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Triacylglycerols (TAGs), a major lipid class in foods and the human body, consist of three fatty acids esterified to a glycerol backbone. They can occur in various isomeric forms, including sn-positional, cis/trans configurational, acyl chain length, double bond positional, and mixed type isomers. Separating isomeric mixtures is of great interest as different isomers can have distinct influence on mechanisms, such as digestibility, oxidative stability, or lipid metabolism. However, TAG isomer separation remains challenging with established analytical methodologies such as liquid-chromatography coupled to mass spectrometry (LC-MS). In this study, we developed a method with cyclic ion mobility mass spectrometry (cIMS-MS) for the separation and identification of all types of TAG isomers. First, the influence of different adducts (Li + , NH 4 + , Na + , and K + ) on the separation was studied. Overall, it was concluded that the sodium adduct is the best choice to efficiently separate all types of TAG isomers. In addition, trends were found in the influence of specific structural features on the drift time order. An order of relative influence (from high to low) was established; (1) degree of unsaturation of the fatty acid(s) on an exterior position (if the total degree of unsaturation(s) is equal in both TAGs), (2) acyl chain length on the exterior positions, (3) cis/trans configuration, and (4) double bond (DB)-position. Finally, various cIMS-MS strategies were developed for the separation of mixtures containing four, five, and six isomers. To conclude, the developed methods can be used for separation of complex mixtures of TAG isomers and have great potential to be expanded to isomers of similar types of lipids such as di- and monoacylglycerols. This study also shows the potential of cIMS-MS to be used for the application on real TAG samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Regioisomers (or positional isomers) of triacylglycerols (TAGs) of milk are known to show differential outcome in relation to human absorption. Quantitation of TAG regioisomers remains a big challenge due to the lack of facile chromatographic separation technique. The feasibility of using fragment ion intensity ratio to determine the ratio of co-eluting AAB/ABA-type regioisomer pairs was confirmed in this study. The ability of C30 stationary phase in resolving interfering TAG isomers was demonstrated for the first time. This allowed us to reveal the complexity of using fragment ion intensity to quantify 1,2-olein-3-palmitin (OOP), 1,3-olein-2-palmitin (OPO), 1,2-olein-3-stearin (OOS), and 1,3-olein-2-stearin (OSO) regioisomers in milk samples. A novel algorithm was proposed to consider the contribution of OPO/OOP and OSO/OOS double bond (DB)-isomers and to eliminate the interference of isobaric ions from other isomers, an aspect overlooked in previous studies. This liquid chromatography-mass spectrometry method that requires no pre-fractioning and a moderate chromatographic separation time of 36 min is simple and, thus, suitable for screening a large number of samples for genetic analysis of this trait. Preliminary results using a small cohort of animals showed that OPO/OOP ratio differs significantly between Jersey and Holstein cows, and a large variation was also observed across individual Holstein cows.

Currently, in vitro embryo production (IVP) is successfully commercially applied in cattle. However, the high sensitivity of embryos to cryopreservation in comparison to in vivo (IVD) embryos slows the dissemination of this biotechnology. Reduced cryotolerance is frequently associated with lipid accumulation in the cytoplasm mainly due to in vitro culture conditions. The objective of this study was to evaluate the lipid composition of biopsied and sexed embryos, produced either in vivo or in vitro from the same Holstein heifers before and after a slow freezing protocol. Lipid extracts were analysed by liquid chromatography-high resolution mass spectrometry, which enabled the detection of 496 features. Our results highlighted a lipid enrichment of IVP embryos in triglycerides and oxidised glycerophospholipids and a reduced abundance in glycerophospholipids. The slow freezing process affected the lipid profiles of IVP and IVD embryos similarly. Lysophosphatidylcholine content was reduced when embryos were frozen/thawed. In conclusion, the embryonic lipid profile is impacted by IVP and slow freezing protocols but not by sex. Lysophosphatidylcholine seemed highly sensitive to cryopreservation and might contribute to explain the lower quality of frozen embryos. Further studies are required to improve embryo freezability by modulating the lipidome.

Background: Dyslipidemia may be linked to meibomian gland dysfunction (MGD) and altered meibum lipid composition. The purpose was to determine if plasma and meibum cholesteryl esters (CE), triglycerides (TG), ceramides (Cer) and sphingomyelins (SM) change in a mouse model of diet-induced obesity where mice develop dyslipidemia., Methods: Male C57/BL6 mice (8/group, age = 6 wks) were fed a normal (ND; 15% kcal fat) or an obesogenic high-fat diet (HFD; 42% kcal fat) for 10 wks. Tear production was measured and meibography was performed. Body and epididymal adipose tissue (eAT) weights were determined. Nano-ESI-MS/MS and LC-ESI-MS/MS were used to detect CE, TG, Cer and SM species. Data were analyzed by principal component analysis, Pearson's correlation and unpaired t -tests adjusted for multiple comparisons; significance set at p ≤ 0.05., Results: Compared to ND mice, HFD mice gained more weight and showed heavier eAT and dyslipidemia with higher levels of plasma CE, TG, Cer and SM. HFD mice had hypertrophic meibomian glands, increased levels of lipid species acylated by saturated fatty acids in plasma and meibum and excessive tear production., Conclusions: The majority of meibum lipid species with saturated fatty acids increased with HFD feeding with evidence of meibomian gland hypertrophy and excessive tearing. The dyslipidemia is associated with altered meibum composition, a key feature of MGD.

This study reports a simple and convenient analytical method for the simultaneous determination of biodiesel and vegetable oils or used cooking oils in petrodiesel and green diesel (hydrotreated vegetable oils or paraffinic diesel). The approach is based on normal-phase high-performance liquid chromatography with refractive index detection. It employed silica stationary phase, n-hexane mobile phase with isopropanol modifier to achieve optimum separation between hydrocarbons (petrodiesel or green diesel), fatty acid methyl esters (biodiesel) and triglycerides (vegetable oils and used cooking oil). In addition to determining vegetable oils or used cooking oils as adulterants in diesel, this method is also proposed as a better alternative to the standard method ASTM D7371, which is currently recommended for determining fatty acid methyl esters in petrodiesel. The method development involved screening of various stationary and mobile phases, with and without modifiers, to achieve acceptable chromatographic resolutions between analytes. Under the optimized method conditions, silica column, and n-hexane containing 0.6% isopropanol as the mobile phase provided the best results. The real-world scenario was simulated for the method validation carried out by fortifying Jatropha seed oil, soybean oil, and used cooking oil in the biodiesel blended petrodiesel and green diesel. Measurement of all analytes was accompanied by high precision, low limit of detection/quantification and linear response range of 0.05 to 50% for biodiesel, and 0.05 to 30% for vegetable oils. The proposed method is simple, fast (runtime 7 min), and does not require sample pre-treatment and backflushing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A 'heart-cut' multidimensional gas chromatography‒mass spectrometry (H/C MDGC‒MS) method for separation and identification of triacylglycerols (TAGs) in extra virgin olive oil was developed. A GC configuration, comprising a non-polar first dimension ( 1 D) column (15 m length) and a mid-polarity second dimension ( 2 D) column (9 m length), was employed. Standard TAGs were used to test and demonstrate the H/C MDGC method, for identification of TAG components and to validate the method. Various chromatographic conditions such as column flow and temperature program were evaluated. The 1 D separation resulted in overlap of some standard TAG peaks. These overlapped 1 D regions of the standard TAGs were H/C to 2 D for further separation and resulted in clearly distinguished individual TAG component peaks. The 1 D separation of olive oil TAGs displayed three major peaks and four minor peaks. The application of the H/C MDGC method to olive oil TAGs resulted in the separation of each sampled 1 D region into two or more TAG peaks. TAG components in olive oil resolved on the 2 D column were identified based on characteristic mass fragment ions such as [M-RCO 2 ] + , [RCO+128] + , [RCO+74] + and RCO + and comparison of their mass spectra with that of the standard TAGs. Sixteen olive oil TAGs were identified by MS after 2 D separation. The repeatability of the H/C method was evaluated in terms of retention time shift and area response in the 2 D and found to be <0.02% and <8% RSD respectively., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

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, 1 H and 13 C 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.

Scope: The effects of triglyceride-rich lipoproteins (TRLs) on the miRNA expression of endothelial cells, which are very involved in atherosclerosis, according to the type of diet are not known., Methods and Results: The differences between the effects of TRLs isolated from blood of subjects after a high-fat meal with extra-virgin olive oil (EVOO) and sunflower oil (SO) on the microRNA-Seq profile related to atherosclerosis in human umbilical vein endothelial cells are analyzed. 28 upregulated microRNAs with EVOO-derived TRLs, which can regulate 22 genes related to atherosclerosis, are found. 21 upregulated microRNAs with SO-derived TRLs, which can regulate 20 genes related to atherosclerosis, are found. These microRNAs are mainly involved in angiogenesis, with a predominance of an anti-angiogenic effect with EVOO-derived TRLs. Other microRNAs upregulated with SO-derived TRLs are involved in cardiovascular diseases. Pathways for the target genes obtained from the upregulated microRNA with EVOO-derived TRLs are involved in lipid metabolism and inflammatory and defense response, while those with SO-derived TRLs are involved in lipid metabolic process., Conclusion: EVOO-derived TRLs seem to produce a more atheroprotective profile than SO-derived TRLs. This study provides alternative mechanisms on the protective role of EVOO against the atherogenic process through microRNA regulation in endothelial cells., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The development of human milk fat substitutes (HMFSs), rich in palmitic acid (16:0) at the sn-2 position of triacylglycerol (TAG) and rich in unsaturated fatty acids (FAs) (oleic acid, 18:1 and linoleic acid, 18:2) at the sn-1(3) positions, has gained popularity. In this study, HMFSs containing polyunsaturated fatty acids (PUFAs) predominantly at the sn-2 position were prepared, and their oxidation stabilities were compared. First, a non-PUFA-containing HMFS (NP-HMFS) was produced by enzymatic reactions using Novozyme ® 435 and Lipozyme ® RM-IM as the enzymes and lard as the raw material. Second, HMFSs, containing 10 % PUFA at the sn-2 or sn-1(3) position, were individually prepared by enzymatic reactions using lard and fish oil as raw materials. Here, sn-2-PUFA-monoacylglycerol (MAG) was extracted from the reaction solution using a mixture of hexane and ethanol/water (70:30, v/v) to produce high-purity sn-2-PUFA-MAG with 78.1 % yield. For the PUFA-containing HMFS substrates, comparable oxidation stability was confirmed by an auto-oxidation test. Finally, HMFSs containing 10 % or 2 % sn-1,3-18:1-sn-2-PUFA-TAG species were prepared by enzymatic reactions and subsequent physical blending. The oxidative stability of sn-1,3-18:1-sn-2-PUFA-HMFS was two-fold higher than that of 1/2/3-PUFA-HMFS in which each PUFA was located without stereospecific limitations in TAG. The removal of PUFA-TAG molecular species with higher concentrations of unsaturated units had a significant effect. In addition, the oxidation stability increased with the addition of tocopherol as an antioxidant. Thus, the combined use of two strategies, that is, the removal of PUFA-TAG molecular species with high concentrations of unsaturated units and the addition of antioxidants, would provide a PUFA-containing HMFS substrate with high oxidative stability.

Triacylglycerols (TAGs) containing less common fatty acids (FAs) were isolated from the seeds of three plants (Santalum album, Crepis foetida, and Leucas aspera). These FAs had allenic (laballenic acid, Lb) and acetylenic (crepenynic, C; ximenynic acids, Xi) bonds. TAGs were analyzed on reversed-phase and chiral columns. High-resolution tandem mass spectrometry identified TAGs by positive electrospray ionization (ESI + ). Twenty-two molecular species of TAGs isolated from the seed oil of Santalum album were separated by RP-HPLC and chiral HPLC methods and identified by positive electrospray ionization tandem MS detection (ESI + -MS). Two major enantiomers, i.e., sn-OOLb and sn-LLLb (O represents oleic acid; and L represents linoleic acid), were synthesized from the appropriate phosphatidylcholines. This allowed the identification of enantiomers after separation by chiral chromatography by tandem mass spectrometry. Similarly, TAGs from the seeds of Crepis foetida, and Leucas aspera were analyzed by reversed-phase chromatography and identified by mass spectrometry. Four enantiomers (sn-OOC, sn-LLC, sn-OOXi, and sn-LLXi) were synthesized. A total of six and three enantiomers of TAGs containing crepenynic and ximenynic acids, respectively, were identified by chiral column analysis. The retention times of TAGs containing allenic and acetylenic bonds were always greater on the reversed-phase column than TAGs with the same number of carbon atoms and the same unsaturation (e.g., LLL versus LLLb). From the chiral column, the regioisomers and enantiomers were eluted in the order of symmetric-asymmetric-asymmetric (i.e., sn-OCO, sn-COO, and sn-OOC). Through tandem mass spectrometry, we were able to identify and distinguish regioisomer [DAG] + -type ions, i.e., [MNH 4 NH 3 RCOOH] + , that can be considered diagnostic. Unfortunately, enantiomers and TAGs with the same numbers of carbon atoms and the same unsaturation levels have identical mass spectra, such as LLL and LLLb., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Ultrahigh-performance supercritical fluid chromatography - mass spectrometry (UHPSFC/MS), ultrahigh-performance liquid chromatography - mass spectrometry (UHPLC/MS), and matrix-assisted laser desorption/ionization (MALDI) - MS techniques were used for the lipidomic characterization of exosomes isolated from human plasma. The high-throughput methods UHPSFC/MS and UHPLC/MS using a silica-based column containing sub-2 μm particles enabled the lipid class separation and the quantitation based on exogenous class internal standards in <7 minute run time. MALDI provided the complementary information on anionic lipid classes, such as sulfatides. The nontargeted analysis of 12 healthy volunteers was performed, and absolute molar concentration of 244 lipids in exosomes and 191 lipids in plasma belonging to 10 lipid classes were quantified. The statistical evaluation of data included principal component analysis, orthogonal partial least square discriminant analysis, S-plots, p-values, T-values, fold changes, false discovery rate, box plots, and correlation plots, which resulted in the information on lipid changes in exosomes in comparison to plasma. The major changes were detected in the composition of triacylglycerols, diacylglycerols, phosphatidylcholines, and lysophosphatidylcholines, whereby sphingomyelins, phosphatidylinositols, and sulfatides showed rather similar profiles in both biological matrices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Red kidney beans ( Phaseolus vulgaris L.) contain bioactive compounds that are known to exhibit antidiabetic effects via inhibition of α-glucosidase. However, information on the nonpolar components that exhibit antidiabetic activity is limited. Here, we report the isolation and structure determination of components with α-glucosidase inhibitory activity, which were obtained from the hexane extract of red kidney beans. Triacylglycerols (TAGs) were identified as the major components exhibiting inhibitory activity against α-glucosidase. The chemical structure of TAGs was determined by a combination of GC-MS and UPLC-MS/MS. The primary TAGs identified were LnLnLn (trilinolenin) and LnLLn (1,3-dilinolenoyl-2-linoleoyl glycerol). The major fatty acids present in these TAGs were α-linolenic acid (ω-3) and linoleic acid (ω-6). These TAGs were also found to inhibit the α-glucosidase activity in a similar fashion as acarbose. These results suggest that TAGs have potency as antidiabetics and support the potential suitability of red kidney beans for diabetes treatment.

Elevated levels of triglyceride-rich lipoproteins (TRLs), both fasting and postprandial, are associated with increased risk for atherosclerosis. However, guidelines for treatment are defined solely by fasting lipid levels, even though postprandial lipids may be more informative. In the postprandial state, circulating lipids consist of dietary fat transported from the intestine in chylomicrons (CMs; containing ApoB48) and fat transported from the liver in VLDL (containing ApoB100). Research into the roles of endogenous versus dietary fat has been hindered because of the difficulty in separating these particles by ultracentrifugation. CM fractions have considerable contamination from VLDL (purity, 10%). To separate CMs from VLDL, we produced polyclonal antibodies against ApoB100 and generated immunoaffinity columns. TRLs isolated by ultracentrifugation of plasma were applied to these columns, and highly purified CMs were collected (purity, 90-94%). Overall eight healthy unmedicated adult volunteers (BMI, 27.2 ± 1.4 kg/m 2 ; fasting triacylglycerol, 102.6 ± 19.5 mg/dl) participated in a feeding study, which contained an oral stable-isotope tracer (1- 13 C acetate). We then used this technique on plasma samples freshly collected during an 8 h human feeding study from a subset of four subjects. We analyzed fractionated lipoproteins by Western blot, isolated and derivatized triacylglycerols, and calculated fractional de novo lipogenesis. The results demonstrated effective separation of postprandial lipoproteins and substantially improved purity compared with ultracentrifugation protocols, using the immunoaffinity method. This method can be used to better delineate the role of dietary sugar and fat on postprandial lipids in cardiovascular risk and explore the potential role of CM remnants in atherosclerosis., (Copyright © 2020 Jones et al.)

The aim of the present research is to investigate the effect of three harvest date on the composition of apricot seed. Indeed, triacylglycerols (TAGs) content and composition were studied in developing Tunisian apricot varieties bitter (Bargoug), semi-sweet (Oud Rhayem) and sweet (Chechi Bazza) cultivars at intervals of early (14 DAP), mid phase (28 DAP) and full phase (55 DAP) of oil accumulation by UHPLC-ESI-MS method. Eleven molecular species of triacylglycerols were detected and identified as LLL, LLO, LLP, LOO, LLS/LOP, LPP, OOO, LOS, OOP, POP and OOS. At 14 DAP, LLO was the major TAGs molecular species with 35.4-52.6% (maximum reached in semi-sweet apricot). Others major TAGs were founded at lower content as LOO (17.5-40.3%) and OOO (5.7-12.7%). However, among maturity, three distinct profiles of TAGs molecular species were observed: bitter apricot was significantly richer in OOO molecular species than cultivars ones. However, semi-sweet and sweet cultivars were richer in LLO and LOO molecular species at different time-dates. These latter may provide a schedule for harvesting Tunisian apricot seeds with high quality of oil content.

Gut microbiota has been implicated in major diseases affecting the human population and has also been linked to triglycerides and high-density lipoprotein levels in the circulation. Recent development in metabolomics allows classifying the lipoprotein particles into more details. Here, we examine the impact of gut microbiota on circulating metabolites measured by Nuclear Magnetic Resonance technology in 2309 individuals from the Rotterdam Study and the LifeLines-DEEP cohort. We assess the relationship between gut microbiota and metabolites by linear regression analysis while adjusting for age, sex, body-mass index, technical covariates, medication use, and multiple testing. We report an association of 32 microbial families and genera with very-low-density and high-density subfractions, serum lipid measures, glycolysis-related metabolites, ketone bodies, amino acids, and acute-phase reaction markers. These observations provide insights into the role of microbiota in host metabolism and support the potential of gut microbiota as a target for therapeutic and preventive interventions.

Microwave (MW) radiation was applied to perform the separation of triacylglycerols (TGs) in oil samples. The novelty of the work lies in the application of MW radiation to assist the separation of several non-polar compounds employing a totally organic mobile phase. Once the influence of the evaporative light scattering detector (ELSD) variables on the sensitivity was optimized, the TGs separation was compared conditioning the column with either a conventional HPLC or a MW oven. Contrary to previous applications in which the mobile phase contained water, the improvement in sensitivity using MW was not as significant in comparison with conventional heating but it allowed a shortening in the retention times of several TGs in about 50% respect elution at room temperature. The method was finally applied for the quantification of most common TGs in almond, tiger nut, and argan oil., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The experiments reported in this study provided a more comprehensive insight into the effect of chemical composition on the crystallization behavior of milk fat (MF). MF was fractionated between 20 and 40 °C into nine fractions with different melting points and was first subjected to the heating step (L20, L30, L40, and S40) followed by the cooling phase (SS40, SL40, SS30, SL30, and LL40). Furthermore, the species of fatty acids (FAs) and triglycerides (TAGs) of the MF fractions were identified. The thermodynamics, crystallization behavior, and polymorphs were determined using differential scanning calorimetry, pulsed nuclear magnetic resonance, and X-ray diffraction, respectively. The results indicated that L40 yielded the highest percentage (∼35% of the total MF) of all the fractions. Enthalpies of the melting and crystallization processes of solid fat content in this study were related to the different FA and TAG compositions of MF and its fractions. High melting fractions (HMFs) were enriched with long-chain saturated fatty acids and tri-saturated (S3) TAGs, and low melting fractions (LMFs) were enriched with short-chain unsaturated FAs and tri-unsaturated (U3) TAGs. Moreover, the various nucleation mechanisms of MF fractions were identified according to the Avrami equation. The polymorphic transformation from a β' form of double chain length structures to a β form of triple chain length occurred in the native MF and HMFs, whereas the LMFs displayed almost no crystals. PRACTICAL APPLICATION: This study represented the first time that nine fractions were obtained using MF fractionation via a heating step, followed by a cooling phase. Furthermore, the chemical composition of MF fractions was investigated. The results obtained from this study might be of specific value in understanding the functional properties of fat-based dairy food in both storage conditions and real-time applications., (© 2019 Institute of Food Technologists®.)

The compositional characteristics and oxidative stability of rice bran oil were determined by observing the formation of oxidative products and alteration in chemical composition of oils during microwave or oven heating. The values of oxidative indicators such as free acidity, peroxide, p-anisidine, total oxidation, thiobarbituric acid and color values, increased faster in refined oils compared to crude ones during heating. In gas chromatography analysis, the percentages of total saturated, monounsaturated and polyunsaturated fatty acids in the studied oils such as lab extracted crude rice bran oil, lab extracted and refined rice bran oil, crude rice bran oil from commercial mill and refined rice bran oil from commercial mill were: 23.07 to 23.56, 41.15 to 42.38 and 34.38 to 35.88, respectively. The heating caused the reduction of polyunsaturated fatty acids content with increasing saturated fatty acids content, and these changes were greater in refined rice bran oil indicating extensive lipid oxidation occurred in refined oil. The change in triacylglycerol species content as determined by High-performance liquid chromatography, was lower in crude oil; the higher stability of these species in crude oil could have contribution to reduce oxidation. During thermal treatment, the generation of hydroperoxides, their degradation and formation of secondary oxidative products evaluated by Fourier-transform infrared spectroscopy, were lower in crude oils. However, the rate of formation of oxidative products in lab prepared samples was lower compared to that in the samples collected from commercial mill. Under extreme thermal condition, the order of oxidative stability: lab extracted crude rice bran oil > crude rice bran oil from commercial mill>lab extracted and refined rice bran oil > refined rice bran oil from commercial mill. The present results will be useful to oil seed processing mills in refining of rice bran oil for economic feasibility and better marketability.

The rapid and simultaneous separation of triacylglycerol (TAG) enantiomers and positional isomers was achieved using chiral high performance liquid chromatography (HPLC). TAGs composed of two fatty acids, which were both saturated (P: palmitic acid or S: stearic acid) and unsaturated (O: oleic acid or L: linoleic acid; e.g., sn-PPO/sn-OPP/sn-POP: 1,2-dipalmitoyl-3-oleoyl-sn-glycerol/1-oleoyl-2,3-dipalmitoyl-sn-glycerol/1,3-dilpalmitoyl-2-oleoylglycerol), were resolved into three peaks using CHIRALPAK IF-3 without recycling on the HPLC system. For example, the mixture of sn-PPO/sn-OPP/sn-POP was resolved in 30 min, although it took 150 min to resolve sn-PPO/sn-OPP using CHIRALCEL OD-RH in a previous study using a recycling HPLC system. This novel chiral HPLC method was applicable for the separation of other TAG isomers, including sn-OOP/sn-POO/sn-OPO, sn-PPL/sn-LPP/sn-PLP, sn-LLP/sn-PLL/sn-LPL, sn-SSO/sn-OSS/sn-SOS, sn-OOS/sn-SOO/sn-OSO, sn-SSL/sn-LSS/sn-SLS, and sn-LLS/sn-SLL/sn-LSL. For TAGs composed of three fatty acids containing both saturated and unsaturated fatty acids, the POL isomers were not sufficiently separated but the PSO and SOL isomers were partially separated into several peaks. Their elution order could be estimated by the fragment ions generated in the ion source of the mass spectrometer. However, TAGs consisting of only saturated or unsaturated fatty acids (e.g., sn-PSP/sn-PPS/sn-SPP and sn-OLO/sn-OOL/sn-LOO) were not separated. This novel chiral HPLC method is especially applicable for the analysis of TAG composition of semi-solid fats such as palm oil.

Objective: Short-chain triacylglycerols (TAGs) in lipid extracts of biological samples are not sufficiently resolved using conventional reversed-phase separation on two C18 columns in series, or using a two-dimensional chromatographic separation with a silver ion column as the second dimension ( 2 D). An additional dimension of separation was required., Results: The hardware and software components to allow a second second-dimension ( 2 D) separation and three total separation dimensions were developed. Two contact closure (CC) activated 4-port, 2-position valves (4P2PVs) for ultra-high performance liquid chromatography (UHPLC) were joined together and used for one of two second dimensions in comprehensive two-dimensional liquid chromatography (2D-LC) coupled to four mass spectrometers simultaneously in parallel in an LC1MS2 × (LC1MS1 + LC1MS1) = LC3MS4 configuration. A timed contact closure circuit (TCCC) controlled the two UHPLC valves, operated by repetitive CCs for the 4P2PVs. The TCCC-controlled 4P2PVs were used to direct a portion of the 1 D eluent to one of the two 2 D's for separation by a quaternary UHPLC system that was not allowed by the commercial 2D-LC system. The 1 D separation was a non-aqueous reversed-phase HPLC instrument used for separation of TAGs; the commercial 2D-LC 2 D binary UHPLC was used for silver-ion chromatography of unsaturated TAGs; and the CC-controlled second 2 D was used for separation of short-chain (SC) saturated TAGs.

Camellia oleifera, C. japonica and C. sinensis are three representative crops of the genus Camellia. In this work, we systematically investigated the lipid characteristics of these seed oils collected from different regions. The results indicated significant differences in acid value (AV), peroxide value (PV), iodine value (IV), saponification value (SV) and relative density of the above-mentioned camellia seed oils (p < 0.05). The C. japonica seed oils showed the highest AV (1.7 mg/g), and the C. sinensis seed oils showed the highest PV (17.4 meq/kg). The C. japonica seed oils showed the lowest IV (79.9 g/100 g), SV (192.7 mg/g) and refractive index (1.4633) of all the oils, while the C. sinensis seed oils showed the lowest relative density (0.911 g/cm 3 ). The major fatty acids in the camellia seed oils were palmitic acid (16:0), oleic acid (18:1) and linoleic acid (18:2); the oleic acid in C. oleifera and C. japonica seed oils accounted for more than 80% of the total fatty acids. The oleic acid levels in the C. oleifera and C. japonica oils were higher than those in the C. sinensis seed oils, while the linoleic acid levels in the former were lower than those in the latter one. Differences also exist in the triacylglycerol (TAG) composition, although the most abundant TAG molecular species in the camellia seed oils was trioleoylglycerol (OOO). Seven sterol species, squalene and α-tocopherol were detected in the camellia seed oils, however, the contents of tocopherol and unsaponifiable molecules in the C. oleifera and C. japonica seed oils were significantly lower than those in the C. sinensis seed oil. These results demonstrated that the varieties of Camellia affected the seed oil lipid characteristics.

Interest has recently been rising in the development of food-compatible Pickering emulsions, i.e., particle-stabilized emulsions, and various biobased particles have been demonstrated as useful for such a purpose. Most of the related work has focused on the physical stability of the emulsions, but whether such particles can be advantageous in terms of chemical stability, and in particular, with regard to lipid oxidation, is largely unexplored. Recently, we found that colloidal lipid particles (CLPs) are efficient Pickering stabilizers, and the objective of the present study was to investigate the oxidative stability of emulsions stabilized with those particles. Three types of sunflower oil-in-water (O/W) emulsions were considered: Pickering emulsions stabilized with colloidal lipid particles (CLPs) made of high melting point (HMP) fat (tripalmitin or palm stearin), adsorbed onto the liquid oil droplets; and, as references, two conventional sodium caseinate-stabilized emulsions, of which one contained only liquid oil, and the other liquid oil mixed with HMP fat as the core of the emulsion droplets. In the presence of iron, the latter oxidized faster than conventional liquid oil and Pickering emulsions, resulting in 2- to 3-fold higher amounts of primary and secondary lipid oxidation products. This may be due to intra-droplet HMP fat pushing oxidizable lipids towards the oil-water interface, which would promote lipid oxidation. This shows that the localization of solid fat in O/W emulsions affects lipid oxidation. We also found that CLP-stabilized Pickering emulsions had similar oxidation rates as conventional sodium caseinate-stabilized emulsions containing only liquid oil. This suggests that the potential of such Pickering particles to prevent lipid oxidation is limited. This could be because diffusion of small pro-oxidant molecules is not hindered by Pickering particles, as they cannot form an interfacial barrier that is structurally homogeneous at such a small scale., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Sea buckthorn ( Hippophae L.) is an economically important shrub or small tree distributed in Eurasia. Most of its well-recognized medicinal and nutraceutical products are derived from its berry oil, which is rich in monounsaturated omega-7 (C16:1) fatty acid and polyunsaturated omega-6 (C18:2) and omega-3 (C18:3) fatty acids. In this study, tandem mass tags (TMT)-based quantitative analysis was used to investigate protein profiles of lipid metabolism in sea buckthorn berries harvested 30, 50, and 70 days after flowering. In total, 8626 proteins were identified, 6170 of which were quantified. Deep analysis results for the proteins identified and related pathways revealed initial fatty acid accumulation during whole-berry development. The abundance of most key enzymes involved in fatty acid and triacylglycerol (TAG) biosynthesis peaked at 50 days after flowering, but TAG synthesis through the PDAT (phospholipid: diacylglycerol acyltransferase) pathway mostly occurred early in berry development. In addition, the patterns of proteins involved in lipid metabolism were confirmed by combined quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and parallel reaction monitoring analyses. Our data on the proteomic spectrum of sea buckthorn berries provide a scientific basic for understanding lipid metabolism and related pathways in the developing berries.

Buglossoides arvensis is indigenous to India and its seed oil is rich in unique and nutritionally important omega-3 fatty acid namely, stearidonic acid (SDA). It is a non-conventional oil seed plant and needs to be agronomically adapt for commercial utilization. In the present study, oil extracted from the agronomically adapted high yielding cultivar of B. arvensis seeds was analyzed for its oil content, fatty acid (FA) composition, physico-chemical characteristics, total lipids and triacylglycerol molecular species. The oil content, peroxide, acid, iodine, p-anisidine values and tocopherol content of the oil were 18.53% (w/w), 2.06 meq of active oxygen / kg of oil, 2.55 mg KOH/g oil, 217.2 g I 2 /100g oil, 10.7 and 774.8 mg/kg oil respectively. Oxidative stability as determined by the induction period was found to be 3.1 h. Polyunsaturated fatty acid (PUFA) content of the oil was 81.3% (of total FA), comprising of α-linolenic acid (ALA; 48.5%), SDA (18.6%), linoleic acid (LA; 10.3%) and γ-linolenic acid (GLA; 3.9%). Profiling of lipid classes showed neutral lipids (89.3%, w/w) as most abundant lipid class followed by glycolipids (7.4%, w/w) and phospholipids (3.3%, w/w). High resolution mass spectrometric analysis of triacylglycerol (TAG) molecular species showed TAGs with C54 carbons in the acyl chain as most abundant. Positional distribution analysis showed GLA and SDA predominantly at the sn-2 position of triacylglycerol. FTIR analysis revealed common characteristics molecular features similar to PUFA rich oils. Overall, the results suggest that B. arvensis seed oil is an excellent ω3-ω6-ω3 or ALA-SDA-GLA source for food and nutraceutical industries.

To develop and use the hazelnut, the main composition, and the physicochemical characteristics, fatty acid compositions, triacylglycerol (TAG) distribution and tocol contents of Hazelnut (Corylus mandshurica Maxim.) which growing in Changbai mountain of Jilin province (HO1) and Anshan city of Liaoning province (HO2) in China were investigated, and the comparative study between the two hazelnut oils and American hazelnut / Turkish hazelnut were also explored. The content of crude lipid and protein in HO1 and HO2 were approximately 54% and 17%, 55% and 16%, respectively. The two hazelnut oils were abundant in unsaturated fatty acids, with the primary unsaturated fatty acids were oleic acid (78%-80%) and linoleic acid (14-16%), which accounted for above 90% of the oils. Therefore, both of the hazelnut oils were important sources of essential fatty acid. In addition, the main saturated fatty acid of the two hazelnut oils were palmitic acid (3%) and stearic acid (1-2%). The main triacylglycerols (TGA) profile were dioleolinolein (OOL), oleodilinolein (OLL) and triolein (OOO). The contents of tocol were 574.44 μg/g, 647.49 μg/g oil in HO1 and HO2, respectively, both of them were higher than that of grape seed oils (454 μg/g), olive oils (209 μg/g) and walnut oils (255 μg/g). The total phytosterol contents were over 2000μg/g and β-sitosterol was the most predominant sterol in two oils.

Studies on avocado oil have focused on the most common commercial cultivars, Hass, Fuerte, and Bacon, rather than the less common varieties, P. americana var. drymifolia and P. americana var. americana, even though the drymifolia variety has a higher oil content and the americana variety is the most common avocado grown in the tropics. The most abundant storage structures for plant oils are the oleosomes, and the aim of this study was to determine the oleosome size, oil yield, and fatty acid composition of the americana and drymifolia varieties, using the Hass cultivar as a reference. Differences were found between the three avocado types for 1) oil yield, with drymifolia having higher and americana lower oil content (p < 0.05%), 2) oleosome size, with Hass having a larger (41.53 µm) and americana a smaller (11.96 µm) size, and 3) fatty acid composition, with the americana and drymifolia varieties showing less monounsaturated fatty acids (oleic) and more polyunsaturated fatty acids (linoleic) and saturated fatty acids (palmitic); while Hass had a high level (60%) of monounsaturated fatty acids. Small but significant differences were also found between oleosome and mesocarp oils isolated from the drymifolia and Hass types.

Cholesterol is considered one of the most abundant sterols present in mammals, amphipathic in nature, and a key constituent of the cell membrane. Its unique chemical structure consisting of four linked hydrocarbon rings, with an aliphatic chain on one end and a hydroxyl group on the other, confers it the ability to form hydrogen bonds with other lipid classes, like phospholipids or sphingolipids head groups. However, due to its hydrophobic moiety, the fatty acid chain, free cholesterol (FC) it is difficult to be analyzed via electrospray ionization (ESI). The method presented in this chapter to identify and quantify free cholesterol and cholesteryl esters (CE) is based on the chemical derivatization of the sample, strategy devised to avoid the problematic of ESI. However, relevant mention should be made to an alternative separation protocol, which uses ultrahigh performance liquid chromatography and in-source collision-induced dissociation to achieve a simultaneous quantification of FC, CE, and triglycerides (TG).

Purpose: The most commonly used method for estimating low-density lipoprotein cholesterol (LDLC) is Friedewald formula (FF). This study aims to extract and validate new modified Friedewald formulae for estimating LDLC according to triglyceride (TG) levels in Iranians., Methods: Total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), LDLC, and TG were measured in 5030 fasted subjects. The original FF was used for estimating LDLC. Data were divided into training and validation data sets. For extracting modified Friedewald formulae, linear regression was used with TG as independent and TC, HDLC, and directly measured LDLC (D-LDLC) as dependent variables, respectively. An overall modified formula was extracted for TG concentrations <400 mg/dL. The specific modified formulae were extracted for different TG categories. The performance of the modified formulae was assessed in the validation data set., Results: The overall derived formula for calculating LDLC was M-LDLC = TC-HDLC-TG/4. The coefficients of TG (specific TG terms) in modified formulae were 2.7, 3.7, 4.6, and 5 for TG <100, 100-200, 200-300, and 300-400 mg/dL, respectively. Compared to the original FF, applying a new modified formula with TG/4 to a validation data set provided a less mean difference (4.03 vs. 10.86 mg/dL), greater kappa coefficient (0.691 vs. 0.505), and better subject classification (80.8 vs. 67.1%). After applying modified formulae with specific TG terms, the difference between M-LDLC and D-LDLC decreased to 1.41 mg/dL., Conclusions: Modified formulae were developed and validated for LDLC estimation that compared to the original FF, provided more accurate estimation of LDLC and better classification of subjects. These findings shall be useful for preventive, diagnostic, and therapeutic purposes.

Purification of triglycerides from fully hydrogenated palm kernel oil (FHPKO) and fully hydrogenated coconut oil (FHCNO) was performed by a chromatographic method. Lipid composition, thermal properties, polymorphism, isothermal crystallization behaviour, nanostructure and microstructure of FHPKO, FHPKO-triacylglycerol (TAG), FHCNO and FHCNO-TAG were evaluated. Removal of minor components had no effect on triglycerides composition. However, the presence of the minor components did increase the slip melting point and promote onset of crystallization. Furthermore, the thickness of the nanoscale crystals increased, and polymorphic transformation from β' to β occurred in FHPKO after the removal of minor components, and from α to β' in FHCNO. Sharp changes in the values of the Avrami constant K and exponent n suggested that the presence of minor components changed the crystal growth mechanism. The PLM results indicated that a coarser crystal structure with lower fractal dimension appeared after the removal of minor components from both FHPKO and FHCNO., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Enantiomers of triacylglycerols (TAGs) containing any combination of very long chain fatty acids (VLCFAs) and/or very long chain polyunsaturated fatty acids (VLCPUFAs) with diolein, dilinolein and didocosahexaenoin were synthesized. Gradient non-aqueous reversed-phase high-performance liquid chromatography/high resolution atmospheric pressure chemical ionization-tandem mass spectrometry (NARP-HPLC/HRMS 2 -APCI) and chiral liquid chromatography were used for the separation and identification of molecular species of these TAGs. Further, NARP-LC and chiral LC were used to separate natural mixtures of TAGs obtained from four natural sources, i.e. ximenia oil (Ximenia americana), green alga (Botryococcus braunii), breweŕs yeast (Saccharomyces pastorianus) and a dinoflagellate (Amphidinium carterae). The ratio of regioisomers and enantiomers in individual samples was determined and a hypothesis has been confirmed on the biosynthetic pathway of natural TAGs, which is based on the preferential representation of VLCFAs and VLCPUFAs in the sn-1 position of the glycerol backbone., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A novel strategy for discriminating genuine and adulterated marine oils is proposed. The strategy consists of i) determining the stereospecific distribution (sn-1, sn-2 and sn-3) of omega 3 polyunsaturated fatty acids (ω-3 PUFA) on the backbone of triacylglycerols by using liquid chromatography tandem mass spectrometry; ii) transforming the qualitative stereospecific information into quantitative data by means of a novel strategy; iii) analyzing the transformed data by principal component analysis. The proposed strategy was tested on pure oils (seal, salmon, cod liver, sandeel, blue whiting, herring), a mixture of blue whiting, herring, sandeel and Norway pout and some intentionally adulterated oils. In addition, some published krill oil data were analyzed to confirm the reliability of the new approach., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Heart-cut multidimensional gas chromatographic (H/C MDGC) methods under suitable flow and high temperature (T) program conditions were developed to separate olive oil triacylglycerols (TAGs). Different column sets were selected for further evaluation, each with relatively short non-polar first dimension ( 1 D) and mid-polar second dimension ( 2 D) columns of high T limits (350 °C). The 1 D separation displayed three major groups of peaks in an area ratio of approximately 5:33:62 (of increasing retention), using flame ionisation detection (FID). Four groups of minor peaks, with 2 of them located between the major peaks, were also detected. The H/C fractions of the minor peaks, and sub-sampled regions across the major peaks eluting from the 1 D outlet, were cryotrapped at the 2 D inlet. The trapped TAGs then underwent temperature programmed 2 D separation. Each of the 'H/C' zones generally gave 2-5 - and in some cases more - separated peaks of TAGs on the 2 D column, under suitable flow condition and phase polarity that resulted in improved separation. Six sub-sampled H/Cs from various regions of the individual peaks from the 1 D column were simultaneously trapped and released to 2 D, resulting in apparently more than 22 individual TAG peaks. According to their different retention times, different TAGs were revealed within each of the 3 major groups, using H/C sub-sampling. A comprehensive sampling strategy that covers most of the 1 D peaks further revealed the presence of more TAGs in the olive oil sample. This tandem column strategy was able to resolve more components than that usually observed on a single column., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The lipid characterization of storage fat, subcutaneous fat and bone marrow, originated from three different bovine categories, calf, young bull and cow, was carried out in order to develop a re-use of these by-products. After the lipid extraction, the compositions in fatty acids, triacylglycerols and cholesterol were determined by GC-FID. A total of 25 fatty acids were identified in all by-products; the oleic acid was the preponderant component, followed by palmitic, stearic, palmitoleic, linoleic and myristic acid. The long chain triacylglycerols (T48, T50 and T52) were the main products, especially in the cow's by-products. The subcutaneous fat of all animals showed the highest cholesterol content, whereas it was present in low amount in the others. Phospholipids were analysed in bone marrow of all the animals and phosphatidylcholine was the most abundant compound. Because of the high fat content and essential fatty acids and the low cholesterol amount, storage fat and bone marrow could represent a valuable lipid resource in food and pharmaceutical industry.

Triglycerides are clinically important marker for atherosclerosis, heart disease and hypertension. Here, a platform for detecting triglycerides in whole blood directly was developed based on hemocompatible ɛ-polylysine-heparin microparticles. The obtained products of ɛ-polylysine-heparin microparticles were characterized by fourier transform infrared (FT-IR) spectra, transmission electron microscopy (TEM) and ζ-potential. Moreover, the blood compatibility of ɛ-polylysine-heparin microparticles was characterized by in vitro coagulation tests, hemolysis assay and whole blood adhesion tests. Considering of uniform particle size, good dispersibility and moderate long-term anticoagulation capability of the microparticles, a Lipase-(ɛ-polylysine-heparin)-glassy carbon electrode (GCE) was constructed to detect triglycerides. The proposed biosensor had good electrocatalytic activity towards triglycerides, in which case the sensitivity was 0.40μAmg -1 dLcm -2 and the detection limit was 4.67mgdL -1 (S/N = 3). Meanwhile, the Lipase-(ɛ-polylysine-heparin)-GCE electrode had strong anti-interference ability as well as a long shelf-life. Moreover, for the detection of triglycerides in whole blood directly, the detection limit was as low as 5.18mgdL -1 . The new constructed platform is suitable for detecting triglycerides in whole blood directly, which provides new analytical systems for clinical illness diagnosis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A full understanding of the origin, formation and degradation of volatile compounds that contribute to wine aroma is required before wine style can be effectively managed. Fractionation of grapes represents a convenient and robust method to simplify the grape matrix to enhance our understanding of the grape contribution to volatile compound production during yeast fermentation. In this study, acetone extracts of both Riesling and Cabernet Sauvignon grape berries were fractionated and model wines produced by spiking aliquots of these grape fractions into model grape juice must and fermented. Non-targeted SPME-GCMS analyses of the wines showed that several medium chain fatty acid ethyl esters were more abundant in wines made by fermenting model musts spiked with certain fractions. Further fractionation of the non-polar fractions and fermentation of model must after addition of these fractions led to the identification of a mixture of polyunsaturated triacylglycerides that, when added to fermenting model must, increase the concentration of medium chain fatty acid ethyl esters in wines. Dosage-response fermentation studies with commercially-available trilinolein revealed that the concentration of medium chain fatty acid ethyl esters can be increased by the addition of this triacylglyceride to model musts. This work suggests that grape triacylglycerides can enhance the production of fermentation-derived ethyl esters and show that this fractionation method is effective in segregating precursors or factors involved in altering the concentration of fermentation volatiles., Competing Interests: The authors declare no conflict of interest.

The complexity of triacylglycerols (TAGs) in edible oils is largely due to the many similar unsaturated TAG compounds, which makes profiling TAGs difficult. In this study, precolumn derivatization with bromine (Br 2 ) was used to improve the separation and detection sensitivity of TAGs in edible oils by RP-HPLC. Oil samples dissolved in n-hexane and TAGs were derived by reaction with a Br2-CCl 4 (1:1, v/v) solution for 3 h at room temperature. The derivate product solution was stable and was best separated and detected by RP-HPLC using a C18 column, with a mobile phase of methanol-n-hexane (91.5:8.5, v/v) at 25°C. A detection wavelength of 230 nm was used. The results showed that the approach enabled the separation and detection of more similar TAGs by RP-HPLC. The method was applied to profile 20 types of edible oil, and the results presented the differences in the TAG profiles of various edible oils, which may be useful in the identification of edible oils.

Medium chain fatty acids (MCFAs), have gained nutritional relevance in the past few years. They are continuously used in obtaining structured lipids like medium chain acylglycerols (MCAs) for various purposes. However, because of their chemical structure pertaining carbon chain length and the presence of saturated and unsaturated fatty acids, sensitive detection techniques are required for their correct identification and separation. In the present work, a specific thin layer chromatography (TLC) method for MCAs was developed. The proposed method consisted of the use of a mixture of hexane: acetone (70:30 v/v) as mobile phase, since it proved effectiveness for the separation of compounds of interest (MCAs) as well as having the necessary sensitivity to separate different species of monoacylglycerols (MAGs), diacylglycerols (DAGs) and triacylglycerols (TAGs) of MCFAs. For observation of the compounds, a single oxidizing agent was not sufficient, thus a combination of visualization reagents was used (first a 10 % solution of sulphuric acid in methanol followed by a 10 % solution of phosphomolybdic acid in methanol) achieving the correct visualization of the desired compounds.

We studied the total phenols and flavonoids, liposoluble antioxidants, fatty acid and triacylglycerol profiles, and oxidative status of oil obtained from Lycium europaeum fruits following supercritical CO 2 extraction (at 30MPa and 40°C). Linoleic (52%), palmitic (18%), oleic (13%), and α-linolenic (6%) were the main oil fatty acids, while trilinolein and palmitodilinolein/oleodilinolein represented the main triacylglycerols. The oil was characterized by high levels of all-trans-zeaxanthin and all-trans-β-carotene (755 and 332μg/g of oil, respectively), α-tocopherol (308μg/g of oil), total phenols (13.6mg gallic acid equivalents/g of oil), and total flavonoids (6.8mg quercetin equivalents/g of oil). The oil showed radical scavenging activities (ABTS and DPPH assays) and inhibited Caco-2 cell growth. Moreover, the incubation of differentiated Caco-2 cells with a non-toxic oil concentration (100μg/mL) induced a significant intracellular accumulation of essential fatty acids. The results qualify L. europaeum oil as a potential source for food/pharmaceutical applications., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Cyclopentyl methyl ether (CPME) was evaluated for extracting oil or triacylglycerol (TAG) from wet cells of the oleaginous yeast Lipomyces starkeyi. CPME is a greener alternative to chloroform as a potential solvent for oil recovery. A monophasic system of CPME and biphasic system of CPME:water (1:0.7) performed poorly having the lowest TAG extraction efficiency and TAG selectivity compared to other monophasic systems of hexane and chloroform and the biphasic Bligh and Dyer method (chloroform:methanol:water). Biphasic systems of CPME:water:alcohol (methanol/ethanol/1-propanol) were tested and methanol achieved the best oil extraction efficiency compared to ethanol and 1-propanol. Different biphasic systems of CPME:methanol:water were tested, the best TAG extraction efficiency and TAG selectivity achieved was 9.9 mg/mL and 64.6%, respectively, using a starting ratio of 1:1.7:0.6 and a final ratio of 1:1:0.8 (CPME:methanol:water). Similar results were achieved for the Bligh and Dyer method (TAG extraction efficiency of 10.2 mg/mL and TAG selectivity of 66.0%) indicating that the biphasic CPME system was comparable. The fatty acid profile remained constant across all the solvent systems tested indicating that choice of solvent was not specific for any certain fatty acid. This study was able to demonstrate that CPME could be used as an alternative solvent for the extraction of oil from the wet biomass of oleaginous yeast. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1096-1103, 2017., (© 2017 American Institute of Chemical Engineers.)

Enterococcus faecalis is a Gram-positive, opportunistic, pathogenic bacterium that causes a significant number of antibiotic-resistant infections in hospitalized patients. The development of antibiotic resistance in hospital-associated pathogens is a formidable public health threat. In E. faecalis and other Gram-positive pathogens, correlations exist between lipid composition and antibiotic resistance. Resistance to the last-resort antibiotic daptomycin is accompanied by a decrease in phosphatidylglycerol (PG) levels, whereas multiple peptide resistance factor (MprF) converts anionic PG into cationic lysyl-PG via a trans-esterification reaction, providing resistance to cationic antimicrobial peptides. Unlike previous studies that relied on thin layer chromatography and spectrophotometry, we have performed liquid chromatography-tandem mass spectrometry (LC-MS/MS) directly on lipids extracted from E. faecalis, and quantified the phospholipids through multiple reaction monitoring (MRM). In the daptomycin-sensitive E. faecalis strain OG1RF, we have identified 17 PGs, 8 lysyl-PGs (LPGs), 23 cardiolipins (CL), 3 glycerophospho-diglucosyl-diacylglycerols (GPDGDAG), 5 diglucosyl-diacylglycerols (DGDAG), 3 diacylglycerols (DAGs), and 4 triacylglycerols (TAGs). We have quantified PG and shown that PG levels vary during growth of E. faecalis in vitro. We also show that two daptomycin-resistant (DapR) strains of E. faecalis have substantially lower levels of PG and LPG levels. Since LPG levels in these strains are lower, daptomycin resistance is likely due to the reduction in PG. This lipidome map is the first comprehensive analysis of membrane phospholipids and glycolipids in the important human pathogen E. faecalis, for which antimicrobial resistance and altered lipid homeostasis have been intimately linked.

Solvent systems are not readily available for the separation of very nonpolar compounds by countercurrent chromatography (CCC). In this study we therefore evaluated the suitability of room temperature ionic liquids (IL) in organic solvents for the CCC separation of the extremely nonpolar lipid compounds tripalmitin (PPP) and cholesteryl stearate (CS). The four IL tested were [C 10 mim][OTf], [C 2 mim][NTf 2 ], [P66614][NTf 2 ], and [P66614][Cl]. Search for a CCC-suited solvent system started with solubility studies with fourteen organic solvents. Following this, combinations were made with one organic solvent miscible and one organic solvent immiscible with IL (147 combinations). Twenty-four initially monophasic mixtures of two organic solvents became biphasic by adding IL. Several unexpected results could be observed. For instance, n-hexane and n-heptane became biphasic with [P66614][Cl]. Further nine systems became biphasic although the IL was not miscible in any of the two components. These 33 solvent systems were investigated with regard to phase ratio, settling time, share of IL in the upper phase and last not least the K U/L values of PPP and CS, which were 8.1 and 7.7 respectively. The most promising system, n-heptane/chloroform/[C 10 mim][OTf] (3:3:1, v/v/v) allowed a partial separation of PPP and CS by CCC which was not achieved beforehand., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Microalgae have the potential to rapidly accumulate lipids of high interest for the food, cosmetics, pharmaceutical and energy (e.g. biodiesel) industries. However, current lipid extraction methods show efficiency limitation and until now, extraction protocols have not been fully optimized for specific lipid compounds. The present study thus presents a novel lipid extraction method, consisting in the addition of a water treatment of biomass between the two-stage solvent extraction steps of current extraction methods. The resulting modified method not only enhances lipid extraction efficiency, but also yields a higher triacylglycerols (TAG) ratio, which is highly desirable for biodiesel production., Results: Modification of four existing methods using acetone, chloroform/methanol (Chl/Met), chloroform/methanol/H 2 O (Chl/Met/H 2 O) and dichloromethane/methanol (Dic/Met) showed respective lipid extraction yield enhancement of 72.3, 35.8, 60.3 and 60.9%. The modified acetone method resulted in the highest extraction yield, with 68.9 ± 0.2% DW total lipids. Extraction of TAG was particularly improved with the water treatment, especially for the Chl/Met/H 2 O and Dic/Met methods. The acetone method with the water treatment led to the highest extraction level of TAG with 73.7 ± 7.3 µg/mg DW, which is 130.8 ± 10.6% higher than the maximum value obtained for the four classical methods (31.9 ± 4.6 µg/mg DW). Interestingly, the water treatment preferentially improved the extraction of intracellular fractions, i.e. TAG, sterols, and free fatty acids, compared to the lipid fractions of the cell membranes, which are constituted of phospholipids (PL), acetone mobile polar lipids and hydrocarbons. Finally, from the 32 fatty acids analyzed for both neutral lipids (NL) and polar lipids (PL) fractions, it is clear that the water treatment greatly improves NL-to-PL ratio for the four standard methods assessed., Conclusion: Water treatment of biomass after the first solvent extraction step helps the subsequent release of intracellular lipids in the second extraction step, thus improving the global lipids extraction yield. In addition, the water treatment positively modifies the intracellular lipid class ratios of the final extract, in which TAG ratio is significantly increased without changes in the fatty acids composition. The novel method thus provides an efficient way to improve lipid extraction yield of existing methods, as well as selectively favoring TAG, a lipid of the upmost interest for biodiesel production.

Advances in mass spectrometry have made the quantitative measurement of proteins across multiple samples a reality, allowing for the study of complex biological systems such as the metabolic syndrome. Although the deregulation of lipid metabolism and increased hepatic storage of triacylglycerides are known to play a part in the onset of the metabolic syndrome, its molecular basis and dependency on dietary and genotypic factors are poorly characterized. Here, we used an experimental design with two different mouse strains and dietary and metabolic perturbations to generate a compendium of quantitative proteome data using three mass spectrometric techniques. The data reproduce known properties of the metabolic system and indicate differential molecular adaptation of the two mouse strains to perturbations, contributing to a better understanding of the metabolic syndrome. We show that high-quality, high-throughput proteomic data sets provide an unbiased broad overview of the behavior of complex systems after perturbation.

The distribution of fatty acid species at the sn-1/3 position or the sn-2 position of triacylglycerols (TAGs) in natural fats and oils affects their physical and nutritional properties. In fats and oils, determining the presence of one or two regioisomers and the identification of structure, where they do have one, as well as their separation, became a problem of fundamental importance to solve. A variety of instrumental technics has been proposed, such as MS, chromatography-MS or pure chromatography. A number of studies deal with the optimization of the separation, but very often, they are expensive in time. In the present study, in order to decrease the analysis time while maintaining good chromatographic separation, we tested different monomeric and polymeric stationary phases and different chromatographic conditions (mobile phase composition and analysis temperature) using Non-Aqueous Reversed Phase Liquid Chromatography (NARP-LC). It was demonstrated that mixed polymeric stationary bonded silica with accessible terminal hydroxyl groups leads to very good separation for the pairs of TAGs regioisomers constituted by two saturated and one unsaturated fatty acid (with double bond number: from 1 to 6). A Nucleodur C18 ISIS percolated by isocratic mobile phase (acetonitrile/2-propanol) at 18°C leads to their separations in less than 15min. The difference of retention times between two regioisomers XYX and XXY are large enough to confirm, as application, the presence of POP, SOP, SOS and PLP and no PPO, SPO, SSO and PPL in Theobroma cacao butter. In the same way, this study respectively shows the presence of SOS, SOP and no SSO, PSO in Butyrospermum parkii butter, POP, SOP, SOS and no PPO, PSO and SSO in Carapa oil and finally POP and no PPO in Pistacia Lentiscus oil., (Copyright © 2016 Elsevier B.V. All rights reserved.)

This study was designed to examine physicochemical characteristics, chemical compositions and biological activities of fenugreek seed oil (FSO) and its pure triglyceride (TG). One fenugreek TG was purified using a bioassay-guided fractionation and administrated to surviving diabetic rats. The free fatty acids percentage as well as, the peroxide, the saponification and the iodine values were 2%, 12 mequiv. O 2 /kg of oil, 189 (mg KOH/g) and 110 (g/100 g of oil), respectively. Linolenic acid (C 18:3 26.14%), Linoleic acid (C 18:2 41.13%) and Oleic acid (C 18:1 17.07%) were the dominant fatty acids in the FSO. β-sitosterol was the major sterol (85.3%) in the FSO. LnLnO (17.1%), LLL (16.6%), OLL and OOLn (8.4%), were the abundant triglycerides. The hexane extract of fenugreek seed (exhibiting the powerful inhibitory activity against alpha-amylase) was purified using a bioassay-guided fractionation affording one fenugreek TG: (11Z)-11- eicosenoic acid 2, 3- bis[((9Z, 12Z, 15Z)-1-oxo-9, 12, 15-octadecatrien-1-yl)oxy] propyl ester. In diabetic rats, the administration of the fenugreek TG inhibited α-amylase activity in small intestine by 36% as compared to untreated diabetic rats. Moreover, fenugreek TG increased insulin sensibility which leads to decrease in blood glucose level by 43%. In addition, this study demonstrated that administration of pure fenugreek TG to diabetic rats ameliorated the glycogen rate in liver and muscle. In addition, the administration of fenugreek TG reverted back the activity of angiotensin converting enzyme respectively in kidney and plasma by 33 and 29%. Interestingly, the fenugreek TG inhibited lipase activity in small intestine by 33% which leads to the regulation of lipid profile. Moreover, the fenugreek TG protected liver-kidney function evidenced by histological study. In conclusion, our finding demonstrates that the administration of fenugreek TG to diabetic rats can make it a potential candidate for industrial application as a pharmacological agent for the treatment of hyperglycemia.

Regioisomers and enantiomers of triacylglycerols (TAGs) containing any combination of stearidonic (18:4n-3) and octadecapentaenoic (18:5n-3) acids were prepared by organic synthesis. Gradient polar organic liquid chromatography/high resolution atmospheric pressure chemical ionization-tandem mass spectrometry (NARP-LC/HRMS 2 -APCI) and chiral liquid chromatography were used for the separation and identification of molecular species of these TAGs. Further, NARP-LC and chiral LC were used to separate natural mixtures of TAGs obtained from the haptophyte alga Coccolithophora sp. cultivated in a salinity range from 7.5 to 60‰. The ratio of regioisomers and enantiomers was found to change with increasing salinity of the culture medium. This can be explained by variable activity of acyltransferases in cells exposed to salt stress., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Although switchgrass has been developed as a biofuel feedstock and its potential for bioethanol and bio-oil from fast pyrolysis reported in the literature, the use of the seeds of switchgrass as a source of triglycerides for biodiesel production has not been reported. Similarly, the potential for extracting triglycerides from coffeeweed (an invasive plant of no current economic value) needs to be investigated to ascertain its potential economic use for biodiesel production., Results: The results show that coffeeweed and switchgrass seeds contain known triglycerides which are 983 and 1000 g kg(-1) respectively of the fatty acids found in edible vegetable oils such as sunflower, corn and soybean oils. In addition, the triglyceride yields of 53-67 g kg(-1) of the seed samples are in the range of commercial oil-producing seeds such as corn (42 g kg(-1) )., Conclusion: The results also indicate that the two non-edible oils could be used as substitutes for edible oil for biodiesel production. In addition, the use of seeds of switchgrass for non-edible oil production (as a feedstock for the production of biodiesel) further increases the total biofuel yield when switchgrass is cultivated for use as energy feedstock for pyrolysis oil and biodiesel production. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)

For LC-MS-based lipidomic analysis of milk, total lipid extraction from raw milk is generally conducted with Folch or Bligh and Dyer methods; both methods are based on two-phase partition of lipids, and thus time-consuming. In this work, three solvent systems for one-phase extraction of milk lipids were compared with the standard Folch method. Two of the solvent systems (butanol/methanol, 3:1 and 1:1) previously tested for lipid extraction from plasma were found to provide adequate extraction for polar lipids, but incomplete extraction for triglycerides, especially highly lipophilic species. By contrast, our newly designed solvent mix composed of butanol, methanol and chloroform (at a 3:5:4 ratio) provided similar extraction efficiency for triglycerides and higher yield for some of the phospholipids, as compared to the Folch method. This new one-phase extraction method is very simple yet comprehensive and thus suitable for high throughput lipid analysis of milk samples., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Carotenoids are naturally found in both free form and esterified with fatty acids in most fruits; however, up to now the great majority of studies only evaluated their composition after saponification. This fact is easily explained by the difficult to analyze carotenoid esters. Preliminary studies showed that cleanup procedures in the extract are necessary for further analysis by LC-MS/MS since triacylglycerols (TAGs) impair the MS detection. Considering these facts, we developed a new cleanup procedure to remove TAGs and other lipids from carotenoid fruit extracts. This procedure is based on physical removal of solid lipids at low temperature followed by open column chromatography on MgO and diatomaceous earth. Before cleanup, four carotenoid diesters and two free xanthophylls were identified in murici (Byrsonyma crassifolia), corresponding to about 65% of the total chromatogram area. After carrying out the two-step cleanup procedure, 35 carotenoids were identified, being 14 monoesters, six free carotenoids and 15 carotenoid diesters. We can conclude that this two-step procedure was successfully applied to murici, an Amazonian fruit, which contains high amounts of lipids., (Copyright © 2016 Elsevier B.V. All rights reserved.)