RESUMO

Brettanomyces bruxellensis is regarded as the main spoilage microorganism in the wine industry, owing to its production of off-flavours. It is difficult to eradicate owing to its high tolerance of adverse environmental conditions, such as low nutrient availability, low pH, and high levels of ethanol and SO2. In this study, the production of volatile phenols and the growth kinetics of isolates from various regions of Chile were evaluated under stressful conditions. Through randomly amplified polymorphic DNA (RAPD) analysis, 15 strains were identified. These were grown in the presence of p-coumaric acid, a natural antimicrobial and the main precursor of off-flavours, and molecular sulfur dioxide (mSO2), an antimicrobial synthetic used in the wine industry. When both compounds were used simultaneously, there were clear signs of an improvement in the fitness of most of the isolates, which showed an antagonistic interaction in which p-coumaric acid mitigates the effects of SO2. Fourteen strains were able to produce 4-vinylphenol, which showed signs of phenylacrylic acid decarboxylase activity, and most of them produced 4-ethylphenol as a result of active vinylphenol reductase. These results demonstrate for the first time the serious implications of using p-coumaric acid, not only for the production of off-flavours, but also for its protective action against the toxic effects of SO2.

RESUMO

Several studies have been published about the potential health effects due to long-term exposure to sulphur dioxide (SO2) and the relative risks (RRs) for different causes of mortality. Broad differences in the RR values are found, however. In this study, we performed an analysis of these studies aiming finding potential explanations for the high variability of the RR reported. The RRs for stratified subgroups were also analysed to identify more susceptible subgroups. A total of 14 studies were identified. Some of them related strong associations between mortality and long-term ambient SO2 exposure, while others found insignificant or no associations to the same mortality indexes. The mean RR values ranged from 0.95 to 1.14 for mortality due to all causes, 0.99 to 3.05 for lung cancer, 0.87 to 1.3 for respiratory diseases, 0.96 to 1.14 cardiovascular diseases and 0.97 to 1.05 for cardiopulmonary diseases mortality. Among the factors that may affect the RR estimations, only the size of studied population and the spatial scales used in exposure assessment showed notable influences. The female population was found to be more susceptible to long-term SO2 exposure. For other stratified subgroups including age, smoking status and income levels, no obvious relationship with RR was observed.

Assuntos

RESUMO

We investigated whether the fructan content, a storage carbohydrate, of Lolium multiflorum 'Lema' plants grown in a subtropical urban environment characterized by typical diurnal profiles of air pollutants and meteorological conditions changed over the course of a day during different seasons. Plants were collected every 2h on the last day of each two-month seasonal field experiment and separated into shoot (stubble or stubble+leaf blades) and roots for carbohydrate analyses and biomass determination. Diurnal contents of total fructose in the stubbles increased with high temperatures. In the roots, fructose accumulation showed a positive relation with hourly variations of both temperature and particulate matter and a negative relation with irradiance and SO2. Seasonal variation in shoot and root biomasses coincided with the seasonal variation of total fructose and were negatively affected by relative humidity and SO2, respectively. We concluded that hourly changes of fructans over the course of a day may increase the ability of L. multiflorum to tolerate short-term oscillations in weather and air pollution commonly observed in the subtropical urban environment, increasing its efficiency in monitoring air quality.

Assuntos

RESUMO

Objetivo: quantificar os teores de dióxido de enxofre residual em camarão-rosa, consumidos em Belém, no estado do Pará, a fim de verificar se as concentrações presentes encontram-se dentro dos valores recomendados pela legislação vigente. Método: estudo analítico dos teores de enxofre residual em camarões por titulação iodométrica a frio, após prévia dissolução das amostras em meio ácido. Resultados: a concentração média de dióxido de enxofre residual nas amostras deFarfantepenaeus subtilis com exoesqueleto foi 501 ±104 ppm e sem exoesqueleto de 538± 117 ppm. Não se observou diferença estatística signifcativa (p>0,05) entre os teores médios de dióxidode enxofre resídual em função do exoesqueleto. Conclusão: as amostras analisadas apresentaram teores de dióxido de enxofre residual acima do limite máximo recomendado na legislação, isto é, 100 ppm. Os resultados indicam a possibilidade da exposição humana ao dióxido de enxofre viaingestão de camarão-rosa.

Objective: To determine the residual sulphur dioxide in Farfantepenaeus subtilis samples from Belém-Pará, and determine if the levels are in agreement with the official recomendations. Method: Analysis by cold iodometric titration after acid dissolution of samples. Results: The meanconcentration of residual sulphur dioxide in Farfantepenaeus subtilis samples was 501 ±104 ppm. The samples analyzed presented residual sulphur dioxide above the limit recommended and characterize the human exposure to this compound

RESUMO

Microbiological, enzymatic and chemical factors interfere on the quality of tropical fruit juices, and impairments can be caused on their sensory and nutritional characteristics , and also on consumers health . The Brazilian legislation allows the use of sulphur dioxide as a food additive for fruit juice conservation. The present paper presents a revision on the use of sulphur dioxide and their respective salts for preserving the quality of industrialized tropical fruit juices, and gives emphasis on their mode of action  ,  and on toxicological aspects.

A qualidade dos sucos de frutas tropicais é influenciada por fatores microbiológicos, enzimáticos e químicos, que podem comprometer suas características sensoriais, nutricionais e a saúde do consumidor. Para a conservação de sucos de frutas a legislação brasileira permite o uso do dióxido de enxofre como um aditivo alimentar. O presente trabalho apresenta uma revisão sobre o uso do dióxido de enxofre e seus respectivos sais na manutenção da qualidade de sucos de frutas tropicais industrializados, com ênfase em seu modo de ação e aspectos toxicológicos  

RESUMO

Se realizó un estudio prospectivo en 94 pacientes asmáticos atendidos en el consultorio del médico de la familia No. 43 perteneciente al Policlínico Docente "Antonio Maceo" del municipio Cerro de Ciudad de La Habana. Durante un año (12 meses consecutivos) relacionamos las eventualidades diarias de su estado de salud con los siguientes contaminantes primarios de la atmósfera: dióxido de nitrógeno, dióxido de azufre y hollín. Las muestras fueron analizadas en el Laboratorio de Higiene del Aire del Instituto Nacional de Higiene y Epidemiología del Ministerio de Salud Pública de Cuba. El análisis estadístico se realizó utilizando el entrecruzamiento de variables, regresión múltiple, el método de paso a paso del paquete estadístico SPSS/PC Plus. Se realizó la matriz de correlación lineal paramétrica. Se obtuvo una correlación directa significativa entre la coriza, la tos, las crisis de asma y los contaminantes primarios de la atmósfera.

A prospective study of 94 asthmatic patients receiving attention at the family physician's office No. 43 from the "Antonio Maceo" Teaching Polyclinic in Cerro municipality, Havana City, was conducted. During a year (12 months in a row) we related their daily health status to the following primary air pollutants: nitrogen dioxide, sulphur dioxide, and soot. The samples were analyzed at the Air Hygiene Laboratory of the National Institute of Hygiene and Epidemiology, Ministry of Public Health. The statistical analysis was made by using the intercrossing of variables, the multiple regression, and the step by step method of the SPSS/PC Plus statistical package. The parametric lineal correlation matrix was also calculated. There was a significant direct correlation among coryza, cough, asthma crises, and the primary air pollutants.