Food additives and contaminants最新文献

Estimations of ochratoxin A (OTA) and 4-deoxynivalenol (DON) exposure of the Belgian population through beer consumption were made using the results of the recent Belgian food survey and the compiled data set of OTA and DON levels in conventionally and organically produced beers in 2003-05. For the consumers of organic beers, the daily intake of OTA was 0.86 (in 2003), 1.76 (in 2004) and 0.72 (in 2005) ng kg(-1) body weight (bw), considering the mean beer consumption (0.638 litres) and the average level of OTA in 2003, 2004 and 2005, respectively. Using the 97.5th percentile of beer consumption (1.972 litres), the corresponding OTA daily intakes were 2.65, 5.44 and 2.24 ng kg(-1) bw, which are close or above the tolerable daily intake (TDI) of 5 ng kg(-1) bw. For the consumers of conventional beers, the OTA intakes were low: 0.23, 0.23 and 0.11 ng kg(-1) bw day(-1) for the average beer consumption, in 2003, 2004 and 2005 against 0.72, 0.73 and 0.34 ng kg(-1) bw day(-1) when the 97.5th percentile level was considered. As for the DON intake, the estimates were quite low for both conventional and organic beer consumers when the provisional maximum TDI (PMTDI) of 1 microg kg(-1) bw was considered. Average consumption of organic beer led to daily intakes of 0.05 and 0.04 microg DON kg(-1) bw in 2003 and 2004, respectively, whilst for conventional beer, daily intakes were 0.07 and 0.05 microg DON kg(-1) bw. At the 97.5th percentile level of beer consumption, daily intakes of 0.15 and 0.13 microg kg(-1) bw were obtained for organic beers against 0.23 and 0.17 microg kg(-1) bw for conventional ones. The results showed that beer could be an important contributor to OTA exposure in Belgium, even though a declining trend seems to be apparent during the last year of monitoring. Therefore, efforts should be devoted to maintain the OTA levels as low as reasonably achievable, especially for organic beer.

Antimony residues, a result of the use of a polycondensation catalyst in the production of polyethylene terephthalate (PET) oven-proof trays, were analysed in ready-to-eat meals. The toxicity of antimony has raised concerns about consumer safety; therefore, the migration of small fractions of these residues into ready meals and foods as a result of cooking directly in the PET trays was studied. A straightforward approach of measuring real samples was selected to obtain accurate exposure data. Background antimony concentration was determined separately from a series of lunch meals, which ranged from not detectable to 3.4 microg kg(-1). Microwave and conventional oven-cooking caused a distinct increase in the concentration of antimony in food and ready meals of 0-17 and 8-38 microg kg(-1), respectively, depending, to a certain extent, on the industrial preparations. The migrated quantities of antimony corresponded to 3-13 microg. For comparison, PET roasting bags and ready-made dough products in PET baking dishes were also evaluated. About half of the products prepared at a temperature of 180 degrees C exceeded the specific migration limit set for food contact material by the European Commission. However, the migrated amounts of antimony relative to the accepted tolerable daily intake (TDI) show that exposure from this type of food is currently not of toxicological concern.

Levels of copper, zinc, calcium and magnesium were measured in alcoholic beverages (whiskies, gins, rums, liquors, brandies, wines and beers) and by-products (non-alcoholic liquors and vinegars) using flame atomic absorption spectrometry (FAAS). Mineral concentrations were found to be significantly different between the nine alcoholic and non-alcoholic by-products studied (p < 0.001). In distilled alcoholic beverages, concentrations measured in rums and brandies were statistically lower than those determined in gins and alcoholic liquors (p = 0.001). For Cu, measured concentrations were statistically different for each of the five groups of distilled alcoholic beverages studied (p < 0.001). In fermented beverages, Zn, Ca and Mg levels were significantly higher than those concentrations determined in distilled drinks (p < 0.005). Contrarily, Cu concentrations were statistically lower (p < 0.001). Wines designated as sherry had significantly higher Ca and Mg levels (p < 0.005). White wines had significantly higher Ca and Zn levels (p < 0.05) compared with red wines and, contrarily, Cu concentrations were significantly lower (p < 0.005). In wine samples and corresponding by-products (brandy and vinegar), statistical differences were established for all minerals analysed (p < 0.01). Remarkably, for Cu, the concentrations determined in brandies were statistically higher. On the basis of element levels and the official data on consumption of alcoholic beverages and by-products in Spain, their contribution to the daily dietary intake (DDI) was calculated to be 124.6 microg Cu day(-1) and 193.3 microg Zn day(-1), 40.3 mg Ca day(-1) and 19.9 mg Mg day(-1). From all studied elements, Cu was the one for which alcoholic beverages constitute a significant source (more than 10% of recommended daily intake). These findings are of potential use to food composition tables.

Operating conditions affect ochratoxin A (OTA) extraction from roasted coffee. The OTA content found in the beverage can thus be greater than that found in the roasted coffee used to prepare it. Three extraction parameters were studied for roasted coffee: type of extraction solvent (alkaline, neutral, acid), temperature (ambient temperature/23 degrees C, 60 degrees C and 85 degrees C), and extraction time (5, 20, 30, 40, 50, 60 and 80 min). The alkaline solvent used in the method recommended by the European Union extracted OTA better, but a maximum content was obtained at 60 degrees C after 50 min. At least a 100% improvement in extraction was obtained when compared with the European Union usual quantification method that is carried out at ambient temperature. It turned out that the OTA extraction parameters for roasted coffee, as defined by that method, were not optimum and needed to be modified. These results were verified in double-extraction experiments showing that OTA is not completely extracted by this method. Confirmation was obtained by comparison of extraction methods on several commercial samples of roasted coffee.

Fumonisins are metabolites produced in corn primarily by the fungus Fusarium verticillioides (F. moniliforme) and are toxic to humans and animals. Fumonisin B(1) (FB(1)) is the primary fumonisin produced and is found frequently in corn kernels, some of which may be used as food or food ingredients. A three-part study was conducted to determine the effects of gamma- and electron beam irradiation on the levels of fumonisins in naturally contaminated field corn, and the effects of microwave-popping on fumonisins in selected, naturally contaminated popcorn. To date, no effective means have been found to reduce consistently mycotoxin levels once foods are contaminated. Aqueous solutions of FB(1) at various concentrations, samples of whole corn, and samples of ground corn containing known levels of FB(1) were irradiated with various levels of cobalt and electron beam irradiation. Popcorn samples, taken from the reject streams of popcorn processing, were popped using normal microwave-popping conditions. FB(1) in aqueous solutions was reduced by 99.7% using a minimal level of irradiation (0.5 kGray). Gamma- and electron beam irradiation did not significantly reduce levels of FB(1) in whole and ground corn. Aspergillus sp., Penicillium sp. and Fusarium sp. fungi were totally eliminated at 30 kGray in ground corn and at 100 kGray in whole corn. The normal commercial cleaning processes for microwave popcorn before packaging reduced fumonisins to <0.03 microg g(-1) for the cleaned product stream. Microwave popping of popcorn from reject streams of the cleaning operation that contained fumonisins resulted in significant reduction of the mould toxin.

A monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for the quantification of imazalil [(RS)-1-(beta-allyloxy-2,4-dichlorophenylethyl)imidazole] in apple, tomato and orange juice samples. From an imazalil hapten, which mimics the analyte structure, several monoclonal antibodies were obtained. An ELISA in the conjugate-coated format was developed and optimized using the antibody showing the highest sensitivity. For standards, the detection limit of the ELISA was 0.2 nM (0.06 ng ml(-1)), with an I(50) value of 1.6 nM (0.5 ng ml(-1)). The study of the influence of matrices on assay reliability indicated that the ELISA could determine imazalil in fruit juices at the low ng ml(-1) level simply by diluting the sample, without any clean-up or concentration step. Recovery and precision of the method were evaluated by spiking juice samples with imazalil in the 10-500 ng ml(-1) range. The mean recovery from fruit juices was 97% and the mean coefficient of variation was approximately 20%. In addition to being precise and accurate, the method has proved to be simple and sensitive, with a quantification limit well below the maximum residue limits for imazalil in these matrices.

A database has been compiled with the levels of important contaminants (mycotoxins, heavy metals and pesticides) measured from 2002 to 2005 in winter wheat (Triticum aestivum) grown in Belgium according to the organic and conventional farming systems. Assuming no further change in contaminant levels during cereal processing and during the preparation of foodstuffs, conservative intakes are estimated for the consumers of cereal-based products such as flour, bread, breakfast cereals, dough and pastry. The results show that for the consumer of organic foodstuffs, estimated daily intakes are 0.56 microg deoxynivalenol (DON), 0.03 microg zearalenone (ZEA), 0.19 microg Cd, 0.28 microg Pb and 0.0006 microg Hg kg(-1) body weight, taking into account the average contaminant levels in unprocessed grains and the average cereal products consumptions in Belgium. For the consumers of conventional foodstuffs, the corresponding estimated daily intakes are 0.99 microg DON, 0.06 microg ZEA, 0.17 microg Cd, 0.12 microg Pb and 0.0007 microg Hg kg(-1) body weight. In addition, it appears that for the consumers of conventional products, intakes of some post-harvest insecticides have to be taken into account (0.11 microg chlorpyriphos-methyl, 0.2 microg dichlorvos and 0.24 microg pirimiphos-methyl kg(-1) bw). When expressed as a percentage of the tolerable/acceptable daily intake (TDI/ADI), it seems that the corresponding estimated (conservative) intakes are the highest for DON (56% for organic and 99% for conventional cereal products), ZEA (16% for organic and 32% for conventional cereal products), and Cd (19% for organic and 17% for conventional cereal products), all other estimated intakes of contaminants (including pesticides) being lower than 10% of the TDI/ADI.

The aim of this study was to examine the relationship between placental polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCBs) toxic equivalent (TEQ) levels and the consumption of various food types in pregnant women from central Taiwan. Placental PCDD/Fs and PCB congener TEQ levels were evaluated in 109 pregnant women and dietary information was obtained by questionnaire. TEQ levels of PCDD/Fs and PCBs were positively associated with age and annual family incomes (p < 0.05). PCDD/F TEQs were significantly associated with freshwater fish and dairy product consumption after adjustment for age and body mass index (BMI) (p < 0.05). For PCB TEQs, significant associations were detected for saltwater fish consumption (p < 0.05). In summary, positive correlations were found between freshwater fish and dairy product intake and PCDD/F levels, and a marginal correlation between saltwater fish intake and the body burden of PCBs in pregnant women from central Taiwan. Risk assessment of PCDD/Fs and PCB in fishery products is warranted in a future study to quantify the benefits of fish consumption during the perinatal period.

A solid-phase microextraction method was developed and used to perform a survey of 2-ethylhexanoic acid (2-EHA) in 63 samples of baby food from 13 European Union countries, as well as from Norway and Switzerland. The levels of 2-EHA did not exceed 3.4 mg kg(-1). The concentrations of 2-EHA in 53 samples (84%) were in the range between <0.1 and 0.5 mg kg(-1). Ten samples showed the presence of the compound in the range between 0.5 and 3.4 mg kg(-1). An exposure assessment showed that the intake of 2-EHA does not exceed the tolerable daily intake (TDI) for infants of 6-12 months of age except one occurrence when taking the worst-case food consumption data available and the highest level of contamination of the survey. In the other cases, the levels of 2-EHA are at 13-fold below the TDI.

An analytical method based on gas chromatography/tandem mass spectrometry (GC-MS/MS) (triple quadrupole device) has been developed for quantification of polycyclic aromatic hydrocarbons (PAHs) in smoked salmon. This method was applied to determine PAH concentrations in smoked fish and assess the impact of four industrial smoking processes on their profiles. Two smokehouse temperatures and three smoke-exposure times were applied. All the smoking techniques used lead to acceptable PAH levels: the quantities recovered are 100 times lower than the legal limit (5 microg kg(-1)) concerning the principal PAH, i.e. benzo[a]pyrene. To compare different smoking processes, the toxic equivalent quantity (TEQ) approach was chosen. Smouldering leads to the highest TEQ, while liquid smoke leads to the lowest TEQ.