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PubMed1983

Evaluation of a testing program for aflatoxin in corn.

A computer model that accounts for sampling and analytical variability was developed to simulate the aflatoxin testing program administered by the North Carolina Department of Agriculture (NCDA) to regulate aflatoxin in corn meal. Monte Carlo solution techniques were employed to account for conditional probabilities that rise from multiple samples being used in the testing program. The NCDA testing program was then evaluated by applying the computer model to a hypothetical group of 1000 corn meal lots with the same distribution of aflatoxin concentrations as was observed among aflatoxin assays made by NCDA on commercial lots of corn meal from 1977 to 1980. The average of the 1000 lots assayed was 17.7 parts per billion (ppb). The model predicted that 79.5% of the lots would be accepted and 20.5% of the lots would be rejected by the NCDA testing program. The accepted and rejected lots contained an average of 5.7 and 64.2 ppb aflatoxin, respectively. The testing program accepted 7.3% of the lots with more than 20 ppb aflatoxin (consumers' risk) and rejected 1.0% of the lots with 20 ppb or less (processors' risk). A correct decision was made 94% of the time.

Aflatoxins↗

PubMed1983

Dilution errors in aflatoxin determinations caused by compounds extracted from peanuts.

Several methods have been developed to analyze peanuts for aflatoxin by using thin layer chromatography (TLC). These methods depend on solvent extraction of aflatoxin from a sample of the product. Unfortunately, solvent solutions used to extract aflatoxin from peanuts also extract measurable quantities of other compounds such as oils, fats, sugars, and protein. The volume of these extracted compounds causes error in measuring the proportion of the solvent solution analyzed for aflatoxin. Also, because the cleanup procedures for some methods are inadequate, the volume of some of these extracted compounds also causes error in measuring the proportion of the extracted aflatoxin placed on TLC plates. These 2 errors cause underestimation of aflatoxin concentrations by approximately 11, 14, and 5% for the CB method, the modified version of the BF method generally used for raw peanuts, and a water slurry method, respectively. The correction specified by the CB method for fats in the extraction solvent reduces the approximate error for the CB method from 11 to 1%.

Aflatoxins↗

PubMedDate not supplied

Improved liquid chromatographic method for determination of aflatoxins in peanut butter and other commodities.

A combination of the extraction and cleanup procedures of Pons and Franz with the liquid chromatographic (LC) derivatization technique of Beebe is proposed as an accurate, precise, and sensitive method for determination of aflatoxins B1, B2, G1, and G2 in various foodstuffs. Mean recoveries of total aflatoxins added in the range 15-34 ng/g to peanut butter were 86-94% in 2 laboratories. Recovery of total aflatoxins (30 ng/g) from shelled peanuts, shelled Brazil nuts, pistachios, cashews, walnuts, and filberts exceeded 86% and from pumpkin seeds was 80%. Coefficients of variation for total aflatoxins were less than 7% for spiked samples and 15% for peanuts naturally contaminated with 16.7 ng/g of total aflatoxin (B1 + B2). Analyses of peanut meal, yellow corn meal, and peanut butter check samples (AOCS Smalley Series 1980/81 and 1981/82, IARC Series 1982/83) by this method compared favorably with reported averages. The detection limit is about 0.3 ng/g for each aflatoxin.

Aflatoxins↗

PubMed1981

Inhibition of aflatoxin production in groundnut with benzoic acid derivatives and possible toxic effect of their aromatic residues.

Benzoic acid, sodium benzoate, ethyl-rho-aminobenzoate and omicron-hydroxybenzoic acid (salicylic acid) have been found to inhibit mycelial growth and aflatoxin production by A. flavus in groundnut. Benzoic acid (10 mg/g) completely inhibited both mycelial growth and aflatoxin production while sodium benzoate achieved the same result at 24 mg/g of medium. Salicylic acid (20 mg/g) completely inhibited both mycelial growth and aflatoxin in production but ethyl-rho-aminobenzoate inhibited both mycelial growth and aflatoxin production at lower concentrations--3 mg/g of medium for total aflatoxin inhibition and 10 mg/g for complete inhibition of mycelial growth. The results of the possible toxic effects of these aromatic compounds showed that at their effective concentrations they were non-toxic to 1-day-old chicks. Their effects on body and liver weights yielded results similar to the controls. The chicks that were fed aflatoxin-contaminated diets experienced depressed body and liver weights and their livers manifested various pathological changes. Groundnut samples which were supplemented with various concentrations of these aromatic compounds did not give any foul odour. These benzoic acid derivatives could be used, therefore, as fungicides especially against toxigenic A. flavus.

Aflatoxins↗

PubMed1981

Aflatoxin B1-induced injury in monkeys.

Short-term effects of small doses of aflatoxin (0.05 mg/kg of body weight twice a week) were studied in rhesus monkeys fed low-protein and high-protein diets. Animals on high- and low-protein diets without aflatoxin administration served as controls. There was no difference in weight gain, hemogram, serum protein levels, and liver function test results between aflatoxin-treated and control animals. However, morphological alterations in hepatocytes in the form of mild degenerative changes, focal areas of necrosis, and increased regenerative activity were seen in the aflatoxin-treated monkeys. Data on cell cycle analysis done by DNA content estimation through microfluorimetry on DNA-fluorescent, acriflavin-stained liver imprints revealed larger number of cells in the S and Gi2 phases in animals given aflatoxin. However, the changes in cell cycle, as well as in morphology, were more marked in the aflatoxin-treated, low-protein-diet group.

Aflatoxins↗

PubMed1981

Effects of aflatoxin consumption on the clinical course of swine dysentery.

Specific-pathogen-free pigs were examined for susceptibility to swine dysentery after daily treatment with aflatoxin B1 (0.07 to 0.14 mg/kg). In the pigs (group II) given both aflatoxin and Treponema hyodysenteriae, the incubation period before the onset of swine dysentery was shorter than that in pigs (group III) given T hyodysenteriae alone. Also, the number of days in which infected pigs showed signs of diarrhea and dysentery was greater in the group given aflatoxin and T hyodysenteriae than in the group given T hyodysenteriae alone. Four of 8 pigs given aflatoxin and T hyodysenteriae died during the experiment, whereas only 1 of 8 infected pigs in the other group died. Pigs in both groups, convalescent from swine dysentery, were immune to rechallenge exposure. Subclinical effects of aflatoxin consumption were evident at necropsy, but clinical signs and lesions of swine dysentery were not observed in group III pigs (given aflatoxin only).

Aflatoxins↗

PubMedDate not supplied

Evaluation of sampling plans used in the United States, United Kingdom, and The Netherlands to test raw shelled peanuts for aflatoxin.

The United States is a large producer and exporter of peanuts. The United Kingdom and The Netherlands are major importers of U.S. peanuts. Each country has a different guideline or legal limit for peanut products containing aflatoxin. Peanuts are tested for aflatoxin in each country by using specifically designed aflatoxin sampling plans to determine if the aflatoxin concentration in a lot of raw shelled peanuts is less than the guideline or legal limit. For raw shelled peanuts, the U.S. plan has the highest sample acceptance limit of 15 ng total aflatoxin/g, the UK plan has a sample acceptance limit of 10 ng total aflatoxin/g, and the Dutch Code of Practice (called the Dutch plan) has the lowest sample acceptance limit at 3 ng aflatoxin B1/g. The U.S. plan uses a maximum of 3 sampling units, each weighing 21.8 kg; the UK plan uses a single sampling unit of 10 kg; and the Dutch plan uses 4 sampling units, each weighing 7.5 kg. The sampling variance is lowest for the U.S. plan and highest for the Dutch plan. The sample preparation variance is lowest for both the Dutch and UK plans and highest for the U.S. plan, primarily because of the mill type used to comminute the kernels in the sample. For a given distribution among lot concentrations, the U.S. plan accepts the greatest number of lots and the Dutch plan rejects the greatest number of lots. The average aflatoxin concentration among accepted lots is highest for the U.S. plan and lowest for the Dutch plan.(ABSTRACT TRUNCATED AT 250 WORDS)

Aflatoxins↗

PubMedDate not supplied

[The effect of aflatoxin B1 on the human lymphocyte blast transformation reaction].

The effect of various aflatoxin B1 concentrations on human peripheral blood lymphocyte blast-transformation reaction was studied. There was aflatoxin B1-induced dose-dependent inhibition of DNA synthesis in the lymphocytes stimulated by phytohemagglutinin. The aflatoxin B1 concentrations causing 50% decreases in DNA synthesis were defined by the regression method. (ID50). Judging from the ID50 values, the treatment of cultured lymphocytes with cytochrome P-448 inductor and lymphocytic exposure in the presence of toxin and hepatic microsomes of mice showed a 6-7-fold increase in the inhibitory action of aflatoxin B1. This indicates that the metabolism of aflatoxin B1 brought about by the cytochrome P-450-dependent monooxygenase system plays an important role in the action of aflatoxin B1 on human lymphocytes.

Aflatoxin B1↗

PubMedDate not supplied

[Accumulation of aflatoxins on wheat grain inoculated by Aspergillus flavus NRRL 2999 and their distribution in grinding products].

The influence of temperature ranging from 15 to 35 degrees C and relative humidity of 75 to 90% on the accumulation of aflatoxins on wheat grain inoculated by Aspergillus flavus NRRL 2999 was investigated. The lowest accumulation of aflatoxins took place at 20 degrees C and relative humidity of 80%. The highest accumulation of aflatoxins appeared in the grain after 3 day storage. Some products of three-graded 78% grinding showed a decrease in the aflatoxin content (flour of the first and second grade). During baking of leavened bread 70-80% of aflatoxins were decomposed. The feasible use of the rapid conditioning and Remix-method to reduce the content of aflatoxins in flour and bread is discussed.

Aflatoxins↗

PubMed1993

Effect of aflatoxin-contaminated feed on morbidity and residues in walleye fish.

The effect of aflatoxin in the feed on the morbidity and toxin residue in the musculature of walleye fish was studied. The fish were divided into 3 groups of 12 each; group 1 served as controls, groups 2 and 3 received feed treated with 50 or 100 ppb toxin for 30 d respectively. Fish were kept in glass aquaria, 4 fish/aquarium, with aerator and solids-waste filter system. Fish were observed for morbidity and mortality. Six fish from each group were sacrificed after 30 d and examined for gross pathological lesions and histopathological changes. In addition, fish musculature were analyzed for aflatoxin. One out of 16 (8%) of the fish fed 100 ppb aflatoxin in 48 h. Pale livers and significant degenerative changes were observed in both toxin-treated groups. Aflatoxin B1, G1 and G2 were detected in the musculature of both groups at a concentration of 5, 10, 15, 20 ppb respectively. After 2 w of aflatoxin withdrawal, no aflatoxin was detectable in the fish muscle. However, marked histopathological lesions were still observed.

Aflatoxins↗

PubMed1993

Steroid hormones retard aflatoxin-induced cytotoxicity.

Protective effect of sex steroid hormones on aflatoxin-induced cytotoxicity on RBC (hemolysis) was examined in vitro. Addition of aflatoxin (2 micrograms/ml) in RBC suspension caused significant increase in hemolysis. Concurrent addition of aflatoxin (2 micrograms/ml) and estradiolbenzoate (100-1200 pg/ml) in RBC suspension significantly retarded aflatoxin-induced hemolysis. Similarly, addition of aflatoxin (2 micrograms/ml) along with testosterone propionate (5-60 ng/ml) in RBC suspension retarded aflatoxin-induced hemolysis. Among the two synthetic hormones studied estradiolbenzoate was more potent than testosterone propionate.

Adult↗

PubMedDate not supplied

[Immunological detection of aflatoxin-albumin adducts in children with chronic hepatitis B infection].

The value of aflatoxins is well known as a carcinogenic, mutagenic and teratogenic, likewise its association with the hepatitis B virus. In addition, it is known the incidence of hepatocellular carcinoma in such viral infection. A study was performed on the albumin adducts-aflatoxins levels in sera determined by ELISA method of children within 3-15 years old at the Service of Pediatric Gastroenterology from the National Institute of Gastroenterology. Samples consisted of 40 patients with chronic active hepatitis (CAH) B, 10 HBsAg+ carriers and 20 controls. The CAH group, showed a 32.5% of positiveness with a maximum levels of 25pg aflatoxin lysine/mg albumin while 20% of HBsAg positive carriers showed levels of un 12.3 pg aflatoxin lysine/mg albumin and 15% of the control group 5pg AF lysine/mg albumin. It can be observed that aflatoxin levels in patients of CAH presented values up to 5 times over the control group. This study suggest the validity of aflatoxin-albumin adducts as a marker of chronic exposure to this carcinogen and its importance in relation with the virus of hepatitis B.

Adolescent↗

PubMedDate not supplied

Determination of aflatoxins in beer.

Aflatoxins B1, B2, G1, and G2 were determined at parts-per-trillion levels in beer by immunoaffinity column cleanup and reversed-phase liquid chromatography (LC) with fluorescence detection after trifluoroacetic acid derivatization. Silanized vials were necessary for the evaporation step in order to obtain good recoveries of aflatoxins from spiked beer samples. Recoveries averaged 90-104%, 94%, 84-87%, and 89% for aflatoxins B1, B2, G1, and G2, respectively, at levels of 9.7-133 ng B1, 46 ng B2, 35-140 ng G1, and 41 ng G2/L. Detection limits were 19-20 ng/L for aflatoxins B1 and G1 and 15-16 ng/L for aflatoxins B2 and G2 (signal-to-noise ratio = 3:1) obtained by using an excitation wavelength of 360 nm; at 340 nm these detection limits were lowered to about 2 ng/L. Analysis of 24 beer samples, the majority from the United States and Mexico, showed natural contamination of one sample of Mexican beer at 49 ng B1/L when determined at 360 nm excitation, but reanalysis of 23 of the samples using 340 nm excitation indicated that an additional 4 Mexican samples and one Brazilian sample contained aflatoxin B1 at low levels (< 10 ng/L).

Aflatoxins↗

PubMed1998

[Determination of selected mycotoxins in food. I. Selection of optimal conditions for the determination of aflatoxin M1 in milk using high-performance liquid chromatography methods].

The aim of this study was to perform a optimized method for determination of aflatoxin M1 in milk. The manner of extraction and clean-up of milk extracts as well conditions of reaction of aflatoxin M1 with TFA and HPLC was described. The main steps of optimized 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 degrees C, 6 minutes) to acetal form--aflatoxin M2a and determination of aflatoxin by means of 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/1 of milk.

Aflatoxin M1↗

PubMed1978

Evaluation of potential for aflatoxin occurrence on celery, cauliflower, lettuce, and taro root inoculated with Aspergillus flavus and A. parasiticus.

Culture samples of lettuce, cauliflower, celery, and taro root (Colocasia esculenta) were assayed for the presence of aflatoxin after inoculation with Aspergillus flavus and A. parasiticus. Cultures of A. flavus produced both aflatoxins B1 and G1 on taro root, but produced by B1 on lettuce, cauliflower, and celery. For taro root, the percentage of aflatoxin G1 produced was considerably greater than that of B1. While A. parasiticus did produce mycelia and spores on the lettuce and taro root samples, there were not detectable levels of any aflatoxin produced. All the samples studied were successfully extracted and analyzed qualitatively and quantatively for the presence of aflatoxin by using official AOAC thin layer chromatographic procedures. There is sufficient evidence that Aspergilli can grow on some leafy produce and one strain produced aflatoxins.

Aflatoxins↗

PubMed2000

In vitro metabolism of aflatoxin B1 by larvae of navel orangeworm, Amyelois transitella (Walker) (Insecta, Lepidoptera, Pyralidae) and codling moth, Cydia pomonella (L.) (Insecta, Lepidoptera, Tortricidae).

Larvae of the navel orangeworm (NOW), Amyelois transitella (Walker), a major pest of almonds and pistachios, and the codling moth (CM), Cydia pomonella (L.), the principal pest of walnuts and pome fruits, are commonly found in tree nut kernels that can be contaminated with aflatoxin, a potent carcinogen. The ability of larvae of these insects to metabolize aflatoxin B1 (AFB1) was examined. A field strain of NOW produced three AFB1 biotransformation products, chiefly aflatoxicol (AFL), and minor amounts of aflatoxin B2a (AFB2a) and aflatoxin M1 (AFM1). With AFL as a substrate, NOW larvae produced AFB1 and aflatoxicol M1 (AFLM1). A lab strain of CM larvae produced no detectable levels of AFB1 biotransformation products in comparison to a field strain which produced trace amounts of only AFL. Neither NOW nor CM produced AFB1-8,9-epoxide (AFBO), the principal carcinogenic metabolite of AFB1. In comparison, metabolism of AFB1 by chicken liver yielded mainly AFL, whereas mouse liver produced mostly AFM1 at a rate eightfold greater than AFL. Mouse liver also produced AFBO. The relatively high production of AFL by NOW compared to CM may reflect an adaptation to detoxify AFB1. NOW larvae frequently inhabit environments highly contaminated with fungi and, hence, aflatoxin. Only low amounts, if any, of this mycotoxin occur in the chief CM hosts, walnuts, and pome fruits. Characterizations of enzymes and co-factors involved in biotransformation of AFB1 are discussed.

Aflatoxin B1↗

PubMed1982

Binding of aflatoxin B1, G1 and M to plasma albumin.

The aflatoxins B1, G1 and their metabolites exist in the systemic blood as protein conjugate. This conjugation is specific to plasma albumin and proceeds enzymatically by liver and kidney cells. The aflatoxin-albumin conjugate is permanent and the conjugation is an irreversible one. This may interpret the acute liver damage of animal ingested a single dose of aflatoxin (3,4). The existence of bound aflatoxin-albumin in the systematic blood could be considered as one factor of low excretions of aflatoxins and their metabolites in urine (5,6,7).

Aflatoxin B1↗

PubMed1982

Aflatoxins in the livers of children with kwashiorkor.

Autopsy liver specimens from Nigeria and South Africa obtained from three kwashiorkors, three marasmic-kwashiorkors and one marasmic child were analysed for the presence of aflatoxins using both high performance liquid chromatography and thin layer chromatography. Significant levels of aflatoxin B1 were found in the livers of the three kwashiorkor children. Aflatoxicol was detected in the liver of one marasmic-kwashiorkor and a small quantity of aflatoxin M1 in the liver of another. No aflatoxins were found in the livers of the third marasmic-kwashiorkor or the marasmic child. These findings extend recent clinical observations that indicate an association between aflatoxins and kwashiorkor.

Aflatoxin B1↗