Characterization Of Triacylglycerols Research Articles

Thladiantha Seed Oils - New Source of Conjugated Fatty Acids: Characterization of Triacylglycerols and Fatty Acids.

In this study, seed oils of Thladiantha nudiflora and Thladiantha dubia were found to contain 55.5 and 44.4% mole of conjugated octadecatrienoic fatty acids, respectively. The presence of moieties of conjugated fatty acids was confirmed by a series from physical methods: UV, IR, 1H and 13C NMR. The triacylglycerols (TAGs) isolated of the seed oils were studied by RP-HPLC with diode array and mass spectrometric detections. It was shown that all 15 TAGs of Thladiantha dubia contain moieties of conjugated fatty acids - punicic, (9Z,11E,13Z)-octadeca-9,11,13-trienoic acid (35.6% mole) and 8.9% mole α-eleostearic, (9Z,11E,13E)-octadeca-9,11,13-trienoic acid. Meanwhile, 24 TAGs of Thladiantha nudiflora seed oil contain both acids in approximately equal proportions (27.4:28.2 % mole). The enrichment for polyunsaturated fatty acids of the hydrolysis product of the seed oils due to urea inclusion complex formation was discussed.

Characterisation of triacylglycerols from bovine milk fat fractions with MALDI-TOF-MS fragmentation

In this study, we used MALDI-TOF-MS to profile and characterise the triacylglycerol (TAG) species of anhydrous bovine milk fat (AMF) and its low melting (olein) and high melting (stearin) fractions obtained by dry fractionation. Silver-ion solid phase extraction (Ag+-SPE) cartridges were utilised to separate the TAGs according to saturation degree. Then, several TAG species were selected and fragmented via post-source decay (PSD) fragmentation. MALDI-TOF-MS TAG profiles and fragmentation patterns were compared to the TAG and fatty acid (FA) compositions obtained by gas chromatography-flame ionization detector (GC-FID). We found that, olein was rich in medium length chain TAG species like CN38:0 and CN40:1, whereas stearin was rich in saturated long chain TAG species from CN42:0 to CN52:0. Separation of the TAGs based on saturation degree allowed successful selection of the TAG parent-ion for fragmentation by eliminating the interferences of TAG species that have the same carbon number but vary in number of double bonds. The TAG fragmentation patterns indicated significant differences between AMF, olein and stearin as a result of the dry fractionation process. Compared to AMF, olein yielded in higher fragments of short-chain saturated and middle-chain unsaturated FAs. Whereas, stearin yielded in saturated and monounsaturated long chain FA fragments. Fragmentation of unsaturated long chain TAGs showed that the TAGs in olein contained more C18:1 and C18:2 than that of AMF and stearin. Stearin on the other hand, contained higher amount of TAG species containing C16:0. These results were in line with the FA compositions obtained from GC-FID and suggest that Ag+-SPE cartridges coupled with MALDI-TOF-MS offer an informative and practical approach to characterise fats and oils with complex TAG composition.

Rapid Characterization of Triacylglycerols in Edible Oils by Matrix-assisted Laser Desorption/Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract Composition and types of triacylglycerols (TAGs) in edible oils are closely related to our health. It is of vital significance to develop fast and high-efficiency methods for determination of TAGs. In this manuscript, qualitative analysis of TAGs was demonstrated using matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). 2,5-Dihydroxybenzoic acid (DHB) was employed as matrix and dichloromethane was used as solvent for dissolving the edible oils. With laser power of 15%, laser frequency of 100 Hz, and 100 laser shots, relative standard deviation (RSD) less than 9% was obtained. Different kinds of edible oils could be directly distinguished from each other using MS and tandem MS (MS/MS) results. With confidence level of 95%, principal component analysis (PCA) results showed that 34 different kinds of edible oils were clearly classified. Moreover, down to 5% of doped canola in olive was identified directly, indicating that MALDI-FTICR-MS has the potential for rapid analysis and screening of edible oils.

Characterization of triacylglycerols in unfermented cocoa beans by HPLC-ESI mass spectrometry

The nutritional value of cocoa butter is mainly determined by the composition of triacylglycerols (TAGs). In this paper we have developed a non-aqueous reversed-phase liquid chromatographic method, using ethanol as the mobile phase, coupled to electrospray ionization (ESI) tandem mass spectrometry to identify TAGs in raw cocoa beans from six different origins. Tandem mass spectrometry was adopted to facilitate the identification of TAGs using unique diacylglycerol product ions and neutral losses. Additionally, two-dimensional m/z retention time maps aided the identification of entire homologous series of TAGs. A total of 83 different TAGs were identified in unfermented cocoa beans, 58 of which were not previously reported in cocoa. Thirty-one of these compounds represent a new class of TAGs characterized by the presence of one to three hydroxyl groups on the unsaturated fatty acid chain. To date, this represents the largest number of TAGs identified in cocoa.

Rapid separation and characterisation of triacylglycerols in ostrich oil by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry

The triacylglycerol (TAG) composition of ostrich oil (Struthio camelus) was determined by non-aqueous reversed-phase ultra-performance liquid chromatography–mass spectrometry. Using a column with 150mm in length, the TAGs were separated efficiently with acetonitrile/2-propanol gradient at flow rate of 0.2mL/min for 20min. Detection is performed by positive APCI mass spectrometry, accurate mass measurements (<3ppm) and definite elemental composition for molecular ions and fragment ions were obtained to enable characterisation of 24 TAGs in both ostrich oil and emu oil. In terms of TAGs composition and contents, the ostrich oils are similar to emu oils. This result indicates that the ostrich oil could be a good choice of substitution for emu oil, which is expensive and comparatively rare, in food, dietetics and cosmetics industry.

One‐step characterization of triacylglycerols from animal fat by MALDI‐TOF MS

AbstractComparative characterization of milk fat, lard, and beef tallow triacylglycerols (TAG) has been achieved by using matrix‐assisted laser desorption/ionization–time‐of‐flight (MALDI‐TOF) mass spectrometry (MS). The samples formed characteristic patterns, with major TAG signals differing in quantity and intensity according to the fat. In milk fat, the significant contribution of short‐chain fatty acids (C4–C10) extends the TAG number to the C20–C60 range. In lard and beef tallow, C12–C18 fatty acids restrict the range to C48–C54, also typical of vegetable oils. Fats originating from ruminants contain odd TAG missing in lard. Signature TAG were identified for each animal fat. C20–C46 specifically fingerprint milk fat; 52:5, 54:5 and 54:6 TAG mark lard; and 55:0, 55:1, 55:2 and 54:0 TAG typify beef tallow. Fats were also analyzed after hydrogenation or bromination; hydrogenation helped to fingerprint the low‐abundant long‐chain TAG and to distinguish short‐chain native TAG from collision‐induced fragments; bromination allowed clear separation of saturated and unsaturated TAG. Differences in the fatty acid composition amongst homologous isobaric TAG of different structures were identified by post‐source decay analysis of hydrogenated precursors. MALDI‐TOF has proven advantageous for simultaneously detecting TAG at various unsaturation degrees within different TAG classes (Cn). The data provide insight into animal fat differentiation on a molecular basis, increasing the analytical description to a new level, proving the so far underestimated capacity of MALDI‐TOF MS in this field.

Characterization of triacylglycerols in madeira laurel oil by HPLC‐atmospheric pressure chemical ionization‐MS

AbstractMadeira laurel oil was fractionated by liquid extraction combined with TLC, and TAGs were analyzed by HPLC coupled with atmospheric pressure chemical ionization‐MS (APCI‐MS). Eluted molecular species compositions of the eluted TAG in the complex natural mixture were determined by GC identification of FAME and byLC‐atmospheric pressure chemical ionization (APCI)‐MS analysis of the lipid. The APCI‐MS spectra of most TAG exhibited [M+H]+ and [M−RCOO]+ ions, which defined the M.W. and the molecular association of fatty acyl residues, respectively. Despite the relatively high degree of saturation, with a saturated/unsaturated ratio of 0.70, no totally saturated TAG nor mixed asymmetric TAG with two saturated FA (SSM or SSU, where S is saturated, M is monounsaturated, and U is unsaturated) were found. This type of molecular structure provides a possible explanation for the relatively low m.p. (12–15°C) and also the high oxidative resistance observed.

Characterization of triacylglycerols in saturated lipid mixtures with application to SALATRIM 23CA

SALATRIM 23CA is a member of the SALATRIM family of triacylglycerols developed by RJR Nabisco Co. It is an interesterification product of triacetin, tripropionin, and hydrogenated canola oil. To characterize this sample, a combination of reversed-phase high-performance liquid chromatography and high-temperature capillary gas chromatography (HTCGC) in sequence was used to separate the SALATRIM 23CA into individual components. An on-line coupling of HTCGC with positive chemical ionization mass spectrometry revealed the structure of the individual components. To obtain detailed quantitative information, a combination of a 5-m OV-1 capillary column and a 25-m methyl 65% phenyl silicone Al-clad column was used to determine the quantities of acylglycerols

Characterization of triacylglycerols in the seeds ofAquilegia vulgaris by chromatographic and mass spectrometric methods

Characterization of triacylglycerols in the seeds of<i>Aquilegia vulgaris</i> by chromatographic and mass spectrometric methods

Characterization of triacylglycerols in the seeds ofAquilegia vulgaris by chromatographic and mass spectrometric methods.

A combination of analytical techniques is generally necessary to properly characterize complex lipid materials. Chromatographic separation in conjunction with spectroscopic characterization was utilized for the analysis of the triacylglycerols in the seeds ofAquilegia vulgaris. Reversed-phase high-performance liquid chromatography (HPLC), micropacked argentation supercritical fluid chromatography (SFC), and combinations of the two techniques were used. The fatty acid profile was determined by gas chromatography/mass spectrometry of the picolinyl esters and by gas chromatography/flame-ionization detection of the methyl esters. The major components were also identified by direct inlet mass spectrometry. The excellent selectivity of packed fused silica argentation SFC for the separation of triacylglycerols was demonstrated.

Synthesis and characterization of triacylglycerols containing linoleate and linolenate

Synthesis and characterization of triacylglycerols containing linoleate and linolenate

Synthesis and characterization of triacylglycerols containing linoleate and linolenate.

Triacylglycerols containing linoleate and linolenate found in vegetable oils were synthesized in gram quantities for oxidation studies. Two acylation methods were examined to convert diacylglycerols or monoacylglycerols to the desired triacylglycerols. Acylations with fatty acid and 1,1'-dicyclohexylcarbodiimide in the presence of 4-dimethylaminopyridine were more rapid, gave triacylglycerols of better isomeric purities and generally better overall yields than the acylations with acid chloride in pyridine. The functional and isomeric purity of the synthetic triacylglycerols were investigated by thin-layer and gas-liquid chromatography of the methyl esters, by lipase hydrolysis, and by(13)C NMR. Quantitative(13)C NMR provided a valuable tool to determine isomeric structures of the unsaturated triacylglycerols and complemented the lipase hydrolysis method. The triacylglycerols purified by dry column chromatography were obtained in the following respective percent yields, functional and isomeric purities: LLLn, 92.1, 99.4, 98.1; LLnLn, 91.7, 99.2, 97.4; LLnL, 84.2, 99.7, 98.9; and LnLLn 77.5, 97.8, 99.0 (where L=linoleoyl and Ln=linolenoyl glycerol residues). These synthetic triacylglycerols are valuable models to elucidate the interrelationship of unsaturated fatty acids on the oxidative stability of polyunraturated vegetable oils.