Ochratoxin A in dried vine fruit: method development and survey

A method is described for the determination of concentrations of the mycotoxin ochratoxin A in dried vine fruits (currants, raisins and sultanas) using acidic methanolic extraction,immunoaffinity chromatography clean-up and HPLC determination. The limit of detection was estimated as 0.2mug/kg, and recoveries of 63-77% were achieved at 5mug/kg. HPLC-mass spectrometric confirmation of the identity of ochratoxin was obtained. Ochratoxin A and aflatoxins were determined in 60 samples of retail dried vine fruits purchased in the United Kingdom. Ochratoxin A was found in excess of 0.2mug/kg in 19 of 20 currant, 17 of 20 sultana and 17 of 20 raisin samples examined, an overall incidence of 88% . The maximum level found was 53.6mug/kg. No aflatoxin was found in any sample analysed, using a method with a detection limit of 0.2mug/kg for each of aflatoxin B1, B2, G1 and G2.     

Lead-content of foodstuffs. 4. Lead-content of infant foods (author's transl)]

The lead contents in more than 120 glass bottles or packages of infant foods were determined. About 75% of the values were below 100 mug Pb/kg of product. The highest value was 238 mug Pb/kg. The weekly intake of a 6 month-old infant (7.2 kg body weight) fed exclusively with commercial baby foods was found to be about 320 mug Pb, or about 45 mug Pb/kg body weight.     

Acrylamide levels in Finnish foodstuffs analysed with liquid chromatography tandem mass spectrometry

Sample clean-up and HPLC with tandem mass spectrometric detection (LC-MS/MS) was validated for the routine analysis of acrylamide in various foodstuffs. The method used proved to be reliable and the detection limit for routine monitoring was sensitive enough for foods and drinks (38 microg/kg for foods and 5 microg/L for drinks). The RSDs for repeatability and day-to-day variation were below 15% in all food matrices. Two hundred and one samples which included more than 30 different types of food and foods manufactured and prepared in various ways were analysed. The main types of food analysed were potato and cereal-based foods, processed foods (pizza, minced beef meat, meat balls, chicken nuggets, potato-ham casserole and fried bacon) and coffee. Acrylamide was detected at levels, ranging from nondetectable to 1480 microg/kg level in solid food, with crisp bread exhibiting the highest levels. In drinks, the highest value (29 microg/L) was found in regular coffee drinks.     

Tetrahydro-beta-carboline carboxylic acids in smoked foods.

This paper reports for the first time in smoked foods the presence of three tetrahydro-beta-carboline carboxylic acids. One of these, 1-hydroxymethyl-tetrahydro-beta-carboline-3-carboxylic acid, which is derived from the interaction of tryptophan and glycolaldehyde, and which has not previously been reported in foods, was observed in 20 samples at levels up to 444 micrograms/kg. The corresponding products which are derived from tryptophan and formaldehyde or tryptophan and acetaldehyde were found respectively in 28 samples at levels up to 22 mg/kg and in 16 samples at levels up to 881 micrograms/kg. Greater concentrations were generally found in those smoked foods having a lower pH value and produced by using a longer fermentation or maturation. Only 1-methyl-tetrahydro-beta-carboline carboxylic acid (156-574 micrograms/kg) was found in the four unsmoked samples analysed.     

Survey of bisphenol A and bisphenol F in canned foods.

Bisphenol A (BPA) and bisphenol F (BPF) have been determined in a range of canned foods. Sixty-two different canned foods were purchased from retail outlets in the UK from January to November 2000 and the contents extracted and analysed by GC-MS for BPA and BPF isomers. The following canned products were analysed: fish in aqueous media, 10 samples; vegetables, 10; beverages, 11; soup, 10; desserts, five; fruit, two; infant formula, four; pasta, five; and meat products, five. BPF isomers were not detected in any of the canned foods with detection limits of 0.005 mg kg(-1) for the 2,2' and 2,4' isomers and 0.01 mg kg(-1) for the 4,4' isomer. BPA was detected in 38 samples with a detection limit of 0.002 mg kg(-1). Of these, BPA was quantified in 37 canned foods at levels from 0.007 mg kg(-1), with one sample of meat containing a mean level of 0.38 mg kg(-1). All other samples contained <0.07 mg kg(-1) BPA.     

Chlorinated hydrocarbons in the daily diet]

The gas chromatographic analysis of the daily diets (without beverages) of men consuming at maximum 4000 kcal per day, in spring, summer and autumn 1971, revealed always residues of chlorinated hydrocarbons. With an average food amount of 1635 g per day, each subject (having an average body weight of 65 kg) ingested 105 mug of DDT, 20 mug of DDE, 20 mug of DDD, and 149 mug of total DDT and 10 mug of lindane, respectively. The contamination was inferior to the ADI values recommended by the WHO/FAO. From winter 1971 to autumn 1972, the authors also analysed the daily diets (including beverages) of 1-3-year-old children (having an average body weight of 12 kg) in a week-nursery. The average food amount of 1230 g per day contained 42 mug of DDT, 12 mug of DDE, 8 mug of DDD, and 64 mug of total DDT and 7 mug of lindane, respectively. From these values a total DDT intake of 5.3 mug/kg of body weight was calculated which exceeds the ADI value for adults. The claim for a zero tolerance for victuals and ready-to-use baby foods is corroborated. Consequently the complete replacement of DDT by other insecticides is a measure which is imperative not only from the viewpoint of prophylaxis but also from that of health policy.     

Acrylamide in Caribbean foods – Residual levels and their relation to reducing sugar and asparagine content

The acrylamide levels in commercial and homemade Caribbean foods were determined by pre-derivatisation of acrylamide to 2-bromopropenamide and analysed by gas chromatography with mass spectrometric (GC/MS) detection. Over 100 Caribbean food samples were analysed for the presence of acrylamide. These samples include: biscuits, breakfast cereals, banana chips and home-prepared foods: breadfruit; Artocarpus altilis, banana fritters, and dumplings. The limit of detection (LOD) for the GC/MS method was found to be dependent on the type of column used for the GC/MS analysis. The DB-1701 and the DB-VRX columns gave LODs of 20 and 4 μg/kg, respectively. Acrylamide has not been found in raw foods or foods which have been cooked by boiling. Its content in all other foods had concentrations in the range, 65–3640 μg/kg. The relationship between acrylamide levels and precursor concentration as well as the health implications of our findings are discussed.     

Incidence of patulin in fruits and fruit juices marketed in Campinas, Brazil

One hundred and eleven samples of processed fruit juices (apple, grape, pineapple, papaya, guava, banana and mango) and 38 samples of sound fruits (apple, papaya, mango, pear and peach) produced and marketed in Brazil, were analysed for patulin by HPLC. Only one out of 30 samples of apple juice was found positive at 17 mug/l. Patulin was not detected in the other foodstuffs. It was found in 14 samples of spoiled fruit samples of apple (150-267 mug/kg), pear (134-245 mug/ kg) and peach (92-174 mug/kg). Confirmation of the identity of patulin was based on the UV spectrum obtained by the HPLC diode array detector, compared with thatof standard patulin, TLC developed by several solvent systems and sprayed with 3-methyl-2-benzothiazolinone hydrazone , and by acetylation with acetic anhydride.     

Deoxynivalenol in barley samples from Uruguay

A survey of the natural occurrence of deoxynivalenol (DON) in barley harvested in Uruguay from 1996 to 2002 was conducted. A total of 292 samples were analyzed for DON by an immunochemical method using inmunoaffinity columns and fluorimetric detection. Between 26 and 100% of the samples were positive for DON while mean DON contents varied between the quantification limit (500 mug/kg) to 6349 mug/kg. Annual maximum levels in individual samples ranged from 1900 mug/kg to 10,000 mug/kg. The mean DON contents were similar from 1996 to 1999 increasing markedly from 2000 to 2002. The percentage of the samples with DON were highest in 1997, 2000, 2001 and 2002 (67, 90, 100 and 100%) as was the accumulated precipitation during the flowering period. A positive correlation between DON levels and precipitation was seen. These results suggest that monitoring for DON barley crops, particularly in years with heavy rainfall during the flowering period, must be regularly performed.     

Survey of 3-monochloropropane-1,2-diol (3-MCPD) in selected food groups, 1999-2000.

A survey of the levels of 3-monochloropropane-1,2-diol (3-MCPD) in a range of selected food products available in the UK is reported. The survey was carried out on behalf of the Food Standards Agency (FSA) to identify the food groups that might provide a significant contribution to 3-MCPD exposure from the diet. Three hundred samples comprising meat, dairy, cereal, soup and miscellaneous products were purchased from retail outlets and analysed using a GC-MS procedure, which had been formally validated by an earlier collaborative trial. 3-MCPD was detected in 89 (30%) of the samples. Three samples, all crackers, contained levels of 3-MCPD > 0.1 mg kg(-1), the highest level being 0.134 mg kg(-1). Levels of 3-MCPD were generally slightly higher in foods after cooking. In all cases where 3-MCPD was detected in cooked foods, it was also present in the uncooked sample.