Exposure and risk characterizations of ochratoxins A and aflatoxins through maize (Zea mays) consumed in different agro-ecological zones of Ghana.

Mycotoxin contamination of foodstuffs is a serious food safety concern globally as the prolonged ingestion of these toxins has the tendency to worsen the risk of hepatocellular carcinoma. This study aimed at estimating ochratoxin A (OTA) and aflatoxin (AF) levels above international (European Food Safety Authority, EFSA) and local (Ghana Standards Authority, GSA) standards as well as the health risks associated with the consumption of maize (n = 180) sampled from six (6) regions representing the agro-ecological zones of Ghana. OTA and AF were measured with High-Performance Liquid Chromatography with a Fluorescence detector. Out of the 180 samples analyzed for total aflatoxins (AFtotal), 131/180 tested positive and 127 (70.50%) exceeded the limits of EFSA and ranged 4.27-441.02 µg/kg. While for GSA, 116 (64.44%) of samples exceeded this limit and ranged between 10.18 and 441.02 µg/kg. For OTA, 103/180 tested positive and 94 (52.22%) of samples between the range 4.00-97.51 µg/kg exceeded the tolerable limit of EFSA, whereas 89 (49.44%) and were in the range of 3.30-97.51 µg/kg exceeded the limits of GSA. Risk assessment values for total aflatoxins (AFtotal) ranged between 50 and 1150 ng/kg bw/day, 0.4-6.67, 0-0.0323 aflatoxins ng/kg bw/day and 1.62-37.15 cases/100,000 person/year for Estimated Daily Intake (EDI), Margin of Exposure (MOE), Average Potency, and Cancer Risks respectively. Likewise, ochratoxin (OTA) values were in the ranges of 8.6 × 10-3-450 ng/kg bw/day, 0.05-2059.97, 0-0.0323 ochratoxins ng/kg bw/day and 2.78 × 10-4-14.54 cases/100,000 person/year. Consumption of maize posed adverse health effects in all age categories of the locations studied since the calculated MOE values were less than 10,000.

Potentially toxic element (PTE) levels in maize, soil, and irrigation water and health risks through maize consumption in northern Ningxia, China.

BACKGROUND: Industrial and agricultural activities result in elevated levels of potentially toxic elements (PTEs) in the local environment. PTEs can enter the human body through the food chain and pose severe health risks to inhabitants. In this study, PTE levels in maize, soil, and irrigation water were detected, and health risks through maize consumption were evaluated. METHODS: Maize, soil, and irrigation water samples were collected in northern Ningxia, China. Inductively coupled plasma-optical emission spectrometry was applied to determine the contents of six PTEs. Bioaccumulation factor was used to reflect the transfer potential of a metal from soil to maize. Health risks associated with maize consumption were assessed by deterministic and probabilistic estimation. Sensitivity analysis was performed to determine variables that pose the greatest effect on health risk results. RESULTS: The levels of Pb and Cr in maize exceeded the standards, while the PTE levels in soil and irrigation water did not exceed the corresponding standards. The bioaccumulation factor values of the six PTEs in maize were all lower than 1 and followed the order of Cd > Zn = As > Cr > Cu > Pb. The hazard index (0.0986) was far less than 1 for all inhabitants implying no obvious non-carcinogenic risk. The carcinogenic risk value was 3.261 × 10- 5, which was lower than the maximum acceptable level of 1 × 10- 4 suggested by United States Environmental Protection Agency (USEPA). Females were at greater risk than males, and the age group of below 20 years had the greater risk among all the groups evaluated. Approximately 0.62% of inhabitants exceeded the level for non-carcinogenic risk, while 8.23% exceeded the level for carcinogenic risk. The As concentration and daily intake of maize contributed 35.8, and 29.4% for non-carcinogenic risk results as well as 61.0 and 18.5% for carcinogenic risk results. CONCLUSIONS: Maize was contaminated by Pb and Cr, whereas the associated soil and irrigation water were not contaminated by PTEs. Inhabitants would not suffer obvious harmful health risks through maize consumption. Arsenic level and daily intake of maize were the most sensitive factors that impact health risks.

Influência da qualidade micotoxicológica e nutricional de híbridos de milho no custo da ração de frangos de corte / Influence of mycotoxicological and nutritional quality of maize hybrids on broiler chickens feed cost

Objetivou-se avaliar as variáveis micotoxicológicas e nutricionais de híbridos de milho com diferentes características que influenciam no custo da ração para frangos de corte. Foram avaliados 26 híbridos de milho geneticamente modificados nas safrinhas de 2016 e 2017, com diferentes germoplasmas, textura de endosperma e duração do ciclo. Nos híbridos, foram avaliados grãos avariados, fumonisinas (B1+B2) (FUM), aflatoxinas (B1+B2+G1+G2) (AFLA), zearalenona (ZEA), deoxinivalenol (DON), umidade, proteína bruta (PB), energia metabolizável aparente corrigida para balanço de nitrogênio (EMAn), aminoácidos digestíveis para aves (lisina, metionina, cistina e treonina) e o respectivo custo da ração inicial para frangos de corte, que foi calculada pelo custo mínimo. A prevalência de FUM, AFLA, ZEA e DON foi de 90, 17, 33 e 0%, com médias de 3067, 1, 38 e 0µg/kg nos dois anos, respectivamente. A média de EMAn e PB foi de 3264kcal/kg e 8,02%, respectivamente, e diferiu (P<0,05) nos dois anos. O custo da ração foi influenciado significativamente (P<0,05) por FUM, PB, EMAn nos dois anos. Híbridos com tecnologia Viptera apresentam menor concentração por FUM e menor custo da ração. Híbridos de ciclo precoce têm menor concentração de FUM, maiores percentuais de PB e de aminoácidos digestíveis e menor custo da ração.(AU)

The objective of this study was to evaluate the mycotoxicological and nutritional variables of maize hybrids with different characteristics that influence the broiler chicken's feed costs. In 2016 and 2017 winter crops, 26 genetically modified hybrids of maize with different germplasm, endosperm texture and cycle duration were evaluated. The analyzed variables were damaged grains, fumonisins (B 1 +B 2 ) (FUM), aflatoxins (B 1 +B 2 +G 1 +G 2 ) (AFLA), zearalenone (ZEA), deoxynivalenol (DON), moisture, crude protein (CP), apparent metabolizable energy corrected for nitrogen balance (AMEn), digestible amino acids for poultry (lysine, methionine, cystine and threonine) and the respective cost of the initial feed for broiler chickens calculated at the minimum cost. The prevalence of FUM, AFLA, ZEA and DON was 90, 17, 33 and 0%, with means of 3067, 1, 38 and 0µg/kg in the two years, respectively. The mean of AMEn and CP was 3264kcal/kg and 8.02%, respectively, and differed (P< 0.05) in the two years. The feed cost was significantly influenced (P<0.05) by FUM, PB, AMEn in two years. Hybrids with Viptera technology show lower concentration per FUM and lower feed cost. Early cycle hybrids have lower concentrations of FUM, higher percentages of CP and digestible amino acids, and lower feed costs.(AU)

Toxicidad oral aguda de los extractos etanólicos de Eucalyptus globulus, Morinda citrifolia, Peperomia glauca, Schinus molle y Zea mays en ratones BALB/c 53 / Acute oral toxicity of Eucalyptus globulus, Morinda citrifolia, Peperomia glauca, Schinus molle and Zea mays ethanolic extracts on BALB/c 53 mice

Objetivo. Evaluar la toxicidad aguda de los extractos etanólicos del Eucalyptus globulus Labill. (eucalipto), Morinda citrifolia L. (noni), Peperomia glauca (pino) (congona), Schinus molle L. (molle) y Zea mays L. (Maíz morado) en ratones Balb/c 53. Materiales y métodos. Se utilizaron 60 ratones machos divididos en seis grupos (eucalipto, noni, congona, molle, maíz morado y control). Los grupos tratados recibieron por vía oral una dosis única de 2000 mg/kg de los extractos etanólicos, y el grupo control recibió polisorbato 2 mL/kg al 3%. Se evaluó ganancia de peso, valores hematológicos (hematocrito, eritrocitos, hemograma, leucocitos, plaquetas), bioquímica sérica (úrea, creatinina, ALT, proteínas totales, albumina, globulinas), histopatología hepática y renal. Resultados. Se observó signos de inquietud, excitación y aparente fotosensibilidad en el grupo eucalipto, por una hora. Se encontró leucopenia en grupos congona, molle, eucalipto y maíz morado; trombocitopenia en grupos eucalipto y molle, y elevación del ALT en los grupos congona y eucalipto, en comparación con los valores del grupo control. La ganancia de peso, los demás valores hematológicos, así como la bioquímica renal y hepática en los otros grupos no fueron significativos. Conclusiones. En las condiciones experimentales no se observó signos de toxicidad ni mortalidad en el ensayo; la DL50 de los extractos etanólicos estaría sobre los 2000 mg/kg.

Objective. This study was performed to evaluate the acute toxicity of ethanolic extracts of Eucalyptus globulus Labill. (Eucalipto), Morinda citrifolia L. (noni), Peperomia glauca (pino) (Congona), Schinus molle L. (molle) y Zea mays L. (maíz morado) in Balb/c mice. Materials and methods. Sixty male mice were divided into 6 groups (Eucalipto, Noni, Congona, Molle, Maíz morado and Control) of 10 each were used. The guide for the Organization for Economic Cooperation and Development (OECD 423) was followed for the study. The treated group received for gavage a single dose at 2000 mg/kg and the control group received polysorbate at 2 mL/kg at 3%. Weight gain, hematological values (hematocrit, erythrocytes, hemogram, leukocytes, platelets), serum biochemistry (urea, creatinine, ALT, total proteins, albumin, globulins), hepatic and renal histopathology were performed. Results. No signs of mortality and morbidity were observed as a consequence of the administration of the extracts, except for the Eucalipto group, which presented restlessness, excitation and apparent photosensitivity for one hour. There was leukopenia in Congona, Molle, Eucalipto and Maíz morado groups; thrombocytopenia in groups Eucalipto and Molle; and elevations of ALT in Congona and Eucalipto groups in comparison than the values from control group. Weight gain and other hematological values, as well as renal and hepatic biochemistry in the other groups were not significant. Conclusions. Under experimental conditions no signs of toxicity or mortality were observed in the trial; the LD50 of the ethanolic extracts would be above 2000 mg/kg.

Ganho de peso, consumo de ração e histologia de órgãos de leitões alimentados com rações contendo baixos níveis de fumonisina B1 / Weight gain, feed consumption and histology of organs from piglets fed rations containing low levels of fumonisin B1

A fumonisina B1 (FB1) é um metabólito secundário produzido principalmente por Fusarium verticilioides em diversos tipos de alimentos, principalmente o milho, o qual constitui a base para composição de rações para várias espécies de animais domésticos. A FB1é particularmente tóxica para suínos, cujas manifestações clínicas são evidentes em animais expostos a altas concentrações de FB1 na ração (em geral, acima de 30mg/kg). No entanto, são escassos os estudos sobre os efeitos da FB1em suínos alimentados com rações contendo baixas concentrações de fumonisinas, as quais são mais prováveis de serem encontradas em condições de campo. O objetivo do estudo foi avaliar os efeitos da exposição de leitões a baixos níveis de FB1 na ração, durante 28 dias, sobre o ganho de peso, consumo de ração, peso relativo de órgãos e aspectos histológicos do baço, fígado, pulmões, rins e coração. Vinte e quatro leitões foram distribuídos em 4 grupos experimentais e alimentados com rações contendo 0mg (controle), 3,0mg, 6,0mg ou 9,0mg FB1/kg de ração. As diferentes dietas não afetaram (P>0,05) o ganho de peso e nem o peso relativo dos órgãos analisados. Não foram constatadas lesões macroscópicas ou histopatológicas no baço, fígado, rins e coração. No entanto, foram observadas lesões histopatológicas nos pulmões de todos os suínos alimentados com rações contaminadas com fumonisinas, indicando que nenhum dos níveis de FB1 usados no experimento poderia ser considerado como seguro para suínos. São necessários novos estudos sobre os mecanismos de ação tóxica da FB1 em suínos, sobretudo em condições de exposição prolongada a baixos níveis de contaminação na ração.

Fumonisin B1 (FB1) is a secondary metabolite produced mainly by Fusarium verticilioides in several types of foods, particularly corn, which is the basis for composition of feed for several domestic animals. FB1 is particularly toxic to pigs, being the clinical manifestations evident in animals exposed to high concentrations of FB1 in the diet (generally above 30mg/kg). However, there are few studies on the effects of FB1 on pigs fed rations containing low concentrations of fumonisin, which are most probably found under field conditions. The aim of the study was to evaluate the effects of a 28-day exposure of piglets to low levels of FB1 in the feed on the weight gain, feed consumption, organ weights and histological aspects of the spleen, liver, lungs, kidneys and heart. Twenty-four pigs were assigned into 4 experimental groups and fed diets containing 0mg (control), 3.0mg, 6.0mg or 9.0mg FB1/kg diet. The different diets did not affect (P>0.05) the weight gain or the weight of organs examined. There were no macroscopic or histological lesions in the spleen, liver, kidneys and heart. However, histological lesions were found in the lungs from all animals fed rations containing fumonisin, hence indicating that none of the FB1 levels used in the experiment could be considered as safe for piglets. Further studies on the mechanisms of toxic action of FB1 in pigs are needed, particularly under conditions of prolonged exposure to low contamination levels in the diet.

Aspergillus section Nigri as contributor of fumonisin B(2) contamination in maize.

Fumonisins (FBs), which are carcinogenic mycotoxins, are known to be typically produced by several phytopathogenic fungal species belonging to the genus Fusarium. F. proliferatum and F. verticillioides, two important pathogens of maize worldwide, are the most common species that produce FBs. The main FBs produced by these species are FB1, FB2 and FB3. Moreover, recently, fungal strains belonging to Aspergillus niger have been also reported to produce FBs (in particular, FB2 and FB4). In a survey on maize carried out in Central Italy, 17 maize kernel samples were collected at harvest and analysed for FB1, FB2 and FB3, as well as fungal contamination, with a particular attention to the species-producing FBs. All 17 samples were contaminated by F. verticillioides and/or F. proliferatum at a level ranging from 13% to 100% of kernels. However, 10 out of 17 samples were also contaminated by Aspergillus section Nigri with a range from 6% to 68% of kernels. There was a significant inverse logarithmic relationship between levels of Fusarium and Aspergillus contamination. All samples were contaminated by FBs; FB1 ranged from 0.09 to 30.2 µg g(-1), whereas FB2 ranged from 0.04 to 13.2 µg g(-1). The ratio of FB2/FB1 contamination in the maize samples was evaluated and the highest values occurred in samples contaminated with Aspergillus section Nigri. Thirty strains of Aspergillus section Nigri isolated from these samples were molecularly identified (based on sequences of two housekeeping genes) and analysed for their capability to produce FB2. Among the 30 strains isolated, 12 were identified as Aspergillus welwitschiae (syn. A. awamori) and 18 as A. tubingensis. FB2 was produced by five out of 12 strains of A. welwitschiae within a range of 0.20-5 µg g(-1). This is the first report showing the capability of Aspergillus section Nigri from maize to produce FB2 and its possibility to contribute to FB accumulation in kernels.

Plurality of opinion, scientific discourse and pseudoscience: an in depth analysis of the Séralini et al. study claiming that Roundup™ Ready corn or the herbicide Roundup™ cause cancer in rats.

A recent paper published in the journal Food and Chemical Toxicology presents the results of a long-term toxicity study related to a widely-used commercial herbicide (Roundup™) and a Roundup-tolerant genetically modified variety of maize, concluding that both the herbicide and the maize varieties are toxic. Here we discuss the many errors and inaccuracies in the published article resulting in highly misleading conclusions, whose publication in the scientific literature and in the wider media has caused damage to the credibility of science and researchers in the field. We and many others have criticized the study, and in particular the manner in which the experiments were planned, implemented, analyzed, interpreted and communicated. The study appeared to sweep aside all known benchmarks of scientific good practice and, more importantly, to ignore the minimal standards of scientific and ethical conduct in particular concerning the humane treatment of experimental animals.

Spontaneous renal tumors in two rats from a thirteen week rodent feeding study with grain from molecular stacked trait lepidopteran and coleopteran resistant (DP-ØØ4114-3) maize.

A thirteen week feeding study was conducted by feeding young adult male and female Sprague Dawley [Crl:CD®(SD)] rats diets containing grain from genetically modified (GM) DP-ØØ4114-3 maize that was either untreated (4114) or treated in the field with glufosinate ammonium (4114GLU). Control rats were fed diets containing the same concentration of near isogenic, non-GM maize grain (091) or one of three types of commercially available non-GM maize grain. At the end of the in-life phase, renal tubule tumors were reported in two male rats consuming diets containing 4114 maize grain. An expert panel of pathologists was convened as a Pathology Working Group (PWG) to review coded kidney histology sections from control (091) and treated (4114 and 4114GLU) male rats. The objectives were for the panel to characterize the histopathologic findings and to interpret their relationship to consumption of the indicated diet. The PWG concluded unanimously that the kidney tumors were characteristic of amphophilic-vacuolar (AV) tumors and AV atypical tubular hyperplasia which represent a distinctive phenotype that has been reported to occur sporadically in young Sprague Dawley Rats. The PWG determined that the neoplasms and atypical tubular hyperplasias were multicentric and bilateral which typifies tumors of familial origin. Degenerative/regenerative or cytotoxic changes consistent with nephrotoxicity leading to tumor induction were not observed in these rats and thus supports the conclusion that tumors were unrelated to consumption of the test diet. It was the unanimous opinion of the PWG that the proliferative renal tubule cell lesions were spontaneous and not related to consumption of diets containing 4114 maize grain.

Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize.

The health effects of a Roundup-tolerant genetically modified maize (from 11% in the diet), cultivated with or without Roundup, and Roundup alone (from 0.1 ppb in water), were studied 2 years in rats. In females, all treated groups died 2-3 times more than controls, and more rapidly. This difference was visible in 3 male groups fed GMOs. All results were hormone and sex dependent, and the pathological profiles were comparable. Females developed large mammary tumors almost always more often than and before controls, the pituitary was the second most disabled organ; the sex hormonal balance was modified by GMO and Roundup treatments. In treated males, liver congestions and necrosis were 2.5-5.5 times higher. This pathology was confirmed by optic and transmission electron microscopy. Marked and severe kidney nephropathies were also generally 1.3-2.3 greater. Males presented 4 times more large palpable tumors than controls which occurred up to 600 days earlier. Biochemistry data confirmed very significant kidney chronic deficiencies; for all treatments and both sexes, 76% of the altered parameters were kidney related. These results can be explained by the non linear endocrine-disrupting effects of Roundup, but also by the overexpression of the transgene in the GMO and its metabolic consequences.

Subchronic toxicity study of corn silk with rats.

AIM OF THIS STUDY: Corn silk is a traditional herbal medicine in China, which has been used in many parts of the world for the treatment of edema as well as for cystitis, gout, kidney stones, nephritis, prostatitis and similar ailments. However, there is little scientific evidence about its safety. As a part of its safety assessment, a subchronic toxicity was performed in this paper. METHODS: The subchronic toxicity was investigated in male and female Wistar rats by dietary administration at concentrations of 0.5%, 2.0% and 8.0% (w/w) for 90 days. Overall health, body weight, food consumption, hematology, blood chemistry, organ weights, gross and microscopic appearance of tissues were compared between test and control groups. RESULTS: A number of significant differences were seen between groups, but none of them was considered to be adverse. Based on the present study, the no-observed-adverse-effect level (NOAEL) of corn silk is at least 8.0% which corresponds to a mean daily corn silk intake of approximately 9.354 and 10.308 g/day/kg body weight for males and females, respectively. CONCLUSION: The results obtained in the present study suggest that consumption of corn silk has no adverse effects and support the safety of corn silk for humans.

HIV and hepatocellular and esophageal carcinomas related to consumption of mycotoxin-prone foods in sub-Saharan Africa.

BACKGROUND: Promotion of the HIV epidemic by aflatoxin is postulated but not yet established. Sub-Saharan populations commonly consume food contaminated by mycotoxins, particularly aflatoxins (predominantly found in peanut, maize, rice, and cassava) and fumonisins, which occur primarily in maize. Aflatoxin promotes hepatocellular cancer, and fumonisin may promote esophageal cancer. OBJECTIVES: This analysis was undertaken to test the hypotheses that consumption of mycotoxin-prone staple foods is 1) related to the incidence of HIV infection in Africa and 2) related to "signature" cancer rates confirming exposure to aflatoxins and fumonisins. DESIGN: World Health Organization data for causes of death and the Food and Agriculture Organization per capita consumption data for commodities in sub-Saharan Africa were used. Per capita Gross Domestic Product and the percentage of Muslims (%Muslim) were the socioeconomic data sets exploited. Relations between causes of mortality, consumption of mycotoxin-prone foods, and socioeconomic variables were evaluated. Models for HIV transmission as a function of maize consumption and %Muslim were estimated. RESULTS: HIV and esophageal cancer deaths were significantly related to maize but were inversely related to %Muslim and rice consumption. HIV infections were minimized (74 compared with 435/100,000 people; odds ratio: 2.41; 95% CI: 1.73, 3.24; P < or = 0.0001) by the combination of low maize consumption and above-median % Muslim. Hepatocellular cancer deaths were positively related to rice but negatively related to maize consumption. CONCLUSIONS: HIV transmission frequency is positively associated with maize consumption in Africa. The relation between cancer and food suggests that fumonisin contamination rather than aflatoxin is the most likely factor in maize promoting HIV. Changes to the quality of maize may avoid up to 1,000,000 transmissions of HIV annually.

[Medical and biological safety assessment of genetically modified maize event MIR604].

There are presented the results of genotoxicologic, immunologic and allergologic examinations which were conducted within the framework of integrated medical and biological assessment of genetically modified rootworm Diabrotica spp.-protected maize event MIR604. Analysis of damages of DNA and structural chromosome aberrations, assessment of the allergenic potential and immunoreactive properties has not confirmed any genotoxic, allergenic and immunotoxic effect of maize event MIR604.

Ecological significance of induction of broad-substrate cytochrome P450s by natural and synthetic inducers in Helicoverpa zea.

The polyphagous corn earworm Helicoverpa zea relies on cytochrome P450 monooxygenases with broad substrate specificities to cope with the wide diversity of phytochemicals it encounters among its numerous host plants. These enzymes also contribute to the ability of this insect to tolerate toxins from sources other than its hosts, including microbial and synthetic toxins. Although upregulation of xenobiotic-metabolizing P450s in some herbivorous insects is closely linked to host plant toxins, transcriptional and/or post-transcriptional regulation of detoxification in this polyphagous species also appears to be relatively unspecialized. Reverse transcription polymerase chain reaction and metabolic analyses indicate that rare and infrequently encountered phytochemicals, as well as synthetic substances, can enhance metabolic activity in an adaptive fashion against both natural and synthetic toxins.

Botulismo em bovinos leiteiros no Sul de Minas Gerais, Brasil / Botulism in dairy cattle in southern Minas Gerais, Brazil

Neste trabalho descreve-se um surto de botulismo decorrente da ingestão de milho contaminado em um sistema de produção de leite, em regime de confinamento, na região Sul de Minas Gerais. O rebanho era composto por 148 vacas holandesas lactantes de alta produção, confinadas em tempo integral e alimentadas com dieta completa, composta de silagem de milho e concentrado. Foram afetados 38 bovinos, verificando-se letalidade de 100 por cento. Amostras de conteúdo intestinal, ruminal e fígado de sete animais necropsiados e amostras de água dos bebedouros e do milho utilizado na alimentação foram submetidas ao bioensaio e à soroneutralização para a detecção de toxina botulínica. Toxinas dos tipos C e D foram detectadas nas amostras de conteúdo intestinal, ruminal e milho. O surto descrito mostra que o milho estocado em condições inadequadas pode ser um fator de risco para a ocorrência da doença.

An outbreak of bovine botulism in a dairy herd caused by ingestion of contaminated maize, in southern Minas Gerais, Brazil is described. The herd was composed by 148 lactating cows of high milk production fed with diet based on maize ensilage and concentrate in a free stall system. Thirty eight cows were affected, with 100 percent of fatality rate. Samples from intestine, rumen and liver of necropsied cattle and drinking water and maize were submitted to the mouse bioassay and soroneutralization tests for detection of Clostridium botulinum toxins. Types C and D toxins were detected in samples from intestinal and rumen contents and maize. The reporter of an outbreak of botulism in cattle associated with an unusual source of toxin, shows that stocked maize in inadequate conditions is a factor of risk for the occurrence of the botulism in dairy cattle.

Pirimiphos-methyl residues in corn and popcorn grains and in some of their processed products

Insecticides are used for stored cereal protection against insect attack and the occurrence of their residues needs to be evaluated not only in grain but also in the processed products. This study evaluates the residue degradation/persistence of the organophosphorous insecticide pirimiphos-methyl in corn and popcorn grains and in some of their processed products such as bran, hominy and corn flour from corn and popped popcorn. Grains were treated with pirimiphos-methyl at the rate of 12 mg.kg-1 (a.i.). Samples were taken and analyzed at zero, 15, 30, 60, 120 and 240 days after treatment. The analytical method consisted of residue extraction with acetone, clean-up partition with acetonitrile/hexane and silica gel column chromatography eluted with a mixture of hexane + acetone. Quantitative measurements were made by gas chromatography, using flame photometric detector (GLC/FPD). The limits of quantitation (LOQs) were: corn grain, hominy and popped popcorn 0.05 mg.kg-1; bran, corn flour and popcorn grain 0.1 mg.kg-1. Pirimiphos-methyl residues were not persistent in either types of grains or in their processed products. At the end of sampling period (240 days), 5 to 8-fold less residues were found in corn bran and popcorn. Hominy and corn flour showed low levels of contamination. Higher residue concentrations in corn bran than in grains are related to the higher oil content in that processed product

Survey of moniliformin in corn cultivated in the state of São Paulo and in corn products commercialized in the city of Campinas, SP

Moniliformin, a toxin produced by Fusarium, was investigated in 22 samples of corn, 17 coming from districts of the state of São Paulo and 4 from experimental plots of the Campinas Institute of Agronomy, Brazil. The toxin was also investigated in 68 samples of corn products commercialized in Campinas, SP. Moniliformin was not detected in any sample.

Sampling plan for the analysis of aflatoxin in peanuts and corn: an update

The aim of this paper was to update the sampling plan for analysis of mycotoxins in grains, formerly published by the author. The proposed alterations were based on the acquired experience on its application and on FAO recommendations. This update restricts the scope of the former plan and establishes a sampling plan for analysis of aflatoxin in peanuts and corn, by means of modified formulas, the minimum number of sacks or points (when in bulk) from which incremental samples should be drawn to make a bulk sample. Fractional exponents (square roots) of the formulas proportionally decrease the number of sacks/points to be sampled as the lot size increases. Operating Characteristic (OC) curves developed for in-shell and shelled peanuts and corn as well as trend curves of the coefficient variation for different sample sizes (weights) are presented.

Assessment of in vitro mutagenicity in Salmonella and in vivo genotoxicity in mice of the mycotoxin fumonisin B(1).

Fumonisin B(1) (FB(1)), a mycotoxin produced by Fusarium moniliforme, is a contaminant of cereals with various and complex cellular effects. FB(1) induces liver cancer in rats and has been linked to esophageal cancer in South Africa and China. The mechanisms of FB(1)-induced carcinogenesis are uncertain and the information on FB(1) mutagenic properties is limited and controversial. FB(1) contamination levels in maize and wheat from Chile were found to be similar to those in other countries. FB(1) was devoid of activity in gene mutation assays with Salmonella typhimurium strains TA100, TA102 and TA98. However, i.p. injection of FB(1) induced an increased frequency of micronuclei in mouse bone marrow polychromatic erythrocytes at 25 and 100 mg/kg. We conclude that FB(1) induces in vivo genotoxicity in the absence of in vitro mutagenicity in Salmonella.

Cytotoxicity and biotransformation inducing activity of rodent beddings: a global survey using the Hepa-1 assay.

Unknown and uncontrolled toxic materials in the environment of experimental animals endanger the reliability of research results. In this study, the cytotoxic and biotransformation inducer activity of beddings obtained from a number of institutes in Africa, Americas, Asia, Australia and Europe were compared using the Hepa-1 in vitro-assay. A great variation in both cytotoxicity and inducer activity was observed. Pine shavings beddings, commonly used all over the world appeared in general to be highly cytotoxic. Extracts of corn cob, rice hulls and straws, used in a few laboratories, were practically non-toxic. Some softwood extracts, especially from pine, were also potent inducers of cytochrome P4501A1. Grass as well as hardwood materials were much less active. Due to great variation in toxicity and inducer activity in the beddings it is possible that, in spite of standardization of feed and other environmental factors, different biological responses to chemicals and drugs in even genetically identical animal strains in different laboratories, may be obtained. Control of bedding, one of the animals' closest environmental factors, for its toxicity and biotransformation enzyme induction is strongly recommended.