Caratteristiche di qualit\ue0 e purezza degli oli d\u2019oliva tra necessit\ue0 di standardizzazione e variabilit\ue0 naturale

Abstract. The improvement of the agricultural surface devoted to olive oil production, highlighted the strong influence of environmental conditions on the oil composition. In the meantime, the establishment of shared rules and standard of composition is mandatory to improve the worldwide trade of olive oils. Rules are established as Regulations that means mandatory rules (laws) within European Union, while outside UE, the Trade Standard by International Olive Council is the reference standard and at worldwide level, the Codex Alimentarius (established by FAO-OMS) is the World Trade Organization reference. The number of members of these three levels of international organization is different and an hard work is to find an acceptable compromised between countries quite different in terms of agricultural scenarios, environmental conditions, economic conditions and social organization. Standards relate to quality and purity characteristics, this classification is very important because while quality is a ranking parameter, purity is a cutting limit, this means that it is necessary to be very careful in admitting any exception in limits. The environmental differences between \u201ctraditional\u201d geographic area of olive cultivation, that\u2019s to say the Mediterranean basin and new areas of cultivation, mainly located in the South Hemisphere, in some cases strongly influence the oil composition, even in some characteristics whose limits are an important borderline to defend olive oil purity. Nevertheless, it\u2019s an evidence that some authentic olive oils exist , that for some parameters exceed the established limits; the very hard issue is that these parameters are purity parameters and that the modification of a limit can open the door to faked oils. Linolenic acid content is an important parameter to highlight the admixtures with soybean oil, however, in some areas, the content of linolenic acid of authent ic ol ive oi ls exceeded the Codex Alimentarius limit; no agreement had been reached between main producing countries and new producing ones and nowadays the Codex Standard has no limit for this acid. Campesterol and \u394-7 Stigmastenol, too, are very useful to highlight the presence of several seed oils (the former) and Compositae oils (the latter), but some cultivar in some geographical areas where the presence of olive in the agricultural landscape is rather recent, present concentration of these sterols higher than the established limit (respectively 4,0% and 0,5%). In all these cases, the problem is not to expel from the market some production of genuine oils, in the meantime not leave any space to possible frauds. A solution had been to build some so called \u201cdecisional trees\u201d, that are based on the principle of admit selected \u201canomalies\u201d for one limit, in the meantime making the other more strictly, with the aim to avoid any possibility that the derogation of one limit can make faked oils not possible to b e distinguished by authentic ones. In this review, some of these cases will be described and critically discussed-

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. Furthermore, the possibility to combine the extraction and clean-up steps by including a layer of an adsorbent retaining interfering compounds directly in the PLE extraction cells makes this technique extremely versatile and selective. After providing a background on the PLE technique and parameters to be optimized, the present review focuses on recent applications (published in the past 10 years) in the field of food contaminants. In particular, applications related to the extraction of environmental and processing contaminants, pesticides, residues of veterinary drugs, mycotoxins, parabens, ethyl carbamate, and fatty acid esters of 3-monochloro-1,2-propanediol and 2-monochloro-1,3-propanediol from different food matrices were considered

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. Among the different cereal-based products analysed (dry semolina and egg pasta, bread, biscuits, and cakes), egg pasta packed in direct contact with recycled paperboard had on average the highest total MOSH level (15.9mgkg(-1)), followed by cakes (10.4mgkg(-1)) and bread (7.5mgkg(-1)). About 50% of the pasta and bread samples and 20% of the biscuits and cake samples had detectable MOAH amounts. The highest concentrations were found in an egg pasta in direct contact with recycled paperboard (3.6mgkg(-1)) and in a milk bread (3.6mgkg(-1))

Endogenous n-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 n-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 n-alkanes in vegetable oils was, therefore, optimized and validated. The optimized method demonstrated good performance characteristics in terms of linearity (R2 > 0.999), recovery (on average 94%), and repeatability (residual standard deviation, RSD < 11.9%). The results were comparable to those obtained with online high-performance liquid chromatography (HPLC)-GC- FID ( RSD < 5.1%). As an example of an application to prove the potentiality of endogenous n-alkanes in revealing frauds, the data set obtained from 16 EVOO, 9 avocado oils (AVO), and 13 sunflower oils (SFO), purchased from the market, was subjected to statistical analysis and principal component analysis. Two powerful indices, namely (n-C29 + n-C31)/(n-C25 + n-C26) and n-C29/n-C25, were found to reveal the addition of 2% SFO in EVOO and 5% AVO in EVOO, respectively. Further studies are needed to confirm the validity of these promising indices

Avaliação da eficiência de um filtro de adsorção com carvão ativado na purificação de biogás proveniente da fração orgânica dos resíduos urbanos. 2017.

Dissertação apresentada junto ao Programa de Pós-Graduação em Desenvolvimento Regional e Meio Ambiente, como requisito para obtenção do título de Mestre em Desenvolvimento Regional e Meio Ambiente. Orientador: Dr. Artur de Souza MoretA digestão anaeróbia é uma alternativa promissora para o tratamento da fração orgânica dos resíduos sólidos urbanos. No entanto, a utilização do biogás em seu estado não purificado não é tão eficiente em virtude da presença de alguns gases contaminantes em sua composição, principalmente o sulfeto de hidrogênio (H2S), que tem alto poder corrosivo. Para aplicação como fonte energética é importante a purificação do biogás para não produzir corrosão nas câmaras de combustão dos equipamentos. O presente trabalho utilizou a digestão anaeróbia para a produção de biogás a partir da fração orgânica dos resíduos sólidos urbanos, provenientes de um refeitório na localidade de Nova Mutum Paraná-RO. O objetivo deste trabalho foi avaliar a produção de biogás e analisar a eficiência de um filtro de adsorção com carvão ativado na remoção dos gases CO2 e H2S. A etapa experimental compreendeu a caracterização dos resíduos, construção de um biodigestor anaeróbio de pequena escala utilizando 03 tambores de Polietileno de Alta Densidade (PEAD) com capacidade de 50 litros cada, monitoramento da produção de biogás por meio do medidor de vazão LAO G 0.6, construção de um sistema de purificação utilizando-se uma coluna recheada com carvão ativado com granulometria 3X6, análise da composição do biogás em um cromatógrafo com Detector de Condutividade Térmica (TCD) da marca Perkin Elmer, modelo Clarus 680, e avaliação da remoção das impurezas (H2S e CO2), comparando as composições das amostras do biogás coletado antes e depois da passagem pelo sistema de adsorção. Utilizou-se o teste t de Student para comparar as médias das amostras estatisticamente. Constatou-se que o biodigestor testado apresentou bons resultados, permitindo manter uma produção viável e constante de gás. As oscilações de temperatura influenciaram na produção e o rendimento obtido com a digestão de 13 kg de resíduos orgânicos inoculados com 2 kg de dejetos suínos foi de 395,5 litros ou 0,3955 m3 de biogás. Uma média de 8,78 litros ou 0,00878 m3 de biogás por dia. Estima-se que uma tonelada de resíduos possa produzir cerca de 8.788,88 litros ou 8,78888 m3 de biogás no tempo de retenção hidráulica de 45 dias. O pH do biogás é ácido e no valor de 3. A análise estatística demonstrou diferença significativa entre as médias do gás sulfeto de hidrogênio, comprovando que houve uma remoção de 100% em todas as amostras. Apesar dos resultados estatísticos não demonstrarem discrepância relevante em relação ao gás carbônico (CO2), percebe-se uma redução de aproximadamente 45% da concentração em todas as amostras após a passagem pelo filtro. Houve um acréscimo na concentração de metano (CH4), confirmando um bom desempenho do filtro de adsorção com carvão ativado, retratando grande potencial para purificação de biogás

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

peer reviewedPolycyclic 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

Novel Methodologies for Food Quality and Provenance Fingerprints Assessment

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Molecularly Imprinted Polymer as Selective Sorbent for the Extraction of Zearalenone in Edible Vegetable Oils

A method based on the selective extraction of zearalenone (ZON) from edible vegetable oils using molecularly imprinted polymer (MIP) has been developed and validated. Ultra-high-pressure liquid chromatography coupled with a fluorescence detection system was employed for the detection of zearalenone. The method was applied to the analysis of zearalenone in maize oil samples spiked at four concentration levels within the maximum permitted amount specified by the European Commission Regulation (EC) No. 1126/2007. As a result, the proposed methodology provided high recoveries (>72%) with good linearity (R2 > 0.999) in the range of 10-2000 μg/kg and a repeatability relative standard deviation below 1.8%. These findings meet the analytical performance criteria specified by the European Commission Regulation No. 401/2006 and reveal that the proposed methodology can be successfully applied for monitoring zearalenone at trace levels in different edible vegetable oils. A comparison of MIP behavior with the ones of QuEChERS and liquid-liquid extraction was also performed, showing higher extraction rates and precision of MIP. Finally, the evolution of ZON contamination during the maize oil refining process was also investigated, demonstrating how the process is unable to completely remove (60%) ZON from oil samples

Evaluation of hydrocarbon contaminants in olives and virgin olive oils from Tunisia

The present paper investigated on the presence of some hydrocarbon contaminants, namely polycyclic aromatic hydrocarbons (PAHs), mineral oil hydrocarbons (MOH) comprising saturated (MOSH) and aromatic (MOAH) compounds, and polyolefin oligomeric saturated hydrocarbons (POSH) in olives and extra virgin olive oils from Tunisia. Olive fruits were collected in sites exposed to different environmental contamination, and the oil extracted both by physical mean (using an Abencor extractor) and with solvent (using microwave assisted extraction, MAE). Analytical determination was performed by SPE cleanup on silica cartridge followed by spectrofluorometric detection, for PAH, and on-line HPLC-GC-FID for MOH and POSH. Oils extracted from olives by physical mean, as well as extra virgin olive oils from the market, had PAH levels never exceeding the EU legal limits. All olive samples showed similar MOSH profiles, but not clear correlation between the variable contamination levels and considered sources of contamination, was evidenced. The average MOSH content in oil extracted from olives by solvent (11.1 mg/kg) was about four time higher than in oil extracted by physical mean (2.6 mg/kg). MOSH in extra virgin oil from the market ranged from 10.3 to 38.0 mg/kg, while MOAH were not detected. The higher MOSH levels found in oils from the market evidenced an important contribution due to oil processing and/or packaging. Two of the samples were clearly contaminated with polyolefin oligomeric hydrocarbons (POSH) migrated from the plastic cap

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. The samples were either in their green state or subjected to different roasting levels. The used methods successfully distinguished the Arabica and Robusta variants targeted in this study based on their tocopherols and TAG profiles, with the latter being particularly effective for discriminating the origins of the Arabica coffee, while tocopherols excelled at differentiating the origin of the Robusta coffee. TAGs and tocopherols were not affected by the type of roasting, from medium to very dark, suggesting it is possible to distinguish between coffee varieties independently from their degree of roasting. The obtained results hold valuable implications for future research regarding coffee fraud and authenticity