Analytical Determination of Squalene in Extra Virgin Olive Oil and Olive Processing By-Products, and Its Valorization as an Ingredient in Functional Food-A Critical Review.

Squalene is a bioactive compound with significant health benefits, predominantly found in extra virgin olive oil (EVOO) and its processing by-products. This critical review explores the analytical determination of squalene in EVOO and various by-products from olive oil production, highlighting its potential as a valuable ingredient in functional foods. An overview of existing analytical methods is provided, focusing on different approaches to sample preparation before analytical determination, evaluating their effectiveness in quantifying squalene concentrations.

The Determination of Triacylglycerols and Tocopherols Using UHPLC-CAD/FLD Methods for Assessing the Authenticity of Coffee Beans.

The authenticity of coffee beans was addressed in this study using an analytical method with minimal sample preparation to achieve simple oil extraction and through the implementation of cost-effective equipment. For this purpose, methods using UHPLC with CAD and FLD detectors were applied to detect triglycerides and tocopherols in coffee, respectively. The coffee samples included two main varieties: Arabica from Brazil, Colombia, Ethiopia, and Uganda, as well as the Robusta variety from Cambodia, Guatemala, India, and Vietnam.

Endogenous -Alkanes in Vegetable Oils: Validation of a Rapid Offline SPE-GC-FID Method, Comparison with Online LC-GC-FID and Potential for Olive Oil Quality Control.

The potential of endogenous -alkane profiling for the assessment of extra virgin olive oils (EVOO) adulteration (blends with cheaper vegetable oils) has been studied by relatively few authors. Analytical methods used for this purpose often involve tedious and solvent-intensive sample preparation prior to analytical determination, making them unattractive. A rapid and solvent-sparing offline solid phase extraction (SPE) gas chromatography (GC) flame ionization detection (FID) method for the determination of endogenous -alkanes in vegetable oils was, therefore, optimized and validated.

Pressurized Liquid Extraction: A Powerful Tool to Implement Extraction and Purification of Food Contaminants.

Pressurized liquid extraction (PLE) is considered an advanced extraction technique developed in the mid-1990s with the aim of saving time and reducing solvent with respect to traditional extraction processes. It is commonly used with solid and semi-solid samples and employs solvent extraction at elevated temperatures and pressures, always below the respective critical points, to maintain the solvent in a liquid state throughout the extraction procedure. The use of these particular pressure and temperature conditions changes the physicochemical properties of the extraction solvent, allowing easier and deeper penetration into the matrix to be extracted.

Monitoring and Occurrence of Heavy PAHs in Pomace Oil Supply Chain Using a Double-Step Solid-Phase Purification and HPLC-FLD Determination.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental and processing contaminants generated by both spontaneous and anthropogenic incomplete combustion processes of organic matter. Contamination of PAHs in vegetable oils can result from several factors and processes, including environmental contamination, oil processing, and migration from food contact materials. The determination of PAHs in edible oil presents a challenge because of the complexity of the matrix.

Evidence of the Possible Interaction between Ultrasound and Thiol Precursors.

The effect of ultrasound (20 kHz, 153 μm) on the prefermentation extraction mechanisms in Sauvignon Blanc grapes was studied, focusing on 3-mercaptohexan-1-ol (3MH) and 4-mercapto-4-methyl-pentan-2-one (4MMP) precursors linked to glutathione (GSH) and cysteine (Cys). The treatment determined a positive extraction trend between the duration (untreated, 3 and 5 min) and the conductivity or the concentration of catechins and total phenols, significantly differentiated after 5 min. Nevertheless, the concentration of the thiol precursors in grape juice not only remained undifferentiated, but that of 3-S-glutathionyl mercaptohexan-1-ol showed a negative trend with the treatment time applied (168 ± 43, 156 ± 36, and 149 ± 32 μg/L, respectively, for control, 3 and 5 min).

In-pipette solid-phase extraction prior to flow-modulation comprehensive two-dimensional gas chromatography with dual detection for the determination of minor components in vegetable oils.

The present research is based on the development of an effective, environmentally-friendly and low-cost method for investigation of minor components in vegetable oils, exploiting the advantages of a miniaturized solid-phase extraction (SPE) and the potential of flow modulation (FM) comprehensive two-dimensional gas chromatography (GC×GC), coupled to a mass spectrometer (MS) and a flame ionization detector (FID). The initial sample preparation step was carried out using a miniaturized approach characterized by a SPE process in a Pasteur pipette. Then, the isolated fraction was injected into an FM GC×GC system.

Mineral oil saturated hydrocarbons (MOSH) in female Fischer 344 rats; accumulation of wax components; implications for risk assessment.

Female Fischer 344 rats were exposed to three MOSH mixtures: oils largely below and above C (S-C25 and L-C25) and a 1:1 mixture of L-C25 with a wax; doses of 400, 1000 and 4000mg/kg feed were administered during 120days. MOSH were determined by on-line HPLC-GC-FID in liver, spleen, adipose tissue and the carcass. The composition of the hydrocarbons accumulated in the tissues was further analyzed by comprehensive two-dimensional GC (GC×GC).

Accumulation of mineral oil saturated hydrocarbons (MOSH) in female Fischer 344 rats: Comparison with human data and consequences for risk assessment.

Female Fischer 344 rats were orally exposed to a mixture of mineral oil saturated hydrocarbons (MOSH) of broad molecular mass range at doses of 40, 400 and 4000mg/kg feed. Amounts and compositions of the MOSH were analyzed in liver, spleen, adipose tissue and the carcass after exposure during 30, 60, 90 and 120d as well as after 90d exposure followed by 30d depuration. At 40mg/kg in the feed, after 30d of exposure, 10.

Characterisation of minor components in vegetable oil by comprehensive gas chromatography with dual detection.

The profile of minor compounds, such as alcohols, sterols, free and alkyl fatty acids, waxes, etc., was investigated in different vegetable oils by a comprehensive gas chromatographic system, coupled with a simultaneous dual detection (flame ionisation detector and mass spectrometer) for quantitative and qualitative purposes. Such a system generated a unique two-dimensional chromatogram to be used as a chemical fingerprint.

Improvement of mineral oil saturated and aromatic hydrocarbons determination in edible oil by liquid-liquid-gas chromatography with dual detection.

Mineral oils, which are mainly composed of saturated hydrocarbons and aromatic hydrocarbons, are widespread food contaminants. Liquid chromatography coupled to gas chromatography with flame ionization detection represents the method of choice to determine these two families. However, despite the high selectivity of this technique, the presence of olefins (particularly squalene and its isomers) in some samples as in olive oils, does not allow the correct quantification of the mineral oil aromatic hydrocarbons fraction, requiring additional off-line tools to eliminate them.

Microwave assisted saponification (MAS) followed by on-line liquid chromatography (LC)-gas chromatography (GC) for high-throughput and high-sensitivity determination of mineral oil in different cereal-based foodstuffs.

A high throughput, high-sensitivity procedure, involving simultaneous microwave-assisted extraction (MAS) and unsaponifiable extraction, followed by on-line liquid chromatography (LC)-gas chromatography (GC), has been optimised for rapid and efficient extraction and analytical determination of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in cereal-based products of different composition. MAS has the advantage of eliminating fat before LC-GC analysis, allowing an increase in the amount of sample extract injected, and hence in sensitivity. The proposed method gave practically quantitative recoveries and good repeatability.

Determination of phthalate esters in vegetable oils using direct immersion solid-phase microextraction and fast gas chromatography coupled with triple quadrupole mass spectrometry.

Phthalates are a group of synthetic compounds mainly used as plasticizers, which have been classified as endocrine-disrupting chemicals and potential human-cancer causing agents. They can be found in high amounts in foods, deriving mainly from plastic packaging. The analytical determination of these compounds is very challenging since they are ubiquitous.

Migration of selected hydrocarbon contaminants into dry semolina and egg pasta packed in direct contact with virgin paperboard and polypropylene film.

Migration of mineral oil saturated hydrocarbons (MOSH), polyolefin oligomeric saturated hydrocarbons (POSH), and polyalphaolefins (PAO from hot melts) into dry semolina and egg pasta packed in direct contact with virgin paperboard or polypropylene (PP) flexible film was studied. Migration was monitored during shelf life (up to 24 months), through storage in a real supermarket (packs kept on shelves), conditions preventing exchange with the surrounding environment (packs wrapped in aluminium foil), and storage in a warehouse (packs inside of the transport box of corrugated board). Semolina pasta packed in virgin paperboard (without hot melts) had a MOSH content lower than 1.

Comparison of different injection modes in edible oil minor components analysis.

Waxes and fatty acid alkyl esters are minor components used as official parameters to control the authenticity and quality of a high-value olive oil product. A poor measurement can lead to a misleading classification of the oil. The official method requires their analysis together by capillary gas chromatography equipped with a flame ionization detector and an on-column injector to avoid discrimination and thermal degradation.

Migration of selected hydrocarbon contaminants into dry pasta packaged in direct contact with recycled paperboard.

This paper deals with the migration of selected hydrocarbon contaminants, namely mineral oil hydrocarbons (MOH), diisopropyl naphthalenes (DIPN) and polyalphaolefins (PAO) from adhesives into dry semolina and egg pasta packaged in direct contact with recycled paperboard. Migration was monitored during its shelf life (for up to two years) simulating storage in a supermarket (packs on shelves) and conditions preventing exchange with the surrounding environment (packs wrapped in aluminium foil). Migration from the secondary packaging (transport boxes of corrugated board) was also studied for semolina pasta.

Fingerprinting of vegetable oil minor components by multidimensional comprehensive gas chromatography with dual detection.

The potentiality of a multidimensional comprehensive gas chromatographic (GC × GC) method, employing a simultaneous dual detection (FID and mass spectrometer), to generate peculiar two-dimensional chromatograms to be used as a chemical fingerprint, was investigated to characterize minor compounds in edible oil, particularly olive oil. The best column combination for this application was investigated comparing two column sets (orthogonal or reverse-type), equivalent in terms of theoretical plate number, but differing in stationary phase combination. The apolar × mid-polar set gave a superior separation power, thus was used for further characterization.

Mineral oil in human tissues, part II: characterization of the accumulated hydrocarbons by comprehensive two-dimensional gas chromatography.

Mineral oil hydrocarbons are by far the largest contaminant in the human body. Their composition differs from that in the mineral oils humans are exposed to, and varies also between different tissues of the same individual. Using the presently best technique for characterizing the composition of mineral oil hydrocarbons, comprehensive two-dimensional gas chromatography (GC×GC), the hydrocarbons in human tissues were compared to those of various mineral oils.

Mineral oil in human tissues, Part I: concentrations and molecular mass distributions.

Of 37 subjects aged 25-91 y (mean 67 y), mineral oil hydrocarbons were measured in subcutaneous abdominal fat tissue, mesenteric lymph nodes (MLN), spleen, liver and lung, for some of them also in kidney, heart and brain. No mineral oil aromatic hydrocarbons (MOAH) were detected. The mean concentration of mineral oil saturated hydrocarbons (MOSH) in the mesenteric lymph nodes was 223 mg/kg, in liver 131 mg/kg, in fat tissue 130 mg/kg, in spleen 93 mg/kg and in lung 12 mg/kg.

Optimisation of pressurised liquid extraction (PLE) for rapid and efficient extraction of superficial and total mineral oil contamination from dry foods.

Pressurised liquid extraction (PLE) represents a powerful technique which can be conveniently used for rapid extraction of mineral oil saturated (MOSH) and aromatic hydrocarbons (MOAH) from dry foods with a low fat content, such as semolina pasta, rice, and other cereals. Two different PLE methods, one for rapid determination of superficial contamination mainly from the packaging, the other for efficient extraction of total contamination from different sources, have been developed and optimised. The two methods presented good performance characteristics in terms of repeatability (relative standard deviation lower than 5%) and recoveries (higher than 95%).

Optimization of pressurized liquid extraction (PLE) for rapid determination of mineral oil saturated (MOSH) and aromatic hydrocarbons (MOAH) in cardboard and paper intended for food contact.

Packaging can represent a primary source of food contamination with mineral oil saturated hydrocarbons (MOSH) and aromatic hydrocarbons (MOAH), especially when recycled cardboard or mineral oil based printing inks are used. A pressurized liquid extraction (PLE) method, followed by on-line LC-GC analysis, has been optimized for rapid mineral oil determination in cardboard and paper samples. The proposed method involves extraction with hexane (2 cycles) at 60°C for 5 min, and allows for the processing of up to 6 samples in parallel with minimal sample manipulation and solvent consumption.

Direct-immersion solid-phase microextraction coupled to fast gas chromatography mass spectrometry as a purification step for polycyclic aromatic hydrocarbons determination in olive oil.

The aim of the present work was to optimize a preparation step for polycyclic aromatic hydrocarbons in a fatty extract. Solid-phase microextraction is an easy preparation technique, which allows to minimize solvent consumption and reduce sample manipulation. A Carbopack Z/polydimethylsiloxane fiber, particularly suitable for extraction of planar compounds, was employed to extract polycyclic aromatic hydrocarbons from a hexane solution obtained after a previous extraction with acetonitrile from oil, followed by a liquid-liquid partition between acetonitrile and hexane.

A high-sample-throughput LC-GC method for mineral oil determination.

The present investigation deals with a method improvement to increase data throughput and reduce solvent consumption for both saturated and aromatic mineral oil hydrocarbon determination using a coupled liquid-gas chromatographic system. The starting point of this work was the method proposed by Biedermann, Fiselier, and Grob in 2009. A total time and solvent reduction of 34 and 23%, respectively, was obtained by speeding up the GC run and reducing the LC-reconditioning step.

Detailed elucidation of hydrocarbon contamination in food products by using solid-phase extraction and comprehensive gas chromatography with dual detection.

The present work is focused on the development/optimization of a comprehensive two-dimensional gas chromatography method, with dual detection [flame ionization (FID) and mass spectrometric], for the simultaneous identification and quantification of mineral-oil contaminants in a variety of food products. The two main classes of contaminants, namely saturated and aromatic hydrocarbons, were previously fractionated on a manually-packed silver silica solid-phase extraction (SPE) cartridge. The quantitative results were compared with those obtained by performing a large volume injection, in a GC-FID system, after the same SPE process and by an on-line liquid-gas chromatography method, with very similar results observed.

Comparison of two different multidimensional liquid-gas chromatography interfaces for determination of mineral oil saturated hydrocarbons in foodstuffs.

This investigation focused on direct comparison of two popular multidimensional liquid-gas chromatography (LC-GC) systems, the Y-interface (retention gap approach) and the syringe-based interface (programmed temperature vaporizer approach). Such transfer devices are structurally very different, and could potentially have a substantial effect on the outcome of a specific application. In this work the application was a topic of much current interest, determination of mineral oil saturated hydrocarbon (MOSH) contamination of a series of food products (rice, pasta, icing sugar, olive oil); the final results were then compared.