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The antioxidant activities of fresh garlic extracts and commercially available garlic products were evaluated using a recently developed technique for the determination of lipid hydroperoxides, initial intermediates in the lipid oxidation process. This measurement system uses reverse-phase column chromatography with chemiluminescence detection. Activity of the garlic preperations was compared to that of synthetic antioxidants. Protection against lipid oxidation provided by garlic extract was found to be concentration dependent, as was the protection provided by many synthetic antioxidants. In addition, garlic extract was also found to scavenge OH radicals, as evidenced by the reduction of the spin trap adduct in the presence of OH radicals.

A total of 118 imported cheeses from 13 countries were analyzed for aflatoxin M

Consecutive outbreaks of acute aflatoxicosis in Kenya in 2004 and 2005 caused > 150 deaths. In response, the Centers for Disease Control and Prevention and the World Health Organization convened a workgroup of international experts and health officials in Geneva, Switzerland, in July 2005. After discussions concerning what is known about aflatoxins, the workgroup identified gaps in current knowledge about acute and chronic human health effects of aflatoxins, surveillance and food monitoring, analytic methods, and the efficacy of intervention strategies. The workgroup also identified public health strategies that could be integrated with current agricultural approaches to resolve gaps in current knowledge and ultimately reduce morbidity and mortality associated with the consumption of aflatoxin-contaminated food in the developing world. Four issues that warrant immediate attention were identified: a) quantify the human health impacts and the burden of disease due to aflatoxin exposure; b) compile an inventory, evaluate the efficacy, and disseminate results of ongoing intervention strategies; c) develop and augment the disease surveillance, food monitoring, laboratory, and public health response capacity of affected regions; and d) develop a response protocol that can be used in the event of an outbreak of acute aflatoxicosis. This report expands on the workgroup’s discussions concerning aflatoxin in developing countries and summarizes the findings.

A peer-verified, gas chromatographic (GC) method is presented for the identification of hydrolyzed inulin syrup (HIS) and high-fructose corn syrup (HFCS) in apple juice. The procedure involves determining the Brix value of the apple juice or apple juice concentrate and preparing a dilution of the test sample to 5.5° Brix. A 100 μL aliquot of the 5.5° Brix test solution is then freeze-dried in a GC autosampler vial. The sugars in the freeze-dried residue are converted to trimethylsilyl derivatives, by the addition of an appropriate silylation reagent, and the vial is heated at 75°C for 30 min. After derivatization, the solution is introduced into a gas chromatograph where the analytes are separated on a 30 m, 0.25 mm id DB-5 column. The method can use hydrogen, helium, or nitrogen as the carrier gas. The analytes and marker compounds are measured by use of a flame ionization detector. Commercial apple juice concentrates were diluted with one of the 2 syrups at 2 levels. Dilution was ascertained by the presence of retrograde sugar markers found in the 2 sugar syrups. All 3 laboratories involved in the study were able to identify the correct diluent in the blind, randomly coded, apple juice test portions. The levels of dilution in the test portions were 0, 6.9% (HIS), 16.0% (HIS), 8.1% (HFCS), and 17.0% (HFCS). No false positive results were reported. Quantitative conclusions can be drawn when the same syrup is used for dilution and as a reference standard.

Four laboratories participated in a mini-collaborative study of AOAC Official Method 971.22, Standards for Aflatoxins, Thin-Layer Chromatographic Method, to extend the method to 3 replacement solvents for benzene for calibration of standard afla- toxin solutions. Triplicate test sample vials, each containing 25 μg of the respective aflatoxin for each of the 4 aflatoxins and for each of the solvents, were prepared and sent to each collaborator. The collaborators dissolved the aflatoxin in each vial in 2 mL solvent, measured the UV spectrum, and reported the absorptivity maxima near 350 nm. The concentrations of the aflatoxins in the test samples were determined by dissolving identical test samples in benzene-acetonitrile (98 + 2) and following the procedure described in AOAC Official Method 971.22. These concentrations were, in turn, used to determine the molar absorptivities in the other 3 solvents (see Table 1). AOAC Official Method 971.22 has been modified to extend its applicability to 3 replacement solvents for benzene for calibration of standard aflatoxin solutions.

Ochratoxin A (OA) is a nephrotoxic and nephrocarcinogenic mycotoxin produced by Aspergillus and Penicillium species. It has been found mainly in cereal grains and coffee beans. The purpose of this study was to investigate the occurrence of OA in cereal grains and in coffee imported to the United States. A modified liquid chromatographic (LC) method for determining OA in green coffee was applied to wheat, barley, green coffee, and roasted coffee. The test sample was extracted with methanol–1% NaHCO3 (7 + 3), and the extract was filtered. The filtrate was diluted with phosphate-buffered saline (PBS), filtered, and passed through an immunoaffinity column. After the column was washed with PBS and then with water, OA was eluted with methanol. The eluate was evaporated to dryness, and the residue was dissolved in acetonitrile–water (1 +1). OA was separated on a reversed-phase C18 LC column with acetonitrile-water-acetic acid (55 + 45 + 1) as eluant and quantitated with a fluorescence detector. Recoveries of OA from the 4 commodities spiked over the range 1–4 ng/g were 71–96%. The limit of detection was about 0.03 ng/g. OA contamination at >0.03 ng/g was found in 56 of 383 wheat samples, 11 of 103 barley samples, 9 of 19 green coffee samples, and 9 of 13 roasted coffee samples. None of the coffee samples contained OA at >5 ng/g; only 4 samples of wheat and 1 sample of barley were contaminated above this level.

Ackee toxicity is associated with consumption of the fruit of the tree Blighia sapida. The problem is endemic in Jamaica, and a number of cases have been reported in the U.S. among Jamaican immigrants. Illness is associated with the method of preparation of the fruit and its ripeness. Malnourished individuals and children appear to be the most susceptible. Levels of the toxic compound, hypoglycin, which are found in the arils and seeds of the fruit, significantly decrease in the arils with ripeness (from 1000 ppm to

Blue cohosh (Caulophyllum thalictroides (L.) Michx., Berberidaceae) is a North American perennial herb which is found as an ingredient in dietary supplement products in the United States. The plant contains the alkaloids N-methylcytisine, baptifoline, anagyrine and magnoflorine. Some of the alkaloids, including the quinolizidine alkaloid anagyrine, are toxic to range animals and have been implicated as teratogens in higher animals. Since the traditional use of the herb involves administration to women of reproductive age to treat menstrual cramps, and to pregnant women in the last 3–4 weeks of pregnancy to ease parturition, therefore the safety of these products to the fetus is of concern. Three of these alkaloids have been determined in authentic blue cohosh and several dietary supplements. Levels found were: 5–850 ppm for N-methylcytisine, 2–390 ppm for anagyrine, and 9–900 ppm for baptifoline. The lower alkaloid concentrations were found in products containing liquid extracts. Alkaloid identities were confirmed by mass spectrometry. © 1998 John Wiley & Sons, Ltd.

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-methanol 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 (RSDr) 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

Electron spin resonance (ESR)1 spin-label oximetry and spin trapping techniques have been used to study the effect of fumonisin B1 (FB1), an amphipathic mycotoxin on lipid peroxidation in egg yolk phosphatidylcholine (EYPC) bilayers. In the study of the interaction between FB1 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 FB1 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.

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, reversedphase 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 fig/g were 88,86, and 85%, respectively. The limit of determination of the method was

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 (RSDr) 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.

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

Four types of L-tryptophan lots produced by genetically modified B. myloliquefaciens strains II-V, which consisted of case-associated (11) with manifestations of EMS, control (16), and other lots (11), were compared by multivariate computer recognition programs (chemometrics) including HCA, PCA, KNN and SIMCA, as well as PLS. In HCA data analysis lots from strains III and V formed discrete clusters, and in PCA and SIMCA, both lots formed separated groups. Lots from strains II and IV were included in a group of lots from strain III. This indicated strains II and IV too were closely related to strain III. When strain vs case-associated control or other lots were compared by four methods, SIMCA provided adequate strain separation and strains were well grouped in case-associated or control lots.

This paper demonstrates that pyrrolizidine alkaloids (PAs) extracted from comfrey root grown in Washington State (USA) can be identified by gas chromatography/matrix isolation/Fourier transform infrared (GC/MI/FTIR) spectroscopy. Infrared spectral bands observed in the fingerprint region were unique even for closely related structures. The identities of the 4 major components, intermedine, lycopsamine, 7-acetylintermedine, and 7-acetylly-copsamine, were confirmed by comparison with standards. Confirmation was also obtained by using the established techniques of electron ionization and positive ion chemical ionization gas chro-matography/mass spectrometry. The infrared spectra observed for the components of the root extract were consistent with known structures of specific PAs. The identities of the minor components, sym-phytine and its isomers symlandine and/or sym-viridine, in the same extract were not confirmed.

The L -tryptophan eosinophilia myalgia syndrome ( L -Trp-EMS), related to ingestion of impure L -Trp, occurred in epidemic proportions in the Unite

An automated liquid chromatography (LC) procedure has been developed for the determination of aflatoxins in corn and peanuts. The automated LC system consists of the following: two pumps, an autosampler, an isolation column (immunoaffinity or methacrylate copolymer), an automated switching valve, a C 18 column, an electrochemical cell, a fluorescence detector, and a data system. Filtered methanol: water (75:25) extracts of the test portions are injected into the LC system. With the switch in position 1, water is pumped through the autosampler and isolation column and then discarded. With the switch in position 2, the mobile phase consisting of methanol:acetonitrile:water (26:18:56), 1 mM KBr, and 1 mM HNO 3 is pumped through the isolation column, C 18 column, electrochemical cell, and detector

By use of GC/MI/FT-IR spectroscopy, the double-bond configurations of fatty acid methyl esters derived from hydrogenated soybean oil and margarine were determined from the positions of observed IR bands.

Partial hydrogenation of vegetables oils causes isomerisation of the unsaturated fatty acids in the triacylglycerol molecules. Some of these isomers have been shown to cause adverse physiological effects in animal feeding studies. The study evaluates the use of supercritical fluid chromatographie with flow-cell Fourier transform infrared spectrometry to determine the relative level of unsaturation and the extent of isomerisation.

The condensation of tryptophan and acetaldehyde affords a bisindolylaminal of tryptophan which is indistinguishable from contaminant “97.” The formation and decomposition of aminals is addressed in light of epidemiological evidence linking them to a recent outbreak of EMS.

An AOAC/IUPAC (International Union of Pure and Applied Chemistry) collaborative study was conducted to evaluate the effectiveness of an immunoaffinity column for the determination of af latoxin. The test portion Is extracted with methanol- water (7 + 3), filtered, diluted to ⦟30% methanol with water, and applied to the affinity column. The column Is washed with water and the concentrated aflatoxins are eluted with methanol. Total aflatoxins are determined by solution fluorometry with bromine (SFB), and Individual toxins are determined by reverse-phase liquid chromatography with postcolumn derlvatizatlon with Iodine (PCD). Corn naturally contaminated with aflatoxins, and peanuts, peanut butter, and corn containing added aflatoxins ( B1:B2:G1G2 = 7:1:3:1) were sent to 24 collaborators In the United States, France, Canada, and the Republic of South Africa. Twelve collaborators used the SFB method, 9 used the PCD method, and 3 used both SFB and PCD methods. Twenty collaborators completed the study (10 used the SFB method, 7 used the PCD method, and 3 used both SFB and PCD methods). Test portions were spiked at 10, 20, and 30 ng/g. For SFB analyses, recoveries of total aflatoxins were 123,105, and 107%, respectively; the relative standard deviation for repeatability (RSDr) ranged from 11.75 to 16.57%, and the relative standard deviation for reproducibility (RSDR) ranged from 10.97 to 33.09%. For PCD analyses, recoveries were 81, 81, and 83%, respectively; the RSDr ranged from 5.20 to 17.22%, and the RSDR ranged from 4.68 to 50.77%. The RSDr for aflatoxins B1, and G1 for spiked test portions ranged from 5.45 to 23.55%, and the RSDR ranged from 4.21 to 57.28%. The RSDr and RSDR for aflatoxins B2 and G2 were higher because of the small amounts added. Analyses by both SFB and PCD methods showed acceptable within-laboratory and betweenlaboratories precision. The method has been adopted official first action by AOAC as an AOAC-IUPAC method.

Tryptophan-associated eosinophilia-myalgia syndrome (L-TRP-EMS) is a newly described syndrome which occurred in epidemic fashion in the United States in the summer and fall of 1989. Epidemiologic data has linked the syndrome to intake of L-tryptophan (L-TRP) from one specific manufacturer, but the precise etiologic compound(s) must be established by replication of the syndrome in an appropriate animal model. In this study, implicated L-TRP, United States Pharmacopeia (USP) grade L-TRP, or vehicle was administered by gavage in a blinded fashion for 38 d to female Lewis rats at doses comparable with those ingested by patients who developed the eosinophilia-myalgia syndrome. Animals receiving implicated L-TRP, but not those receiving USP grade L-TRP or vehicle, developed histologic signs consistent with fasciitis and perimyositis, specific pathologic features of human L-TRP-EMS. Peripheral blood eosinophilia was not observed. Hypothalamic corticotropin releasing hormone mRNA levels were lower and plasma corticosterone levels tended to be lower in the animals that received implicated L-TRP. Plasma L-kynurenine was higher in both L-TRP-treated groups compared to the vehicle-treated animals. The female Lewis rat is known to be susceptible to a wide variety of inflammatory diseases. Identification of specific inflammatory changes in this rat following exposure to implicated L-TRP indicates that this animal model will be important in subsequent investigations into the etiology, pathogenesis, and treatment of human L-TRP-EMS.

Apparent threshold densities were determined for a series of coumarin derivatives using a supercritical fluid chromatograph with a flame ionization detector. The extraction cell was an LC stainless steel precolumn. Milligram quantities of the model compounds were extracted. Coumarin functionality and extrac tion temperature affected the measured threshold densities. The addition of two hydroxyl groups onto the coumarin structure caused the compound to be unextractable at 60°C with densities up to 0.90 g/mL. For those compounds that were completely extracted, coumarin, 7-methoxycoumarin, 3-phenylcoumarin, and psoralen, the apparent threshold density increased with increasing melting point.

Analyse chromatographique de l'acide C 18 =2 trans 9, trans 12, produit pendant l'hydrogenation des huiles et la transformation des margarines et differentiation des autres isomeres en C 18 . Comparaison du taux d'isomeres trans dans 2 margarines commerciales

Risk analysis for trichothecene mycotoxins and other food contaminants, which are to a significant extent unavoidable, presents considerable challenges. Risk assessment is constrained by uncertainties associated with the lack of adequate data, and risk management must consider the fact that mycotoxin contamination can have serious impacts on trade and food sufficiency. These factors necessitate good communication between the risk assessors and risk managers in formulating the questions to be addressed by the risk assessment. Risk assessment must be an iterative process, since the problem formulation and the risk assessment may need to be revised to reflect new data and theories. In addition to providing advice to risk managers, risk assessment should provide a blueprint for future research by illustrating what observations will influence a prediction. The international risk assessments completed for deoxynivalenol, T-2 and HT-2 toxins, and nivalenol have noted a number of issues regarding the lack of adequate intake data for exposure assessment and significant gaps in toxicological studies for hazard characterizations. Addressing these uncertainties would provide risk managers with better guidance for control measures.

In studies to determine the cause or causes of the eosinophilia myalgic syndrome (EMS) and to monitor the purity of L-tryptophan preparations, an HPLC method has been developed for determining 1,1'-ethylidenebis(L-tryptophan) (EBT) in L-tryptophan (W) preparations. The W preparations are extracted with 0.1% trifluoroacetic acid (TFA) and filtered, and the EBT is purified by passage through a Sep-Pak C18 cartridge. The cartridge is washed with water and 6% acetonitrile in water, and EBT is eluted with methanol. The water-diluted eluate is then chromatographed on a silica-based, reversed-phase HPLC column with a gradient of water and 80% acetonitrile, both solvents containing 0.1% TFA. EBT absorbance is measured at 280 nm. The average recovery of EBT from L-tryptophan powder, spiked over the range 1.2-4.8 micrograms/g, was 91%. The limit of determination was approximately 0.6 micrograms/g. Sixteen test samples of W products manufactured by the company to which most of the cases of EMS have been traced contained > 70 micrograms of EBT/g. Three nonpatient-related test samples either did not contain EBT or contained < 2 micrograms of EBT/g.

Chemical studies were conducted to determine the origin of the 3-(phenylamino)alanine (PAA) contaminant in EMS-associated L-tryptophan samples. Anthranilic acid, a biosynthetic precursor of the L-tryptophan, was heated at 80°C for 6 h under acidic conditions to produce 140 μg of aniline/g of anthranilic acid. The presence of aniline was verified by HPLC-UV and GC-MS. PAA (160 μg of PAA/g of aniline) was produced by heating aniline and serine at 80°C for 6 h under basic conditions. PAA was confirmed by HPLC-UV and LC-MS. These results suggest that PAA could be formed under the fermentation and purification conditions used to produce L-tryptophan on an industrial scale.

Mycotoxins have a wide range of toxic effects, including carcinogenicity, neurotoxicity, immunotoxicity, and reproductive and developmental toxicity. Regulatory limits have been established for some of the well-known mycotoxins such as the aflatoxins, deoxynivalenol, ochratoxin A, and patulin in order to minimize human and animal exposure. Regulatory limits must be developed using science-based risk assessments to avoid unnecessary economic loss. Exposure data from surveillance studies are needed for risk assessments. Quality of data generated in these surveys depends on the analytical methods used and the adherence to quality assurance principles by skillful analysts.

Fumonisin B1 (FB1), 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, FB1 might have on nuclear membrane lipids and DNA. The data suggested that FB1 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 FB1-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.

Electron spin resonance (ESR) spin-label oximetry has been used to study the effects of fumonisin B1 (FB1), 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% FB1 increased the oxygen transport properties of both saturated and unsaturated membranes at 37 degrees 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.

The eosinophilia-myalgia syndrome (EMS) has been associated with ingestion of L-tryptophan (L-TRP) produced by a single manufacturer. Epidemiological data implicated 1,1'-ethylidenebis (L-tryptophan) (EBT) (peak 97 or peak E) as a possible etiologic agent. We showed previously that Lewis rats treated with the L-TRP implicated in EMS develop fasciitis and perimyositis similar to those seen in human EMS. We now report the pathology associated with the treatment of Lewis rats with synthetic EBT and/or L-TRP. All animals treated for 6 wk with case-associated L-TRP or EBT developed significant myofascial thickening, compared with animals in the vehicle control and control L-TRP groups. However, even those animals receiving the control L-TRP showed a mild but significant increase in the thickness of the myofascia, compared with vehicle-treated control animals. All animals except vehicle controls also exhibited significant pancreatic pathology, including fibrosis and acinar changes. Only animals treated with case-associated L-TRP for 6 wk showed evidence of immune activation with increased frequency of CD8, Ia, and IL-2 receptor-positive cells in the peripheral blood. Animals receiving L-TRP or EBT for < 6 wk did not show significant differences in myofascial thickness, although these animals did show pancreatic acinar changes. Although these results demonstrate for the first time the pathological effects of EBT, they do not rule out the possibility that other impurities in the EMS-case-associated L-TRP may also contribute to some of the features of EMS.

Drought in 1988 caused a high incidence of aflatoxin contamination in corn samples in nine states including TX, OK, IA, IN, IL, SD, MD, WI and MN (Wall Street Journal, 1988a). In Illinois, 27% of 52 corn samples contained more than 20 ng aflatoxins/g (Wall Street Journal, 1988b). On October 4, 1988, the U.S. Food and Drug Administration (FDA) established enforcement levels for aflatoxins in corn used in feed (Rothschild, 1988). The levels were 100, 200 and 300 ng/g depending on the animal consuming the feed containing the aflatoxin-contaminated corn. FDA enforcement action could also be supported when corn containing in excess of 20 ng total aflatoxins/g was destined for food used by humans, for feed used by immature animals and by dairy animals, or if its destination was not known.

Description d'une methode de separation de ces 3 mycotoxines, avec dosage fluoridensitometrique. La limite de detection est de l'ordre de 50 μg/g

A joint AOAC/IUPAC (International Union of Pure and Applied Chemistry) interlaboratory study of an enzyme-linked immunosorbent screening assay (ELISA) for aflatoxins was conducted in laboratories in Canada, France, Japan, South Africa, Switzerland, The Netherlands, Tunisia, and the United States. Twenty-eight samples of raw and roasted peanuts, corn, whole cottonseed, cottonseed meal, ammoniated cottonseed meal, and poultry feed containing various quantities of natural aflatoxins and supplemented when appropriate with aflatoxin B1 were distributed to participating laboratories for testing. The assay is based on conjugation of pure aflatoxin B1 to an enzyme and the competition between this conjugate and (free) aflatoxins in the product for aflatoxin-specific antibodies coated onto microtiter well walls. After a wash step to remove all unbound aflatoxins, a substrate, added to each well, is catalyzed from a colorless to a green solution by any bound enzyme-conjugated aflatoxin Bf present. The intensity of the color decreases as the amount of free aflatoxin B1 in the product increases. Overall correlation was good between ELISA and thin-layer chromatographic (TLC) results for cottonseed products and mixed feed. Variable results were reported for corn and peanut product samples. Although some positive samples (> 15 ng/g) of cottonseed products and mixed feed were reported to contain < 15 ng/g by visual determination, a review of data for absorbance measurements showed that the contamination level was close to the ≥ 15 ng/g standard and would not have been reported as negative under routine screening. Variation in ELISA results may have been due to several factors such as: lack of homogeneity of the aflatoxin contamination in the samples (prestudy TLC analysis samples were collected randomly from a pool of subsamples), interferences that resulted from incomplete removal of hexane during the filtration step, and antibody strips at or past their expiration date. The ELISA method has been adopted official first action as a screening method to determine the presence or absence of aflatoxin B1 at a concentration of ≥ 15 ng/g in cottonseed products and mixed feed.

The mold genus Alternaria is a widely distributed plant pathogen. Some of these species, e.g., A. alternata, are common decay organisms of fruits and vegetables. Two novel perylene oxide metabolites, altertoxins II and III, have been identified in extracts of A. alternata isolates that exhibit mutagenic responses in the Ames Salmonella typhimurium assay. These identifications were based on mass, optical rotational, and 1H- and 13C-nmr spectral studies. Previous reports of related perylene dione mycotoxins have been clarified.

Liquid chromatographic (LC) methodology potentially useful for the characterization of orange juice, with particular regard to detecting adulteration of orange juice by computer pattern recognition analysis, has been developed. After dilution with methanol the juice is extracted with hexane to remove the carotenoids, which are chromatographed on a C18 column with an acetonitrile-methanol-methylene chloride mobile phase and detection at 450 nm. Further extraction of the juice with methylene chloride isolates the methoxylated flavones, which are chromatographed by reverse phase LC with an acetonitrile-methanol-water mobile phase and detection at 280 nm. The flavanone glycosides remaining in solution are chromatographed on a C18 column with an acetonitrile-water mobile phase and detection at 280 nm. The precisions of the heights of the 32 LC peaks selected for pattern recognition analysis were determined from 5 replicate analyses of a single juice. Coefficients of variation of the replicates ranged from 0.3 to 4.5%, with an average of 2.1%. Adulteration of products with sodium benzoate-fortified pulpwash or grapefruit juice can be detected by this method. Pattern recognition analysis of the data obtained for 80 authentic and 19 adulterated orange juices showed that the method is potentially useful for distinguishing between authentic and adulterated products.

Recherche de modifications de structure des facteurs responsables de l'activite anticancereuse presentee par les legumes de type chou, chou de Bruxelles, chou-navet et induites par les traitements technologiques

Separation and Quantitation of 3,3',4,4'-Tetrachlorobiphenyl and 3,3',4,4',5,5'-Hexachlorobiphenyl in Aroclors Using Florisil Column Chromatography and Gas-Liquid Chromatography LaVerne R. Kamops, William J. Trotter, Susan J. Young, Audrey C. Smith, John A. G. Roach, and Samuel W. Page Division of Chemistry and Physics, Food and Drug Administration, U.S. Department of Health, Education, and Welfare, Washington, DC 20204

Irganox 1010 is an antioxidant used in food packaging. The degradation products of Irganox 1010 in a 50% aqueous ethanol system at 90C were examined by GC/MS and GC/MI/FTIR. The data suggest Irganox 10101 is hydrolyzed to form (3) benzenepropanoic acid, 3,5-bis (1,1-dimethylethyl)4-hydroxy-which reacts with solvent ethanol to form (f) its ethyl ester. The 4 other decomposition products (a) 2.5 cyclohexadiene-I,4-dione, 2,6-bis(1.1-dimethylethyl)-; (B) 3.5-bis-(1,1,-dimethylethyl)-2.5 cyclohexadiene-4-one spiro (5'-tetrahydrofuran-2'-one); (C) benzofuran, 2,3-dihydro-3.3-dimethyl-5 ethenyl-7-(1,1-dimethylethyl)-and (D) benzaldehyede, 3.5-bis-(1,1-dimethylethyl)-4-hydroxy-, can result from osidation, dehydration and decarboxylation processes of (E).