1,721,007 research outputs found
Polycyclic Aromatic Hydrocarbons (PAHs) in Olive Pomace Oil: Occurrence, Analytical Determination, and Mitigation Strategies
No full textEnvironmental pollution, agricultural practices, climate change, and the various stages of edible oil production are responsible for oil contamination with various chemicals. Among vegetable fats, olive pomace oils (OPOs) have higher polycyclic aromatic hydrocarbon (PAH) contents, exceeding the limits in some cases. Several methods for the determination of PAHs in animal and vegetable fats and oils have been published over the years, but they have often failed to eliminate matrix-specific interferences in OPO. The few methods proposed or applied for the specific analysis of PAHs in OPO over the past 20 years are mainly based on two different analytical approaches, namely liquid chromatography-fluorescence detector (LC-FLD) and gas chromatography-mass spectrometry (GC–MS). In the case of the LC-FLD approaches, liquid–liquid extraction with appropriate solvents and one or more purification steps on stationary phases of different compositions are performed. In the case of GC techniques, on the other hand, the most commonly used sample preparation is liquid–liquid partitioning. Due to widespread public concern about PAH contamination, several studies have been conducted to explore ways to mitigate the presence of PAHs in OPOs (i.e., refining processes)
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
Full text linkSqualene 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. Studies not primarily centered on analytical methodologies or squalene quantification were excluded. A critical gap identified is the absence of an official method for squalene determination, which hinders comparability and standardization across studies, underscoring the importance of developing a reliable, standardized method to ensure accurate quantification. The valorization of squalene involves advocating for its extraction from olive oil processing by-products to enhance sustainability in the olive oil industry. By recovering squalene, the industry can not only reduce waste but also enhance functional food products with this health-promoting compound. Additionally, there is a need for economically sustainable and environmentally friendly extraction techniques that can be scaled up for industrial application, thus contributing to a circular economy within the olive oil sector
Monitoring and Occurrence of Heavy PAHs in Pomace Oil Supply Chain Using a Double-Step Solid-Phase Purification and HPLC-FLD Determination
Full text linkPolycyclic 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. Since PAHs are present at lower levels than triglycerides, it is necessary to isolate the compounds of interest from the rest of the matrix. To this purpose, a new purification approach based on a double solid-phase extraction (SPE) step followed by high performance liquid chromatography–fluorometric detector (HPLC-FLD) analysis was developed. The method involves a first purification step by using a 5 g silica SPE cartridge, previously washed with dichloromethane (20 mL), dried completely, and then conditioned with n-hexane (20 mL). The triglycerides are retained by the silica, while the PAH-containing fraction is eluted with a mixture of n-hexane/dichloromethane (70/30, v/v). After evaporation, the residue is loaded on a 5 g amino SPE cartridge and eluted with n-hexane/toluene (70/30, v/v) before HPLC-FLD analysis. The focus was the evaluation of the contribution of the various phases of the pomace oil supply chain in terms of the heavy PAHs (PAH8) concentration. Data collected showed that pomace contamination increased (by 15 times) as storage time increased. In addition, the process of pomace drying, which is necessary to reduce its moisture content before solvent extraction of the residual oil, appeared to significantly contribute to the total heavy PAHs content, with increases in value by up to 75 times
Metodo ELISA automatizzato per una rapida valutazione della presenza/assenza di lisozima nel vino
Full text linkDa ormai molti anni, il lisozima, ricavato dal bianco d’uovo, è ampiamente utilizzato nelle cantine in alternativa all’anidride solforosa come agente antimicrobico per il controllo delle popolazioni di batteri lattici nei vini bianchi e rossi, o anche per ritardare, o inibire del tutto, la fermentazione malo-lattica durante la fermentazione alcolica.
i vini trattati con additivi allergenici quali uova, latte e i loro derivati, nonché i solfiti, devono essere sottoposti a un'etichettatura specifica se la loro presenza può essere rilevata nel prodotto finale.
Come metodo di riferimento per la ricerca di residui allergenici in vino, l’OIV propone un approccio immunoenzimatico ELISA.
La possibilità di ricercare con una medesima tecnica ELISA multiparametrica completamente automatizzata l’eventuale presenza di tutti i possibili allergeni derivanti da uovo e latte costituirebbe un auspicabile obiettivo per tutti i laboratori di controllo qualità, soprattutto per gli aspetti legati all’ottimizzazione dei tempi e dei costi analitici
In questo lavoro si è voluto pertanto confrontare i risultati ottenuti con due differenti approcci, cromatografico (HPLC-FLD) e immunoenzimatico automatizzato (ELISA), sia su vini bianchi non trattati che su vini addizionati di lisozima a livelli da 0,1 a 10 mg/L, focalizzando l’attenzione non solo sulle caratteristiche prestazionali dei diversi metodi, ma anche su considerazioni relative ai tempi e costi di impiego e sulla possibilità di utilizzare il test ELISA come approccio per uno screening rapido sulla presenza/assenza di tale enzima in vino
A novel mutation of HFE explains the classical phenotype of hereditary hemochromatosis in a C282Y carrier
No full textHereditary hemochromatosis (HH) is the most autosomal recessive disorder in Caucasians, affecting approximately 1 in 300 person. It is characterized by iron overload in many organs, leading to cirrhosis, hepatocellular carcinoma, diabetes, arthritis, heart failure and hypogonadism.
Most of HH patients are homozygous for the C282Y mutations. Some C282Y-carrier patients have been identified to be compound heterozygous for other mutations (H63D, S65C, G93R, IVS3+1G>T, 203delT).
We report a patient with classical HH who is compound heterozygous for C282Y and a novel missense mutation in the exon 4.
This is a 848A>C mutation that causes glutamine to proline substitution at position 283 (Q283P). We hypothesize that the Q283P variant may disrupt the beta2-microglobulin binding site in the HFE protein
Pressurized liquid extraction for the determination of bioactive compounds in plants with emphasis on phenolics
No full textPressurized liquid extraction (PLE) is considered an advanced extraction technique because it can save time and reduce solvent consumption compared to traditional extraction methods. It is a solid-liquid extraction performed at high temperatures and high pressure. Considering the importance of enhancing the value of by-products or waste products and the increased use of high-temperature extraction methods for bioactive compounds, this work aims to provide a comprehensive review regarding PLE, focusing on thermolabile plant compounds such as phenolic compounds. Not only traditional PLE approaches are described, but also subcritical water applications that reduce the consumption of organic solvents, as well as online approaches to improve the separation of compounds. Finally, the PLE technique is compared with other conventional and non-conventional methods used in the literature for the same bioactive compounds. PLE can provide significant recovery of bioactive compounds (i.e., phenolic compounds, carotenoids, chlorophylls, and anthraquinones) from various plant extracts, with the possibility of obtaining green extracts for analytical purposes and various industrial applications
Use of Fourier Transform Infrared Spectroscopy (FT-IR) to rapidly verify the botanical authenticity of gum arabic
Full text linkAutomated ELISA approach for a rapid evaluation of the presence/absence of lysozyme in wine
No full textFingerprinting of vegetable oil minor components by multidimensional comprehensive gas chromatography with dual detection
No full textThe potentiality of a multidimensional comprehensive gas chromatographic (GC x 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 x mid-polar set gave a superior separation power, thus was used for further characterization. Different levels of information were extrapolated from the two-dimensional chromatogram. Using the FID, reliable quantification of the alkyl esters fatty acids and waxes was obtained, comparable to the results obtained using the official method, as required by the European legislation. However, thanks to a slight modification of the sample preparation method, the increased separation power obtained using the GC x GC method, and the support of the mass spectrometer detector, further diagnostic information was extrapolated considering the free sterol and tocopherol fractions. In particular, the profiles of extra virgin olive oil samples were compared with a hazelnut oil sample, highlighting that the latter was characterized by a larger number of compounds, completely absent in the extra virgin olive oil samples, which can be used to detect illegal admixtures
Characterisation of minor components in vegetable oil by comprehensive gas chromatography with dual detection
No full textThe 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. Multi-level information, due not only to a more "comprehensive" preparation technique, but also thanks to the exploitation of a more powerful and sensitive analytical determination allowed the extrapolation of diagnostic information from the minor components profile of different vegetable oils, along with their characteristic profile. Furthermore, an admixture of an extra virgin olive oil with a low amount of sunflower and palm oils was evaluated, attesting to the powerful diagnostic information provided by the proposed approach. (C) 2016 Elsevier Ltd. All rights reserved
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