Analysis of fatty acids by gas chromatography, and its relevance to research on health and nutrition

Iridium Isotope Tag-Assisted LC-MS Method for Global Profiling and Quantification of Nonvolatile Serum Fatty Acids in Nonalcoholic Fatty Liver Mice

Highly accurate and sensitive measurements of fatty acids (FAs) in biological samples are essential for advancing our understanding of their diverse biofunctions. In this work, based on the characteristic isotope pattern of iridium (191/193Ir), we employed an iridium-encoded amine (Ir-NH2) as the derivatization reagent to establish a selective and sensitive liquid chromatography-mass spectrometry (LC-MS) method for rapid identification and accurate quantification of FAs in biological samples. Upon derivatization, nonvolatile FAs were transformed into amide derivatives tagged with a charged iridium tag, exhibiting improved sensitivity and selectivity in the electrospray ionization (ESI) positive ion mode. By leveraging the unique 2.002 Da mass shift and the 3:5 peak intensity ratio from the natural 191Ir and 193Ir isotopes, we can rapidly and efficiently screen the potential carboxyl-containing metabolites from biological samples. Compared to other existing methods, our technique offers higher sensitivity, better signal-to-noise ratio, lower detection limit (1.2-8.4 pg/mL), and easier quantification due to the clear identification of iridium-tagged derivatives. With this method, a total of 58 FAs, including both saturated and unsaturated types, were detected in mice serum lipid extracts, with carbon chain lengths varying from C9 to C24. More importantly, this method was successfully employed for global profiling of nonvolatile serum FAs from mice with nonalcoholic fatty liver disease (NAFLD), providing a novel means for detecting them and offering new avenues for exploring their functional roles and disease associations.

Characterization of Vegetable Oils for Direct Use in Polyurethane-Based Adhesives: Physicochemical and Compatibility Assessment

This study evaluates the compatibility and innovative applications of unmodified vegetable oils, including rapeseed, sunflower, linseed, castor, and used cooking oils, in the production of sustainable polymeric materials, particularly polyurethane adhesives. Fatty acid composition was characterized using GC-MS, functional groups were identified by FTIR, and physicochemical properties, such as hydroxyl value, acid value, viscosity, and density, were measured using conventional analytical techniques. The results highlight significant differences in the properties of the oils, influencing their suitability for specific industrial applications. Castor oil, with its high ricinoleic acid content and hydroxyl value, was identified as the most suitable option for bio-based polyols and polyurethane production. Compatibility tests confirmed that unmodified oils can be effectively blended with polyols, ensuring stability and homogeneity without chemical modification. This approach simplifies production, reduces reliance on petrochemical feedstocks, and advances the development of environmentally friendly polyurethane adhesives. Future research will focus on optimizing formulations and assessing the long-term performance of adhesives incorporating unmodified vegetable oils.

Nutraceutical potential of Mediterranean agri-food waste and wild plants: Green extraction and bioactive characterization

The agricultural waste and wild plants of the Mediterranean region offer significant nutraceutical potential, rich in bioactive compounds such as phenolics, carotenoids, lipids and volatile organic compounds. These compounds exhibit health-promoting properties, including antioxidant, neuroprotective and anti-inflammatory effects. Advanced analytical techniques such as HPLC, GC-MS and NMR are essential for the accurate chemical characterization of these bioactives. Green extraction methods, including ultrasound-assisted, enzyme-assisted and cold plasma-assisted extractions, provide efficient and environmentally friendly alternatives to classical techniques for the isolation of bioactive compounds. The valorization of Mediterranean agricultural by-products, such as olive pomace, grape seeds, and citrus peels, exemplifies sustainable approaches to the utilization of these underutilized resources. This chapter explores the bioactive characterization and green extraction methods that contribute to unlocking the nutraceutical potential of Mediterranean plant waste and wild plants, highlighting their role in the development of functional foods and natural health products.

Genetic analysis of the X-linked Adrenoleukodystrophy ABCD1 gene in Drosophila uncovers a role in Peroxisomal dynamics

X-linked adrenoleukodystrophy (X-ALD) is a progressive neurodegenerative disorder caused by a loss-of-function (LOF) mutation in the ATP-binding cassette subfamily D member 1 (ABCD1) gene, leading to the accumulation of very long-chain fatty acids (VLCFAs). This disorder exhibits striking heterogeneity; some male patients develop an early childhood neuroinflammatory demyelination disorder, while other patients, including adult males and most affected female carriers, experience a chronic progressive myelopathy. Adrenocortical failure is observed in almost all male patients, with age of onset varying sometimes being the first diagnostic finding. The gene underlying this spectrum of disease encodes an ATP-binding cassette (ABC) transporter that localizes to peroxisomes and facilitates VLCFA transport. X-ALD is considered a single peroxisomal component defect and does not play a direct role in peroxisome assembly. Drosophila models of other peroxisomal genes have provided mechanistic insight into some of the neurodegenerative mechanisms with reduced lifespan, retinal degeneration, and VLCFA accumulation. Here, we perform a genetic analysis of the fly ABCD1 ortholog Abcd1 (CG2316). Knockdown or deficiency of Abcd1 leads to VLCFA accumulation, salivary gland defects, locomotor impairment and retinal lipid abnormalities. Interestingly, there is also evidence of reduced peroxisomal numbers. Flies overexpressing the human cDNA for ABCD1 display a wing crumpling phenotype characteristic of the pex2 loss-of-function. Surprisingly, overexpression of human ABCD1 appears to inhibit or overwhelm peroxisomal biogenesis to levels similar to null mutations in fly pex2, pex16 and pex3. Drosophila Abcd1 is therefore implicated in peroxisomal number, and overexpression of the human ABCD1 gene acts a potent inhibitor of peroxisomal biogenesis in flies.

Egg vs. Oil in the Cookbook of Plasters: Differentiation of Lipid Binders in Wall Paintings Using Gas Chromatography-Mass Spectrometry and Principal Component Analysis

Wall paintings are integral to cultural heritage and offer rich insights into historical and religious beliefs. There exist various wall painting techniques that pose challenges in binder and pigment identification, especially in the case of egg/oil-based binders. GC-MS identification of lipidic binders relies routinely on parameters like the ratios of fatty acids within the plaster. However, the reliability of these ratios for binder identification is severely limited, as demonstrated in this manuscript. Therefore, a more reliable tool for effective differentiation between egg and oil binders based on a combination of diagnostic values, specific markers (cholesterol oxidation products), and PCA is presented in this study. Reference samples of wall paintings with egg and linseed oil binders with six different pigments were subjected to modern artificial ageing methods and subsequently analysed using two GC-MS instruments. A statistically significant difference (at a 95% confidence level) between the egg and oil binders and between the results from two GC-MS instruments was observed. These discrepancies between the results from the two GC-MS instruments are likely attributed to the heterogeneity of the samples with egg and oil binders. This study highlights the complexities in identifying wall painting binders and the need for innovative and revised analytical methods in conservation efforts.

Particulate organic emissions from incense-burning smoke: Chemical compositions and emission characteristics

Incense burning is a common practice in Asian cultures, releasing hazardous particulate organics. Inhaling incense smoke can result in adverse health effects, yet the molecular compositions of incense-burning organics have not been well investigated due to the lack of measurement of intermediate-volatility and semi-volatile organic compounds (I/SVOCs). To elucidate the detailed emission profile of incense-burning particles, we conducted a non-target measurement of organics emitted from incense combustion. Quartz filters were utilized to trap particles, and organics were analyzed by a comprehensive two-dimensional gas chromatography-mass spectrometer (GC × GC-MS) coupled with a thermal desorption system (TDS). To deal with the complex data obtained by GC × GC-MS, homologs are identified mainly by the combination of selected ion chromatograms (SICs) and retention indexes. SICs of 58, 60, 74, 91, and 97 were utilized to identify 2-ketones, acids, fatty acid methyl esters, fatty acid phenylmethyl esters, and alcohols, respectively. Phenolic compounds contribute the most to emission factors (EFs) among all chemical classes, taking up 24.5 % ± 6.5 % of the total EF (96.1 ± 43.1 μg g-1). These compounds are largely derived from the thermal degradation of lignin. Biomarkers like sugars (mainly levoglucosan), hopanes, and sterols are extensively detected in incense combustion fumes. Incense materials play a more important role in shaping emission profiles than incense forms. Our study provides a detailed emission profile of particulate organics emitted from incense burning across the full-volatility range, which can be used in the health risk assessments. The data processing procedure in this work could also benefit those with less experience in non-target analysis, especially GC × GC-MS data processing.

Profiling of branched chain and straight chain saturated fatty acids by ultra-high performance liquid chromatography-mass spectrometry

Branched chain fatty acids (BCFAs) are one of the important sub categories of fatty acids (FAs) which have unique functions in nature. They are commonly analyzed by GC-MS after derivatization to methyl esters (FAMEs). On the other hand, there is a lack of isomer-selective LC-MS methods which allow the distinction of different isomers with wide coverage of carbon chain length. In this work, a systematic retention and isomer selectivity study on seven commercially available UHPLC columns (six polysaccharide columns Chiralpak IA-U, IB-U, IC-U, ID-U, IG-U and IH-U; one Acquity UPLC CSH C18 column) was performed. Various experimental factors were evaluated including column temperatures, gradient profiles and flow rates to elucidate their effects on the separation ability of homologous series of BCFAs with distinct chain lengths, different branching types and branching positions. In general, IG-U outperformed the other columns in terms of isomer selectivity especially for the short and medium-chain BCFA isomers while RP C18 showed good potential in terms of selectivity for long-chain BCFA isomers. Furthermore, after the evaluation of the chromatographic retention pattern on the various columns and method optimization, we report a methodology for untargeted isomer-selective BCFA profiling without precolumn derivatization with UHPLC-ESI-MS/MS by quadrupole-time-of-flight instrument with SWATH acquisition. The best method provides selectivity for constitutional isomers of BCFAs covering distinct chain length (C5-C20) with different branching types (methyl or ethyl) and branching positions (2Me, 3Me, 4Me, 6Me, anteiso and iso-BCFAs) with an optimized LC condition on Acquity UPLC CSH C18 column. Finally, the optimized method was applied for the BCFAs profiling in lipid extracts of Staphylococcus aureus samples. Besides, pooled human platelets and pooled human plasma were evaluated as mammalian samples for presence of BCFAs as well. The new method showed strong potential for BCFA profiling in bacterial samples including different isomers anteiso and iso-BCFAs, which could be a useful tool for related subdisciplines in metabolomics and lipidomics in particular in combination with electron-activated dissociation MS. Compared to GC, the presented isomer selective LC methods can be also of great utility for preparative purposes. Equivalent (carbon) chain length numbers were calculated for RP18 and Chiralpak IG-U and compared to those of FAMEs obtained by GC.

Synthesis of a new hydrophobic coating film from stearic acid of buffalo fat

This experiment involved the chemical conversion of pure stearic acid from buffalo adipose tissue to a waxy stearyl stearate, which was subsequently applied as a coating film to extend the shelf life of recently harvested fruits. Fat was extracted from minced adipose tissue using the dry rendering procedure, and it was then characterized. The extracted fat was hydrolyzed into a mixture of free fatty acids and glycerol. The supercritical CO₂ extractor was used for stearic acid individual extraction in pure form from the free fatty acid mixture, and it was confirmed according to its melting point (69.2-70.0 °C), elemental analysis, GC-MS for esterified fatty acids. The isolated stearic acid was used for the synthesis of a new hydrophobic wax named stearyl stearate. The chemical structure of the prepared compound was established according to its elemental analysis and spectral data. The new hydrophobic wax was used as a coating film to enhance the shelf life of freshly harvested tomato fruits. Therefore, stearyl stearate solution (2.00% w/v diethyl ether) was used for tomato coating and compared to chitosan-coated tomatoes, where weight loss, pH, fruit firmness, ascorbic acid concentration, and total soluble solids were studied for a period of 15 days at 23 ± 1.0 °C and 65 ± 2.0% relative humidity. The results revealed that coating with stearyl stearate solution (2.00% w/v diethyl ether) could delay tomatoes' ripening during the experiment condition. A sensory evaluation of the coated tomatoes was carried out and showed acceptable taste for the tomatoes that were coated with stearyl stearate. On the other hand, the acute oral toxicity of stearyl stearate using albino mice showed complete safety up to 25 g/kg mice weight.

Evaluation of the New Individual Fatty Acid Dataset for UK Biobank: Analysis of Intakes and Sources in 207,997 Participants

The Oxford WebQ is an online 24 h dietary assessment tool used by several large prospective studies. This study describes the creation of the new individual fatty acid (FA) dataset for the Oxford WebQ and reports intakes and sources of dietary individual FAs in the UK Biobank. Participants who completed ≥1 (maximum of five) 24 h dietary assessments were included (n = 207,997). Nutrient intakes were obtained from the average of all completed 24 h dietary assessments. Nutrient data from the UK McCance and Widdowson's The Composition of Foods and the US Department of Agriculture food composition tables were used to calculate intakes of 21 individual FAs. The individual FA dataset included 10 saturated fatty acids (SFAs), 4 monounsaturated fatty acids (MUFAs), and 7 polyunsaturated fatty acids (PUFAs; including alpha-linolenic (18:3), eicosapentaenoic (20:5), and docosahexaenoic (22:6) acids). Palmitic (16:0; mean ± standard deviation (SD): 13.5 ± 5.7 g/d) and stearic (18:0; 5.2 ± 2.5) acids were the main contributors to SFAs, and the main sources of these were cereals and cereal products (mostly desserts/cakes/pastries), milk and milk products (mostly cheese and milk), and meat and meat products. Oleic acid (18:1; 24.2 ± 9.8) was the main MUFA, derived mainly from cereals and cereal products, and meat and meat products. Linoleic acid (18:2; 9.7 ± 4.3) was the main PUFA, derived mostly from cereals and cereal products, and vegetables (including potatoes) and vegetable dishes. The individual FA dataset for the Oxford WebQ will allow future investigations on individual FAs and disease risk.

Assessment of Sargassum sp., Spirulina sp., and Gracilaria sp. as Poultry Feed Supplements: Feasibility and Environmental Implications

Eutrophication, coupled with ocean acidification and warming, results in an increased concentration of marine algae, severely impacting some regions. Several algae are a rich source of protein and minerals. Marine algae are rich in bioactive molecules with antioxidants, anti-inflammatory, anti-fungal, and antimicrobial properties. These properties make them attractive for usage in the pharmaceutical industry. This study evaluated Sargassum sp., Spirulina sp., and Gracilaria sp. for use as poultry feed. Chemical analyses show that crude protein (CP) in analyzed algae was 9.07–63.63%, with a fiber content of 0.15–17.20%, and a crude fat range of 0.152–2.11%, suggesting that algae can partially substitute imported protein sources used for poultry feed. A rapid impact assessment matrix (RIAM) was used to assess the environmental footprint of algae usage in poultry feed. The environmental assessment results show promising opportunities to help harvest the algae from the marine area. However, the feasibility of establishing outdoor algal ponds is not environmentally viable in the Middle East.

Determination of n-3 index and arachidonic acid/eicosapentaenoic acid ratio in dried blood spot by gas chromatography

Background: Clinical and epidemiological studies suggest that analysis of the polyunsaturated fatty acids (PUFAs) is essential to evaluate nutritional requirements and disease risk. We describe a simple, sensitive and non-invasive method for estimating the n-3 index and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio in dried blood spots (DBSs). Experimental: After obtaining DBSs on a spot card, PUFAs were transesterified (direct, acidic transesterification) and subsequently extracted with n-hexane. Gas chromatography with flame ionization detection (GC-FID) was used to analyze the extracted PUFAs, and then n-3 index and AA/EPA ratio were calculated. Method validation showed satisfactory precision and linearity. Conclusion: This analysis is simple and reliable to estimate PUFA status, and it was successfully applied to samples from 20 subjects, demonstrating its applicability.

Metabolite profiling of Bruguiera cylindrica reveals presence of potential bioactive compounds

Bruguiera cylindrica parts are commonly used in Chinese and Indian traditional medicine to treat diarrhea, fever, and many ailments. The present study aims non targeted analysis of key secondary metabolites of B. cylindrica by gas chromatography mass spectrometry (GC-MS) and ultra-high performance liquid chromatography hybrid quadrupole-Exactive-Orbitrap high resolution mass spectrometry (UHPLC-Q-Exactive Orbitrap HRMS). GC-MS and UHPLC-Q-Exactive Orbitrap HRMS were utilized for metabolic profiling of ethyl acetate extract of B. cylindrica leaves. Key metabolites in the extract were identified and predicted based on chemical similarity using online databases such as ChemSpider and mzCloud. Thirty-six compounds belonging to different classes of secondary metabolites viz. flavonoids, fatty acids, fatty acid amides, carboxylic acids, and alkaloids were identified in the extract. Pentacyclic triterpenes like betulin, ursolic acid and a tropine, an alkaloid with potential pharmacological and therapeutic activities such as anticancer properties, neuromuscular blockers and antioxidants, were also identified. This study combined GC-MS and UHPLC-Q-Exactive Orbitrap HRMS with available online database for effective and rapid identification of bioactive metabolites in the ethyl acetate extract of mangrove without individual standard application. This is the first report on the HRMS based secondary metabolic profiling of B. cylindrica, with comprehensive map of its biologically important metabolites.

Chickpea (Cicer arietinum L.) as a Source of Essential Fatty Acids - A Biofortification Approach

Chickpea is a highly nutritious pulse crop with low digestible carbohydrates (40-60%), protein (15-22%), essential fats (4-8%), and a range of minerals and vitamins. The fatty acid composition of the seed adds value because fats govern the texture, shelf-life, flavor, aroma, and nutritional composition of chickpea-based food products. Therefore, the biofortification of essential fatty acids has become a nutritional breeding target for chickpea crop improvement programs worldwide. This paper examines global chickpea production, focusing on plant lipids, their functions, and their benefits to human health. In addition, this paper also reviews the chemical analysis of essential fatty acids and possible breeding targets to enrich essential fatty acids in chickpea (Cicer arietinum) biofortification. Biofortification of chickpea for essential fatty acids within safe levels will improve human health and support food processing to retain the quality and flavor of chickpea-based food products. Essential fatty acid biofortification is possible by phenotyping diverse chickpea germplasm over suitable locations and years and identifying the candidate genes responsible for quantitative trait loci mapping using genome-wide association mapping.

Analytical Methods for Extraction and Identification of Primary and Secondary Metabolites of Apple (Malus domestica) Fruits: A Review

Apples represent a greater proportion of the worldwide fruit supply, due to their availability on the market and to the high number of existing cultivar varieties and apple-based products (fresh fruit, fruit juice, cider and crushed apples). Several studies on apple fruit metabolites are available, with most of them focusing on their healthy properties’ evaluation. In general, the metabolic profile of apple fruits strongly correlates with most of their peculiar characteristics, such as taste, flavor and color. At the same time, many bioactive molecules could be identified as markers of a specific apple variety. Therefore, a complete description of the analytical protocols commonly used for apple metabolites’ characterization and quantification could be useful for researchers involved in the identification of new phytochemical compounds from different apple varieties. This review describes the analytical methods published in the last ten years, in order to analyze the most important primary and secondary metabolites of Malus domestica fruits. In detail, this review gives an account of the spectrophotometric, chromatographic and mass spectrometric methods. A discussion on the quantitative and qualitative analytical shortcomings for the identification of sugars, fatty acids, polyphenols, organic acids, carotenoids and terpenes found in apple fruits is reported.

Association between a novel dietary lipophilic index (LI) with metabolic phenotypes in a community-based study in Tabriz- Iran

BACKGROUND

Dietary fatty acids are important dietary determinants of metabolic disorders in human. However, it is important to develop an index that considers not only the amount of dietary fatty acids but also the structure, fluidity and melting point of them. In the current study we investigated the association between a novel dietary lipophilic index (LI) with metabolic profile and dyslipidemia in a community based study in Tabriz-Iran.

METHODS

Dietary data were collected using a validated, 79-food item, semi-quantitative food frequency questionnaire, and dietary LI was calculated. Anthropometric variables were measured and metabolic profile including blood sugar, serum lipids and liver enzymes were assessed. Metabolic syndrome was defined according to the adult treatment panel (ATP) III criteria.

RESULTS

The mean age of the participants was 42.53 ± 12.03 years and most of the participants were women. Mean of dietary LI was 34.99 ± 6.91. Higher dietary LI was associated with higher body mass index (BMI) (β = 0.17, P < 0.04), waist circumference (β = 0.18, P < 0.01) and systolic blood pressure (β = 0.27, P < 0.01). Also LI was increased with increasing waist circumference (0.001), low density lipoprotein cholesterol (LDL-C) (0.001), and negatively associated with high density lipoprotein cholesterol (HDL-C) (0.001).

CONCLUSION

The novel dietary LI was considered as a useful tool in prediction of cardio-metabolic risk factors including general and central obesity, dyslipidemia and metabolic syndrome in a population-based study in Iran. Further researches in other disease and populations could highlight the application of this index in clinical settings.

Gelatin nanoparticles enable water dispersibility and potentialize the antimicrobial activity of Buriti (Mauritia flexuosa) oil

Background

Buriti oil presents numerous health benefits, but due to its lipophilic nature and high oxidation, it is impossible to incorporate it into aqueous food matrices. Thus, the present study evaluated whether powder nanoparticles based on porcine gelatin (OPG) and in combination with sodium alginate (OAG) containing buriti oil obtained by O/W emulsification followed by freeze-drying enabled water dispersibility and preserved or increased the antimicrobial activity of the oil.

Results

OPG presented spherical shape, smooth surface, smaller particle size and polydispersity index [51.0 (6.07) nm and 0.40 (0.05)], and better chemical interaction between the nonpolar amino acids and the hydrophobic oil chain. OPG also presented a higher dispersibility percentage [85.62% (7.82)] than OAG [50.19% (7.24)] (p < 0.05), and significantly increased the antimicrobial activity of the oil by 59, 62, and 43% for Pseudomonas aeruginosa, Klebsiella pneumonia, and Staphylococcus aureus, respectively.

Conclusions

Thus, nanoencapsulation in gelatin is a promising strategy to increase the potential to use buriti oil in foods.

HILIC-ESI-FTMS with All Ion Fragmentation (AIF) Scans as a Tool for Fast Lipidome Investigations

Lipidomics suffers from the lack of fast and reproducible tools to obtain both structural information on intact phospholipids (PL) and fatty acyl chain composition. Hydrophilic interaction liquid chromatography with electrospray ionization coupled to an orbital-trap Fourier-transform analyzer operating using all ion fragmentation mode (HILIC-ESI-FTMS-AIF MS) is seemingly a valuable resource in this respect. Here, accurate m/z values, HILIC retention times and AIF MS scan data were combined for PL assignment in standard mixtures or real lipid extracts. AIF scans in both positive and negative ESI mode, achieved using collisional induced dissociation for fragmentation, were applied to identify both the head-group of each PL class and the fatty acyl chains, respectively. An advantage of the AIF approach was the concurrent collection of tandem MS-like data, enabling the identification of linked fatty acyl chains of precursor phospholipids through the corresponding carboxylate anions. To illustrate the ability of AIF in the field of lipidomics, two different types of real samples, i.e., the lipid extracts obtained from human plasma and dermal fibroblasts, were examined. Using AIF scans, a total of 253 intact lipid species and 18 fatty acids across 4 lipid classes were recognized in plasma samples, while FA C20:3 was confirmed as the fatty acyl chain belonging to phosphatidylinositol, PI 38:3, which was found to be down-regulated in fibroblast samples of Parkinson's disease patients.

Systematic evaluation of nutritional and safety characteristics of Hengshan goat leg meat affected by multiple thermal processing methods

Hengshan goat meat produced exclusively in Shaanxi province of China is the product of national geographical indication. In current study, nutritional and safety indexes of Hengshan goat leg meat were investigated and the quality changes induced by seven commonly used processing methods were systematically evaluated. Comparing with control, meats treated with thermal processing demonstrated decreased redness, enhanced texture properties, increased protein, fat and mineral contents, as well as sharply raised fatty acids. Amino acid contents in pan-fried, deep-fried, and roasted samples were reduced with the most obvious valine scores declined 15%, 13%, and 21%, respectively. Also, thermal treatments conducted in smoke exposure circumstances caused mass formation of nitrite and polycyclic aromatic hydrocarbons (PAHs), evidenced by the 5.8-fold, 3.3-fold, and 3.8-fold increments of nitrite contents in pan-fried, deep-fried, and roasted meats, respectively, and the appearance of six extra PAHs. Steaming, boiling, and braising were proved to be suitable processing methods for preserving better nutritional values while delivering less carcinogenic hazard. Our results established nutritional database for Hengshan goat leg meat and provide reference for choosing its reasonable thermal processing pattern. PRACTICAL APPLICATION: Processed meats showed decreased redness, enhanced texture properties, increased protein, fat and mineral contents, as well as sharply raised fatty acids compared with those of raw meat. Steaming, boiling, and braising delivered more balanced nutrition and less carcinogens in contrast to meats processed with other methods. Frying and roasting caused low amino acid levels and formed mass nitrite and polycyclic aromatic hydrocarbons in meats. Our results established nutritional database for Hengshan goat leg meat and provide reference for its reasonable thermal processing.

UPLC-ELSD Analysis of Algal Lipid Classes and Derivatization of Bound and Free Fatty Acids and Sterols for GC-MS Methods

Constituents of microalgae and sample preparation for UPLC-ELSD and GC-MS analyses are described. Bound fatty acids from acylglycerols, alkylacylglycerols, galactosyldiacylglycerols, glycerophospholipids, and sterol esters are derivatized by using transesterification with sodium methoxide to form fatty acid methyl esters. Compounds containing free hydroxyl groups, either present originally or formed during previous step, like free fatty acids, sterols, α-tocopherol, phytol, and nonesterified alkoxyglycerols, are trimethylsilylated. The compounds in algal lipid extract are subsequently derivatized by these two steps.

Quantitative Mapping of Triacylglycerol Chain Length and Saturation Using Broadband CARS Microscopy

Lipid droplets (LDs), present in many cell types, are highly dynamic organelles that store neutral lipids, primarily triacylglycerols (TAGs). With the discovery of new LD functions (e.g., in immune response, protein clearage, and occurrence with disease), new methods to study LD chemical composition in situ are necessary. We present an approach for in situ, quantitative TAG analysis using label-free, coherent Raman microscopy that allows deciphering LD TAG composition in different biochemically complex samples with submicrometer spatial resolution. Employing a set of standard TAGs, we generate a spectral training matrix capturing the variation caused in Raman-like spectra by TAG backbone, chain length, and number of double bonds per chain, as well as the presence of proteins or other diluting molecules. Comparing our fitting approach to gas chromatography measurements for mixtures of standard TAGs and food oils, we find the root mean-square error for the prediction of TAG chemistry to be 0.69 CH₂ and 0.15 #C=C. When progressing to more complex samples such as oil emulsions and LDs in various eukaryotic cells, we find good agreement with bulk gas chromatography measurements. For differentiated adipocytes, we find a significant increase in the number of double bonds in small LDs (below 2 μm in diameter) compared to large LDs (above 2 μm in diameter). Coupled with a relatively limited sample preparation requirement, this approach should enable rapid and accurate TAG LD analysis for a variety of cell biology and technological applications.

Nutrient, fibre, sorbitol and chlorogenic acid content of prunes (Prunus domestica): an updated analysis and comparison of different countries of origin and database values

Current prune composition data are outdated and require a comprehensive and comparative re-analysis. This novel study aimed to: (i) analyse and compare prune composition from major countries of origin; and (ii) provide a comprehensive compositional analysis of prunes of USA origin and compare this with UK and USA database data. Prune samples were analysed for major nutrients and bioactive compounds and compared between countries of origin. Total fibre was higher in prunes from the USA (12.0 g/100 g) and Chile (11.5 g/100 g) compared with France (8.4 g/100 g) and Argentina (8.9 g/100 g), while prunes from all countries contained high levels of sorbitol (11.2-15.5 g/100 g). Differences in energy and starch values compared with national databases reflected different approaches to sampling and analysis. In conclusion, prunes contain high levels of fibre and other bioactive compounds. Variations between country of origin and database values highlight the importance of transparency in documenting sampling and analysis methods.

Neighborhood food environment, dietary fatty acid biomarkers, and cardiac arrest risk

We explored links between food environments, dietary intake biomarkers, and sudden cardiac arrest in a population-based longitudinal study using cases and controls accruing between 1990 and 2010 in King County, WA. Surprisingly, presence of more unhealthy food sources near home was associated with a lower 18:1 trans-fatty acid concentration (-0.05% per standard deviation higher count of unhealthy food sources, 95% Confidence Interval [CI]: 0.01, 0.09). However, presence of more unhealthy food sources was associated with higher odds of cardiac arrest (Odds Ratio [OR]: 2.29, 95% CI: 1.19, 4.41 per standard deviation in unhealthy food outlets). While unhealthy food outlets were associated with higher cardiac arrest risk, circulating 18:1 trans fats did not explain the association.

Connecting the nutrient composition of seasonal pollens with changing nutritional needs of honey bee (Apis mellifera L.) colonies

Free-ranging herbivores have yearly life cycles that generate dynamic resource needs. Honey bee colonies also have a yearly life cycle that might generate nutritional requirements that differ between times of brood rearing and colony expansion in the spring and population contraction and preparation for overwintering in the fall. To test this, we analyzed polyfloral mixes of spring and fall pollens to determine if the nutrient composition differed with season. Next, we fed both types of seasonal pollens to bees reared in spring and fall. We compared the development of brood food glands (i.e., hypopharyngeal glands - HPG), and the expression of genes in the fat body between bees fed pollen from the same (in-season) or different season (out-of-season) when they were reared. Because pathogen challenges often heighten the effects of nutritional stress, we infected a subset of bees with Nosema to determine if bees responded differently to the infection depending on the seasonal pollen they consumed. We found that spring and fall pollens were similar in total protein and lipid concentrations, but spring pollens had higher concentrations of amino and fatty acids that support HPG growth and brood production. Bees responded differently when fed in vs. out of season pollen. The HPG of both uninfected and Nosema-infected spring bees were larger when they were fed spring (in-season) compared to fall pollen. Spring bees differentially regulated more than 200 genes when fed in- vs. out-of-season pollen. When infected with Nosema, approximately 400 genes showed different infection-induced expression patterns in spring bees depending on pollen type. In contrast, HPG size in fall bees was not affected by pollen type, though HPG were smaller in those infected with Nosema. Very few genes were differentially expressed with pollen type in uninfected (4 genes) and infected fall bees (5 genes). Pollen type did not affect patterns of infection-induced expression in fall bees. Our data suggest that physiological responses to seasonal pollens differ between bees reared in the spring and fall with spring bees being significantly more sensitive to pollen type especially when infected with Nosema. This study provides evidence that seasonal pollens may provide levels of nutrients that align with the activities of honey bees during their yearly colony cycle. The findings are important for the planning and establishment of forage plantings to sustain honey bees, and in the development of seasonal nutritional supplements fed to colonies when pollen is unavailable.

Comparative compositional analysis of transgenic potato resistant to potato tuber moth (PTM) and its non-transformed counterpart

In this study, the compositions of transgenic potatoes (TPs) resistant to potato tuber moth (Phthorimaea operculella) were compared with those of its non-transgenic (NTP) counterparts. The light inducible promoter, phosphoenolpyruvate carboxylase led to the expression of Cry1Ab only in the leaves and light-treated tubers of the TPs. No significant differences were found in the moisture, ash, dry weight, total soluble protein, carbohydrate, starch, fiber, ascorbate, cations, anions, fatty acids, and glycoalkaloids contents of TP and NTP. Moreover, light treatment significantly affected the contents of ascorbate, acetate and nitrite anions, palmitic, stearic and linolenic fatty acids, α-haconine and α-solanine glycoalkaloids in TP and NTP tubers. While, significant differences were observed in the amino acid contents in light-treated tubers of TPs than the NTP ones. Although, light treatment in potato tubers resulted in marked metabolic changes, all the variations observed in the metabolites compositions were found to be within the desired reference ranges for potato plants. In conclusion, the results indicated that the TPs were substantially and nutritionally equivalent to the NTP counterparts.

Recent advances in lipid separations and structural elucidation using mass spectrometry combined with ion mobility spectrometry, ion-molecule reactions and fragmentation approaches

Lipids are a vital class of molecules that play important and varied roles in biological processes, however, fully understanding these roles is extremely difficult due to the immense number and diversity of possible lipid species. While recent advances in chromatography and high resolution mass spectrometry have greatly progressed knowledge about distinct lipid species and functions, effectively separating many lipids still remains problematic. Isomeric lipids have made lipid characterization especially difficult and occur due to subclasses having the same chemical composition, or species having multiple acyl chain connectivities (sn-1, sn-2, or sn-3), double bond positions and orientations (cis or trans), and functional group stereochemistries (R versus S). To aid in isomer characterization, ion mobility spectrometry separations, ion-molecule reactions and fragmentation techniques have increasingly been added to lipid analysis workflows. In this manuscript, we review the current state of these approaches and their capabilities for improving the identification of lipid species.

Chemical Profiling and Bioactivity of Body Wall Lipids from Strongylocentrotus droebachiensis

The lipids from gonads and polyhydroxynaphthoquinone pigments from body walls of sea urchins are intensively studied. However, little is known about the body wall (BW) lipids. Ethanol extract (55 °C) contained about equal amounts of saturated (SaFA) and monounsaturated fatty acids (MUFA) representing 60% of total fatty acids, with myristic, palmitic and eicosenoic acids as major SaFAs and MUFAs, respectively. Non-methylene-interrupted dienes (13%) were composed of eicosadienoic and docosadienoic acids. Long-chain polyunsaturated fatty acids (LC-PUFA) included two main components, n6 arachidonic and n3 eicosapentaenoic acids, even with equal concentrations (15 μg/mg) and a balanced n6/n3 PUFA ratio (0.86). The UPLC-ELSD analysis showed that a great majority of the lipids (80%) in the ethanolic extract were phosphatidylcholine (60 μg/mg) and phosphatidylethanolamine (40 μg/mg), while the proportion of neutral lipids remained lower than 20%. In addition, alkoxyglycerol derivatives-chimyl, selachyl, and batyl alcohols-were quantified. We have assumed that the mechanism of action of body wall lipids in the present study is via the inhibition of MAPK p38, COX-1, and COX-2. Our findings open the prospective to utilize this lipid fraction as a source for the development of drugs with anti-inflammatory activity.

The Fatty Acid Profile in Patients with Newly Diagnosed Diabetes: Why It Could Be Unsuspected

Context

Several studies have shown a link between proinflammatory activity and the presence or deficit of some fatty acids. Inflammation is associated with several diseases including diabetes.

Objective

To characterize and compare the fatty acids profiles in children with inaugural type 1 diabetes, diabetic children (at least 1 year after diagnosis), and healthy children.

Design

Plasma fatty acids profiles in children with inaugural diabetes, children with noninaugural diabetes, and controls, all of whom were prepubescent with a BMI < 85th percentile, were evaluated.

Results

Omega-3 fatty acid levels were higher in recently diagnosed subjects with diabetes than in controls. The ratio of omega-6/omega-3 fatty acids was higher in the control population. Omega-6 fatty acid levels were higher in the nonrecent diabetic subjects than in the children with recently diagnosed diabetes, and the levels were higher in the nonrecent diabetes group compared to the control group.

Conclusion

Our findings showed higher levels of alpha-linolenic acid, EPA, and DHA, as well as mono- and polyunsaturated fatty acids, in diabetic children. These findings reinforce the importance of precocious nutritional attention and intervention in the treatment of diabetic children.

Imaging and lipidomics methods for lipid analysis in metabolic and cardiovascular disease

Cardiometabolic diseases exhibit changes in lipid biology, which is important as lipids have critical roles in membrane architecture, signalling, hormone synthesis, homoeostasis and metabolism. However, Developmental Origins of Health and Disease studies of cardiometabolic disease rarely include analysis of lipids. This short review highlights some examples of lipid pathology and then explores the technology available for analysing lipids, focussing on the need to develop imaging modalities for intracellular lipids. Analytical methods for studying interactions between the complex endocrine and intracellular signalling pathways that regulate lipid metabolism have been critical in expanding our understanding of how cardiometabolic diseases develop in association with obesity and dietary factors. Biochemical methods can be used to generate detailed lipid profiles to establish links between lifestyle factors and metabolic signalling pathways and determine how changes in specific lipid subtypes in plasma and homogenized tissue are associated with disease progression. New imaging modalities enable the specific visualization of intracellular lipid traffic and distribution in situ. These techniques provide a dynamic picture of the interactions between lipid storage, mobilization and signalling, which operate during normal cell function and are altered in many important diseases. The development of methods for imaging intracellular lipids can provide a dynamic real-time picture of how lipids are involved in complex signalling and other cell biology pathways; and how they ultimately regulate metabolic function/homoeostasis during early development. Some imaging modalities have the potential to be adapted for in vivo applications, and may enable the direct visualization of progression of pathogenesis of cardiometabolic disease after poor growth in early life.

Determination of fatty acids and lipid classes in salmon oil by near infrared spectroscopy

Near-infrared (NIR) spectroscopy was evaluated as a rapid method for the determination of oleic, palmitic, linoleic and linolenic acids as well as omega-3, omega-6, and to predict polyunsaturated, monounsaturated and saturated fatty acids, together with triacylglycerides, diglycerides, free fatty acids and ergosterol in salmon oil. To do it, Partial Least Squares (PLS) regression models were applied to correlate NIR spectra with aforementioned fatty acids and lipid classes. Results obtained were validated in front of reference procedures based on high performance thin layer and gas chromatography. PLS-NIR has a good predictive capability with relative root mean square error of prediction (RRMSEP) values below or equal to 1.8% and provides rapid analysis without the use of any chemicals making it an environmentally friendly methodology.

Suitability of selected chromatographic columns for analysis of fatty acids in dialyzed patients

Gas chromatography-mass spectrometry is a preferred method for fatty acid (FA) analysis in biofluids from patients with metabolic diseases. Complex characteristics of FAs make their analysis particularly challenging. Selection of an appropriate chromatographic column is particularly important component of the process as it provides optimal separation and detection of possibly all FAs present in the sample. However, no accurate protocol for comparative evaluation of capillary columns for the analysis of whole serum FA profile in patients with chronic kidney disease (CKD) has been developed thus far. Therefore, in the present study four columns were examined to select the one providing optimal separation and determination of FA profiles in this group of patients. Moreover, serum FA profiles obtained with the selected column in CKD patients subjected to peritoneal dialysis and healthy controls were compared. Thirty-seven component FAME Mix and sera from CKD patients were used to optimize chromatographic conditions and to select the most appropriate column. The ZB-5 column turned out to be the most appropriate for the analysis of whole FA profile in CKD patients' sera. Then, this column was used to compare FA profiles in patients subjected to peritoneal dialysis and in healthy controls. The analysis demonstrated many abnormalities in the FA profile of CKD patients. Further studies involving larger groups of patients presenting with other stages of CKD are required to explain the impact of the disease progression on composition of serum FAs.

Trans-Himalayan Rhodiola imbricata Edgew. root: a novel source of dietary amino acids, fatty acids and minerals

Roots of Rhodiola imbricata Edgew from Indian trans-Himalayan cold desert known for their nutritional and medicinal attributes were evaluated for the dietary amino acids, fatty acids and mineral composition. Nine essential and twelve non-essential amino acids were quantified. The contents ranged between 91.33 and 1640.67 µg/g. Histidine (1434.33 µg/g), lysine (1329.33 µg/g) and threonine (1015.67 μg/g) were dominant essential amino acids, while glycine (1640.67 µg/g), proline (1263.67 µg/g), alanine (1142.33 µg/g), cystine HCL (1136.33 μg/g) and nor leucine (1038.67 μg/g) were major non essential amino acids. The total lipid was found to be rich source of saturated fatty acids such as capric acid (19.91%), caproic acid (10.87%), palmitic acid (9.42%), lignoceric acid (6.16%) and behenic acid (5.71%), which together constituted 52% of the lipid content. Linoleic acid (15.06%), oleic acid (12.38%), arachidonic acid (8.38%), linolelaidic acid (6.11%) and docosadienoic acid (5.99%) were prominent unsaturated fatty acids (UFAs). Mono unsaturated fatty acids (MUFAs) and poly unsaturated fatty acids (PUFAs) were 35.64% and 12.33% of the lipid content respectively. Calcium (11034.17 mg/kg), potassium (2143.25 mg/kg), iron (1441.17 mg/kg), magnesium (581.99 mg/kg), phosphorous (376.72 mg/kg) and sodium (109.75 mg/kg) were detected as the major dietary minerals.

Circulating concentrations and relative percent composition of trans fatty acids in healthy Canadian young adults between 2004 and 2010: a cross-sectional study

BACKGROUND

Trans fatty acids (TFAs) produced from industrial partial hydrogenation of vegetable oils have been the subject of much research regarding their negative effect on the development of chronic diseases, and recommendations to label foods with partially hydrogenated vegetable oils and limit their levels were introduced in Canada in 2003 and 2007, respectively. Our aim was to determine temporal changes in circulating plasma TFAs in a population of young healthy Canadian adults after the introduction of the guidelines.

METHODS

In this study, circulating plasma concentrations and relative percent composition of individual TFAs over time (2004-2010) were determined in a cross-sectional cohort of young healthy Canadian adults as part of the Toronto Nutrigenomics study.

RESULTS

A total of 1294 participants were included in the cohort. Relative to 2004, total TFA levels were significantly lower in 2005-2009 (p < 0.05), but not in 2010. Although levels of 16:1t9 and 18:1t11 declined after 2004, levels of 18:1t9 and 18:1t10 were significantly lower in 2005-2009 (p < 0.05), but not in 2010.

INTERPRETATION

Trans fatty acids were lower in 2009 relative to 2004, but not different in 2010, suggesting that young Canadians may remain vulnerable to partially hydrogenated vegetable oil exposure and that there is a need for further monitoring of specific food categories and vulnerable populations.

Conductometric Gradient Ion Exclusion Chromatography for Volatile Fatty Acids

We describe a fatty acid vapor extractor (FAVE) as a postcolumn device for sensitive detection following ion exclusion chromatographic (ICE) separation of weak acids. The device consists of a single length of a permselective membrane tube surrounded by a jacket that consists of two isolated sections. The separation column effluent flows through the lumen. A suitable strong acid is put in the upstream, short section of the jacket and permeates in, rendering the lumenal flow strongly acidic (pH ≤ 2) that suppresses eluite weak acid dissociation. A lipophilic polysiloxane membrane is selectively permeable to volatile fatty acids (VFAs). A small fraction of the VFAs transfer to a cocurrent receptor stream of water (or a weak base, e.g., dilute hydroxylamine), flowing through the second, longer section of the jacket. Even though the transferred amount of VFAs may be very small (0.5-5%), significantly better detection limits than conventional suppressed conductometric ICE (SCICE) is possible because of the low and stable background (noise <1 nS/cm). It also permits gradient elution, not possible in SCICE. The polysiloxane based FAVE device is highly selective for VFAs, it shows no response to dicarboxylic acids, hydroxycarboxylic acids, or aromatic acids. As such, trace detection of VFAs in the FAVE extractant is possible while other components can still be monitored conventionally in the FAVE lumenal effluent. Various parameters, related both to device design and operation were studied. The FAVE provides isolation from the eluent matrix and can be used for other detectors where the eluent matrix is incompatible with the detector.

Label-free in situ imaging of oil body dynamics and chemistry in germination

Plant oleosomes are uniquely emulsified lipid reservoirs that serve as the primary energy source during seed germination. These oil bodies undergo significant changes regarding their size, composition and structure during normal seedling development; however, a detailed characterization of these oil body dynamics, which critically affect oil body extractability and nutritional value, has remained challenging because of a limited ability to monitor oil body location and composition during germination in situ Here, we demonstrate via in situ, label-free imaging that oil bodies are highly dynamic intracellular organelles that are morphologically and biochemically remodelled extensively during germination. Label-free, coherent Raman microscopy (CRM) combined with bulk biochemical measurements revealed the temporal and spatial regulation of oil bodies in native soya bean cotyledons during the first eight days of germination. Oil bodies undergo a cycle of growth and shrinkage that is paralleled by lipid and protein compositional changes. Specifically, the total protein concentration associated with oil bodies increases in the first phase of germination and subsequently decreases. Lipids contained within the oil bodies change in saturation and chain length during germination. Our results show that CRM is a well-suited platform to monitor in situ lipid dynamics and local chemistry and that oil bodies are actively remodelled during germination. This underscores the dynamic role of lipid reservoirs in plant development.

High-Throughput Quantitative Lipidomics Analysis of Nonesterified Fatty Acids in Human Plasma

We present a high-throughput, nontargeted lipidomics approach using liquid chromatography coupled to high-resolution mass spectrometry for quantitative analysis of nonesterified fatty acids. We applied this method to screen a wide range of fatty acids from medium-chain to very long-chain (8 to 24 carbon atoms) in human plasma samples. The method enables us to chromatographically separate branched-chain species from their straight-chain isomers as well as separate biologically important ω-3 and ω-6 polyunsaturated fatty acids. We used 51 fatty acid species to demonstrate the quantitative capability of this method with quantification limits in the nanomolar range; however, this method is not limited only to these fatty acid species. High-throughput sample preparation was developed and carried out on a robotic platform that allows extraction of 96 samples simultaneously within 3 h. This high-throughput platform was used to assess the influence of different types of human plasma collection and preparation on the nonesterified fatty acid profile of healthy donors. Use of the anticoagulants EDTA and heparin has been compared with simple clotting, and only limited changes have been detected in most nonesterified fatty acid concentrations.