No abstract

In the present work, we have investigated the effect of essential oils obtained from Origanum vulgare L. (oregano) and Thymus vulgaris L. (thyme) on growth and ultrastructure of diverse evolutive forms of Trypanosoma cruzi. Culture epimastigotes and bloodstream trypomastigotes were incubated for 24 h with different concentrations of oregano or thyme essential oils and with thymol (the main constituent of thyme), and the inhibitory concentration (IC)(50) was determined by cell counting. Crude extract of oregano essential oil inhibited epimastigote growth (IC(50)/24 h = 175 microg/ml) and also induced trypomastigote lysis (IC(50)/24 h = 115 microg/ml). Thyme essential oil presented IC(50)/24 h values of 77 microg/ml for epimastigotes and 38 mug/ml for trypomastigotes, while treatment with thymol resulted in an IC(50)/24 h of 62 microg/ml for epimastigotes and 53 microg/ml for trypomastigotes. Scanning electron microscopy of treated cells showed few morphological alterations at the plasma membrane. Observation by transmission electron microscopy showed cytoplasmic swelling with occasional morphological alterations in plasma and flagellar membrane. Our data indicate that oregano and thyme essential oils are effective against T. cruzi, with higher activity of thyme, and that thymol may be the main component responsible for the trypanocidal activity.

Three elite tomato (Solanum lycopersicum L., syn. Lycopersicon esculentum Mill.) breeding lines (TOM‐687, TOM‐688, TOM‐689) with high foliar acylsugar (AS) contents were obtained, and used along with two low‐AS lines (TOM‐690, TOM‐684) in hybrid combinations, to obtain six hybrids between one low‐AS line × one high‐AS line (= hybrids with intermediate AS levels), one hybrid between two high‐AS lines (= high‐AS hybrid), and one hybrid between two low‐AS lines (= low‐AS hybrid). These genotypes were tested for resistance to three different tomato pests (spider mites [Tetranychus urticae Koch], silverleaf whitefly [Bemisia argentifolii Bellows & Perring], and the South American tomato pinworm [Tuta absoluta (Meyrick)]) along with hybrid TEX‐154 (low‐AS) and/or Solanum pennellii Correll ‘LA‐716’ (high‐AS wild accession). In all three instances, high‐AS genotypes showed higher levels of pest resistance than low‐AS genotypes. Hybrids with intermediate AS levels showed resistances that were just as high as those of high‐AS genotypes for Bemisia argentifolii and Tuta absoluta, and nearly as good as those for Tetranychus urticae. Acylsugars were confirmed as being a major component of the high levels of pest resistances found in S. pennellii—a component that was successfully introgressed into elite tomato breeding lines. Acylsugar‐mediated pest resistance is effective against a broad spectrum of tomato pests. Because high‐AS breeding lines are scarce, the deployment of hybrids between high‐AS line × low‐AS line would be a quick, viable alternative to obtain commercial pest‐resistant hybrids.

Recebido em 9/3/05; aceito em 5/7/05; publicado na web em 20/1/06 USING ACTIVATED CARBON TO REMOVE COPPER FROM SUGAR CANE SPIRIT. Copper content is of great concern among sugarcane-spirit producers. It is released from copper-made distillers, during the distillation process. Activated carbon has been used to remove copper. However, depending on the amount of carbon and the duration of reaction, it can also remove higher alcohols and esters, which are important in the final product. A sugarcane spirit with 9 mg L -1 of copper was shaken with 2 to 26 g L -1 of activated carbon, during 10 to 1440 minutes. Then, copper and organic compounds were measured. At least 12 g L -1 of carbon and 60 min shaking time were necessary to decrease copper bellow 5 mg L -1 . However, other components of the product were also affected.Keywords: sugar cane spirit; activated carbon; adsorption. INTRODUÇÃOBebida obtida por destilação do mosto fermentado de cana-deaçúcar, a aguardente de cana, caninha ou cachaça deve seguir alguns padrões de qualidade importantes para o consumo. A cachaça é a segunda bebida mais consumida pelos brasileiros. Estima-se o consumo de 70 milhões de doses diárias, o que representa, em média, aproximadamente 6 L (habitante ano -1 ). Dados oficiais apontam uma produção de 1,6 bilhão de L por ano, sendo 90% de cachaça industrial e 10% de cachaça artesanal.O Governo Federal decidiu considerar a cachaça uma bebida genuinamente brasileira desencadeando, com isso, um processo de valorização da bebida com o objetivo de estimular o aumento de produção e a melhoria de qualidade visando a ampliação do mercado externo. A meta do Brasil é exportar 10 milhões de L. Minas Gerais tem capacidade para suprir 10% desse montante 1 . Além do aumento de produção, o mercado tem feito crescer a preocupação com a qualidade da bebida 2 . A cachaça produzida em alambiques de cobre tem grande procura pelo sabor e pela forma artesanal como é produzida 3 . Entretanto, a quantidade de cobre nesta cachaça tem sido motivo de preocupação. Originado durante o processo de destilação, esse elemento tem seu limite máximo estabelecido em 5 mg L . Durante o processo de destilação, ou durante o tempo em que o alambique não está em uso, há formação de "azinhavre" (carbonato básico de cobre) nas paredes internas. Essa mistura solúvel [CuCO 3 , Cu(OH) 2 ] é dissolvida pelos vapores alcoólicos ácidos, sendo responsável pela contaminação da bebida 5 . Apesar de possuir odores mais agradáveis do que os verificados em aguardentes destiladas em alambiques de aço inox, a cachaça produzida em alambiques de cobre pode provocar problemas à saúde, quando este elemento ocorre em concentrações elevadas 6 . O cobre é um metal essencial à saúde humana, estando presente em todos os fluidos e muitos tecidos humanos. Esse elemento, juntamente com aminoácidos, ácidos graxos e vitaminas, é necessários para os processos metabólicos.O excesso de cobre pode ser tóxico por causa da afinidade do metal com grupos S-H de muitas proteínas e enzimas, sendo associado a doenças com...

Recebido em 26/1/10; aceito em 27/8/10; publicado na web em 24/11/10 ANALYSIS OF ORGANIC CONTAMINANTS AND COPPER IN CACHAÇA. The objective of the present study was the evaluation of the presence of organic and inorganic contaminants in samples of aged cachaça from the South of the state of Minas Gerais. Furfural, methanol and copper were determined by colorimetric reactions, while the analyses of ethyl carbamate and acrolein were performed by GC/ MS and HPLC, respectively. High levels of furfural and copper were obtained. All samples showed concentrations below the established by legislation for the ethyl carbamate, and for acrolein, only one sample showed higher levels. Methanol was not detected in the samples.Keywords: beverage; contaminants; wood. INTRODUÇÃODe acordo com o Decreto nº 4851 de 2003 e com a Instrução Normativa nº 13 de 30/6/ 2005, aguardente de cana é a bebida com graduação alcoólica de 38 a 54% v/v à 20 °C, obtida do destilado alcoólico simples de cana-de-açúcar ou pela destilação do mosto fermentado do caldo de cana-de-açúcar, podendo ser adicionada de açúcares até 6 g/L, expressas em sacarose. A cachaça, entretanto, foi definida como sendo a denominação típica e exclusiva da aguardente de cana produzida no Brasil, com graduação alcoólica de 38 a 48% v/v à 20 ºC, obtida pala destilação do mosto fermentado do caldo de cana-de-açúcar com características sensoriais peculiares, podendo ser adicionada de açúcares até 6 g/L, expressos em sacarose. 1,2As bebidas alcoólicas fermento-destiladas distinguem-se uma das outras pela presença de componentes secundários que irão formar um "buquê" característico de cada bebida. Esses componentes secundá-rios se formam juntamente com o álcool etílico durante o processo de fermentação do mosto, mudam de caráter e proporção durante a destilação, havendo uma posterior maturação do produto. 3,4 No entanto, alguns compostos são indesejáveis à bebida devido, principalmente, as suas propriedades tóxicas, cancerígenas e características que depreciam a qualidade do produto final.Devido à complexidade da composição química da cachaça esta é dividida em fração orgânica e inorgânica. A primeira é constituída basicamente de alcoóis, aldeídos, ésteres, ácidos carboxílicos, cetonas, carbamato de etila e compostos sulfurados. Dependendo do teor e dos compostos presentes, a bebida pode ser classificada como desejável ou não, em relação à aceitação sensorial, ou em tóxica e não tóxica, em relação à saúde. A fração inorgânica é constituída principalmente por íons metálicos, tais como alumínio, cádmio, cálcio, chumbo, cobalto, cobre, cromo, ferro, etc. 5A legislação brasileira, Decreto n° 2314 de 04/09/1997 estabelece o limite máximo de cobre em 5 mg/L de produto. 6 No entanto, no mercado internacional o limite máximo estabelecido é de 2 mg/L tornando-se, assim, um entrave para as exportações da bebida. 7 Embora nesta concentração o cobre não possa ser considerado como tóxico, a sua presença contribui para ressaltar o sabor ácido na bebida, além de facilitar os processos oxidativo...

The growth of ochratoxigenic fungus and the presence of ochratoxin A (OTA) in grapes and their derivatives can be caused by a wide range of physical, chemical, and biological factors. The determination of interactions between these factors and fungal species from different climatic regions is important in designing models for minimizing the risk of OTA in wine and grape juice. This study evaluated the influence of temperature, water activity (aw), and pH on the development and production of OTA in a semisynthetic grape culture medium by Aspergillus carbonarius and Aspergillus niger strains. To analyze the growth conditions and production of OTA, an experimental design was conducted using response surface methodology as a tool to assess the effects of these abiotic variables on fungal behavior. A. carbonarius showed the highest growth at temperatures from 20 to 33°C, aw between 0.95 and 0.98, and pH levels between 5 and 6.5. Similarly, for A. niger, temperatures between 24 and 37°C, aw greater than 0.95, and pH levels between 4 and 6.5 were optimal. The greatest toxin concentrations for A. carbonarius and A. niger (10 μg/g and 7.0 μg/g, respectively) were found at 15°C, aw 0.99, and pH 5.35. The lowest pH was found to contribute to greater OTA production. These results show that the evaluated fungi are able to grow and produce OTA in a wide range of temperature, aw, and pH. However, the optimal conditions for toxin production are generally different from those optimal for fungal growth. The knowledge of optimal conditions for fungal growth and production of OTA, and of the stages of cultivation in which these conditions are optimal, allows a more precise assessment of the potential risk to health from consumption of products derived from grapes.

This research evaluated the antimicrobial effect of the winter savory (Satureja montana L.) essential oil (EO) against Clostridium perfringens type A (ATCC 3624) inoculated in mortadella-type sausages formulated with different levels of sodium nitrite (NaNO₂: 0 ppm, 100 ppm and 200 ppm) in addition to EO at concentrations of 0.0%, 0.78%, 1.56% and 3.125% stored at 25°C for 30 days. The EO extracted by hydrodistillation and analyzed by gas chromatography-mass spectrometry (CG-MS) was tested in vitro using an agar well diffusion method for determination of minimum inhibitory concentration (MIC) on C. perfringens. According to compositional analysis of the winter savory EO, 26 chemical compounds were identified, and the major constituents were thymol (28.99%), p-cymene (12.00%), linalool (11.00%) and carvacrol (10.71%). The results obtained showed that EO applied at a concentration of 1.56%, which was defined as the MIC, exhibited antimicrobial activity against C. perfringens in the in vitro assays, and the transmission electron microscopy (TEM) revealed structural damage and cell lysis of C. perfringens caused by EO treatment. A synergistic effect between NaNO₂ and EO was observed. In mortadella-type sausages formulated with 100 ppm of NaNO₂ and EO at all concentrations tested, the population of target microorganisms was reduced (p≤0.05) compared to control samples during all storage period. This data suggests the potential combined use of savory EO and minimal amounts of the synthetic additive, NaNO₂ to control C. perfringens in mortadella, which goes according to current market trends, where consumers are requesting natural products.

Recebido em 30/7/10; aceito em 16/11/10; publicado na web em 25/2/11 IDENTIFICATION OF ETHYL CARBAMATE DURING THE AGING OF CACHAÇA IN AN OAK BARREL (Quercus sp) AND A GLASS VESSEL. The objective of the present study was the identification and quantification of ethyl carbamate (EC), by HPLC-FLD, after different periods of storage in an oak (Quercus sp) barrel and a glass vessel. The concentration of EC in the cachaça samples varied from