Regina Prado Zanes Furlani

Valor nutricional de cogumelos comestíveis

The aim of this study was to evaluate and to compare the proximate composition, vitamin C (ascorbic acid), dietary fiber and phosphorus contents of the more cultivated mushrooms in Brazil (Agaricus bisporus, Lentinula edodes, and Pleorotus spp.). Five different batches, from different brands of each mushroom were analyzed according to methods described in the Association of Official Analytical Chemists International. For total solids, protein, fat, ash, carbohydrates and dietary fiber, the average values, on a dry weight basis, were respectively: 9.37, 23.22, 4.71, 8.89, 63.17 and 34.0 g.100 g -1. For phosphorus and vitamin C, the average values on a wet weight basis were: 104.13 and 6.67 mg.100 g -1. From their compositions, the mushrooms studied here were shown to be excellent nutritional foods, presenting high protein and dietary fiber contents, low fat contents and reasonable sources of phosphorus, although poor vitamin C sources.

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.

Warehouse control of Aspergillus flavus link and A. parasiticus speare on peanuts (Arachis hypogaea) by phosphine fumigation and its effect on aflatoxin production

Six stacks of 36 bags containing ca. 50 kg of unshelled peanuts with moisture contents in the range of 18.0 to 21.0% (wet basis) (average 19.3%) were formed in a commercial warehouse located in a peanut-producing area in São Paulo, Brazil. Three stacks were fumigated with phosphine for 7 days. An initial dose of 3.0 g of aluminum phosphide per m3 was applied. A second and a third application of the same dose were carried out 24 and 144 h later. Before fumigation, infection by Aspergillus flavus and/or A. parasiticus was either not detected in the peanut mass or was very low (1 to 13%), but contamination with aflatoxins (up to 191 μg/kg) was found in all stacks. After the fumigation treatments, a striking increase in infection was observed in the nonfumigated stacks (73 to 100% infected kernels) while in the fumigated stacks, A. flavus and/or A. parasiticus were either not detected or were isolated in insignificant amounts, indicating that phosphine was able to control fungal development in spite of the high moisture content of the kernels. After the fumigation period, the contamination levels of aflatoxins in the treated stacks remained unchanged, while the untreated stacks showed a staggering increase (up to 10,000 μg/kg of peanuts). After a month, however, no difference was observed in aflatoxin contamination and infection by A. flavus and A. parasiticus between the untreated and the treated stacks.

Contents of folates in edible mushrooms commercialised in the city of Campinas, São Paulo, Brazil

In this study, folates were evaluated in the main species of mushroom cultivated in Brazil. The species analysed were Agaricus bisporus (button mushroom), Lentinula edodes (shiitake) and Pleorotus ostreatus (shimeji). The five main forms of folate found in foods were determined: tetrahydrofolic acid (THFA), 10-methyl folic acid (10MFA), 5-methyl tetrahydrofolic acid (5MTHFA), 10-formyl folic acid (10FFA) and 5-formy tetrahydrofolic acid (5FTHFA). The methodology employed used extraction with phosphate buffer, clean up with trichloroacetic acid and separation of the vitamins by high-performance liquid chromatography, with simultaneous ultraviolet and fluorescence detection. The results obtained for total folate were 551 to 1404 µg.100 g -1 for the button mushroom, 606 to 727 µg.100 g -1 for shiitake and 460 to 1325 µg.100 g -1 for shimeji. The data showed that mushrooms could be considered as sources of folates and that their contribution of these

Polycyclic aromatic hydrocarbons in teas using QuEChERS and HPLC-FLD

ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are food-processing contaminants considered to be carcinogenic and genotoxic. Due to its drying process stage, teas may be contaminated with PAHs. The aim of the study was to validate an analytical method involving QuEChERS and HPLC-FLD for the determination of PAH4 in teas and evaluate the contamination levels in 10 different types of teas from Brazil. Recoveries varied from 54% to 99% and relative standard deviations from 1% to 21%. Limits of detection and quantification were from 0.03 to 0.3 µg/kg and 0.1 to 0.5 µg/kg, respectively. Mate tea presented the highest PAH levels, with PAH4 varying from 194 to 1795 µg/kg; followed by black (1.8–186 µg/kg), white (24–119 µg/kg), and green teas (3.1–92 µg/kg). Teas with lowest PAH4 were strawberry, lemongrass, peppermint, and boldo. Only trace levels of PAHs were detected in tea infusions, so apparently it would not affect PAH intake by Brazilian population.

Species Related Differences in Brazilian Green Coffee Contaminated by Ochratoxin A

Ochratoxin A is a toxic metabolite produced mainly by strains of Penicillium verrucosum and Aspergillus ochraceus. P. verrucosum seems to predominate in temperate climates and A. ochraceus in warm ones (Moss, 1996). Ochratoxin A is acutely toxic to birds, mammals and fish and the kidney is its main target organ followed by the liver. Its teratogenic and immunotoxic action have been described by Busby and Wogan (1981) and it has been shown to be a potent carcinogenic to rats (NTP, 1989). The International Agency for Research on Cancer (IARC) has classified ochratoxin A in the group 2B of substances that means it is possibly carcinogenic to humans (IARC, 1993). Ochratoxin A has been suggested as the causative agent in the endemic human nephropathy affecting villagers in the Balkans (Plestina, 1996). More recently nephropathies have been reported in Algeria and Tunisia, similarly to the case of the Balkans where the toxin was found in bodily fluids and in the food consumed by the population (Crepy et al. 1993). The half-life of ochratoxin A in humans was estimated as 35 days (Schlater et al., 1996). In 1995, the FAO/WHO Joint Expert Committee on Food Additives evaluated ochratoxin A and established a Provisional Tolerable Weekly Intake (PTWI) of 100 ng per kg of body weight (JEFCA, 1995). The toxin carcinogenic activity was not taken into consideration in this evaluation.