This study focuses on the activity of wine against the important food-borne pathogen Campylobacter jejuni. The kinetics of inactivation of two strains of C. jejuni (one food-borne and one clinical) were characterised in various scenarios of exposure to wine and wine components. Undiluted wine was found to rapidly inactivate C. jejuni (>6D inactivation within 30 s); further inactivation data were obtained from experiments performed in wine diluted with water (1:2 and 1:4). Experiments with isolated antimicrobial fractions of wine (ethanol and certain organic acids) suggest that these two components act synergistically, demonstrating an inactivation capacity similar to wine itself. The results indicate that the exposure of contaminated food to wine, as in marinade conditions, significantly reduces the number of viable cells of C. jejuni. A model stomach, containing a food matrix and a synthetic gastric fluid, was used to infer the effect of wine against C. jejuni in a consumption-like scenario. Wine was found to potentiate the anti-Campylobacter effect of gastric fluid. The results strongly suggest that the ingestion of wine during a meal may greatly diminish the quantity of C. jejuni persisting further in the alimentary tract, thus lowering the risk of infection.

Under a climate change scenario, vineyards will experience serious challenges in the future. In an attempt to overcome such difficulties, this experiment offers a study on the effect of regulated deficit irrigation as a method for short-term adaptation to climate change in cv. Touriga Francesa, grafted into the rootstock 110R in the Douro region during a three-year period. Water stress on the plant and its effects on canopy, production, and quality of musts were analyzed. Rainfed vines (R0) were compared to three deficit irrigation regimes as a function of estimated crop evapotranspiration (ETc): R25 (25% ETc), R50 (50% ETc), and R75 (75% ETc). Water was applied on a weekly basis whenever predawn water potential showed moderate water stress until 15 days prior to harvest. The results suggest that rainfed plants under these circumstances suffered, in general, a negative impact on vine performance, while moderate water stress had more favorable effects on fruit composition, as well as in yield. Nonetheless, further studies should be conducted as irrigation did not show consistent effects on yield or berry composition.

SUMMARYThe Diagnosis and Recommendation Integrated System (DRIS) is an alternative tool for the evaluation of nutritional status and fertilizer recommendation of several crops. However, as this methodology implies the establishment of norms or standards, without which one cannot infer about the nutritional status of a crop, in Portugal this tool has little application. The aim of this study was to establish preliminary DRIS norms for vineyards in Portugal. From 2007 to 2009, petiole samples were collected on a set of 199 selected plots. The DRIS norms were established according to the proposed by Beaufils (1973), based on the results of the laboratory procedures. The results suggest the need for further studies in order to validate the DRIS norms presented. In the future it will be important to increase the number of observations for the establishment of DRIS norms, as well as to determine the relevance of establishing specific nutritional standard according the edaphic, climatic and varietal variability of Portuguese wine regions. RESUMOO Sistema Integrado de Diagnóstico e de Recomendação, em língua inglesa Diagnosis and Recommendation Integrated System (DRIS) constitui uma ferramenta alternativa para a avaliação do estado nutricional e a fundamentação da recomendação de fertilização de diversas culturas. Todavia, em Portugal este é um recurso ainda pouco divulgado uma vez que tal metodologia implica o estabelecimento de valores de referência ou normas, sem os quais não se poderá inferir sobre o estado nutricional de uma dada cultura. Neste trabalho, pretendeu-se estabelecer normas DRIS para a cultura da vinha em Portugal Continental. Para tal, entre 2007 e 2009, selecionou-se um conjunto de parcelas, nas quais foram recolhidas 199 amostras de pecíolos. As normas DRIS foram calculadas de acordo com a metodologia proposta por Beaufils (1973), a partir dos resultados da análise laboratorial. Os resultados obtidos sugerem a necessidade de estudos posteriores, com vista à validação das normas DRIS apresentadas. Futuramente será importante aumentar o número de parcelas consideradas para o estabelecimento das normas DRIS, assim como averiguar a pertinência do estabelecimento de padrões nutricionais mais específicos, de acordo com a variabilidade edafoclimática e varietal das regiões vitivinícolas portuguesas.