An assessment of potential applications with pulsed electric field in wines

Pulsed electric fields (PEF) is a non-thermal processing technology that uses instantaneous, pulses of high voltage for a short period in the range of milliseconds to microseconds; the application of high intensity electric field on toasted wood chips leads to a quick diffusion of extractable molecules. Currently most PEF studies, in the field of oenology, have been focusing on the application of PEF as a pretreatment of grape musts by examining the microbial inactivation and the enhancement of polyphenol extraction. In this study a post-treatment of wine is introduced as method to enhance the wood flavor in the wine with a green noninvasive technology. Major phenolic aldehydes that have been identified as the characteristic compounds of oak volatile compounds were selected as markers and were analyzed instrumentally to compare the influence of PEF processing to non-treated samples. PEF treated samples brought about higher concentrations of the examined oak compounds in the samples treated with PEF, which may explain the advantages of its application. The modulation of the intensity of the electric field and the period of pulses influenced the concentrations of the volatile phenols that were leached out. Differences found between the assayed treatments indicate that PEF application could be a potential practice for a rapid extraction of volatile compounds from oak

Amino acids content in 'Tempranillo' must from three soil types over four vintages

Amino acids are the main grape nitrogen compounds and the principal source of N for yeasts, being precursors of several volatile compounds. Therefore, N compound concentrations in musts can affect sensorial characteristics of wines. The aim of this study was to analyse the influence of N-NO3- and N-NH4+ contents from different soils on profile and content of amino acids in 'Tempranillo' grapes. In order to determine this soil influence on must quality, three plots were selected in AOC Rioja, classified as Fluventic Haploxerepts, Typic Calcixerepts, and Petrocalcic Palexerolls. The results showed that amino acids and yeast assimilable nitrogen (YAN) content allowed us to differentiate samples from the three soils, and in each soil type, samples of each season. In general, must contents of total amino acids and some of them, as alanine, threonine, and tyrosine, were more influenced by soil type; YAN, proline, histidine, serine, and glycine concentrations mainly depended on the interaction soil-vintage. In conclusion, free amino acids concentration could be a tool to differentiate musts coming from different soils

Foliar Application of Several Nitrogen Sources as Fertilisers to Tempranillo Grapevines: Effect on Wine Volatile Composition

Foliar nitrogen applications to the vineyard make it possible to improve grape and wine phenolic and amino acid concentration. However, to our knowledge, there is little information about their impacts on the volatile composition of wine. Therefore, the aim of this work was to evaluate the effects of the application of several nitrogen sources in Tempranillo vineyards on wine volatile composition during the first season. Subsequently, two dosages of phenylalanine and urea were applied to the vineyard with the aim of evaluating their effect on wine volatile composition. The results show that the different nitrogen sources applied to the grapevines during the first season did not affect higher alcohols, fatty acids, esters and other volatile compounds in the wines. The two dosages of phenylalanine and urea applied to the vineyard during the second vintage barely affected wine volatile composition. Consequently, this study shows that foliar nitrogen treatments in vineyards did not modify the wine aromatic profile

Volatile composition of wines elaborated from organic and non-organic grapes

The aim of this work was to study the evolution of volatile compounds during the alcoholic fermentation of organic and non-organic grapes. To do this, grapes were cultivated using organic and non-organic grapes; their tasting showed some differences between both types of Monastrell grapes. Throughout the alcoholic fermentation, the samples of organic grapes had higher concentration of total alcohols but lower concentration of esters and acids than the samples of conventional ones. Therefore, the volatile composition of wines from two different cultivated grapes using both agronomic practices was different. Moreover, regarding to the volatile compounds that contributed directly to wine aroma, generally organic wine had more chemicals and floral aromas, while the wines from conventional practices had more fruity aromas. Principal component analysis (PCA) showed that it is possible to differentiate between both types of wines in terms of concentration of volatile compounds formed during the alcoholic fermentation. Consequently, agronomic practices affected the grape taste, the wine volatile composition and its quality.Peer Reviewe

Effects on chlorophyll and carotenoid contents in different grape varieties (Vitis vinifera L.) after nitrogen and elicitor foliar applications to the vineyard

Photosynthetic pigments, including carotenoids are important secondary metabolites, which play a key role in photosynthesis. There is little information about the effects of nitrogen and elicitor applications on chlorophyll and carotenoid concentrations in grapes. The aim of this work was therefore to study the effects of the foliar application of nitrogen sources and elicitors to Tempranillo, Garnacha and Graciano (Vitis vinifera L.) grapevines on chlorophyll and carotenoid contents. The results showed that β-carotene and lutein were the most abundant carotenoids in all the samples, ranging from 1336 and 227 to 7054 and 1382 μg/g, respectively. The applied treatments had greater impact on chlorophyll and carotenoid contents in Tempranillo grapes than in Graciano and Garnacha varieties. The content of chlorophyll was determined by the variety factor, while the concentration of carotenoids was influenced by the interaction of variety and treatment factors, depending on the type of foliar application.EEA MendozaFil: Gutiérrez Gamboa, Gastón. Instituto de Ciencias de la Vid y del Vino. Grupo VIENAP; EspañaFil: Marín San Román, S. Instituto de Ciencias de la Vid y del Vino. Grupo VIENAP; EspañaFil: Jofre, Viviana Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Rubio Bretón, Pilar. Instituto de Ciencias de la Vid y del Vino. Grupo VIENAP; EspañaFil: Pérez Alvarez, Eva Pilar. Instituto de Ciencias de la Vid y del Vino. Grupo VIENAP; EspañaFil: Garde Cerdán, Teresa. Instituto de Ciencias de la Vid y del Vino. Grupo VIENAP; Españ

Inactivation of Brettanomyces bruxellensis by High Hydrostatic Pressure technology

Póster presentado en el XXV Congreso de la Sociedad Española de Microbiología (SEM), celebrado en Logroño del 7 al 10 de julio de 2015.Peer Reviewe