White wine protein analysis by capillary zone electrophoresis

Capillary zone electrophoresis was evaluated as a method for the analysis of wine proteins. Seven wines from three different varieties, Chardonnay, Sauvignon blanc, and Muscat of Alexandria, were used in this systematic analysis of the effect of variables of capillary electrophoresis conditions on wine protein profiles. While there was some differences in the magnitude of protein peaks as a function of vintage and winemaking conditions, each of the varieties displayed a distinct and distinguishable protein profile. If wine is analyzed directly, both proteinaceous and nonproteinaceous UV-absorbing materials are detected. The protein fraction can be obtained from wines by ultrafiltration and analyzed separately. Resuspension of the retentate proteins following ultrafiltration under conditions allowing sample stacking yielded the greatest number and sharpest separation of peaks. The electrophoresis running buffer impacted protein profiles and number of peaks, as expected. Protein peaks were found to be protease-sensitive, suggesting that wine proteins are not intrinsically resistant to protease degradation. Hazes induced by heat/chill treatment effectively stripped the wines of protein content. Capillary zone electrophoresis represents an excellent tool in the analysis of wine proteins and has the potential to differentiate wine varietals

Varietal differentiation of must and wines by means of protein fraction

Native electrophoresis, SDS electrophoresis, and isoelectric focusing were used to determine electrophoretic patterns of 10 grape musts and 14 varietal wines made from white grapes. Nine of the musts from the Macabeo, Xarel-lo, and Parellada grape varieties were fermented on an industrial scale under similar conditions. Five wines were produced in a pilot plant (500 L), with different inoculation of yeasts and with or without added SO2 from the Malvar grape variety. The electrophoretic patterns obtained with the three techniques were similar for musts from the same variety, but different when musts from different varieties were compared. The electrophoretic patterns of the resulting wines were different from original musts. The electrophoretic patterns of the wines from the same variety were very similar in spite of the different conditions under which they were produced. © 1993 by the American Society for Enology and Viticulture. All rights reserved

Ultra Performance Liquid Chromatography Coupled to Ultraviolet-Vis and Mass Spectrometry Detector for Screening of Organic Acids and Polyphenols in Red Wine

Peer Reviewe

Pressurization and cold storage of strawberry purée: Colour, anthocyanins, ascorbic acid and pectin methylesterase

The effect of pressurization and cold storage of strawberry purée on colour, anthocyanins, ascorbic acid and pectin methylesterase was investigated. Samples were treated at pressures of 100, 200, 300 and 400 MPa, at two temperatures, 20 °C and 50 °C, for 15 min. Ascorbic acid content remained fairly constant after all the high pressure treatments in comparison to the control. However, the values of the samples pressurized at 50 °C were lower than the samples pressurized at 20 °C. Concentration of anthocyanins remained similar after all pressure treatments at both temperatures. Pectin methylesterase decreased in the samples pressurized at 50 °C, and it is remarkable that with this enzyme inactivation a gel-network formation in the strawberry purée was not found. However, a gel-network was observed in the control and in all the samples pressurized at 20 °C throughout cold storage. Immediately after pressurization, strawberry colour showed significant differences between the two temperatures, but no differences were observed between pressures. However, after cold storage no significant differences were observed, for hue and chroma parameters, between the samples pressurized at the two temperatures.This work has been supported by the Education and Science Ministry, through the Science National Plan I+D+I. Project: AGL 2007-63314/ALI.Peer Reviewe

Análisis sensorial descriptivo de vinos tintos crianza riojanos: valoración de los críticos de vinos

Póster presentado en el XII Congreso de los Grupos de Investigación Enológica (GIENOL 2013, Nuevas perspectivas en investigación vitivinícola), celebrado en Madrid del 18 al 21 de junio de 2013.Peer Reviewe

Overhead spray water treatment as a mitigation strategy for reducing vine stress and preserving grape quality during heatwaves

Trabajo presentado en el Oeno MacroWine celebrado en Burdeos (Francia), del 10 al 13 de julio de 202

Sensory Attributes of Rioja Red Wines and their relationship with quality perception of consumers

Póster presentado en la Third Edition of International Conference Series on Wine Active Compounds (WAC2014), celebrada en Borgoña (Francia) del 26 al 28 de marzo de 2014.A complex problem in food product is to identify what are the parameters driving consumers’ liking. The main goal of this study was to apply the technique classically used to understand consumer preference, internal preference mapping to the quality assessment of twenty-nine red wine by eighty-five regular consumers. The wines were subjected to a sensory descriptive analysis by trained panelist and to a categorization task by consumers’ preference. Quality assessment was performed by means of a categorization task which was subsequently correlated to the aromatic wine sensory space obtained. The PCA carried out on the wine*consumers matrix showed a wide dispersion in quality perception among consumers. The HCA indicates the presence of three well defined groups of consumers (QC1, QC2 and QC3) Pearson correlation coefficients show no significant correlations between the three groups of consumers indicating a quality concept different between them. The concept of quality of the three groups of consumers when they evaluate wines aged in oak barrels is directly related to the presence of "toasted/wood” and the absence of the veggie/animal attributes. It is noteworthy that only the consumers QC2 considered positive the concept of fruity and floral aromas as quality in a wine barrel aged. Mouthfeel attributes described for these wines were considered in a different way for the quality assessment carried out by the three consumer groups.Peer Reviewe

Vinos tintos crianza riojanos: una relación entre el análisis sensorial descriptivo, valoración de profesionales y percepción de calidad de consumidores.

Póster presentado en el XII Congreso de los Grupos de Investigación Enológica (GIENOL 2013, Nuevas perspectivas en investigación vitivinícola), celebrado en Madrid del 18 al 21 de junio de 2013.Peer Reviewe

High tolerance of wild Lactobacillus plantarum and Oenococcus oeni strains to lyophilisation and stress environmental conditions of acid pH and ethanol

A total of 76 Lactobacillus plantarum and Oenococcus oeni wild strains were recovered from traditionally elaborated Spanish red wines and were investigated with respect to their response to acid pH, lyophilisation, temperature and ethanol concentrations which are normally lethal to lactic acid bacteria. Both L. plantarum and O. oeni strains were able to grow at pH 3.2, were highly resistant to lyophilisation treatment and proliferated in the presence of up to 13% ethanol at 18°C. Therefore, it is shown that both species are highly tolerant to stress conditions and that similarly to O. oeni strains, L. plantarum strains are of interest in beverage biotechnology. © 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved

In-mouth sensory properties of red wine and their relationship with non-volatile chemical composition

Monográfico 25. Investigación e innovación al servicio de la alimentación en La Rioja: avances en el campo de la Enología y en otros porductos riojanos.[ES] Este trabajo muestra las relaciones entre la composición química no volátil y las características organolépticas percibidas en boca, centrándose principalmente en la astringencia. Este atributo es muy complejo y habitualmente descrito con diferentes subcualidades como “secante”, “punzante”, “rugoso”, “aterciopelado” o “sedoso” entre otras. Entre la composición química no volátil de los vinos, la composición polifenólica juega un papel destacado en la astringencia; sin embargo, no está clara la implicación de los diferentes compuestos. El análisis de estos compuestos en dos diferentes grupos de vinos ha permitido calcular modelos estadísticos significativos con capacidad predictiva para la astringencia. Las proantocianidinas o taninos juegan junto con otros compuestos un papel relevante en estos modelos matemáticos. La investigación de las tres subcualidades de la astringencia en la fracción tánica de diferentes vinos ha permitido encontrar que la concentración en la que estos compuestos están presentes puede inducir la subcualidad de la astringencia percibida.[EN] This work shows the relationships between nonvolatile chemical composition and in-mouth organoleptic characteristics, particularly astringency. This attribute is very complex and it is usually described with different subqualities as “dried”, “puckering”, “rough”, “velvety” or “silky” among others. The phenolic compounds have a prominent role in the astringency; however it is not clear the involvement of the different phenolic compounds in this sensory property. The analysis of these compounds in two groups of wines has allowed to obtain statistically significant models with predictive capacity for astringency perception. The proanthocyanidins or tannins and other phenolic compounds have an important role in these mathematic models. The research of three subqualities of astringency in the tannic fraction of different wines has allowed to find the concentration rages at which these compounds are able to induce the subquality of the perceived astringency.Peer Reviewe