Contaminants in organically and conventionally produced winter wheat (Triticum aestivum) in Belgium

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 µg deoxynivalenol (DON), 0.03 µg zearalenone (ZEA), 0.19 µg Cd, 0.28 µg Pb and 0.0006 µg 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 µg DON, 0.06 µg ZEA, 0.17 µg Cd, 0.12 µg Pb and 0.0007 µg 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 µg chlorpyriphos-methyl, 0.2 µg dichlorvos and 0.24 µg 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.     

Five-year survey of ochratoxin A in processed sultanas from Turkey

The results of surveillance for ochratoxin A (OTA) in 1885 samples of sultanas taken during five crop years between 1999 and 2003 are reported. The analytical method was based on extraction with methanol + sodium bicarbonate and clean-up by immunoaffinity column chromatography followed by high-performance liquid chromatography with fluorescence detection. The limit of detection for OTA was 0.3 µg kg^-1. The results show that 9.3% of the samples contained no detectable levels of OTA, whereas 0.6% had concentrations exceeding 10 µg kg^-1; the remaining 90.3% had levels within the range 0.3-10 µg kg^-1. The overall mean OTA concentration in the total number of 1885 samples taken was 1.36 ± 2.91 µg kg^-1; the overall median was calculated as 0.90 µg kg^-1.     

Annual variation of deoxynivalenol in Danish wheat flour 1998-2003 and estimated daily intake by the Danish population

The occurrence of deoxynivalenol (DON) in Danish wheat flour was studied during the period 1998-2003 by either capillary gas chromatography with electron capture detection and liquid chromatography coupled to an ion trap mass spectrophotometer. A total of 151 samples were collected from mills and the retail market in Denmark. Contamination levels varied considerably from year-to-year with the highest concentrations occurring in samples from the 2002 harvest with mean and median concentrations of 255 and 300 µg kg^-1, respectively. Compared to other harvest years, 2002 had the highest amount of precipitation around flowering time, i.e. from the end of June to the beginning of July covering weeks 25-27. The lowest average levels were found in samples from the 2001 harvest, where weeks 25-27 were dry compared with other harvest years. The highest value (705 µg kg^-1) was obtained in a flour sample from the 2002 harvest, but none of the tested samples exceeded the maximum limit of 750 µg kg^-1, which has been recently introduced by the European Commission for DON in flour used as raw materials in food products. Calculation of chronic or usual intake by a deterministic approach showed that intake did not exceed the TDI of 1 µg kg^-1 bw day^-1 either for the whole population or for children. A probabilistic approach also showed that intake in general was below the TDI, but intake for children in the 99% percentile amounted to more than 75% of the TDI. The highest intake is calculated to be 2.5 µg kg^-1 bw day^-1.     

Aflatoxin and ochratoxin A content of spices in Hungary

In October and November 2004, 91 spice samples (70 ground red pepper, six black pepper, five white pepper, five spice mix and five chilli samples), the majority of which originated from commercial outlets, were analysed for aflatoxins B₁, B₂, G₁ and G₂ (AFB1, AFB2, AFG1, AFG2) and ochratoxin A (OTA) content by high-performance liquid chromatography (HPLC) after immunoaffinity column clean-up. Eighteen of the 70 ground red pepper samples contained AFB1, seven of them in a concentration exceeding the 'maximum level' of 5 µg kg^-1 (range 6.1-15.7 µg kg^-1). Of the other spices assayed, the AFB1 contamination of one chilli sample exceeded 5 µg kg^-1 (8.1 µg kg^-1). Thirty-two of the 70 ground red pepper samples contained OTA, eight of them in a concentration exceeding the 10 µg kg^-1 'maximum level' (range 10.6-66.2 µg kg^-1). One chilli sample was contaminated with OTA at 2.1 µg kg^-1. The AFB1 and OTA contamination of ground red pepper exceeding the 'maximum level' (5 and 10 µg kg^-1, respectively) was obviously the consequence of mixing imported ground red pepper batches heavily contaminated with AFB1 and OTA with red pepper produced in Hungary. This case calls attention to the importance of consistently screening imported batches of ground red pepper for aflatoxin and ochratoxin A content and strictly prohibiting the use of batches containing mycotoxin concentrations exceeding the maximum permitted level.     

Estimated intake of intense sweeteners from non-alcoholic beverages in Denmark

In 1999, 116 samples of non-alcoholic beverages were analysed for the intense sweeteners cyclamate, acesulfame-K, aspartame and saccharin. High contents of cyclamate close to the maximum permitted level in 1999 of 400 mg l^-1 were found in many soft drinks. The estimated intake of the sweeteners was calculated using the Danish Dietary Survey based on 3098 persons aged 1-80 years. The estimated intake with 90th percentiles of 0.7, 4.0 and 0.2 mg kg^-1 body weight (bw) day^-1 for acesulfame-K, aspartame and saccharin, respectively, was much lower than the acceptable daily intake (ADI) values of 15, 40 and 2.5 mg kg^-1 bw day^-1 for acesulfame-K, aspartame and saccharin, respectively. However, the 90th percentile of the estimated cyclamate intake in 1-3 year olds was close to the ADI value of 7 mg kg^-1 bw day^-1; and the 99th percentile in the 1-10 year olds far exceeded the ADI value. Boys aged 7-10 years had a significantly higher estimated intake of cyclamate than girls. The 90th percentile for the whole population was 1.8 mg kg^-1 bw day^-1. After the reduction in the maximum permitted level in the European Union in 2004 from 400 to 250 mg cyclamate l^-1, the exposure in Denmark can also be expected to be reduced. A new investigation in 2007 should demonstrate whether the problem with high cyclamate intake is now solved.     

Screening survey of deoxynivalenol in beer from the European market by an enzyme-linked immunosorbent assay

Deoxynivalenol (DON) was analysed in 313 beer samples collected from the European retail market using a commercially available immunoassay kit (enzyme-linked immunosorbent assay, ELISA). The incidence rate was about 87%, while most samples (73%) had contamination levels lower than 20 ng ml^-1. The contamination ranged between 4.0 and 56.7 ng ml^-1, with an average of 13.5 ng ml^-1. A statistically significant correlation between alcohol levels and DON contamination was found, as well as a significant difference between bottom, top and spontaneous fermenting beers. Twenty-seven beer samples were compared using a second ELISA kit and a good correlation was obtained between the two kits (r = 0.93). Although when compared with gas chromatography-mass spectrometry the ELISA tended to overestimate the results, a good correlation (r = 0.94) between the two methods was observed. Monitoring of DON in beer is important considering that DON production is dependent on the weather and that it can contribute significantly to the tolerable daily intake of DON, especially for frequent beer consumers.     

Australian survey of acrylamide in carbohydrate-based foods

A method was developed and validated for the determination of acrylamide in carbohydrate-based foods. Solid-phase extraction employing a mixed-bed anion and cation exchange cartridge in series with a C18 extraction disk was used to clean-up water extracts of food samples before analysis by liquid chromatography coupled with tandem mass spectrometry detection. The limit of detection was calculated as approximately 25 μg kg^-1 and the limit of reporting was 50 μg kg^-1. The average method recovery for 84 samples from a range of matrices reporting was 99% with a relative standard deviation of 11.2%. A survey was conducted of 112 samples of carbohydrate-based foods composited from 547 products available in the Australian market. The analytical results were used in conjunction with Australian food consumption data derived from the 1995 National Nutrition Survey (NNS) to prepare preliminary dietary exposure estimates of Australians to acrylamide through only the food groups examined. Mean dietary exposure to acrylamide resulting from consumption of the foods tested, for Australians aged 2 years and above, was estimated as 22-29 µg day^-1 (equivalent to 0.4-0.5 µg kg^-1 bodyweight day^-1) and between 73 and 80 µg day^-1 (1.4 and 1.5 µg kg^-1 bodyweight day^-1) for 95th percentile consumers. Young children (2-6 years) consuming acrylamide-containing foods had a higher acrylamide exposure on a per kilogram bodyweight basis (mean 1.0-1.3 µg kg^-1 bodyweight day^-1). The estimated exposure of Australians to acrylamide is similar to that estimated for other countries.     

Determination of ochratoxin A in grapes of Greek origin by immunoaffinity and high-performance liquid chromatography

A simple analytical method for ochratoxin A (OTA) determination in grapes is described, using aqueous methanolic extraction, an immunoaffinity column clean-up step and high-performance liquid chromatography with fluorescence detection. Mean recovery was 94% (RSD = 4.0%) with a detection limit of 0.4 ng g^-1 and quantification limit of 1.20 ng g^-1. Repeatability (r) and reproducibility (R) were 1.17 and 1.34, respectively. OTA determinations were applied to 50 grape samples (23 different varieties) originating from representative regions of Greece. Results showed the presence of OTA in 86% of samples tested (n = 50). Traces were found in 56% of samples but OTA was not detectable in 14% of samples. Traces were also found in 4% of red, organically grown samples. The most contaminated were three samples of red grapes, two from Central Greece (2.69 and 1.41 ng g^-1), both table and wine-making grapes. The third sample (1.46 ng g^-1), originating from the island of Samos, was used only in wine-making. Mean (1.06 ng g^-1) and median (0.76 ng g^-1) OTA concentrations in red grapes were slightly higher compared to the mean (0.82 ng g^-1) and median (0.65 ng g^-1) concentrations in white grape samples. The study shows that the potential risk for a person of 60 kg ranged from 0.9 to 9 ng kg^-1 bw day^-1 and is dependent on the quantity of grapes consumed daily.     

Determination of ochratoxin A in virgin olive oils of Greek origin by immunoaffinity column clean-up and high-performance liquid chromatography

An improved specific analytical method for ochratoxin A (OTA) determination in olive oil is described, using a methanolic-aqueous extraction, an immunoaffinity column clean up step and high-pressure liquid chromatography with fluorescence detection. The mean recovery was found at 108% (relative standard deviation, RSD = 4.7%) and the detection limit (DL) was estimated at 4.6 ng kg^-1. Along with OTA, aflatoxin B₁ (AFB₁) was determined using the same extract. The recovery factor was 84.8% (RSD = 17.8%) and the DL was 56 ng kg^-1 olive oil. Both determinations were applied in 50 samples of olive oil originated from representative regions of Greece. Results revealed the presence of OTA in 88% of samples tested (n = 44, mean 267 ng kg^-1). Among them, 10 were contaminated with more than 500 ng kg^-1 (median 568 ng kg^-1), 10 with 200-500 ng kg^-1 (median 260 ng kg^-1), 15 with 100-200 ng kg^-1 (median 140 ng kg^-1), nine with DL-100 (median 60 ng kg^-1) and in six samples, OTA was not detectable. Interestingly, most contaminated samples were from Southern Greece. Results of AFB₁ determination showed the presence of aflatoxin B₁ (60 ng kg^-1) in only one olive oil sample also from Southern Greece. The levels of OTA found in Greek olive oil were relatively low as compared with other commodities such as cereals or wine reported in the literature.     

FTIR-ATR infrared spectroscopy for the detection of ochratoxin A in dried vine fruit

A method of screening sultanas for ochratoxin A (OTA) contamination, using mid-infrared spectroscopy/Golden Gate single-reflection ATR (attenuated total reflection), is described. The main spectral characteristics of sultanas from different sources were identified in a preliminary acquisition and spectral analysis study. Principal component analysis (PCA) showed that samples of various origins had different spectral characteristics, especially in water content and the fingerprint region. A lack of reproducibility was observed in the spectra acquired on different days. However, spectral repeatability was greatly improved when water activity of the sample was set at 0.62. A calibration curve of OTA was constructed in the range 10-40 µg OTA kg^-1. Samples with OTA levels higher than 20 µg kg^-1 were separated from samples contaminated with a lower concentration (10 µg OTA kg^-1) and from uncontaminated samples. The reported methodology is a reliable and simple technique for screening dried vine fruit for OTA.     

Contribution of water and cooked rice to an estimation of the dietary intake of inorganic arsenic in a rural village of West Bengal, India

Arsenic contamination of rice plants by arsenic-polluted irrigation groundwater could result in high arsenic concentrations in cooked rice. The main objective of the study was to estimate the total and inorganic arsenic intakes in a rural population of West Bengal, India, through both drinking water and cooked rice. Simulated cooking of rice with different levels of arsenic species in the cooking water was carried out. The presence of arsenic in the cooking water was provided by four arsenic species (arsenite, arsenate, methylarsonate or dimethylarsinate) and at three total arsenic concentrations (50, 250 or 500 µg l^-1). The results show that the arsenic concentration in cooked rice is always higher than that in raw rice and range from 227 to 1642 µg kg^-1. The cooking process did not change the arsenic speciation in rice. Cooked rice contributed a mean of 41% to the daily intake of inorganic arsenic. The daily inorganic arsenic intakes for water plus rice were 229, 1024 and 2000 µg day^-1 for initial arsenic concentrations in the cooking water of 50, 250 and 500 µg arsenic l^-1, respectively, compared with the tolerable daily intake which is 150 µg day^-1.     

Fumonisin B1, fumonisin B2, zearalenone and ochratoxin A contamination of maize in Croatia

Mycotoxins are products of moulds that frequently contaminate maize. In this study the presence of mycotoxins fumonisin B₁ (FB₁), fumonisin B₂ (FB₂), zearalenone (ZEA) and ochratoxin A (OTA) was determined in 49 maize grain samples collected in autumn 2002. The most frequent finding was that of FB₁(100%), followed by ZEA (84%) and OTA (39%), while FB₂ was found only in three samples. The co-occurrence of two and three mycotoxins was found in 55 and 37% of samples, respectively. The concentrations (mean ± SD) of FB₁, ZEA and OTA in positive samples were 459.8 ± 310.7, 3.84 ± 6.68 and 1.47 ± 0.38 µg kg^-1, respectively, and the concentrations of FB₂ in three positive samples were 68.4, 109.2 and 3084.0 µg kg^-1. Although such low concentrations of mycotoxins are not a significant source of exposure in countries with a European diet, a few samples with extreme values indicate that thorough control is needed.     

Usage of saccharin in food products and its intake by the population of Lucknow, India

A survey of the usage patterns of the artificial sweetener, saccharin, in edible products and a study of its intake pattern in different population groups has been carried out. Of the different edible commodities, ice candy (87 samples) and crushed ice (14 samples), commonly consumed by children, and pan masala (16 samples) and pan flavourings (10 samples), consumed by the habitual population, were collected from different areas of Lucknow, India. Saccharin was extracted from the samples according to an AOAC method and analysed by HPLC. The consumption pattern of ice candy and crushed ice was determined for 6-20 year olds from a household dietary survey using the food frequency recall method (414 families having 1039 subjects). The consumption of pan masala and pan was assessed by a survey of habitual adult consumers comprising 782 and 1141 subjects, respectively. The average and maximum amounts of saccharin in pan masala samples were 12 750 and 24 300 mg kg^-1, respectively, which are 1.6- and 3-fold higher than the maximum permitted levels allowed under Prevention of Food Adulteration (PFA) Act of India. In pan flavourings, the average and maximum amount of saccharin was 12.2 and 20.1%, i.e. 1.52- and 2.5-fold higher than the permissible limits of the PFA Act. The samples of ice candy and crushed ice showed average and maximum levels of 200 and 700 mg kg^-1 and 280 and 460 mg kg^-1, respectively. The average intake of saccharin through ice candy and crushed ice was less than 21% of the acceptable daily intake (ADI) (5 mg kg^-1 body weight (bw) day^-1). However, the maximum intake of saccharin, especially in the 6-10-year age group, contributed 57 and 68% of the ADI through ice candy and crushed ice, respectively. Maximum consumption of saccharin in all the age groups, if consuming both ice candy and crushed ice, results in exceeding the ADI by 54% for subjects in the 6-10-year age group. Hence, the 6-10-year age group population may be at risk of exceeding the ADI for saccharin. The average and maximum theoretical daily intake of saccharin through pan masala alone was 1.84 and 13.33 mg kg^-1 bw day^-1, contributing 37 and 267% of the ADI, whereas the estimated (maximum) daily intake was 810% of the ADI. The estimated maximum daily intake (EDI) of saccharin through pan was 6.87 mg kg^-1 bw day^-1, which was 137% of the ADI. Thus, individuals in the maximum consumption group for pan masala or pan may be susceptible to toxic effects of saccharin, including bladder distention, elevated urine osmolality and bladder cancer.     

Consumer exposure to substances in plastic packaging. I. Assessment of the contribution of styrene from yogurt pots

A generic methodology for the assessment of consumer exposure to substances migrating from packaging materials into foodstuffs during storage is presented. Consumer exposure at the level of individual households is derived from the probabilistic modeling of the contamination of all packed food product units (e.g. yogurt pot, milk bottle, etc.) consumed by a given household over 1 year. Exposure of a given population is estimated by gathering the exposure distributions of individual households to suitable weights (conveniently, household sizes). Calculations are made by combining (i) an efficient resolution of migration models and (ii) a methodology utilizing different sources of uncertainty and variability. The full procedure was applied to the assessment of consumer exposure to styrene from yogurt pots based on yearly purchase data of more than 5400 households in France (about 2 million yogurt pots) and an initial concentration c₀ of styrene in yogurt pot walls, which is assumed to be normally distributed with an average value of 500 mg kg^-1 and a standard deviation of 150 mg kg^-1. Results are discussed regarding both sensitivity of the migration model to boundary conditions and household practices. By assuming a partition coefficient of 1 and a Biot number of 100, the estimated median household exposure to styrene ranged between 1 and 35 µg day^-1 person^-1 (5th and 95th percentiles) with a likely value of 12 µg day^-1 person^-1 (50th percentile). It was found that exposure does not vary independently with the average consumption rate and contact times. Thus, falsely assuming a uniform contact time equal to the sell-by-date for all yogurts overestimates significantly the daily exposure (5th and 95th percentiles of 2 and 110 µg day^-1 person^-1, respectively) since high consumers showed quicker turnover of stock.     

Dioxins and polychlorinated biphenyls (PCBs) in fish oil dietary supplements: Occurrence and human exposure in the UK

Commercially available fish oil supplements sourced from retail outlets in the UK, as well as by mail order, were surveyed in 2000-02 for dioxin (PCDD/Fs) and polychlorinated biphenyl (PCB) content. Sampled products were representative of market share. The WHO-TEQ values for these products ranged from 0.18 to 8.4 ng kg^-1 for ΣPCDD/F and from 1.1 to 41 ng kg^-1 for Σ dioxin-like PCBs. The results suggest a downward trend in the levels of dioxins in fish oil supplements over the last decade, since levels for similar products ranged from 0.3 to 10 ng kg^-1 for ΣPCDD/F WHO-TEQ in 1996. Levels of ICES (International Council for the Exploration of the Seas) 7 PCBs in the current study ranged from 8.3 to 267 µg kg^-1. Subsequent to this survey, European Union legislation has been introduced that includes a maximum limit of 2 ng kg^-1 WHO-TEQ for dioxins in fish oil products for human consumption. Twelve of the 33 products reported here would have exceeded this limit. Negotiations are in progress to incorporate dioxin-like PCBs into the European Union regulations. When manufacturer-recommended doses were applied to the observed levels, the estimated upper bound human exposure to dioxins and dioxin-like PCBs from dietary intake of these products ranged from 0.02 to 7.1 pg WHO-TEQ kg^-1 body weight day^-1 for adults and from 0.02 to 10 pg WHO-TEQ kg^-1 body weight day^-1 for schoolchildren. This level rises to 1.8-8.9 pg WHO-TEQ kg^-1 body weight day^-1 for adults and 1.4-14 pg WHO-TEQ kg^-1 body weight day^-1 for schoolchildren when combined with the average exposure from the whole diet in 1997. Again, subsequent to this survey, the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT) revised the UK tolerable daily intake (TDI) for mixtures of dioxins and dioxin-like PCBs from 10 to 2 pg WHO-TEQ kg^-1 body weight day^-1. This is in line with the tolerable weekly intake (TWI) of 14 pg WHO-TEQ kg^-1 body weight set by the Scientific Committee on Food (SCF).     

Comparison of various assays used for detection of beta-lactam antibiotics in poultry meat

In this study, microbiological tests for the detection of beta-lactam antibiotics in meat and meat products were evaluated. The traditional FPT (four plate test, containing Bacillus subtilis and Kocuria rhizophila), BsDA (Bacillus stearothermophilus disc assay) and a newly developed microbiological test, Premi®Test (containing Bacillus stearothermophilus) were included in the study. The limit of detection (LOD) of the Premi®Test was compared with the LOD of the traditional methods. The detection limits of the tests were determined by using beta-lactam antibiotic standards dissolved in meat juice, as well as meat tissue obtained from laying hens after experimental administration of amoxicillin. Positive samples, based on inhibition of growth of the organism in the test, were confirmed by high performance liquid chromatography (HPLC). Growth inhibition in the traditional tests is visible as a clear zone on the plate, whereas for Premi®Test, this is based on the absence of a colour change of the test. The LODs of antibiotics tested were as follows: Penicillin G (PENG) 5 µg kg^-1, amoxicillin (AMOX) 10 µg kg^-1, ampicillin (AMP) 25 µg kg^-1, oxacillin (OXA) 30 µg kg^-1, and cloxacillin (CLOX) 30 µg kg^-1 on the plate with Bacillus stearothermophilus. Beta-lactam antibiotics can be detected also on one plate seeded with Kocuria rhizophila, although the LODs are higher: PENG 10 µg kg^-1, AMOX 25 µg kg^-1, AMP 30 µg kg^-1, OXA 50 µg kg^-1, and CLOX 50 µg kg^-1. Premi®Test was performed according to the Standard Operating Procedure intended for detection of beta-lactam antibiotics in poultry tissues with following LODs: PENG 4 µg kg^-1, AMOX 5 µg kg^-1, AMP 5 µg kg^-1, OXA 40 µg kg^-1, CLOX 50 µg kg^-1. All tests are able to detect beta-lactam antibiotics such as penicillin G, ampicillin, amoxicillin, oxacillin and cloxacillin below the maximum residue level (MRL). However, the detection limits of the Premi®Test for PENG, AMOX and AMP were below the limits of BsDA and the plate containing Kocuria rhizophila.     

Lead and cadmium in meat and meat products consumed by the population in Tenerife Island, Spain

The aim of this study was to determine the levels of lead and cadmium in chicken, pork, beef, lamb and turkey samples (both meat and meat products), collected in the island of Tenerife (Spain). Lead and cadmium were measured by graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations of lead and cadmium were 6.94 and 1.68 µg kg^-1 in chicken meat, 5.00 and 5.49 µg kg^-1 in pork meat, 1.91 and 1.90 µg kg^-1 in beef meat and 1.35 and 1.22 µg kg^-1 in lamb meat samples, respectively. Lead was below the detection limit in turkey samples and mean cadmium concentration was 5.49 µg kg^-1. Mean concentrations of lead and cadmium in chicken meat product samples were 3.16 and 4.15 µg kg^-1, 4.89 and 6.50 µg kg^-1 in pork meat product, 6.72 and 4.76 µg kg^-1 in beef meat product and 9.12 and 5.98 µg kg^-1 in turkey meat product samples, respectively. The percentage contribution of the two considered metals to provisional tolerable weekly intake (PTWI) was calculated for meat and meat products. Statistically significant differences were found for lead content in meats between the chicken and pork groups and the turkey and beef groups, whereas for cadmium concentrations in meats, significant differences were observed between the turkey and chicken, beef and lamb groups. In meat products, no clear differences were observed for lead and cadmium between the various groups.     

Quantitative analysis of ochratoxin A in wine and beer using solid phase extraction and high performance liquid chromatography-fluorescence detection

A reliable and accurate method is described for the quantitative analysis of ochratoxin A (OTA) in wine and beer. The method involves the use of disposable non-polar polymeric and aminopropyl solid-phase extraction cartridges to isolate the mycotoxin from alcoholic beverages. Extracts were subsequently analysed using reverse-phase high-performance liquid chromatography-fluorescence detection with post column ammoniation to improve the limit of detection. The precision of the method determined at three levels in both wine and beer was less than 5% (RSD). Standard addition studies in both wine and beer showed that the recovery of OTA varied between 90 and 106% over a concentration range of 0.016-1.284 µg l^-1. The detection and quantification limits were shown to be better than 0.004 (S/N = 3) and 0.016 µg l^-1 (S/N = 10) for both beer and wine.     

Methylmercury determination in fish and seafood products and estimated daily intake for the Spanish population

The mercury content of 25 samples of fish and seafood products most frequently consumed in Spain was determined. A simple method comprising cold vapour and atomic absorption spectrometry was used to determine separately inorganic and organic mercury. In all samples inorganic mercury content was below 50 µg kg^-1. There was wide variability, among not only the mercury levels of different fish species, but also for different samples of the same species — with the methylmercury content ranging from below 54 to 662 µg kg^-1. The highest mean methylmercury content was found in fresh tuna. Based on an average total fish consumption of 363 g/person week^-1, the methylmercury intake was estimated to be 46.2 µg/person week^-1. Therefore, the mercury intake of Spanish people with a body weight ≤ 60 kg is lower than the Joint FAO/WHO Expert Committee on Food Additives (JECFA) provisional tolerable weekly intake (PTWI) of 1.6 µg kg^-1 body weight, but exceeds the US National Research Council (NRC) limit of 0.7 µg kg^-1 body weight week^-1 based on a benchmark dose.     

Use of a food-consumption database with packaging information to estimate exposure to food-packaging migrants: expoxidized soybean oil and styrene monomer

There is no set protocol for completing refined exposure assessments of food-packaging migrants in the European Union. One novel method that could be used to provide more realistic exposure assessments and also reduce uncertainty in the exposure estimation could be the use of food consumption surveys that also have packaging information. The aim of the current study was to estimate exposure to two food-packaging migrants (expoxidized soybean oil (ESBO) and styrene monomer) using a food-consumption database that collected packaging information. The Irish National Children's Food Survey (NCFS) was completed in 2003-04 and it collected information on the type and amount of food consumed by 594 Irish children aged 5-12 years, in addition to the type of packaging used for these foods. The Irish Food Packaging Database (IFPD) was completed in parallel to this food consumption survey and recorded exact information on the contact layer used for the packaging. In a database that combined information from the NCFS and the IFPD, the packaging materials that could contain the target migrants were identified. If a food was packaged in a material that could contain the migrant, it was assumed that the migrant was present in the food. For the exposure assessment of ESBO the 90th percentile migration values of ESBO in foods derived from the literature were used. This was similar to a method as used by the European Food Safety Authority (EFSA) in their exposure assessment of ESBO for adults. Two scenarios of styrene exposure were undertaken in this study. In the first scenario the 90th percentile migration value for styrene found in foods was used; in the second scenario the maximum level of styrene found in foods was used. These migration values were derived from the literature. The mean intake of ESBO for Irish children was 0.023 mg kg^-1 body weight day^-1, which is well below the tolerable daily intake (TDI) of 1 mg kg^-1 body weight day^-1 set by the Scientific Committee for Food (SCF) in 1999. The food group that contributed most to ESBO intake was tomato sauces packed in glass jars with polyvinyl chloride (PVC)-lined metal lids (46.8%). For styrene, the mean intake was 0.122 µg kg^-1 body weight day^-1 when using the 90th percentile migration values and 0.169 µg kg^-1 body weight day^-1 when using the maximum migration values. These estimated intakes are below the provisional maximum tolerable daily intake (PMTDI) of 40 µg kg^-1 body weight day^-1, which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1984. Therefore, the estimated intakes of the two migrants are not of concern for Irish Children and uncertainty is reduced in the assessment due to the fact that information is available on the type of foods consumed the type of packaging used for these foods.