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.     

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.     

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.     

Survey of pesticide residues in table grapes: Determination of processing factors, intake and risk assessment

The differences in residue pattern between Italy and South Africa, the main exporters of table grapes to the Danish market, were investigated. The results showed no major differences with respect to the number of samples with residues, with residues being found in 54-78% of the samples. Exceedances of the European Union maximum residue limit (MRL) were found in five samples from Italy. A number of samples were rinsed to study the possible reduction of residues. For copper, iprodione, procymidone and dithiocarbamates a significant effect of rinsing was found (20-49% reduction of residues). However, no significant effect was found for organophosphorus pesticides and pyrethroids, whereas the number of samples with residues of benzilates, phenylamids and triazoles was insufficient to demonstrate any significant effects. An intake calculation showed that the average intake from Italian grapes was 3.9 µg day^-1 for pesticides and 21 µg day^-1 for copper. Correspondingly, the intakes from South African grapes were 2.6 and 5.7 µg day^-1, respectively. When the total exposure of pesticides from grapes were related to acceptable daily intake, expressed as the sum of Hazard Quotients, the exposure were approximately 0.5% for Italian samples and 1% for South African samples.     

Dietary intake of tin in Japan, and the effects on intake of canned food and beverage consumption

The study reported herein was initiated to examine dietary tin intake (Sn-D) in Japan to elucidate the possible effects of consumption of canned food (including beverages) on Sn-D, and to compare the intake among regions and between the two sexes in reference to the current provisional tolerable weekly intake and intake in other countries. Urinary tin levels (Sn-U) were also studied. Duplicate diet samples (24 h) together with records of food intake were collected in 1999-2004 from 111 adult residents in four areas of Japan. After exclusion of incomplete samples, 95 valid samples were subjected to determination of tin by inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. Among the 95 cases, 37 women additionally provided urine samples. Distribution of Sn-D was markedly skewed. Median Sn-D was 5.6 µg day^-1 for total subjects, which was about one-tenth of the values previously reported for the Japanese population; the difference was most probably attributable to the difference in the methods of determination. Consumption of canned foods led to a substantial increase in Sn-D. Thus, the median Sn-D for canned food consumers of 35.7 µg day^-1, was eight-fold higher than the median Sn-D for non-consumers of 4.5 µg day^-1. Sn-U (as corrected for creatinine concentration) distributed log-normally with a geometric mean of 2.0 µg (g cr)^-1. No effect of canned food consumption was evident on Sn-U. When compared internationally, Sn-D for the Japanese population was substantially lower than Sn-D for populations in other industrialized countries.     

Occurrence of ochratoxin A in sweet wines produced in Spain and other countries

A survey for the presence of ochratoxin A (OTA) was undertaken from 2001 to 2005 in 188 samples of sweet wines produced in Spain and in 102 samples originating from other countries: France (n = 49), Austria (9), Chile (9), Portugal (9), Greece (6), Italy (5), Germany (3), Hungary (2), Slovenia (2), Switzerland (2), Canada (1), Japan (1), New Zealand (1), Ukraine (1), South Africa (1) and the USA (1). The analytical method was based on immunoaffinity chromatography clean-up and high-performance liquid chromatography (HPLC) with fluorescence detection. The limit of detection (defined as a signal-noise ratio = 3) was estimated to be 0.01 µg l^-1. The limit of quantification (0.02 µg l^-1) was checked as being the lowest measurable concentration. OTA was detected in 281 out of 290 samples analysed (96.9% positive) at concentrations ranging from 0.01 to 4.63 µg l^-1. The overall mean and median levels were estimated to be 0.50 and 0.14 µg l^-1, respectively. In Spanish sweet wines OTA was found in 99% of the samples, with mean and median values of 0.65 and 0.19 µg l^-1, respectively. The mean value obtained in this study for OTA in the Spanish sweet wines would result in an intake of about 37.5 and 3.2 ng day^-1 of OTA for regular consumers and for the overall population, respectively. These figures represent a minor contribution to the provisional tolerable weekly intake (PTWI) or TWI established by the Joint Expert Committee on Food Additives (JECFA) and the European Food Safety Authority: 3.8 and 3.1% for regular consumers; and 0.4 and 0.3% for the whole adult population, respectively.     

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.     

Intake of ochratoxin A and deoxynivalenol through beer consumption in Belgium

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 µg kg^-1 bw was considered. Average consumption of organic beer led to daily intakes of 0.05 and 0.04 µg DON kg^-1 bw in 2003 and 2004, respectively, whilst for conventional beer, daily intakes were 0.07 and 0.05 µg DON kg^-1 bw. At the 97.5th percentile level of beer consumption, daily intakes of 0.15 and 0.13 µg kg^-1 bw were obtained for organic beers against 0.23 and 0.17 µg 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.     

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.     

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.     

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.     

Survey of formaldehyde, acetaldehyde and oligomers in polyethylene terephthalate food-packaging materials

Polyethylene terephthalate (PET) is frequently used as a packaging material for beverage bottles, fruit and vegetable trays, and egg crates in Japan. Levels of formaldehyde (FA), acetaldehyde (AA) and PET oligomers in various PET food packaging were determined. PET samples were initially dissolved in trifluoroacetic acid with 2,4-dinitrophenylhydrazine to derivatize formaldehyde and acetaldehyde to their dinitrophenylhydrazones. The stable derivatives along with the oligomers were analysed using HPLC with ultraviolet light detection at 360 and 254 nm, respectively. The PET pellets contained 3.5-12.4 µg g^-1 AA and 4.0-7.2 mg g^-1 oligomers, while FA was below the determination limit. FA, AA and oligomer levels in Japanese bottles were 0.6-3.0 µg g^-1, 8.4-25.7 µg g^-1 and 5.0-8.7 mg g^-1, ND-1.6 µg g^-1, 5.0-13.1 µg g^-1 and 4.9-8.2 mg g^-1 in French and Italian bottles, and ND-1.2 µg g^-1, 9.1-18.7 µg g^-1 and 5.6-8.0 mg g^-1 in US and Canadian bottles, respectively. Compared with European bottles, Japanese bottles contain higher FA and AA levels. In sheet-moulding products, their contents were determined as ND-1.1 µg g^-1, 11.5-43.1 µg g^-1 and 4.6-9.2 mg g^-1, respectively. The results show that sheet-moulding products contain lower FA and higher AA in comparison with bottles. FA and AA are considered to be generated from PET during the heating process for moulding the pellets to bottles or sheet-moulding articles and de-aeration during the sheet-moulding process is effective in removing FA. In contrast, the level of the oligomers remains unchanged during the moulding process from pellets to bottles or sheet products.     

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.     

Current incidence of N-nitrosodimethylamine in beers worldwide

A range of beers (n = 138) from 42 countries were analysed for the presence of N-nitrosodimethylamine (NDMA) using a chemiluminescence technique with a limit of quantification of 0.1 µg L^-1. The overwhelming majority of samples (79%) did not contain detectable NDMA, and only three samples exceeded 0.5 µg L^-1. No association was found between NDMA content and beer strength, type or geographical origin. It was noted that water can be a potential source of NDMA in beverages.     

The occurrence of nitrofuran metabolites in the tissues of chickens exposed to very low dietary concentrations of the nitrofurans

The global problem of food products contaminated by residues of the banned carcinogenic nitrofuran drugs has prompted research into how such residues accumulate in tissues. In the study described here, two aspects have been investigated where the nitrofurans accumulate in tissues from chickens exposed to either a dietary or an environmental source of contamination. Twenty groups of broilers were fed a diet containing one of the nitrofurans: furazolidone, nitrofurazone, nitrofurantoin or furaltadone at concentrations of 30, 100, 300, 1000 and 3000 µg kg^-1. At the lowest concentration of furazolidone contamination (0.01% of the therapeutic dose) tissue bound AOZ metabolite residues were detected in liver (1.1 ± 0.2 µg kg^-1) and in muscle (0.33 ± 0.03 µg kg^-1). Similar results were obtained for AMOZ (0.6 ± 0.2 µg kg^-1 in liver), the tissue bound metabolite of furaltadone. There was no appreciable accumulation of nitrofurantoin in chicken muscle. The AHD metabolite was not detected in muscle from birds fed nitrofurantoin at either 30 or 100 µg kg^-1. For nitrofurazone the concentrations of the SEM metabolite were higher in muscle than in liver for all dietary concentrations. The potential for a contaminated environment to cause nitrofuran residues in chickens was investigated. Six chickens were placed in a pen that was previously occupied by birds fed a diet containing 3000 µg kg^-1 of furazolidone. After 24 hours' exposure of the chickens to the litter in the pen, AOZ residues of 0.13 ± 0.04 and 0.10 ± 0.03 µg kg^-1 were detected in liver and muscle, respectively. The results of both experiments have implications for the poultry industry in trying to eliminate nitrofurans from their production systems, and for regulatory analysts faced with the detection of low concentrations of the drugs, both in tissues and in feedingstuffs.     

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.     

Justifying the need to prescribe limits for toxic metal contaminants in food-grade silver foils

The use of silver foils in various food preparations is a common practice in Middle Eastern and South East Asian countries. The FAO/WHO Joint Expert Committee on Food Additives (JECFA) has included silver in the list of food additives, but specifications were not prepared. Indian food legislation has included food-grade silver foil and laid down a purity requirement of 99.9%. This leaves an unspecified margin of 0.1% or 1000 µg g^-1 for contaminants. Therefore, a study to investigate the levels of metallic contaminants in food-grade silver foil was undertaken. Of 178 foils analysed, 161 (90%) contained silver, whilst 10% were fraudulently made up of aluminium. In the case of silver foils, 46% of the samples adhered to the desired purity requirement of 99.9%, while 54% had a lower silver content. Copper was present in 86.3% of the silver foils, while chromium, nickel and lead contamination was found in over 54% of samples. Cadmium levels were detected in 28% of the silver foils and manganese was present in 6.8% of samples. In silver foils showing metal contaminants, average levels were found for nickel (487 µg g^-1), lead (301 µg g^-1), copper (324 µg g^-1), chromium (83 µg g^-1), cadmium (97 µg g^-1) and manganese (43 µg g^-1), which being appreciable justify the need to prescribe limits for some metals in food-grade silver foil as well as for silver powder used in confectioneries and medicinal preparations. The work reported here should encourage manufacturers to use high-purity raw materials and take suitable precautions to reduce unwarranted exposure of consumers to toxic metal contaminants.     

Migration of monomers from liquid crystalline poly(p-hydroxybenzoic acid-co-2-hydroxy-6-naphthoic acid)

Liquid-crystalline co-polyesters (e.g. a random copolyester based on p-hydroxybenzoic acid (HBA) and 2-hydroxy-6-naphthoic acid (HNA) known as Vectra A950) offer good barrier properties, but for food-contact use require overall and specific migration testing. For Vectra A950 films, the highest overall migration level obtained was 2.3 mg kg^-1 in olive oil (10 days at 40°C) well below the EC limit of 60 mg kg^-1. The highest specific migration for p-hydroxybenzoic acid was 15.2 μg dm^-2 in olive oil (2h at 175°C). For 2-hydroxy-6-naphthoic acid, the highest value obtained was 4.3 μg dm^-2 in 10% ethanol (4h at 100°C), although it was not on the EC positive and cannot yet be used for food-contact materials. At conditions considered as severe, the estimated daily intake for p-hydroxybenzoic acid was calculated as 11.9 μg/person day^-1 and for 2-hydroxy-6-naphthoic acid it was 5.3 μg/person day^-1. The results exceed the threshold of regulation of 1.5 μg/person day^-1.