Lucia Maria Valente Soares

Survey of Brazilian tomato products for alternariol, alternariol monomethyl ether, tenuazonic acid and cyclopiazonic acid

Alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TEA) are secondary metabolites of Alternaria species. Cyclopiazonic acid (CPA) is produced by fungi belonging to the ubiquitous genera of Penicillium and Aspergillus and has been found in a wide range of foods. These toxins were searched for by liquid chromatography with diodearray detection in tomato products processed and sold in Brazil. Eighty samples of tomato products were examined (juice 11, pulp 22, purée 22, paste 24 and whole stewed tomato 1). Eleven brands sold nationwide were covered. TEA was found in seven samples of tomato pulp (39–111ng/g) and four samples of tomato pure´e (29–76ng/g). CPA was found in six samples of pulp (64–178ng/g) and two samples of purée (36–117ng/g). Co-occurrence of TEA and CPA was found in two samples of purée and one of pulp. This is the first time that the presence of CPA has been reported in tomato products. Neither AME nor AOH were detected in the samples.Alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TEA) are secondary metabolites of Alternaria species. Cyclopiazonic acid (CPA) is produced by fungi belonging to the ubiquitous genera of Penicillium and Aspergillus and has been found in a wide range of foods. These toxins were searched for by liquid chromatography with diodearray detection in tomato products processed and sold in Brazil. Eighty samples of tomato products were examined (juice 11, pulp 22, puree 22, paste 24 and whole stewed tomato 1). Eleven brands sold nationwide were covered. TEA was found in seven samples of tomato pulp (39–111ng/g) and four samples of tomato pure´e (29–76ng/g). CPA was found in six samples of pulp (64–178ng/g) and two samples of puree (36–117ng/g). Co-occurrence of TEA and CPA was found in two samples of puree and one of pulp. This is the first time that the presence of CPA has been reported in tomato products. Neither AME nor AOH were detected in the samples.

Ochratoxin A in Brazilian roasted and instant coffees.

Thirty-four samples of roast and ground coffee, 14 samples of instant coffee and two samples of decaffeinated instant coffee were collected in markets and supermarkets in the city of Campinas, Brazil, and analysed for ochratoxin A using immunoaffinity columns for clean-up and HPLC with fluorescence detection for quantification. The limit of detection was 0.2 ng/g ochratoxin A. Twenty-three samples of ground and roast coffee were found to be contaminated with the toxin at levels ranging between 0.3 and 6.5 ng/g. The average concentration in all 34 samples was 0.9 ng/g. All samples of instant coffee contained ochratoxin A at levels ranging from 0.5 to 5.1 ng/g, with an average figure of 2.2 ng/g. Roast and ground coffee is the type of coffee most used by Brazilians for the preparation of the beverage. Considering that an average Brazilian adult takes five cups of coffee per day, which corresponds to 30 g of roast and ground coffee, the probable daily intake of ochratoxin A by a 70 kg adult would be 0.4 ng/kg bw, which is far below the current Provisional Tolerable Daily Intake of 14 ng/kg bw for ochratoxin A as set by the Codex Alimentarius. To study the transfer of ochratoxin A into coffee brew, the beverage was prepared by two methods: (a) the drip method and (b) the Brazilian country style method. No significant difference was observed between the two methods in terms of extraction of the toxin using five contaminated samples containing between 0.8 and 6.5 ng/g ochratoxin A. The drip method extracted 86 +/- 15% and the Brazilian country style 74 +/- 20% of the ochratoxin A initially present in the roast and ground coffee.

Fumonisins B1 and B2 in Brazilian corn-based food products

Eighty-one samples of corn products were acquired from markets and supermarkets in the city of Campinas, SP, Brazil, and were analysed for fumonsins B1 and B2 (FB1 and FB2). Forty samples (49%) were positive for FB1

Mycotoxins and fungi in wheat harvested during 1990 in test plots in the state of São Paulo, Brazil

Wheat from two cultivars with contrasting characteristics were harvested in ten experimental plots located in wheat producing areas of the State of São Paulo, Brazil. The samples (10 of each cultivar) were analyzed by a gaschromatographic method for deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), toxins T-2 (T-2) and HT-2, T-2 tetraol, T-2 triol, and by a thin-layer chromatographic method for zearalenone (ZEN), aflatoxins B1, B2, G1, G2, ochratoxin A and sterigmatocystin. No mycotoxins were detected in 13 samples. DON was found in four samples (0.47–0.59 µg/g), NIV in three samples (0.16–0.40 µg/g), T-2 in two samples (0.40, 0.80 µg/g), DAS in one sample (0.60 µg/g), and ZEN in three samples (0.04–0.21 µg/g). The wheat samples were also examined for the incidence of fungi.Alternaria, Drechslera, Epicoccum andCladosporium were the prevailing genera. Among theFusarium spp.,F. semitectum was present in 19 samples andF. moniliforme in 18 samples. NoF. graminearum was isolated in the samples.

Mycoflora and aflatoxin/fumonisin production by fungal isolates from freshly harvested corn hybrids

A microbiota fungica de 66 amostras de tres hibridos de graos de milho recem-colhido, provenientes de 3 regioes do Estado de Sao Paulo - Brasil (Assis, Capao Bonito e Ribeirao Preto), foram analisadas perante a influencia dos fatores abioticos (teor de umidade, atividade de agua, precipitacao pluvial e temperatura media) na frequencia de isolamento de fungos, bem como a potencialidade toxigenica das cepas de Aspergillus flavus e Fusarium moniliforme quanto a producao de aflatoxinas e fumonisinas, respectivamente. As analises microbiologicas demonstraram predominância de Fusarium spp., Penicillium spp. e Aspergillus spp. e outros dois generos de fungos filamentosos, isolados de graos com atividade de agua entre 0,30 e 0,99 e teor de umidade entre 5,0% e 20,2%. Entre Fusarium spp, F.moniliforme foi a mais frequentemente isolada, enquanto que, em relacao ao genero Aspergillus, predominou A. flavus nas tres regioes. Todas as cepas de Fusarium moniliforme isoladas (40), produziram fumonisinas, que variaram de 20 mg/g a 2168 mg/g (FB1) e 10 mg/g a 380 mg/g (FB2). Referente a 10 cepas de Aspergillus flavus isoladas, 6 cepas (60,0%) produziram aflatoxinas, que variaram de 615 mg/kg a 30.750 mg/kg (AFB1) e 11 mg/kg a 22 mg/kg (AFB2).

Incidência de fumonisina B1, aflatoxinas B1, B2, G1 e G2, ocratoxina A e zearalenona em produtos de milho

Research concerning the presence of mycotoxin in food has been conducted in the Southwest and South regions of Brazil over the last two decades. Research in other regions has been limited to aflatoxin in peanuts and Brazil nuts. The aim of this work is to study the presence of fumonisin B1, aflatoxins B1, B2, G1, and G2, ochratoxin A and zearalenone in 74 samples of corn products acquired in shops and food markets in the city of Recife (PE) from 1999 to 2001. Fumonisin B1 was determined by high performance liquid chromatography and fluorescence was detected. The other toxins were determined by thin layer chromatography. Fumonisin B1 was found in 94.6% of the samples in levels from 20 to 8600 µg/kg. Only 5 samples contained aflatoxin B1 and the highest level found was 20 µg/kg. Two samples were over 20 µg/kg for the sum of B1, B2, G1 e G2 (21.5 µg/kg for pre-cooked corn flour and 23.3 µg/kg for corn grits). Aflatoxins G1 and G2, ochatoxin A and zearalenone were not detected in any of the samples. All samples contaminated with aflatoxins were also contaminated with fumonisin B1.

Ochratoxin A in Brazilian green coffee

Ocratoxina A e um composto nefrotoxico, teratogenico e imunotoxico produzido por especies de Aspergillus e Penicillium. Foi demonstrado ser carcinogenico para ratos e e possivelmente carcinogenico para humanos. Recentemente a toxina despertou atencao por ter sido encontrada em cafe e ter sido objeto de regulamentacao por paises importadores. O Brasil e o maior produtor de cafe no mundo e tambem seu maior consumidor. Para conduzir uma avaliacao inicial da situacao do cafe produzido no pais e oferecido a sua populacao, cento e trinta e duas amostras de cafe verde brasileiro, provenientes de 5 Estados produtores (Minas Gerais, Parana, Sao Paulo, Espirito Santo, e Bahia) e destinadas ao mercado nacional, foram coletadas em pontos de comercializacao nas cidades de Londrina e Santos, Brasil, e analisadas para ocratoxina A. A toxina foi isolada em colunas de imunoafinidade e quantificada em cromatografo liquido de alta eficiencia com detector de fluorescencia. O limite de deteccao foi 0,7ng/g e o coeficiente de variacao medio entre duplicatas foi 11%. Vinte e sete amostras estavam contaminadas com a toxina e a concentracao media para as amostras contaminadas foi 7,1ng/g de ocratoxina A. Nem o numero total de defeitos e nem o numero de cada defeito especifico encontrado na classificacao das amostras de acordo com o sistema brasileiro de classificacao (preto, meio-preto, ardido, verde-preto, verdes, brocados, coco) mostrou ter qualquer relacao com a contaminacao presente nas amostras.

Fumonisin B1 and ochratoxin A in beers made in Brazil

A presenca de fumonisina B1 (FB1) e de ocratoxina A (OTA) foi investigada em amostras de cerveja fabricada no Brasil. FB1 foi pesquisada em 58 amostras de cerveja provenientes de 30 fabricas localizadas em nove Estados. As amostras foram concentradas, e a toxina isolada atraves de coluna de troca ionica forte, derivacao com OPA e analise por CLAE com fluorescencia associada. O limite de deteccao foi 0,26 ng.mL-1 e a recuperacao media foi de 98%. Vinte e cinco amostras continham FB1 em concentracoes de 1 a 40 ng.mL-1. Cerveja (123 amostras) proveniente de 36 fabricas localizadas em 5 Estados foi analisada para OTA atraves de coluna de imunoafinidade seguida de CLAE com detector de fluorescencia. O limite de deteccao foi 0,1 ng.mL-1 e a recuperacao media foi de 92%. Cinco amostras continham OTA em concentracoes de 1 a 18 ng.mL-1. Os resultados indicam que a contaminacao da cerveja brasileira por FB1 e por OTA nao e geograficamente limitada e que nao contribui significativamente para a ingestao de FB1 por consumidores. Por outro lado, no caso de consumo alto e regular, esta pode contribuir substancialmente na ingestao de OTA, porem ainda abaixo do maximo considerado toleravel para a toxina.

Composição mineral de sucos concentrados de frutas brasileiras

Information on the composition of Brazilian foods is scant. Concentrate fruit juices commercialized in glass bottles are widely used by Brazilian families. The present work eight nutritionally important elements (K, Na, Ca, Mg, Fe, Zn, Cu, Mn) in commercial concentrated fruit juices, pineapple (3 brands), West Indian cherry (2 brands), cashew (5 brands), guava (3 brands), mango (2 brands), passion fruit (5 brands), and Surinam cherry (1 brand) were determined by flame atomic absorption spectrometry. The juices contribution to childrens diet, considering an intake of 300 mL per day and using the dilution suggested by the maker, is high in potassium for all juices analyzed (170 - 930% of the recommended daily allowance, RDA). The pineapple and West Indian cherry juices offer 6 and 12% of the iron RDA, respectively. The manganese present in pineapple, mango, guava, and West Indian cherry juices contribute with 38, 14, 8 e 7% of the RDA, respectively. Magnesium varies between 9% of the RDA in pineapple juice and 2% in the passion fruit and cashew ones. Zinc and copper varied between less then 1 - 2% of the RDA in cashew and Surinam cherry juices and 2 to 6% in the other juices. For adults the contribution to the diet is proportionately less but by no means to be disregarded.

The development of an analytical method for two mycotoxins, patulin and verruculogen, and survey of their presence in commercial tomato pulp

The mycotoxin patulin causes gastroinstestinal distress, neurotoxic and immunotoxic effects in animals. It can be produced by several species of Penicillium, Aspergillus and Byssochlamys and it has been found in fruits, vegetables and cereals. Verruculogen is a toxin produced mainly by Penicillium and Aspergillus spp. and causes severe tremors in affected animals. Tomatoes are especially susceptible to fungi invasion and their products need to be investigated for possible mycotoxin contamination. A method for the determination of patulin and verruculogen in tomato products was developed involving an extraction with ethyl acetate, a cleanup by silica gel column and determination and confirmation by high performance liquid chromatography with diode array detector. The quantification limits of the method, defined as the minimum amount that allowed quantification and confirmation by the DAD detector, were 10 ng/g and 20 ng/g. The average recovery for patulin at five levels of addition (from 20 to 200 ng/g) was 75% and at the single level of 100 ng/g was 90 % .The average recovery for verruculogen at five levels of addition (from 50 to 300 ng/g) was 54% and at the single level of 100 ng/g was 52%. The processing of two tomato plants was followed during 1996, 1997, and 1998. Eighty-four samples of tomato pulp were analyzed for patulin and verruculogen. The toxins were not detected in any of the samples.