Effects of a chemical company fire on the occurrence of polycyclic aromatic hydrocarbons in plant foods

On Friday, September 1, 2006, the facilities of a chemicals distributor in the Spanish town of Caldas de Reis, were almost completely destroyed as a result of a fire. Comprehensive liquid chromatography-fluorescence detection (LC-FD) analyses were performed on plant foods to determine the toxic impact of this kind of accident on population. PAHs from a polluted atmosphere are generally transferred to plants by particle-phase deposition on the waxy leaf cuticle or by uptake in the gas phase through stomata. PAH levels in all samples were not alarming (total PAHs were below 4.240 ng/g) and the PAH profiles were similar, with the exception of peppers, in all vegetal materials (5-to-4 rings ratio of 1–2), suggesting the similarity in source type (the fire). PAH concentrations in plants were related to their surface exposed to air, indicating that the contribution of soil/water PAHs to plants (aerial part) accumulation was insignificant.     

Training of panellists for the sensory control of bottled natural mineral water in connection with water chemical properties

As bottled mineral water market is increasing in the world (especially in emergent and developed countries), the development of a simple protocol to train a panel to evaluate sensory properties would be a useful tool for natural drinking water industry. A sensory protocol was developed to evaluate bottled natural mineral water (17 still and 10 carbonated trademarks). The tasting questionnaire included 13 attributes for still water plus overall impression and they were sorted by: colour hues, transparency and brightness, odour/aroma and taste/flavour/texture and 2 more for carbonated waters (bubbles and effervescence). The training lasted two months with, at least, 10 sessions, was adequate to evaluate bottled natural mineral water. To confirm the efficiency of the sensory training procedure two sensory groups formed the whole panel. One trained panel (6 persons) and one professional panel (6 sommeliers) and both participated simultaneously in the water tasting evaluation of 3 sample lots. Similar average scores obtained from trained and professional judges, with the same water trademarks, confirmed the usefulness of the training protocol. The differences obtained for trained panel in the first lot confirm the necessity to train always before a sensory procedure. A sensory water wheel is proposed to guide the training in bottled mineral water used for drinking, in connection with their chemical mineral content.     

Survey of polycyclic aromatic hydrocarbons in canned bivalves and investigation of their potential sources

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants in the marine environment derived from uncontrolled petroleum spills, marine transports, discharges from ships, and urban runoff. The NW coast of Spain (Galicia) has a characteristic hydrography, defined by a continuous suite of estuarine systems called “Rías Gallegas”. Some of these estuaries support important industrial and urban centres while others are preserved from human influence. The PAH contents in invertebrate organisms, such as bivalves, have been widely investigated because they are good bioindicators of pollution due to their ability to filter the water. 12 PAHs were determined in canned mussels (Mytilus galloprovincialis), clams (Venerupis pullastra), cockles (Cerastoderma edule) and knives (Ensis ensis) from the Galician “Rías Gallegas” to perform a possible risk assessment on these contaminants. Pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene and benzo[a]pyrene were detected in all the selected samples by liquid chromatography coupled with fluorescence spectroscopy. With regard to benzo[a]pyrene, which represents the most potentially carcinogenic PAHs, European Regulation 1881/2006/EC fixed at 10 μg/kg of wet weight the MRL (maximum residual level) in bivalve molluscs. None of these marine invertebrates showed values higher than the MRL and therefore, they do not suppose risk for human health. Mussels hydrocarbon body burden levels were highest than exhibited by others bivalves. Some factors may determine this feature, as lipid content or habitat. Lower PAH levels of five and six benzene rings were detected in canned mussels in pickle sauce (vegetable oil, vinegar, paprika, salt and other spices) than in mussels in natural sauce (water, salt and other spices). PAHs migration from mussels to the vegetable oil in pickle sauce was verified to be the reason.     

The use of manures for detection and quantification of polycyclic aromatic hydrocarbons and 3-hydroxybenzo[a]pyrene in animal husbandry

PAHs from a polluted atmosphere are generally transferred to plants by particle-phase deposition on the waxy leaf cuticle or by uptake in the gas phase through stomata. Thus, they are also present in ingredients for animal feed. Generally, toxic substances are metabolized before or after absorption through the intestinal tract. This is the case of 3-hydroxybenzo[a]pyrene, which can be found free or in its glucuronide and/or sulphate conjugate forms. This article develops a procedure to monitor the carry-over of PAHs from feed to food of animal origin based on the analysis of animal manure. Eleven PAHs and 3-hydroxybenzo[a]pyrene were measured in four animal manures (cow, horse, rabbit and pig) by liquid chromatography with fluorescence detection. benzo[a]pyrene, benzo[b]fluoranthene and benzo[k]fluoranthene were found in all the selected samples, but their total levels were not alarming (benzo[a]pyrene equivalents (microg/kg)<3.1). 3-hydroxybenzo[a]pyrene was quantified in all the samples exempting rabbit manure. The highest total PAH levels were detected in cow manure (9.0 microg/kg), while the highest 3-OH-B[a]P level was determined in horse samples (13 microg/kg).     

Occurrence of polycyclic aromatic hydrocarbons and their hydroxylated metabolites in infant foods

Eleven polycyclic aromatic hydrocarbons (PAHs) have been analysed in commercial milk formulae and infant cereals. Two hydroxylated PAHs metabolites (1-OH-Pyr and 3-OH-B[a]P) and their conjugates were also analysed in milk samples. To determine the selected PAH metabolites, a simple, fast quantitative and economic method was developed. This method comprising ultrasound-assisted solvent extraction, enzymatic hydrolysis, solid-phase clean-up and detection by liquid chromatography with fluorescence detection (LC–FD) and liquid chromatography tandem mass spectrometry (LC–MS/MS) as confirmatory technique. The method was evaluated by constructing calibration curves, measurement of recovery, precision and the limits of detection. The purpose of this survey was to determine the selected analytes, to assess the exposure of babies and infants and to produce data for comparison with proposed limits that were being considered at the time of the survey. The results showed that not only no samples would have exceeded the limit for benzo[a]pyrene which is used as an indicator for the presence of PAHs, but also no hydroxy PAH metabolites have been detected.     

Effects of toasting procedures on the levels of polycyclic aromatic hydrocarbons in toasted bread

Some polycyclic aromatic hydrocarbons (PAHs), particularly those with a high molecular weight, have been classified as probably carcinogens to humans by the International Agency for Research on Cancer (IARC). The significance of the determination of PAHs is reflected by the special attention of the European Union, which is paying to regulate the maximum allowed levels of PAHs in foodstuffs such as smoked foods. Like other thermally processed foodstuffs, toasted bread can contain these carcinogenic chemicals, not only due to a contamination at source but also during toasting. In order to check PAHs generated from toasting in sandwich bread, several treatment conditions were evaluated: direct toasting (flame-toasting, coal-grilling or gas oven-toasting) or indirect toasting (electric oven-toasting). PAHs were extracted by solid–liquid extraction (SLE) and determined by liquid chromatography with fluorescence detection (LC-FD). Based on the results, the used toasted technique would strongly affect in PAH levels in the final product. No samples obtained by electric oven and toaster were polluted; otherwise the samples toasted by charcoal and flame grilling presented very important levels. Up to 350 μg/kg of total PAHs were detected in toasted samples by wood flame. Differences between different ways of toasting could be ascribed to deposition of PAHs from smoke. Finally, several commercial toasted samples of bread were tested to determine PAHs. Overall, the PAH levels were very low. Benzo[a]pyrene ranged from no detectable to 0.23 μg/kg.