies microbial communities from top soil to groundwater table. FEMS Microbiol Ecol 2009; 67:171-82. [DOI: 10.1111/j.1574-6941.2008.00608.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
91
|
Jenske R, Vetter W. Enantioselective analysis of 2- and 3-hydroxy fatty acids in food samples. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:11578-11583. [PMID: 19090708 DOI: 10.1021/jf802772a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
2-Hydroxy fatty acids (2-OH-FAs) and 3-hydroxy fatty acids (3-OH-FAs) were recently identified at trace levels in dairy products and other food samples (vegetable oils and animal brains). Due to the asymmetric carbon bearing the hydroxy group, they are chiral. This study focused on the enantioselective determination of 2- and 3-OH-FAs in food. For this purpose, extracted saponifiable lipids were converted into methyl esters, and the resulting fatty acid methyl esters (FAMEs) were separated into OH-FAMEs (minor fraction) and non-OH-FAMEs (bulk fraction). OH-FAMEs were then derivatized with (R)-(-)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride [(R)-(-)-MTPA-Cl, Mosher's reagent] to produce the corresponding MTPA-O-FAMEs. MTPA-O-FAME diastereomers were then analyzed by gas chromatography with electron capture negative-ion mass spectrometry (GC/ECNI-MS) in the selected ion monitoring (SIM) mode. In the food samples, both (S)- and (R)-enantiomers of 2- and 3-OH-FAs were detected, with the (R)-enantiomer being enantiopure or predominant with one exception. Especially 2- and 3-OH-16:0 were found to contain relevant proportions of the (S)-enantiomer. The differences in enantiomeric composition of 2- and 3-OH-16:0 detected for cheese samples were proposed as markers for authenticity controls.
Collapse
Affiliation(s)
- Ramona Jenske
- University of Hohenheim, Institute of Food Chemistry, Garbenstrasse 28, D-70599 Stuttgart, Germany
| | | |
Collapse
|
92
|
Jenske R, Vetter W. Gas chromatography/electron-capture negative ion mass spectrometry for the quantitative determination of 2- and 3-hydroxy fatty acids in bovine milk fat. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:5500-5505. [PMID: 18570427 DOI: 10.1021/jf800647w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
2- and 3-hydroxy fatty acids (2- and 3-OH-FAs) are bioactive substances reported in sphingolipids and bacteria. Little is known of their occurrence in food. For this reason, a method suitable for the determination of OH-FAs at trace levels in bovine milk fat was developed. OH-FAs (and conventional fatty acids in samples) were converted into methyl esters and the hydroxyl group was derivatized with pentafluorobenzoyl (PFBO) chloride to give PFBO- O-FA methyl esters. These derivatives with strong electron affinity were determined by gas chromatography interfaced to mass spectrometry using electron-capture negative ion in the selected ion monitoring mode (GC/ECNI-MS-SIM). This method proved to be highly sensitive and selective for PFBO-O-FA methyl esters. For the analysis of samples, two internal standards were used. For this purpose, 9,10-dideutero-2-OH-18:0 methyl ester (ISTD-1) from 2-OH-18:1(9 c) methyl ester as well as the ethyl ester of 3-PFBO-O-12:0 (ISTD-2) was synthesized. ISTD-1 served as a recovery standard whereas ISTD-2 was used for GC/MS measurements. The whole-sample cleanup consisted of accelerated solvent extraction of dry bovine milk, addition of ISTD 1, saponification, conversion of fatty acids into methyl esters by use of boron trifluoride, separation of the methyl esters of OH-FAs from nonsubstituted FAs on activated silica, conversion of OH-FAs methyl esters into PFBO-O-FA methyl esters, addition of ISTD-2, and measurement by GC/ECNI-MS-SIM. By this method, ten OH-FAs were quantified in bovine milk fat with high precision in the range from 0.02 +/- 0.00 to 4.49 +/- 0.29 mg/100 g of milk fat.
Collapse
Affiliation(s)
- Ramona Jenske
- Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, D-70599 Stuttgart, Germany
| | | |
Collapse
|
93
|
Screening of GLA (γ-Linolenic Acid) from Fungi by Gas Chromatography and Mass Spectroscopy. THE KOREAN JOURNAL OF MYCOLOGY 2007. [DOI: 10.4489/kjm.2007.35.2.096] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
94
|
Vetter W, Thurnhofer S. Analysis of fatty acids by mass spectrometry in the selected ion monitoring mode. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/lite.200700062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
95
|
Vetter W, Gaul S, Thurnhofer S, Mayer K. Stable carbon isotope ratios of methyl-branched fatty acids are different to those of straight-chain fatty acids in dairy products. Anal Bioanal Chem 2007; 389:597-604. [PMID: 17639356 DOI: 10.1007/s00216-007-1438-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Revised: 06/08/2007] [Accepted: 06/15/2007] [Indexed: 11/29/2022]
Abstract
Methyl-branched fatty acids (MBFAs) are the dominant form of fatty acid found in many bacteria. They are also found at low levels in a range of foodstuffs, where their presence has been linked to bacterial sources. In this study we evaluated the potential of compound-specific isotope analysis to obtain insights into the stable carbon isotope ratios (delta(13)C values in per thousand) of individual MBFAs and to compare them to the stable carbon isotope ratios of straight-chain fatty acids in food. Due to their low abundance in foodstuffs, the MBFAs were enriched prior to gas chromatography coupled to isotope ratio mass spectrometric (GC-IRMS) analysis. After transesterification, urea complexation was used to suppress the 16:0 and 18:0 methyl esters that were dominant in the samples. Following that, silver-ion high performance liquid chromatography was used to separate the saturated from the unsaturated fatty acids. The resulting solutions of saturated fatty acids obtained from suet, goat's milk, butter, and human milk were studied by GC-IRMS. The delta(13)C values of fatty acids with 12-17 carbons ranged from -25.4 per thousand to -37.6 per thousand. In all samples, MBFAs were most depleted in carbon-13, followed by the odd-chain fatty acids 15:0 and 17:0. 14:0 and 16:0 contained the highest proportions of carbon-13. The results from this study illustrate that MBFAs have distinctive delta(13)C values and must originate from other sources and/or from very different substrates. These measurements support the initial hypothesis that delta(13)C values can be used to attribute MBFAs to particular sources.
Collapse
Affiliation(s)
- Walter Vetter
- Institute of Food Chemistry, University of Hohenheim, Garbenstr. 28, 70593 Stuttgart, Germany.
| | | | | | | |
Collapse
|
96
|
Thurnhofer S, Hottinger G, Vetter W. Enantioselective Determination of Anteiso Fatty Acids in Food Samples. Anal Chem 2007; 79:4696-701. [PMID: 17508720 DOI: 10.1021/ac0702894] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anteiso fatty acids (aFAs)-long-chain carboxylic acids with a methyl branch on the (n - 2)-carbon-are among the most simple fatty acids that are chiral. The most frequently occurring aFAs in food are 12-methyltetradecanoic acid (a15:0) and 14-methylhexadecanoic acid (a17:0), structures where the asymmetric carbon is more than 10 carbons separated from the polar head group. Previously, only enantioseparation of 4-methyl-substituted carboxylic fatty acids has been reported by gas chromatography. Here we present the first direct partial enantioresolution of synthesized racemic a15:0-a17:0 on a capillary column coated with 50% heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-beta-cyclodextrin diluted in OV1701. Synthesized (S)-(+)-enantiomers were used to demonstrate that the elution order was (R)- prior to (S)-enantiomers. Using this system, food samples (butter, goat's milk fat, suet, human milk, seal oil, cod liver oil) known to contain aFAs were analyzed. Prior to the enantioselective gas chromatography, unsaturated fatty acids were preseparated by urea complexation, silver ion high performance liquid chromatography (Ag+-HPLC), or both from food samples. The fractions of the food samples enriched with methyl-branched fatty acids were then analyzed by GC/MS in the SIM mode. The measurements confirmed that the (S)-enantiomer of a15:0 (ee >96%), a16:0, and a17:0 (ee >90%, respectively) dominated in all samples. While the (R)-enantiomers could not be identified in samples from ruminants and human milk, their presence could be established in cod liver and seal oil (ee <86%).
Collapse
Affiliation(s)
- Saskia Thurnhofer
- Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, 70599 Stuttgart, Germany
| | | | | |
Collapse
|
97
|
Exclusive quantification of methyl-branched fatty acids and minor 18:1-isomers in foodstuff by GC/MS in the SIM mode using 10,11-dichloroundecanoic acid and fatty acid ethyl esters as internal standards. Eur Food Res Technol 2007. [DOI: 10.1007/s00217-007-0619-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
98
|
Chen DW, Zhang M, Shrestha S. Compositional characteristics and nutritional quality of Chinese mitten crab (Eriocheir sinensis). Food Chem 2007. [DOI: 10.1016/j.foodchem.2006.10.047] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
99
|
Synthesis of (S)-(+)-enantiomers of food-relevant (n-5)-monoenoic and saturated anteiso-fatty acids by a Wittig reaction. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.11.059] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
100
|
Thurnhofer S, Vetter W. Application of ethyl esters and d3-methyl esters as internal standards for the gas chromatographic quantification of transesterified fatty acid methyl esters in food. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:3209-14. [PMID: 16637674 DOI: 10.1021/jf053022j] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ethyl esters (FAEE) and trideuterium-labeled methyl esters (d3-FAME) of fatty acids were prepared and investigated regarding their suitability as internal standards (IS) for the determination of fatty acids as methyl esters (FAME). On CP-Sil 88, ethyl esters of odd-numbered fatty acids eluted approximately 0.5 min after the respective FAME, and only coelutions with minor FAME were observed. Depending on the problem, one or even many FAEE can be added as IS for the quantification of FAME by both GC-FID and GC-MS. By contrast, d3-FAME coeluted with FAME on the polar GC column, and the use of the former as IS requires application of GC-MS. In the SIM mode, m/z 77 and 90 are suggested for d3-methyl esters of saturated fatty acids, whereas m/z 88 and 101 are recommended for ethyl esters of saturated fatty acids. These m/z values give either no or very low response for FAME and can thus be used for the analysis of FAME in food by GC-MS in the SIM mode. Fatty acids in sunflower oil and mozzarella cheese were quantified using five saturated FAEE as IS. Gravimetric studies showed that the transesterification procedure could be carried out without of loss of fatty acids. GC-EI/MS full scan analysis was suitable for the quantitative determination of all unsaturated fatty acids in both food samples, whereas GC-EI/MS in the SIM mode was particularly valuable for quantifying minor fatty acids. The novel GC-EI/MS/SIM method using fatty acid ethyl esters as internal standards can be used to quantify individual fatty acids only, that is, without determination of all fatty acids (the common 100% method), although this is present. This was demonstrated by the exclusive quantification of selected fatty acids including methyl-branched fatty acids, erucic acid (18:1n-9trans), and polyunsaturated fatty acids in cod liver oil and goat's milk fat.
Collapse
Affiliation(s)
- Saskia Thurnhofer
- University of Hohenheim, Institute of Food Chemistry (170b), Garbenstrasse 28, D-70599 Stuttgart, Germany
| | | |
Collapse
|