Conteúdo de cloretos em vinhos brancos de diferentes países / Chloride content in white wines from different countries

Avaliaram-se 172 vinhos brancos de diferentes países com o objetivo de determinar a influência do país produtor na concentração de cloretos. A análise de cloretos, realizada pelo Laboratório de Bebidas de Origem Vegetal do Espírito Santo (Labeves), foi feita pelo método potenciométrico, no qual a dosagem é feita diretamente na amostra, utilizando-se um eletrodo de Ag/AgCl. Organizaram-se os dados coletados para teor de cloretos, presentes nos certificados de análise emitidos pelo Labeves, de forma a compor um banco de dados onde os vinhos foram discriminados conforme o país de origem. Austrália e Argentina foram os países que apresentaram maior concentração de cloretos. Concluise que o país produtor tem influência na concentração de cloretos em vinhos brancos.

White wines (172 samples) from different countries were evaluated to determine the influence of origin in their chloride concentration. Chlorides analysis, performed at the Laboratório de Bebidas de Origem Vegetal do Espírito Santo (Labeves), was done using potentiometric method, in which dosing was done directly on the sample, using an electrode of Ag / AgCl. A database was organized with the amount of chloride which was used to classify wines according to its country origin. Australia and Argentina wines presented higher concentrations of chlorides. The origin has, thus, influence in the chloride concentration in white wines.

Occurrence of Brettanomyces/Dekkera in Brazilian red wines and its correlation with ethylphenols

The yeast Brettanomyces/Dekkeracan cause important spoilage in wines, with the production of ethylphenols and other off-flavor compounds. This study aimed at determining the presence of this yeast and the ethylphenols produced by them in Brazilian red wines, establishing their relationship with other chemical characteristics. Isolates of Brettanomyces/Dekkerawere quantified by plating 126 samples of dry red wine in selective culture medium, while ethylphenols were analyzed by solid phase extraction and GC/FID. Free and total SO2, alcohol, total dry extract, residual sugar, total and volatile acidity, and pH were also determined. Brettanomyces/Dekkerawas present in 27% of samples. Ethylphenols were detected in most samples, with amounts higher than the threshold limit of 426 mg/L found in 46.03% of samples. The majority of wine samples showed inadequate levels of SO2and residual sugars, facts that might facilitate microbial spoilage. The passage in barrels and the grape varieties (Cabernet Sauvignon and Merlot), did not show any influence on the levels of contamination or ethylphenols contents. The prevalence of Brettanomyces/Dekkeraand the concentrations of ethylphenols were high considering the sensory impact they can cause. The growth of Brettanomyces/Dekkerawas dependent on the levels of SO2and alcohol of wines. Knowledge of the contamination, the presence of ethylphenols, and their relationship with the chemical characteristics of wines can entice effective measures to prevent Brettanomyces/Dekkeraand contribute to improve the general quality of Brazilian red wines.

Atividade antioxidante em vinhos de jabuticaba e de uva / Antioxidant activity in wines made from jabuticaba and grape

Samples of red and white dry wines made from jaboticaba and grape were analyzed with the purpose of verifying the antioxidant activity of compounds present in the wines. Different volumes of duplicate samples were spectrophotometrically analysed in a ?-carotene/linoleic acid system, every 15 minutes, for two hours. It was observed that the red wine made from jabuticaba presented a better antioxidant activity and inhibition values close to the ones obtained with BHT (a synthetic antioxidant usedin the food industry), with inhibition around 65%. The kinetic study revealed that wines made from jabuticaba are good free-radical scavengers with F <1 in phase 1 of the oxidative chain reaction, with better results than the wines made from grapes. The jabuticaba wine is a good source of antioxidants. However, further studies are necessary, especially concerning the profile of bioactive compounds, since it is a much appreciated beverage in several regions in Brazil

Actividad antioxidante en vinos de jabuticaba:comparación con vinos de uva. Muestras de vinostintos y blancos secos de jabuticaba y uva fueronanalizadas con la finalidad de verificar la actividad antioxidante de los compuestos presentes. Fue utilizado el sistema ?-caroteno/ácido linoleico, en el cual fueron hechas medidasespectrofotométricas de volúmenes de 20?L,50?L, 100?L y 200?L de muestras en duplicadocon lecturas a cada 15 minutos durante doshoras. Fue verificado que el vino tinto de jabuticaba presentó mejor actividad antioxidante con una inhibición de la oxidación próxima a los valores del BHT (antioxidante sintéticoutilizado en la industria alimenticia), inhibiciónen torno de 65%. El estudio cinético reveló quevinos de jabuticaba son eficientes comosecuestradores de radicales libres con F<1 en lafase 1 de la cadena oxidativa, y con resultadossuperiores a los vinos de uvas. El vino dejabuticaba es una buena fuente de antioxidantes,pero son necesarios más estudios en relación aeste, especialmente debido a ser de producciónnacional y a la ausencia de datos sobre el perfilde los compuestos activos de esta bebida muy apreciada en varias regiones del Brasil.

Amostras de vinhos tintos e brancos secos dejabuticaba e uva foram analisadas com afinalidade de verificar a atividade antioxidantedos compostos presentes. Foi utilizado o sistema?-caroteno/ácido linoleico, no qual foram feitasmedidas espectrofotométricas dos volumes de 20?L, 50?L, 100?L e 200?L das amostras em duplicata com leituras a cada 15 minutos porduas horas. Foi verificado que o vinho tinto dajabuticaba apresentou melhor atividade antioxidante e que o mesmo obteve valores deinibição da oxidação próximos ao do BHT (antioxidante sintético utilizado na indústriaalimentícia), com inibição em torno de 65%. No estudo cinético, foi revelado que vinhos de jabuticaba são bons sequestradores de radicais livres com F<1 na fase 1 da cadeia oxidativa ecom resultados superiores aos vinhos de uvas.O vinho de jabuticaba é uma boa fonte de antioxidantes, no entanto, faz-se necessáriomais estudos e em especial sobre perfil de compostos bioativos por se tratar de uma bebida muito apreciada em várias regiões do Brasil.