Analysis of the unsaponifiable fraction of lipids belonging to various milk-types by using comprehensive two-dimensional gas chromatography with dual mass spectrometry/flame ionization detection and with the support of high resolution time-of-flight mass spectrometry for structural elucidation

Sterol, tocopherol, and bioactive fatty acid differences between conventional, high-quality, and organic cow milk

Milk contains several components that are important for human nutrition and health. To date, studies on organic and conventional milk have focused on their gross composition and fatty acid content, but little attention has been paid to the differences between other minor components, such as sterols and vitamins that may have functional actions. The aim of this study was to investigate the nutritional differences among 3 types of milk from a dairy plant: conventional, high-quality, and organic (in compliance with European regulations) milk, focusing on minor components such as sterols of animal and plant origin (phytosterols), tocopherols, and bioactive fatty acids. Cholesterol ranged from 271.37 mg/100 g of fat in conventional milk to 278.76 mg/100 g of fat in organic milk. Lanosterol was the main minor animal sterol in cow milk (ranging from 3.41 to 4.37 mg/100 g of fat), followed by desmosterol. The amount of total plant sterols in the analyzed milk ranged from 4.43 mg/100 g of fat in organic to 4.71 mg/100 g of fat in high-quality milk. Brassicasterol was the main sterol of plant origin which varied from 2.6 mg/100 g of fat in conventional and organic milk, to 2.93 mg/100 g of fat in high-quality milk. The second most present phytosterol was β-sitosterol, which ranged from 0.86 mg/100 g of fat in conventional to 0.97 mg/100 g of fat in high-quality, and organic milk. The results of the study showed no significant differences in gross and sterol composition between the 3 types of milk. However, the only significant difference found was in the fatty acid profile, with a higher n-3 content found in high-quality milk than in conventional and organic milk. These findings suggest that the investigated product categories and labels have minimal effect on the sterol and fatty acid profile of commercial cow milk.

Pharmacological Effects of the Lipidosterolic Extract from Kigelia africana Fruits in Experimental Benign Prostatic Hyperplasia Induced by Testosterone in Sprague Dawley Rats

Background

The use of phytotherapics is very frequent in men with prostatic diseases, sexual disorders and infertility, and many associations are commercially available. Various vegetable products used as drugs or nutraceuticals are attributed to possess the capacity to exert benefic effects on the reproductive system, and most of these drugs have a rich and varied lipidosterolic fraction, primarily responsible for the effects related to the male genital sphere. Kigelia africana (Lam.) Benth. (Bignoniaceae) is a plant used in African folk medicine as a vegetal remedy for various diseases, including some disorders of the male reproductive system; however, its potential activities have not yet been fully explored. The aim of the present study was to investigate whether the lipidosterolic hexane extract (LHE) from K. africana fruits, analyzed by comprehensive two-dimensional gas chromatography-mass spectrometry/flame ionization detection (GC×GC-MS/FID), can prevent or reverse benign prostatic hyperplasia (BPH) in rats.

Methods

BPH was induced in experimental groups by daily subcutaneous injections of testosterone propionate (TP) for four weeks. β-sitosterol (β-s) was used as positive control. On day 28, the animals were sacrificed by cervical dislocation after anesthesia. Prostates were excised, weighed, and used for macroscopic and histological studies. Testosterone and dihydrotestosterone (DHT) levels in prostate were measured.

Results

The results showed that LHE significantly reduced the prostatic weight, prostatic index, prostatic levels of testosterone and DHT, and the histopathological alterations (including the epithelial thickness, stromal proliferation, and lumen area) induced by testosterone. These effects were superior to those demonstrated by β-s and appear to be due to a partial antiandrogenic activity of LHE.

Conclusion

The results obtained showed that the LHE can prevent, and reverse testosterone induced prostatic hyperplasia, and support the traditional use of Kigelia africana in some disorders of the reproductive system.

Identification of milk quality and adulteration by surface-enhanced infrared absorption spectroscopy coupled to artificial neural networks using citrate-capped silver nanoislands

Milk is one of the most important multicomponent superfoods owing to its rich macronutrient composition. It requires quality control at all the production stages from the farm to the finished products. A localized surface plasmon resonance optical sensor based on a citrate-capped silver nanoparticle (Cit-AgNP)–coated glass substrate was developed. The fabrication of such sensors involved a single-step synthesis of Cit-AgNPs followed by surface modification of glass slides to be coated with the nanoparticles. The scanning electron microscope micrographs demonstrated that the nanoparticles formed monolayer islands on glass slides. The developed surface-enhanced infrared absorption spectroscopy (SEIRA) sensor was coupled to artificial neural networking (ANN) for the qualitative differentiation between cow, camel, goat, buffalo, and infants’ formula powdered milk types. Moreover, it can be used for the quantitative determination of the main milk components such as fat, casein, urea, and lactose in each milk type. The qualitative results showed that the obtained FTIR spectra of cow and buffalo milk have high similarity, whereas camel milk resembled infant formula powdered milk. The most difference in FTIR characteristics was evidenced in the case of goat milk. The developed sensor adds several advantages over the traditional techniques of milk analysis using MilkoScan™ such as less generated waste, elimination of pre-treatment steps, minimal sample volume, low operation time, and on-site analysis.

Deeper investigation of oxygen-containing compounds in oleaginous feedstock (animal fat) by preparative column chromatography and comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry

The production of renewable fuels as biodiesel and bio-jet fuel is usually originated by the transformation and processing of oleaginous feedstocks, mainly composed of triacylglycerols. Currently, a significant part of the triacylglycerol production relies on grassy oil crops or other woody oil plants, representing more than 120 million metric tons every year. Considering that the worldwide triacylglycerol demand is expected to rise in the future, alternative routes are necessary to ensure a sustainable biodiesel industry and limit diesel price volatility. In this context, the use of animal fats could be an interesting alternative for biodiesel production as the production of animal byproducts represents nearly 17 million tons per year in the European Union only (2020). Animal fats, however, contain large amounts of no-esterified fatty acids and other oxygen compounds, reducing the yield of biodiesel. Therefore, a specific pretreatment is needed before the trans-esterification process. The setup of such appropriate pretreatments requires detailed upstream characterization of the minor components present in the feedstock. For this purpose, the minor component profile of animal fat was investigated by comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry. This was preceded by an innovative sample fractionation and focalization of these minor components by a preparative liquid chromatographic column method. The overall method permitted to extract different levels of information from the two-dimensional chromatograms, leading to a tentative identification of more than 150 compounds, mainly oxygenated, belonging to different chemical classes.

Oxidative Quality of Dairy Powders: Influencing Factors and Analysis

Lipid oxidation (LO) is a primary cause of quality deterioration in fat-containing dairy powders and is often used as an estimation of a products shelf-life and consumer acceptability. The LO process produces numerous volatile organic compounds (VOC) including aldehydes, ketones and alcohols, which are known to contribute to the development of off-flavours in dairy powders. The main factors influencing the oxidative state of dairy powders and the various analytical techniques used to detect VOC as indicators of LO in dairy powders are outlined. As the ability to identify and quantify specific VOC associated with LO improves this review highlights how these techniques can be used in conjunction with olfactory and sensory analysis to better understand product specific LO processes with the aim of maximizing shelf-life without compromising quality.

A preliminary investigation into the unsaponifiable fraction of donkey milk: Sterols of animal origin, phytosterols, and tocopherols

We investigated the main sterols, phytosterols, and the α- and γ-tocopherol content in donkey milk during the first 2 mo of lactation. Cholesterol was the main sterol in milk (mean ± standard deviation = 0.97 ± 0.443 g/100 g of fat). Lanosterol was the main minor sterol of animal origin, followed by desmosterol (0.003 ± 0.001 and 0.001 ± 0.001 g/100 g of fat, respectively). Of the phytosterols, β-sitosterol was the main sterol of vegetal origin in donkey milk (0.005 ± 0.002 g/100 g of fat), but lower levels of campesterol, brassicasterol, and stigmasterol were also recorded. Mean levels of α- and γ-tocopherol were 0.01 ± 0.007 and 0.003 ± 0.001 g/100 g of fat, respectively. We observed no significant changes in sterol or tocopherol content during the first 2 mo of lactation. The presence of lanosterol in donkey milk is of particular interest, because lanosterol is a potential drug and has important physiological effects. The presence of phytosterols, which are considered nutraceutical molecules, enhances the nutritional quality of donkey milk fat for consumers.

Adding extra-dimensions to hazelnuts primary metabolome fingerprinting by comprehensive two-dimensional gas chromatography combined with time-of-flight mass spectrometry featuring tandem ionization: Insights on the aroma potential

The information potential of comprehensive two-dimensional gas chromatography combined with time of flight mass spectrometry (GC × GC-TOFMS) featuring tandem hard (70 eV) and soft (12 eV) electron ionization is here applied to accurately delineate high-quality hazelnuts (Corylus avellana L.) primary metabolome fingerprints. The information provided by tandem signals for untargeted and targeted 2D-peaks is examined and exploited with pattern recognition based on template matching algorithms. EI-MS fragmentation pattern similarity, base-peak m/z values at the two examined energies (i.e., 12 and 70 eV) and response relative sensitivity are adopted to evaluate the complementary nature of signals. As challenging bench test, the hazelnut primary metabolome has a large chemical dimensionality that includes various chemical classes such as mono- and disaccharides, amino acids, low-molecular weight acids, and amines, further complicated by oximation/silylation to obtain volatile derivatives. Tandem ionization provides notable benefits including larger relative ratio of structural informing ions due to limited fragmentation at low energies (12 eV), meaningful spectral dissimilarity between 12 and 70 eV (direct match factor values range 222-783) and, for several analytes, enhanced relative sensitivity at lower energies. The complementary information provided by tandem ionization is exploited by untargeted/targeted (UT) fingerprinting on samples from different cultivars and geographical origins. The responses of 138 UT-peak-regions are explored to delineate informative patterns by univariate and multivariate statistics, providing insights on correlations between known precursors and (key)-aroma compounds and potent odorants. Strong positive correlations between non-volatile precursors and odorants are highlighted with some interesting linear trends for: 3-methylbutanal with isoleucine (R² 0.9284); 2,3-butanedione/2,3-pentanedione with monosaccharides (fructose/glucose derivatives) (R² 0.8543 and 0.8860); 2,5-dimethylpyrazine with alanine (R² 0.8822); and pyrroles (1H-pyrrole, 3-methyl-1H-pyrrole, and 1H-pyrrole-2-carboxaldehyde) with ornithine and alanine derivatives (R² 0.8604). The analytical work-flow provides a solid foundation for a new strategy for hazelnuts quality assessment because aroma potential could be derived from precursors' chemical fingerprints.

Comprehensive comparative compositional study of the vapour phase of cigarette mainstream tobacco smoke and tobacco heating product aerosol

A simple direct sample collection/dilution and introduction method was developed using quartz wool and Tenax/sulficarb sorbents for thermal desorption and comprehensive two-dimensional gas chromatography (TD-GC × GC) analyses of volatile organic compounds from vapour phase (VP) fractions of aerosol produced by tobacco heating products (THP1.0) and 3R4F mainstream tobacco smoke (MTS). Analyses were carried out using flame ionisation detection (FID) for semi-quantification and both low and high resolution time-of-flight mass spectrometry (LR/HR-TOFMS) for qualitative comparison and peak assignment. Qualitative analysis was carried out by combining identification data based on linear retention indices (LRIs) with a match window of ±10 index units, mass spectral forward and reverse library searches (from LR and HRTOFMS spectra) with a match factor threshold of >700 (both forward and reverse), and accurate mass values of ± 3 ppm for increased confidence in peak identification. Using this comprehensive approach of data mining, a total of 79 out of 85 compounds and a total of 198 out of 202 compounds were identified in THP1.0 aerosol and in 3R4F MTS, respectively. Among the identified analytes, a set of 35 compounds was found in both VP sample types. Semi-quantitative analyses were carried out using a chemical class-based external calibration method. Acyclic, alicyclic, aromatic hydrocarbons and ketones appeared to be prominent in 3R4F MTS VP, whereas larger amounts of aldehydes, ketones, heterocyclic hydrocarbons and esters were present in THP1.0 aerosol VP. The results demontsrate the capability and versatility of the method for the characterization and comparison of complex aerosol samples and highlighted the relative chemical simplicity of THP1.0 aerosol in comparison to MTS.

An Overview of Chemical Profiles, Antioxidant and Antimicrobial Activities of Commercial Vegetable Edible Oils Marketed in Japan

This study analyzed chemical components and investigated the antioxidant and antimicrobial activities of fourteen vegetable edible oils marketed in Japan. High-performance liquid chromatography (HPLC) was used to identify and quantify principal phenolic acids and flavonoids. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, sunflower, safflower, canola, soybean, Inca inchi, sesame, and rice bran showed markedly greater activity, whilst the percentage of lipid peroxidation inhibition (LPI%) in sunflower, canola, cotton, grape, flax, perilla, Inca inchi, perillartine, and rice bran were significantly higher than other oils. Maximum total phenol content (TPC) was recorded in flax, followed by perillartine, rice bran, and perilla, whereas total flavonoid content (TFC) was the greatest in Inca inchi and sesame. Benzoic acid was the most common constituent, followed by vanillic acid, p-hydroxybenzoic acid, ferulic acid, and p-coumaric acid. On the other hand, luteolin was the most abundant flavonoid, followed by esculetin, myricetin, isoquercetin, and kaempferol, while fisetin was detected only in sunflower. In general, all of the edible oils showed antimicrobial activity, but the growth inhibition of Staphylococcus aureus and Escherichia coli of cotton, grape, chia, sesame, and rice bran were greater than other oils.

Two-Dimensional Gas Chromatography Coupled With Mass Spectrometry in Food Analysis

The development of instrumental analytical techniques provided the opportunity for in-depth characterization of many food matrices. In particular, the use of gas chromatography coupled with mass spectrometry gives impressive results in terms of quality and authenticity testing, conducting food freshness evaluations and contamination assessments. A new variant of gas chromatography, namely two-dimensional gas chromatography (GC × GC), and various versions of mass spectrometry have been developed since last 15 years, and they still remain at the time of their renaissance. The present critical review is focused on the use of GC × GC coupled with mass spectrometry for qualitative and quantitative reasons in food analysis. It is explained how powerful analytical tool is above-mentioned technical solution. Special attention is devoted to the issues related to the development of this technique during last years in terms of key construction elements, such as modulators and MS detectors. Finally, the critical discussion on many various aspects including advantages and more important disadvantages, caused probable moderate interest of this solution, in food analytics is concerned.

Determination of Vitamin E in Cereal Products and Biscuits by GC-FID

A rapid, precise and accurate method for the determination of vitamin E (α-tocopherol) in cereal products and biscuits has been developed. The uncertainty was calculated for the first time, and the methods were performed for different cereal products and biscuits, characterized as “superfoods”. The limits of detection and quantification were calculated. The accuracy and precision were estimated using the certified reference material FAPAS T10112QC, and the determined values were in good accordance with the certified values. The health claims according to the daily reference values for vitamin E were calculated, and the results proved that the majority of the samples examined showed a percentage daily value higher than 15%.

Recent applications of gas chromatography with high-resolution mass spectrometry

Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well.

Determination of free steroidal compounds in vegetable oils by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry

A method based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOF/MS) was developed to analyze steroidal compounds in vegetable oils, which could provide better separation and higher sensitivity than conventional one dimensional gas chromatography, and allowed determination of 31 sterols and triterpene alcohols in one injection. Furthermore, the approach also permitted separation and detection of small amounts of other compounds (may be steroidal compounds whose molecular structures have not been confirmed), which were obscured in the lower-resolution single-column technique. With the help of the GC × GC system, a more elaborate and complete information regarding the distributions and concentrations of free phytosterols and triterpene alcohols in safflower seed oil, soybean oil, rapeseed oil, sunflower seed oil and peanut oil were obtained. The proposed method could potentially open a new opportunity for the more in-depth knowledge of the steroidal compounds of vegetable oils.

Supercritical fluid chromatography for lipid analysis in foodstuffs

The task of lipid analysis has always challenged separation scientists, and new techniques in chromatography were often developed for the separation of lipids; however, no single technique or methodology is yet capable of affording a comprehensive screening of all lipid species and classes. This review acquaints the role of supercritical fluid chromatography within the field of lipid analysis, from the early developed capillary separations based on pure CO₂ , to the most recent techniques employing packed columns under subcritical conditions, including the niche multidimensional techniques using supercritical fluids in at least one of the separation dimensions. A short history of supercritical fluid chromatography will be introduced first, from its early popularity in the late 1980s, to the sudden fall and oblivion until the last decade, experiencing a regain of interest within the chromatographic community. Afterwards, the subject of lipid nomenclature and classification will be briefly dealt with, before discussing the main applications of supercritical fluid chromatography for food analysis, according to the specific class of lipids.

A Simultaneous Metabolic Profiling and Quantitative Multimetabolite Metabolomic Method for Human Plasma Using Gas-Chromatography Tandem Mass Spectrometry

For the first time it is possible to simultaneously collect targeted and nontargeted metabolomics data from plasma based on GC with high scan speed tandem mass spectrometry (GC-MS/MS). To address the challenge of getting broad metabolome coverage while quantifying known biomarker compounds in high-throughput GC-MS metabolomics, we developed a novel GC-MS/MS metabolomics method using a high scan speed (20 000 Da/second) GC-MS/MS that enables simultaneous data acquisition of both nontargeted full scan and targeted quantitative tandem mass spectrometry data. The combination of these two approaches has hitherto not been demonstrated in metabolomics. This method allows reproducible quantification of at least 37 metabolites using multiple reaction monitoring (MRM) and full mass spectral scan-based detection of 601 reproducible metabolic features from human plasma. The method showed good linearity over normal concentrations in plasma (0.06-343 to 0.86-4800 μM depending on the metabolite) and good intra- and interbatch precision (0.9-16.6 and 2.6-29.6% relative standard deviation). Based on the parameters determined for this method, targeted quantification using MRM can be expanded to cover at least 508 metabolites while still collecting full scan data. The new simultaneous targeted and nontargeted metabolomics method enables more sensitive and accurate detection of predetermined metabolites and biomarkers of interest, while still allowing detection and identification of unknown metabolites. This is the first validated GC-MS/MS metabolomics method with simultaneous full scan and MRM data collection, and clearly demonstrates the utility of GC-MS/MS with high scanning rates for complex analyses.