Aristolochia: Aristolochic acid, endemic nephropathy and renal failure in the Balkans.
Frost & Sullivan Research Report, Published: 21 Jun 2001, Price: US$ 5,400
Edited by M Magan and M Olsen, Woodhead Publishing 2004, Hardback 488 pages, ISBN 1855737337, £135.00
Mycotoxins, toxic compounds produced by fungi, pose a significant contamination risk in both animal feed and foods for human consumption. With its distinguished editors and international team of contributors, Mycotoxins in food summarises the wealth of recent research on how to assess the risks from mycotoxins, detect particular mycotoxins and control them at differing stages in the supply chain.
Part 1 addresses risk assessment techniques, sampling methods, modelling and detection techniques used to measure the risk of mycotoxin contamination and the current regulations governing mycotoxin limits in food. Part 2 looks at how the risk of contamination may be controlled, with chapters on the use of HACCP systems and mycotoxin control at different stages in the supply chain. Two case studies demonstrate how these controls work for particular products. The final section details particular mycotoxins, from ochratoxin A and patulin to zearalenone and fumonisins.
Mycotoxins in food will be a standard reference for all those concerned with ensuring the safety of food.
Edited by D Watson, Woodhead Publishing 2004, Hardback 704 pages, ISBN 1855737345, £160.00
This wide-ranging text reviews the wealth of recent research on assessing and managing the risks from pesticide, veterinary and other chemical residues in food. After an introductory chapter on the key issues in food toxicology, Part 1 covers the assessment and management of risks, with individual chapters on genetic susceptibility to dietary carcinogens, good agricultural practice and HACCP systems, targeted and rapid methods for analysing residues in food and ways of assessing the mutagenicity of chemicals in food. Part 2 looks at veterinary residues, covering their safety, toxicology and detection. Part 3 examines pesticides, with chapters on surveillance and detection methods for fungicides and herbicides. In the final part, there are chapters summarising a wide range of other chemical residues in food, from xenostrogens/endocrine disruptors and dietary estrogens to polycyclic aromatic hydrocarbons, dioxins and polychlorinated biphenyls.
Pesticides, veterinary and other residues in food will be a standard reference for all those concerned with ensuring the safety of food.
About the editor: Dr D Watson is Head of Branch 5 of the Chemical Safety and Toxicology Division of the UK Food Standards Agency. He has written and edited numerous publications, including the highly-successful Food chemical safety Volume 1: Contaminants and Food chemical safety Volume 2: Additives for Woodhead Publishing and is a Fellow of the Royal Society of Chemistry and the Institute of Biology.
This extensive report compiles the most current, complete information available on mycotoxins in order to provide an understanding of their associated risks and impacts on plant, animal, and human systems. The report seeks to educate those making decisions that affect regulation and control of foods and feeds as well as to illuminate the potential for mycotoxins to impact international trade of commodities and food products. Among the topics covered are fungal growth and mycotoxin development, occurrence of mycotoxins in food and feed, mycotoxins and human disease, and mycotoxicoses of animals. Co chairs: John L. Richard, Romer Labs, Inc., Union, Missouri, and Gary A. Payne, Department of Plant Pathology, North Carolina State University, Raleigh. Council for Agricultural Science and Technology (CAST), R139, January 2003, ISBN 1-887383-22-0, 199 pp., US $50.00.
Additional information
edited by D. Barug, H. van Egmond, R. Lopez-Garcia, T. van Osenbruggen and A. Visconti
Mycotoxins are toxic secondary metabolites of moulds belonging essentially to the Aspergillus, Penicillium, and Fusarium genera. They can be produced on a wide range of agricultural commodities and under a diverse range of situations. Due to their various toxic effects and their good thermal stability, the presence of mycotoxins in foods and feeds is potentially hazardous to the health of both humans and animals. Mycotoxins may cause damage to e.g. liver, kidney or the nervous system, some are even carcinogenic. There is growing concern for ways in which these fungi and their mycotoxins can be prevented from entering the human and animal food chain. And worldwide changes in legislation ever increase the need for more precise and sensitive mycotoxin analytical methods.
"Meeting the mycotoxin menace" contains the peer-reviewed papers of the second World Mycotoxin Forum held 17-18 February 2003 in Noordwijk, the Netherlands. The book focusses on the various aspects related to the presence, prevention, control, sampling and analysis of mycotoxins in agricultural commodities, foods and feeds. In this publication special attention is given to new developments in this field. The editors firmly believe that the very nature of the themes chosen and the excellence of the papers by invited experts from various disciplines will draw an audience from both the food and feed industry, regulatory authorities and science. Wageningen Academic Press, 2004, 320 pages, hardcover, ISBN: 9076998280, price (Euros): €80
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PROCEEDINGS OF THE X INTERNATIONAL IUPAC SYMPOSIUM ON MYCOTOXINS AND PHYCOTOXINS
21-25 May 2000, Guarujá (Brazil)
Edited by Willem J. de Koe, Robert A. Samson, Hans P. van Egmond, John Gilbert and Myrna Sabino
ISBN 90-9014801-9, 576 pages, http://www.dekoe.nl/
Mycotoxins and Food Safety: Book Series: ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY, Volume 504
Contents
Mycotoxin Protocols: Series: Methods in Molecular Biology, Volume 157
Contents
ABSTRACT
The aim of this study was to perform a optimised method for determination of aflatoxin M1 in milk . The extraction and clean-up procedures of milk samples as well the conditions of reaction of aflatoxin M1 with TFA and HPLC were described. The main steps of optimised method were: extraction of samples with chloroform, clean-up of extracts on SPE C18 columns and by means of extraction with n-hexane, derivatisation of aflatoxin M1 with TFA (60 centigrade, 6 minutes) to acetal form-aflatoxin M2a and determination of aflatoxin by means the RP-HPLC technique. The mobile phase was a mixture of methanol, isopropanol and water (18+7+75). Fluorometric detection was made at 370/418-700 nm. The mean recovery of aflatoxin M1 dependent on fortification level was 62-67%, limit of detection was 0,01 microgram/l of milk.
ABSTRACT
The aim of this study was to perform a optimised method for determination of fumonisins B1 and B2 in corn products. The manner of extraction and clean-up of corn products extracts as well conditions of reaction of fumonisins with OPA was described. The main steps of optimised analytical procedure were: extraction of sample with methanol and water (3+1), clean-up of extracts on SAX column, derivatisation with OPA, and determination by means of RP-HPLC. The mobile phase was a mixture of methanol, water and acetic acid (75+24+1). Fluorometric detection was made at 370/440 nm. The mean recovery of fumonisins dependent on fortification level and product was 64-95%, limit of detection for each fumonisins was 15 microgram/kg.
ABSTRACT
A liquid chromatographic (LC) method for determining deoxynivalenol (DON) in white flour, whole wheat flour, and bran at or above the U.S. Food and Drug Administration advisory level of 1 µg/g was evaluated by an interlaboratory study. Test samples of processed wheat (flour and bran) were extracted by blending with acetonitrile-water (84 + 16). Extracts were filtered and passed through a solid-phase extraction (SPE) column. The eluate was then chromatographed on a reversed-phase LC column with a water-medianol gradient. DON was measured at 220 nm. Naturally contaminated white flour, whole wheat flour, and bran samples and spiking solutions of DON to be added to the 3 commodities at 0.5, 1.0, and 2.0 µg/g were sent to 4 collaborators in Kansas, Louisiana, Missouri, and Washington states. Three collaborators completed the study. Average recoveries of DON from the 3 commodities spiked at 0.5, 1.0, and 2.0 µg/g were 94, 87, and 97%, respectively. Within-laboratory relative standard deviations for repeatability (RSD-r) ranged from 3.1 to 21.7% and between-laboratory relative standard deviations for reproducibility (RSDR) ranged from 10.8 to 38.7%. On the basis of the results of this study, the SPE/LC method for DON in white flour, whole wheat flour, and bran was adopted as a peer-verified method by AOAC INTERNATIONAL.
ABSTRACT
Electron spin resonance (ESR)-1 spin-label oximetry and spin trapping techniques have been used to study the effect of fumonisin B-1 (FB-1), an amphipathic mycotoxin on lipid peroxidation in egg yolk phosphatidylcholine (EYPC) bilayers. In the study of the interaction between FB-1 and lipid bilayers our results show that fumonisin disturbs the ordering of membranes, enhances oxygen transport in membranes, and also increases membrane permeability. In our model system, lipid peroxidations were initiated by extended incubation of the liposomes, or by inducing Fe2+ ions, UV illumination of H2O2 or ultrasound irradiation. As an indication of the rates of lipid oxidation in EYPC, the consumption of molecular oxygen was studied by monitoring the oxygen concentration in the aqueous phases of the liposomes. Lipid-derived free radicals generated during the oxidation process were measured by a spin trapping method. The incorporation of FB-1 in the test samples made the membranes highly susceptible to oxidation. Our results provide the first evidence that the fumonisins appear to increase the rate of oxidation, promote the free radical intermediate production and accelerate the chain reactions associated with lipid peroxidation. The disruption of membrane structure, the enlargement of the relative oxygen diffusion-concentration products, as well as the enhancement effects on membrane permeability, thus provide additional insights into potential mechanisms by which the fumonisins could enhance oxidative stress and cell damage.
ABSTRACT
Fumonisin B-1 (FB-1), a contaminant of corn, has been reported to be a hepatocarcinogen in rats. In an attempt to understand its mechanisms of action, a model system of isolated rat liver nuclei was used to determine what effects, if any, FBI might have on nuclear membrane lipids and DNA. The data suggested that FB-1 induced lipid peroxidation concurrently with DNA strand breaks in this in vitro system. Iron and copper had no statistically significant stimulatory effects on these reactions. In addition, the active oxygen scavengers catalase, superoxide dismutase (SOD), mannitol and sodium azide had no significant inhibitory effects on the FB-1-induced DNA strand breaks. However, a small but significant reduction in lipid peroxidation by catalase and mannitol was observed. These results suggested that hydroxyl radicals may be the initiators of the nuclear membrane lipid peroxidation, which results in production of peroxyl radicals. In turn, the peroxyl radicals may be responsible for the DNA strand breaks. An alternative explanation is that the hydroxyl radicals, produced close to the DNA-bound metal ions, may induce direct site-specific strand breaks, which are insensitive to the scavengers of active oxygen.
ABSTRACT
Patulin production was evaluated in Gala and Fuji apple cultivars inoculated with P. expansum NRRL 1172 and a toxigenic P. variabile strain isolated from commercialized apples. Samples for analysis were taken from apples stored under combined conditions of time and temperature, which ranged from 15-90 days and 0-25EC, respectively. Patulin was produced throughout the storage temperatures tested by both Penicillium strains. Patulin production was negative until 30 days post-inoculation in apples stored at 0EC, but increase of temperature to 4EC restricted the safety threshold. P. variabile produced higher concentrations of patulin in inoculated apples than P. expansum NRRL 1172.
ABSTRACT
Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic molds in the Aspergillus, Penicillium, and Fusarium genera occurring in food commodities and foodstuffs. Mycotoxin production is dependent mainly on both well-defined ranges of temperature and A-w and favorable environmental conditions. The relevance of mycotoxins to human health is rather well established and includes a wide variety of toxic effects (carcinogenic power, immunosuppressive action, etc.). Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot or food commodity and, consequently, of the impact of mycotoxins on human health. In this paper the main sources of error in the evaluation of the actual impact of mycotoxins on human health are reviewed. In particular, the errors associated with the sampling, subsampling, and analysis steps are reviewed. As far as the biomarker approach is concerned, the errors deriving from a limited knowledge of the metabolism of the single toxin and of the metabolites derived from the parent toxin in biological fluids are briefly outlined.
ABSTRACT
Methods for the analysis of mycotoxins in foods are presented. Techniques for aflatoxins, trichothecenes, zearalenone, fumonisins, ochratoxin A and patulin are outlined.
ABSTRACT
Aflatoxins B-1 and G-1 were screened in 60 samples of scratched broiler feed, in Goias State, Brazil, using thin layer chromatography as the method of detection. Samples of ration provided to the chickens were collected from feeder troughs in the farms. Only 1.66% of contamination was detected that corresponded to one sample with 28 ppb of aflatoxin B-1.
ABSTRACT
As a means of assessing the performance of European laboratories who contribute analytical data on food contamination to the World Health Organization (WHO) Global Environmental Monitoring Scheme (GEMS), a series of five proficiency testing exercises were carried out during 1993 and 1994. In total 136 laboratories from 21 different countries took part in one or more of the exercises which covered the analysis of trace elements (lead, cadmium and mercury) in milk powder, pesticides (organochlorine, organophosphorus and pyrethroid) in spinach powder, nitrate in spinach powder, aflatoxins in nut-based animal feed and patulin in apple juices. The proficiency testing was carried out according to the ISO/IUPAC/AOAC INTERNATIONAL Harmonized Protocol and laboratories were awarded z-scores signifying their analytical capability based on their reported results for each of the respective exercises. Overall 60% of laboratories were satisfactory for accuracy for trace element analysis, 41% for pesticides, 43%for nitrate, 88% for aflatoxins and 53% for patulin. These results gave an overall poorer performance (68%) than the average for other similar schemes (79%), indicating the need for care in collating data for such programmes as GEMS and the need for remedial measures to assist in improving performance.
ABSTRACT
Ninety six feedstuffs given to dairy cattle from four milk producing areas of the Sao Paulo state, Brazil (Sorocaba, Cotia, Vale do Paraiba and Itupeva) were analyzed over a one-year period (June 1992 to August 1993) for the presence of contaminating fungi, toxigenic or not, and aflatoxins. In addition, the occurrence of aflatoxins M-1 and M-2 in raw milk from the studied dairy cows was evaluated in 144 milk samples. Fungal species were isolated on potato-dextrose agar and identified by routine mycological techniques. Detection and quantification of aflatoxins were done by thin layer chromatography (TLC). The most frequent fungi recovered from feeds were Fusarium spp. (67.7%; main isolate: F. moniliforme), Aspergillus spp. (58.3% main isolate: A. flavus) and Penicillium spp. (52.0%), followed by eight other fungi genera. The numbers of colony forming units (CFU/g) ranged from 3.5 times 10-3 to 1.1 times 10-6 (Fusarium spp.), 3.0 times 10-2 to 7.8 times 10-3 (Aspergillus spp.) and 1 times 10-2 to 3.1 times 10-5 (Penicillium spp.). Twelve (46.1%) of the 26 A. flavus isolates were group B aflatoxins producers and 3 of the A. parasiticus isolates were group B and G aflatoxins producers. The presence of aflatoxins B-1 and B-2 was observed in 14 (14.6%) of the feed samples analyzed at levels that ranged between 11.5 and 287 µg/kg (AFB-1) and 19 and 40 µg/kg (AFB-2). No carryover of mycotoxins to raw milk was observed. Nonetheless, despite these negative results under the experimental conditions used, the continuous evaluation of levels of aflatoxin M-1 and M-2 in dairy products is always necessary since either favorable or unfavorable conditions for mycotoxin production may vary over different periods.
ABSTRACT
Efficiency of 2 commercial ELISA kits for detection of aflatoxin B1, were evaluated. Detection limits of the 2 kits for alfatoxin B1 in corn extracts were 5 and 20 p.p.b., respectively. Results of analyses of 53 samples of corn, fish feed (spiked samples), peanuts and peanut products were compared with results obtained using a multi-toxin TLC method with a quantification limit of 4.0 p.p.b. Results obtained by ELISA and TLC showed good agreement. The ELISA method was more rapid, simpler, and used less organic solvents than the TLC method. It did, however, produce some false positives, indicating that positive results should be confirmed. [From En summ.]
ABSTRACT
This book provides an insight into selected areas of food contaminant analysis in which recent advances have been made or where the contaminant is of topical interest. Information on analytical techniques is provided but the main emphasis is placed on applications. The book is intended as a reference source for food analysts and analytical chemists, both in government laboratories and in the food industry, and regulatory officials and toxicologists. The book consists of the following 10 chapters: Sampling and sample plans for food surveillance exercises, by Crosby, N. T. (pp. 1-31; 13 ref.); Automated clean-up techniques for trace component analysis in complex biological matrices including foods, by Shepherd, M. J. (pp. 32-64; many ref.); Chromatographic and allied methods of analysis for selected mycotoxins, by Sydenham, E. W. & Shephard, G. S. (pp. 65-146; many ref.); Inductively coupled plasma-mass spectrometry (ICP-MS) for the analysis of trace element contaminants in foods, by Crews, H. M. (pp. 147-186; many ref.); Applications of immunoassay to pesticide analysis, by Kaufman, B. M. (pp. 187-218; many ref.); Bioassay and chemical methods for analysis of paralytic shellfish poison, by Burdaspal, P. A. (pp. 219-253; many ref.); Analysis of food contaminants by combined liquid chromatography-mass spectrometry (LC-MS), by Gilbert, J. (pp. 254-304; many ref.); Analysis of foods and biological samples for dioxins and PCBs by high resolution gas chromatography-mass spectrometry, by Hannah, D. J., Porter, L. J. & Buckland, S. J. (pp. 305-331; 21 ref.); Approaches to evaluating high-temperature food packaging materials as sources of food contamination, by Hollifield, H. C. & Begley, T. H. (pp. 332-367; many ref.); and Progress in developing European statutory methods of analysis, by Wood, R. (pp. 368-416; 13 ref.). A 10-pp. subject index is included. (VJP)
ABSTRACT
Milk products such as cheeses may be contaminated by aflatoxin M-1 when manufactured with milk from dairy cattle that have consumed aflatoxin B-1-contaminated feeds. The usefulness of immunoaffinity columns to determine aflatoxin M-1 content in many kinds of cheeses with very good recoveries is demonstrated. The analysis of aflatoxin M-1 in a 1990 to 1995 limited survey in France shows that the occurrence of this mycotoxin in cheeses is rather infrequent. With the exception of samples from 1989 to 1990 when aflatoxin B-1-contaminated maize meals were incidentally imported to supplement dairy cattle feed, very few samples were found with above 0.200 Fg of aflatoxin M-1 per kg of cheese, the maximum acceptable level.
ABSTRACT
A liquid chromatographic (LC) method for determining deoxynivalenol (DON) in white flour, whole wheat flour, and bran was developed. A 25 g test portion was extracted with acetonitrile-water (84 + 16), and the extract was filtered and applied to a column containing a combination of charcoal, Celite, and other adsorbents. The eluate was then chromatographed on a silica-based, reversed-phase LC column by using a gradient of water and methanol. DON was measured at 220 nm. Average recoveries of DON from white flour, whole wheat flour, and bran spiked at 1 µg/g were 88, 86, and 85%, respectively. The limit of determination of the method was lt 0.5 µg/g. A total of 562 wheat-based products from the 1993 crop year were collected by 21 U.S. Food and Drug Administration District Offices and analyzed by this method in Kansas City, Seattle, and New Orleans District Laboratories. The numbers of samples with DON contamination gtoreq 1 µg/g from 163 bran, 272 white flour, 90 whole wheat flour, and 37 miscellaneous test samples were 20, 28,14, and 2, respectively. About 52, 50, 40, and 27% of the same test samples were contaminated with DON at levels gt 0.1 µg/g.
ABSTRACT
Mycotoxins, the toxic compounds produced by mold secondary metabolism, represent a relevant source of danger to humans through alimentary channels. Efforts have been made by researchers and by national authorities to assess mycotoxin incidence in food, but often results are to be considered approximate or inaccurate due to the huge difficulties posed by sampling procedures. More recently the evaluation of mycotoxins in biological fluids have been given increasing attention since the results may offer valuable indications, although general on the overall status of mycotoxin contamination in food and feed. The assessment of the degree of exposure to these contaminants in the population or in specific groups can also be pursued. Researches on mycotoxins in biological fluids greatly contribute to clarify the mechanism of health impairment attributable to these toxic compounds and to elucidate the dose-response relationship. Despite the considerable efforts devoted to mycotoxin research in the past few decades, improvements in methodology has to be achieved mainly in sampling procedures and in quality assurance of the laboratories involved in mycotoxin analysis, as well as in the selection of appropriate biomarkers.
ABSTRACT
Mycotoxin analysis in food and biological fluids is receiving more and more concern, in view also of increasing involvement by the European Union regarding legislation. Basically all the analytical steps regarding mycotoxin analysis have to be performed according to accurate criteria which are strictly connected to the quality of results in terms of reliability. The only rationale for reducing this difficulty is to apply quality assurance principles. Quality assurance principles define, in fact, the rules to be observed for performing this analysis with a degree of uncertainty that is as low as may be possible. In particular sampling techniques, if carried out improperly, give rise to uncertainty concerning the representativeness of samples that is so critical as to induce a dramatic source of errors in the final analysis. Therefore it seems appropriate to plan training courses for personnel on the various side-effects related to the available sampling and subsampling techniques depending on the commodity. Other contributions to the overall error derive from improper methodologies used by technicians in the pre-treatment step of the samples (incorrect use of glassware, standard solutions. etc.), and finally from the operations involved in the whole analytical procedure. In addition, the use of reference materials and certified reference materials together with the utilization of validated methods of analysis will be dealt with as concrete procedures for obtaining the certainty of final results of good quality. This aspect takes on a relevant outcome if applied to official control activities from authorized bodies acting at a national level.
ABSTRACT
An AOAC International-international Union of Pure and Applied Chemistry-international Fruit Juice Union (AOAC-IUPAC-IFJU) collaborative study was conducted to evaluate a liquid chromatographic (LC) procedure for determination of patulin in apple juice. Patulin is a mold metabolite found naturally in rotting apples. Patulin is extracted with ethyl acetate, treated with sodium carbonate solution, and determined by reversed-phase LC with UV detection at 254 or 276 nm. Water, water-tetrahydrofuran, or water-acetonitrile was used as mobile phase. Levels determined in spiked test samples were 20, 50, 100, and 200 µg/L. A test sample naturally contaminated at 31 µg/L was also included. Twenty-two collaborators in 10 countries analyzed 12 test samples of apple juice. Recoveries averaged 96%, with a range of 91-108%. Repeatability relative standard deviations (RSD-r) ranged from 10.9 to 53.8%. The reproducibility relative standard deviation (RSDR) ranged from 15.1 to 68.8%. The LC method for determination of patulin in apple juice has been adopted first action by AOAC INTERNATIONAL.
ABSTRACT
Electron spin resonance (ESR) spin-label oximetry has been used to study the effects of fumonisin B-1 (FB-1), a sphingoid-like mycotoxin, on oxygen transport in phosphatidylcholine (PC) bilayers. Moreover, the use of spin labels attached to different carbons of fatty acids makes it possible to do structural and oximetric determinations with the same test sample. Specifically, the incorporation of 10 mol% FB-1 increased the oxygen transport properties of both saturated and unsaturated membranes at 37 degree C by ca. 30% and decreased the ordering of the hydrocarbon chains near the surface of the membranes; concomitantly, oxygen transport near the center of bilayers was diminished slightly, and the relative oxygen diffusion-concentration product profile curves were markedly flattened.
ABSTRACT
Eighty-three samples of liver and kidney from swine and poultry for human consumption were analysed for aflatoxins B-1, M-1 and aflatoxicol residues by means of thin-layer chromatography. Aflatoxin B-1 was detected in one sample of pig liver from Rio Grande do Sul (Brazil) at a level of 27ng/g (ppb) while none of the poultry kidney and liver samples showed aflatoxins and aflatoxicol. Traces of aflatoxin M-1 were found in one sample of kidney tissue. Aflatoxins B-1, M-1, and aflatoxicol recovered of artificially contaminated meat tissues were: 74% to 95.2% for aflatoxin B-1; 60 to 80% for aflatoxin M-1 and 80 to 95% for aflatoxicol.
ABSTRACT
With an increased emphasis on analytical quality assurance for food analysis, many laboratories have adopted quality systems through accreditation and are additionally demonstrating the accuracy of their analysis by participation in proficiency testing schemes. In this paper a food analysis proficiency testing scheme known as FAPAS is described which was launched in 1990 and in which approximately 375 laboratories world-wide now participate. The scheme covers a wide range of determinations ranging from proximates (moisture, fat, ash etc.), veterinary drug residues, pesticides, mycotoxins, trace elements through to more generic testing of laboratory performance for GC and HPLC analysis. Trends from the results obtained over the past 6 years indicate that continued participation in FAPAS leads to steady improvements in performance for participants.
ABSTRACT
The carcinogenicity of ochratoxin A is discussed and the hazard assessment and risk assessment for ochratoxin A are defined.
ABSTRACT
The mechanisms of toxicity of ochratoxin A and the preventive action of aspartame in experimental models of ochratoxicosis in rats are discussed.
ABSTRACT
The nephrotoxicity of ochratoxin A is discussed, including the incidence of endemic nephropathy in man and mechanisms of toxicity.
ABSTRACT
The mechanisms of ochratoxin toxicity are discussed, including action on different enzymes, lipid peroxidation and genotoxicity.
ABSTRACT
The carcinogenicity of ochratoxin A is discussed, including experimental genotoxicity tests of ochratoxin A and DNA adduct formation. Human risk assessment for ochratoxin A is also considered.
ABSTRACT
The contamination of animal feed with ochratoxin A is discussed, including the potential contamination of meat and animal products, fate of ochratoxin A through the feed-food chain, occurrence of ochratoxin A in raw materials, processed animal feeds, degradation of ochratoxin A during processing and control of ochratoxin A.
ABSTRACT
The contamination of meat and meat products with ochratoxin A and the effects of meat processing on ochratoxins are discussed.
ABSTRACT
The contamination of commercial roast and ground and instant coffees with ochratoxin A and the effects of green coffee processing on ochratoxin A content, including decaffeination, roasting and brewing are discussed.
Food Additives and Contaminants, (1996) Vol. 13, No. Suppl., pp. 27-28. 8 ref. Occurrence and significance of ochratoxin A in food. Workshop held 10-12 January, 1996, in Aix-en-Provence, France.
ABSTRACT
The contamination of cereals with ochratoxin A and the effects of processing (such as milling) on the occurrence of ochratoxin A in cereals are briefly discussed.
ABSTRACT
The contamination of bread by ochratoxin A and the fate of ochratoxin A during flour preparation and breadmaking are briefly discussed.
ABSTRACT
The contamination of beers with ochratoxin A and the effects of the malting and brewing processes on ochratoxin A in contaminated barley are discussed.
ABSTRACT
The effects of food processing and detoxification treatments on ochratoxin A are discussed, including heating, malting (barley), roasting (coffee) and treatment of feeds with adsorbents or gamma irradiation.
ABSTRACT
The results of an EC Scientific Co-operation (SCOOP) project undertaken in 1995 to provide information on European dietary exposure to ochratoxin A, to determine risk assessment, are discussed.
ABSTRACT
Electron spin resonance (ESR) spectroscopy and spin label techniques have been used to study the effects of fumonisin B-1 (FB-1) and hydrolyzed fumonisin backbone (AP-1) on the structural and dynamic properties of phosphatidylcholine membranes at the molecular level. Multilamellar liposomes consisting of dimyristoylphosphatidylcholine (DMPC) and egg yolk phosphatidylcholine (EYPC) were used. Six different nitroxide spin labels were used to determine what effects FB-1 may impart on the ordering and mobility of lipids in membranes. The experimental results disclose the following: (1) In the fluid phase membrane, FB-1 significantly increases the fluidities of n-doxylstearic acid (SA) spin labels (SL) attached to carbons 5 and 7, which disorders the alkyl chains and perturbs the surface region of the bilayer; by comparison, minimal effects were detected near the center of the bilayer. (2) In the gel phase, FB-1 and AP-1 imparts marked rigidifying effects on membrane fluidity, which enlarges the change in ordering on the phase transition even further. (3) FB-1 also restricts the mobility of the (rigid) cholestane spin label. (4) A reduction in mobility of the tempo-stearate spin label suggests that the tricarballylic acid (TCA) moieties of FB-1 might mimic the structure of polar headgroups in phospholipids. The present results may provide additional mechanisms to elucidate the toxicological activities of the fumonisins.
ABSTRACT
Currently available methods for determination of ochratoxin A in foods, such as liquid chromatography (HPLC), thin layer chromatography and ELISA, and the use of immunoaffinity column purification of extracts, are discussed. Proposed specific regulations for ochratoxins, established in 8 countries, are also considered.
ABSTRACT
The structure and formation of ochratoxin A is discussed, including factors influencing the production of ochratoxin A, analogues of ochratoxin and the stability of ochratoxin.
ABSTRACT
This workshop, organised by the International Life Sciences Institute Europe, aimed to assess the risk of the population at large to ochratoxin A (OTA) exposure, particularly from food. The 16 sessions covered all aspects of OTA, including the formation of OTA, its occurrence in food, its fate during processing, analytical problems, exposure assessments and the toxicology of OTA.
ABSTRACT
Wheat and barley from the 1993 crop year were analyzed for deoxynivalenol (DON). A total of 630 samples were collected by the Federal Grain Inspection Service in 25 states and analyzed using a commercially available, direct competitive, enzyme-linked immunosorbent assay. The limit of determination was about 0.5 µg/g. DON contamination in the 483 wheat samples averaged 2.0 µg/g and ranged from lt 0.5 to 18 µg/g. DON contamination in the 147 barley samples averaged 4.2 µg/g and ranged from lt 0.5 to 26 µg/g. About 40% of the wheat samples and 57% of the barley samples contained DON levels that were greater than the U.S. Food and Drug Administration 1982 advisory level of 2g/g for DON in wheat designated for milling (human consumption).
ABSTRACT
Liver and kidney tissues and urine from calves chronically or acutely intoxicated by aflatoxin were surveyed to detect the presence of aflatoxins B-1, M-1 (AFB-1, AFM-1) and aflatoxicol (AFL). Aflatoxins B-1, M-1, and aflatoxicol were not found in the liver, kidney or urine from animals intoxicated by chronic forms. However in a calf that received a single dose of 0.8 mg of AFB-1/kg of live weight and one submitted to a single dose of 1.8 mg of AFB-1/kg of live weight detectable levels of aflatoxins occurred in tissues and urine.
ABSTRACT
Ochratoxin A (OA) is a mycotoxin detected in a variety of food and feeds mostly from countries with temperate or continental climate, because the fungi that produce it, mainly Aspergillus ochraceus, Penicillium verrucosum, and Penicillium viridicatum, can grow under a great variety of climate conditions. The aim of this article was, firstly, to confirm the occurrence of OA in human milk in Italy. Then, a preliminary calculation of OA intake via human milk was made, from ingested food. For this investigation, food and milk samples were collected, continuously for a week, from 4 lactating mothers. The obtained results revealed a significant exposure of sucklings and mothers to OA levels high er than the tolerable daily intake as estimated from animal models. On the basis of these data, a major effort in planning surveillance and research programs to control OA contamination in food, feed, and biological fluids should be pursued.
ABSTRACT
In order to estimate the incidence of ochratoxin A (OA) in biological fluids, a study was carried out to determine the concentration of OA in breast milk of donor mothers in Italy. Out of 111 samples, 22 were contaminated in the range 0.1-12 µg/kg.
ABSTRACT
Worldwide there are either statutory limits or in some instances advisory guidelines for the maximum levels of mycotoxins in foods and feeds. These limits which have been agreed for the protection of human health and as standards for trade are often set at surprisingly low levels in view of both the problems of sampling and the abundant evidence of the difficulties of mycotoxin analysis, particularly so when approaching the limits of detection. Improved methodology for mycotoxins and improvements in performance even of expert laboratories have, however, been achieved through intercomparison exercises organised by the EC Measurement and Testing programme (formerly BCR). On a wider scale, participation in proficiency testing through schemes such as the UK Food Analysis Performance A ssessment Scheme (FAPAS) have indicated that between 10 and 40% of laboratories experience difficulties in obtaining satisfactory results in monitoring mycotoxins. Reference materials provide an important means of checking method performance. BCR has made a unique contribution in the production and certification of maize and wheat reference materials naturally contaminated with the Fusarium mycotoxin 4-deoxynivalenol (DON), which has now been available for purchase for some 2 years.
ABSTRACT
A method for estimating Alternaria mycotoxins in fruit and vegetables was used for the examination of 110 raw or processed samples. 32 of 44 raw samples were mouldy. Approx. 50% of mouldy samples of strawberry, raspberry, black currant, gooseberry, blueberry and tomato contained Alternaria mycotoxins. Values for alternariol and alternariol methyl ether in mouldy samples ranged from 3 to 420 and from 10 to 100 micro g/kg, respectively. Traces of alternariol were detected in 3 samples of processed tomato and raspberry.
ABSTRACT
The laboratory of the Biological Chemistry Section of the Adolfo Lutz Institute has been asked to analyze ochratoxin A levels in green coffee beans exported to Greece and Lebanon since October 1989. The request follows the establishment of a maximum tolerance limit of 20 mg/kg of OA for the imported products by these countries. The present study was undertaken to determine the most appropriate method for a routine OA analysis of green coffee beans at the Adolfo Lutz Institute. Two methods for ochratoxin A analysis by thin-layer chromatography were compared, namely AOAC (1990) and the Soares and Rodriguez-Amaya (1985) method as modified by Milanez and Sabino (1989). Accuracy (recovery of spiked samples), precision (day-to-day reproducibility) and practicality (applicability cost, speed, equipment and skill requirements, as well as exposure risk) were the parameters used for comparison. The results showed that both methods are reliable. The coefficients of variation obtained were less thin 30%, which are considered adequate for OA evaluation and demonstrate a good reproducibility. Recoveries from the spiked samples were over 70% and thus within levels acceptable for mycotoxin analysis. However, the practicality data indicated that the method of Soares and Rodriguez-Amaya (1985) as modified by Milanez and Sabino (1989) is more suitable for routine use.
ABSTRACT
Lactic acid bacteria strains, normally employed in food manufacture, were put to grow in association with A. parasiticus. Growth conditions reproducing natural ripening of food products were chosen. Different results were obtained testing different strains L. casei and L. lactis were able to reduce toxin production whereas L. cremoris stimulated fungal toxinogenesis. L. cremoris and L. lactis were able to metabolized performed aflatoxins changing them in other hydroxyl derivative that are less detrimental to human health.
A method using immunoaffinity as a purification step for the determination of aflatoxin M-1 in cheese is described. A simple solvent extraction with dichloromethane followed by a washing step with N-hexane gives a prepurified extract. A comparison between two ways of aflatoxin M-1 purification, by solid-phase extraction clean-up and by immunoaffinity, was carried out. The use of immunoaffinity columns containing monoclonal antibodies against aflatoxin M-1 gives the best result, i.e. a very clean preparation containing purified aflatoxin M-1. The quantification of aflatoxin M-1 is then performed by high performance liquid chromatography using fluorometric detection. This method was successfully carried out on naturally-contaminated and spiked cheeses. Recoveries are about 75%. The limit of quantification is 0-020 Fg of aflatoxin M-1 per kg of cheese. This method seems suitable for use in monitoring programmes for aflatoxin M-1 contamination in dairy products such as cheese.
ABSTRACT
Relationships between growth and differentiation and secondary metabolism in microorganisms are reviewed and discussed. The trophophase/idiophase concept is illustrated by patulin biosynthesis. Other features of the biosynthesis of secondary metabolites (such as beta-lactams, mycophenolic acid, rubratoxin, enniatin, tentoxin and citrinin) are also presented. Examples of secondary metabolism in relation to differentiation of selected prokaryotes (bacteria and actinomycetes) are also given. The major part of the review concerns relationships of differentiation and secondary metabolite production in fungi. The following metabolites are discussed: cephalosporin C, brefeldin A, ergot alkaloids, solanopyrone phytotoxins, verruculogen, griseofulvin, penitrems, paxilline, patulin, anthraquinone s, mycosporines, P-factor, cyclopenin, cyclopenol, zearalenone, and sex hormones of lower fungi (trisporic acid, antheridiol and sirenin).
ABSTRACT
The between-box aflatoxin distribution for a bulk consignment of whole dried figs (11 tonnes) has been established by the individual analysis of 200 boxes (analysed as single samples of 12 kg each of homogenized material) randomly selected from a total of 850 boxes. The within-box aflatoxin distribution for three boxes was investigated by the analysis of 12 subsamples in each case made up of packets of figs totalling 1 kg in weight. Of the 200 boxes, 134 contained less than 10 mg/kg total aflatoxins whereas the highest level found was 227 µg/kg. The highest level of aflatoxins found in a single 1 kg unit was 2063 µg/kg. The batch average aflatoxin contamination determined on the basis of a single 20 kg homogenized sample (20 times 1 kg subsamples) was 33 µg/kg, compared to a level of 15 µg/kg calculated as the average of 200 determinations. Evaluations are made of different possible ways of sampling and the confidence that can be associated with each of these is estimated.