Triacylglycerols (TAGs) in edible oils: Determination, characterization, quantitation, chemometric approach and evaluation of adulterations (original) (raw)
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Discrimination of vegetable oils by triacylglycerols evaluation of profile using HPLC/ELSD
Food Chemistry, 2006
This paper describes an HPLC procedure for the determination of triacylglycerol (TAG) profile in vegetable oils. Sample preparation consisted in the dissolution of the oils in acetone and filtration. The chromatographic separation was achieved using a Kromasil 100 C 18 column (at 25°C) and gradient elution with acetone and acetonitrile. Elution was performed at a solvent flow rate of 1 mL/min. Detection was accomplished with an evaporative light scattering detector (ELSD), with the following settings: evaporator temperature 40°C, air pressure 3.5 bars and photomultiplier sensitivity 6. TAG peaks were identified taking into account the logarithms of a in relation to homogeneous TAG (relative retention times to triolein) and their quantification was based on the internal normalization method.
Journal of Agricultural and Food Chemistry, 2010
In Slovenia two superb vegetable oils with high added nutritional value are produced: "Ekstra deviško oljčno olje Slovenske Istre (extra virgin olive oil from Slovene Istra)" and " Stajersko prekmursko bučno olje (pumpkin seed oil from Slovenia)". Their quality and genuineness must be monitored as adulteration can easily be undertaken. Olive oil genuineness determination experiences can show how analyses following an experience data-driven decision tree gathering several chemical determinations (fatty acids, (E) -isomers of fatty acids, sterol and tocopherol determinations) may be helpful in assessing the pumpkin seed oil from Slovenia genuineness. In the present work a set of HPLC triacylglycerol determinations was performed, based on the nine main triacylglycerols (LLLn, LLL, PLL, LOO, PLO, OOO, POO, SPL, and SLS) on a limited number of different pumpkin seed oils from northeastern Slovenia. The performed determinations showed that stereospecific analyses of triacylglycerols together with other chemical determinations can be useful in building a protocol for the evaluation of the genuineness of pumpkin seed oil from Slovenia.
Analytica Chimica Acta, 2012
The characterization and authentication of fats and oils is a subject of great importance for market and health aspects. Identification and quantification of triacylglycerols in fats and oils can be excellent tools for detecting changes in their composition due to the mixtures of these products. Most of the triacylglycerol species present in either fats or oils could be analyzed and identified by chromatographic methods. However, the natural variability of these samples and the possible presence of adulterants require the application of chemometric pattern recognition methods to facilitate the interpretation of the obtained data. In view of the growing interest in this topic, this paper reviews the literature of the application of exploratory and unsupervised/supervised chemometric methods on chromatographic data, using triacylglycerol composition for the characterization and authentication of several foodstuffs such as olive oil, vegetable oils, animal fats, fish oils, milk and dairy products, cocoa and coffee.
Food Analytical Methods, 2017
Here, we describe an isocratic ultra-high performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (UHPLC-APCI-MS) method for the characterization and the quantification of triacylglycerols (TAGs) in vegetable oils. The linearity and the precision of the method are validated, and the limits of detection are estimated. The APCI-MS detector shows a linear response from 1 to 1000 μg/mL, and the correlation coefficients (r 2) obtained for standards TAGs exceed 0.995. As compared to previous methods, the proposed method is rapid, simpler, and more sensitive. The limits of detection estimated for several standard TAGs varies from 0.03 to 0.05 injected nanograms (6 to 10 μg/L). The application of the proposed method to the analysis of sesame oil allowed us to unambiguously identify 30 TAG species whereas previous methods have detected 19 TAGs, at the most. Among vegetable oils, sesame oil became an attractive target for adulteration due to its high commercial value. Most of the previous studies of TAG profiles of sesame oils had been devoted to the analysis of sesame oils originating from Asia and some Sub-Saharan countries. To the best of our knowledge, the TAG profiles of sesame oils from other origins are still unknown. The results we obtained for the four Tunisian sesame seed varieties clearly indicate that sesame oils can be classified according to their equivalent carbon number differences (ΔECN) with some rules similar to those required for olive oils.
Journal of the American Oil Chemists’ Society, 1994
Two methods for stereospeclfic analysis of triacylglycerois are compared. Procedure A, based on stereospecific phosphorylation of sn-l,2~liacylglycerols to phosphatidic acids, and procedure ]3, based on separation of the diastereomeric 1,2(2,3Fdiacylglycerol urethane derivatives by high-performance liquid chromatography on silica, were applied to olive oil triacyl-sn-glycerols. Statistical evaluation of the results showed good reproducibility, and Student's t-test indicates no statistical differences between the two considered procedures, although some small differences were observed and discussed. Fifteen samples of extra-virgin olive oil, produced in the same region (Umbria, Italy), were analyzed with the two considered procedures. naphthyl)ethyl isocyanate" purification of the products on octadecylsilyl solid-phase extraction columns and separation of the diastereomeric 1,2(2,3)-diacylglycerol urethane derivatives by HPLC on silic& The two fractions were then transesterified and analyzed by gas chromatography to determine the fatty acid composition (2).
Varietal Authentication of Extra Virgin Olive Oils by Triacylglycerols and Volatiles Analysis
Foods
In recent years, there is an increasing interest in high-quality extra virgin olive oils (EVOOs) produced from local cultivars. They have particular chemical/organoleptic characteristics and are frequently subjected to fraud, whereby the control of quality requires a powerful varietal check. In the present research, triacylglycerols (TAGs) and volatiles have been studied as chemical markers for the authentication of EVOO samples from four Italian varieties of Olea europea (Dolce Agogia, Frantoio, Leccino, and Moraiolo). The monocultivar EVOO samples have been subjected to a chemical–enzymatic chromatographic method in order to perform a stereospecific analysis, an important procedure for the characterization of TAG of food products. The results, combined with chemometric analysis (linear discriminant analysis, LDA), were elaborated in order to classify Italian EVOO monocultivar samples. In accordance with the total and intrapositional fatty acid (FA) composition of TAG fraction, the...
Fingerprints of triacylglycerols from oils
SEDERE. info sedere@.com (available on request), 2023
Chromatograms of TAG from 92 oils gained in NARP-ELSD are shown. identification was confirmed by LC-MS. Isomeric C18:3 TAG were well separated. Pseudo quantitative analysis of TAG from 172 oils is reported. Index of occurence of TAG is also reported.
Journal of the American Oil Chemists' Society, 2007
Using a 1,3-regioselective lipase as a catalyst, soybean oil and olive oil were interesterified with the short-chain triacylglycerol tributyrin (1,2,3-tributyrylglycerol) to produce mixtures of structured triacylglycerols (SL-TAG). The SL-TAG were purified by column chromatography and analyzed by both normalphase (silica column; NP SIL ) and reversed-phase [octadecyl silane (ODS) column] high-performance liquid chromatography (HPLC). Individual SL-TAG molecular species were detected by evaporative lightscattering detection, and characterized by mass spectrometry. NP SIL HPLC successfully separated the newly synthesized SL-TAG into two groups of TAG: one composed of one butyryl group and two long-chain fatty acyl groups (from soybean or olive oil); the second was composed of two butyryl groups and one long-chain fatty acyl group. The SL-TAG species were further analyzed by reversed-phase HPLC which gave a more detailed separation of the TAG species present in the two SL-TAG.
International Journal of Food Properties, 2018
Sesame oil is a high-value edible vegetable oil, and concern about its authenticity has gained much attention for commercial and consumer health reasons. The present study compares the application of triacylglycerols (TAGs), fatty acids, and volatile organic compounds (VOCs) as markers for discriminating pure sesame oils from those adulterated with corn or soybean oils. The profiles of TAGs, fatty acids, and VOCs in oil samples were established by high-performance liquid chromatography-evaporative light scattering detector, gas chromatography (GC)-flame ionization detector, and GC-time-of-flight mass spectrometer, respectively. Data from six TAGs, seven fatty acids, and six VOCs were employed separately to classify oil samples via principal component analysis (PCA). The PCA results indicate that VOCs show much greater promise than TAGs and fatty acids for detecting corn or soybean oil adulteration (approximately 5% w/w content) of sesame oils.