Iria Yebra-Pimentel

A Critical Review about Human Exposure to Polychlorinated Dibenzo-p-Dioxins (PCDDs), Polychlorinated Dibenzofurans (PCDFs) and Polychlorinated Biphenyls (PCBs) through Foods

Dioxins include polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and part of polychlorinated biphenyls (PCBs). Only the compounds that are chlorinated at the 2,3,7, and 8 positions have characteristic dioxin toxicity. PCDDs, PCDFs and PCBs accumulate in the food chain due to their high lipophilicity, high stability, and low vapor pressure. They are not metabolized easily; however their hydroxylated metabolites are detected in feces. They cause a wide range of endocrine disrupting effects in experimental animals, wildlife, and humans. Endocrine related effects of PCDDs, PCDFs and PCBs on thyroid hormones, neurodevelopment and reproductive development were referenced. In addition, some studies of contamination of foods, bioaccumulation, dietary exposure assessment, as well as challenges of scientific research in these compounds were reviewed.

Searching ingredients polluted by polycyclic aromatic hydrocarbons in feeds due to atmospheric or pyrolytic sources

The primary aim of the proposed work is to propose the potential sources of pollution by polycyclic aromatic hydrocarbons (PAHs) in feeds and ingredients. To reach this propose the development of a simple, fast, quantitative and economic method for determining PAHs using liquid-liquid extraction (LLE), clean-up and detection by liquid chromatography with fluorescence detection (LC-FD) in polluting feeds and ingredients was developed. The overall method quantification limits range from 0.020 to 4.0μg/kg and analyte recoveries are between 70% and 105% with relative standard deviations (RSD) lower than 20%. Molecular patterns of PAHs were used to study their distribution in the selected samples by cluster analysis, separating them in two groups: contaminated by atmospheric or pyrolytic sources. In order to find a relationship between the nutritional composition (protein, fibre, ash and fat content), and the hypothetical toxicity of selected feeds, a partial least squared (PLS) analysis was used, showing that fibre was a major contributor. Moreover, the complete data set of 27 feed samples and 25 feed ingredients x 13 PAH concentrations were analysed by PCA to find out what ingredients were controlling PAH pollution.

A Critical Review about the Health Risk Assessment of PAHs and Their Metabolites in Foods

Polycyclic aromatic hydrocarbons (PAHs) are a family of toxicants that are ubiquitous in the environment. These contaminants generate considerable interest, because some of them are highly carcinogenic in laboratory animals and have been implicated in breast, lung, and colon cancers in humans. Dietary intake of PAHs constitutes a major source of exposure in humans. Factors affecting the accumulation of PAHs in the diet, their absorption following ingestion, and strategies to assess risk from exposure to these hydrocarbons following ingestion have received very little attention. This review, therefore, focuses on concentrations of PAHs in widely consumed dietary ingredients along with gastrointestinal absorption rates in humans. Metabolism and bioavailability of PAHs in animal models and the processes, which influence the disposition of these chemicals, are discussed. Finally, based on intake, disposition, and tumorigenesis data, the exposure risk to PAHs from diet is presented. This information is expected to provide a framework for refinements in risk assessment of PAHs.

The potential of solvent-minimized extraction methods in the determination of polycyclic aromatic hydrocarbons in fish oils

Fish oil has been identified as one of the most important contributors to the level of Persistent Organic Pollutants (POPs) in feed products. The determination of polycyclic aromatic hydrocarbons (PAHs) in fish oils is complicated due to the fat matrix, which affects both extraction efficiency and analytical quality. This article reviews and addresses two of the most relevant analytical methods for determining 11 mutagenic and carcinogenic PAHs, as well as two EPA indicator PAHs in fish oils. We discuss and critically evaluate two different extraction procedures, such as ultrasound-assisted solvent extraction (USAE) and ultrasound-assisted emulsification-microextraction (USAEME). Clean-up of extracts was performed by solid-phase extraction using C18 and glass columns containing silica gel and florisil for USAE or only C18 for USAEME. Detection of the selected PAHs was carried out by high-performance liquid chromatography coupled with fluorescence detection for determination. Optimization of the variables affecting extraction by the selected extraction techniques was conducted and recoveries ranged from 70% to 100% by USAE and from 70% to 108% by USAEME with estimated quantification limits between 0.020 and 2.6 μg/kg were achieved. Moreover, the applicability of the selected methods was evaluated by the analysis of real samples. To our knowledge, this is the first time that USAEME has been applied to the determination of PAHs in food matrices, such as oil fish samples. The methods proposed were applied to the determination of the target PAHs in fish samples from different countries, and it was found that the low PAH contamination of the selected fish oils could mainly occur by atmospheric sources.

Effect of Beer Marinades on Formation of Polycyclic Aromatic Hydrocarbons in Charcoal-Grilled Pork

The effect of marinating meat with Pilsner beer, nonalcoholic Pilsner beer, and Black beer (coded respectively PB, P0B, and BB) on the formation of polycyclic aromatic hydrocarbons (PAHs) in charcoal-grilled pork was evaluated and compared with the formation of these compounds in unmarinated meat. Antiradical activity of marinades (DPPH assay) was assayed. BB exhibited the strongest scavenging activity (68.0%), followed by P0B (36.5%) and PB (29.5%). Control and marinated meat samples contained the eight PAHs named PAH8 by the EFSA and classified as suitable indicators for carcinogenic potency of PAHs in food. BB showed the highest inhibitory effect in the formation of PAH8 (53%), followed by P0B (25%) and PB (13%). The inhibitory effect of beer marinades on PAH8 increased with the increase of their radical-scavenging activity. BB marinade was the most efficient on reduction of PAH formation, providing a proper mitigation strategy.

Inputs of polychlorinated biphenyl residues in animal feeds

Animal nutrition constitutes an important issue for the animal production industry. Products intended for animal feed may contain undesirable substances which could endanger animal health or, because of their presence in livestock products, human health or the environment. In this sense, several incidents related with the presence of persistent organic pollutants, particularly with polychlorinated biphenyls (PCBs), have happen in food and feed additives. Animal feed and feed components are challenging matrices for the determination of residues and contaminants. The variability of these matrices is enormous. It ranges from relatively simple ones like those based on wheat to all kinds of by-products from agro and food industry, such as cereal oils. Firstly, this article reviews and addresses the extraction efficiency of ultrasonic assisted solvent extraction (UASE) and focused ultrasonic solvent extraction (FUSE) for determining selected PCBs in animal feed and ingredients. Detection of these pollutants was carried out by gas chromatography (GC) coupled to electron capture detection (ECD); tandem mass spectrometry (MS/MS) was used as confirmatory technique. Recoveries ranged from 70% to 98% by UASE and from 75% to 106% by FUSE with estimated quantification limits between 0.11 and 0.3 μg/kg in feeds and ingredients and between 0.2 and 0.75 μg/kg in fats. Once the method was optimised, it was applied to 18 feed samples as well as 16 ingredients. PCBs were detected in almost all the selected samples. As expected, the samples of animal origin as shell powder and fish oil showed the highest concentrations of 56 and 29 ng/g, which are equivalent to toxicological concentrations of 123 and 18 ng WHO-TEQDL-PCBs/kg, respectively. Feeds and ingredients from vegetable origin ranged from non-detected to 7.1 μg/kg. PCB 77 and 169 were the discriminant congeners in the selected samples of feed and ingredients. Samples showed that the pattern of PCBs depends on the sources of contamination.

Optimization of purification processes to remove polycyclic aromatic hydrocarbons (PAHs) in polluted raw fish oils

Fish oils are one of the main sources of health promoting nutrients such as n-3 fatty acids in animal and human diet. Nevertheless, they could be an important source of persistent organic pollutants (POPs). Different strategies of decontamination processes to reduce polycyclic aromatic hydrocarbon (PAH) levels in fish oils, such as solvent extraction (ethanol) and adsorbent extraction using commercially available (activated carbon) and sustainable adsorbents (mussel shell and wood ashes), were compared. Adsorption conditions were evaluated and optimized by an experimental design and the experimental results were adjusted to response surfaces. In this way, PAH removals increased with increasing of individual PAH molecular weight and they range from 80% to 100% using activated carbon and from 10% to 100% using wood ashes. Pine wood ashes showed similar removal rates to activated carbon (87%-100%) excluding F (51%) and P (42%). No PAH removal was observed using mussel shell ashes. Ethanol extraction was also optimized and showed a good performance in the extraction of PAHs. However, it does affect their ω-3 fatty acid contents. Finally, real oil samples from different fishing areas: Spain, South America, and North Europe were selected for the decontamination experiments under experimental conditions previously optimized.

Feed Ingredients Mainly Contributing to Polycyclic Aromatic Hydrocarbon and Polychlorinated Biphenyl Residues

Animal nutrition constitutes an important issue for the animal production industry. Products intended for animal feed may contain undesirable substances which could endanger animal health or, because of their presence in livestock products, human health or the environment. In this sense, several incidents related with the presence of persistent organic pollutants, particularly with polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), have happen in food and feed additives. Simple, fast, quantitative, and economic methods for determining PAHs and PCBs in potentially polluting feed ingredients were developed and evaluated. The methods involved liquid-liquid extraction (LLE), clean-up, and detection by liquid chromatography with fluorescence detection (LC-FD) for PAHs and gas chromatography (GC) coupled to electron capture detection (ECD) for PCBs, using tandem mass spectrometry (MS/MS) as confirmatory technique. The overall method quantification limits range from 0.020– 4.0 μg/Kg for PAHs and from 0.20–0.75 μg/Kg for PCBs, analyte recoveries are between 70 and 105% with relative standard deviations (RSD) lower than 20%. Once the method was optimized, it was applied to 25 feed ingredients considered as potential candidates for feedstuff. As expected, the samples of animal origin as shell powder and fish oil showed the highest PCB concentrations of 56 and 29 ng/g, which are equivalent to toxicological concentrations of 123 and 18 ng WHO-TEQDL-PCBs/Kg, respectively. Opposite results were obtained with PAHs and the highest PAH4 levels were detected alfalfa (47 μg/Kg), calcium phosphate (27 μg/Kg), and palm oil (23 μg/Kg) used as feed ingredients.

Feeds and Corresponding Footprints of Residual Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls Based on Their Constituents

Food safety is central to any society, having important economic, social, and environmental implications. International comparisons have shown that the European Union is the worlds largest producer of food and drink products. It is not surprising therefore that the Agro-food sector has major importance/influence on the economy of Europe. The first link in the agro-food chain is animal feed, and therefore the risks associated to them, as is the case of the distribution of carcinogenic polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), are of paramount importance. Simple, fast, quantitative, and economic methods for PAHs and PCBs potentially polluting feeds were developed. The PAHs were detection by liquid chromatography with fluorescence detection (LC-FD) and the PCBs by gas chromatography (GC) coupled to electron capture detection (ECD), using tandem mass spectrometry (MS/MS) as confirmatory technique. The complete data set of 27 feed samples x 13 PAH and PCB concentrations were analyzed by Principal Component Analysis (PCA) to find out what feeds were controlling PAH and PCB contamination.

Decontamination solutions for polychlorinated biphenyls (PCBs) in raw fish oils from environmentally contaminated sea fishes

Fish oil has been identified as one of the most important contributors to the levels of polychlorinated biphenyls (PCBs) in food and feed products. In this study, PCB adsorption from fish oil onto activated carbon (AC), other sustainable adsorbents (mussel shell and wood waste ashes) and organic solvent such as ethanol were compared and optimized. Regarding to adsorbents, PCBs were extracted from fish oil by a 2.0% adsorbent material dose, during 6.0 h at 25 °C. Solvent extraction was carried out using 2 × 5.0 mL ethanol by manually stirring for 3.0 min, and then by Ultrasound-Assisted Solvent Extraction (UASE) for 5.0 min. The results showed that removal rates obtained by using adsorbent materials ranged from 0.0 to 10% for marker PCBs, from 0.0 to 37% for mono-ortho-PCBs, from 0.0 to 74% for PCB11 and from 0.0 to 95% for non-ortho-PCBs. Regarding to solvent extraction, ethanol was used by manually stirring and then by Ultrasound-Assisted Solvent Extraction (UASE). The samples were then centrifuged (2000 rpm/10 min) and the alcoholic phase was removed. With this method, removal efficiencies were much better (85-116%); nevertheless, high eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) removal rates (70-78 and 71-79%, respectively) were detected. We can conclude that adsorption with adsorbents depends on the geometry of PCB congeners, as well as both type of adsorption material and their origin, and that several sorption cycles are needed. Adsorption with ethanol could be the most effective methodology but nutritional quality was impaired, what makes necessary to look for other not so polar removal solvents.