Caracterización de la composición fenólica de uvas y vinos de la variedad Malbec (Vitis vinifera L.): su relación con el origen geográfico, factores vitivinícolas y valor comercial

La variedad Malbec (Vitis vinifera L.) es considerada el cultivar tinto emblemático de Argentina, sin embargo a pesar de su importancia económica y cultural existe un gran desconocimiento sobre su composición química. El objetivo de este trabajo fue caracterizar la composición fenólica de uvas y vinos de esta variedad en relación a otros cultivares, al origen geográfico, a ciertos manejos vitivinícolas y a su valor comercial. Entre los resultados más relevantes, se observaron diferencias cualitativas y cuantitativas en los parámetros globales y en el perfil de flavonoides y no-flavonoides en uvas y vinos en comparación con otras variedades tintas, se confirmó la influencia de la región de procedencia y año de cosecha en combinación con las prácticas de aclareo de racimos y sangrado parcial de jugo, y se encontró una mayor riqueza fenólica y polisacarídica en vinos de alta gama. Adicionalmente, los dihidroflavonoles representaron un rasgo taxonómico distintivo de esta variedad.Malbec (Vitis vinifera L.) is a wine grape variety considered to be the emblematic red cultivar of Argentina, but despite its economic and cultural importance there is a lack of knowledge about its chemical composition. The aim of this study was to characterize the phenolic composition of grapes and wines of this variety compared to other cultivars, geographical origin, some viticultural and winemaking practices, and its commercial value. Among the most relevant results, were observed qualitative and quantitative differences in global phenolic parameters and the profile of flavonoids and non-flavonoids in grapes and wines compared to other varieties, it was confirmed the influence of geographical zone and season in combination with the practices of cluster thinning and partial juice runoff prior to fermentation, and it found a greater phenolic and polysaccharidic richness in premium wines. Additionally, dihydroflavonols represented a taxonomic distinctive feature of this variety

Partial dealcoholization of a Malbec wine through pervaporation with a PDMS membrane: Effect of operation temperature on process economics, volatile aroma composition and sensory properties

In the present work, partial dealcoholization of a Malbec red wine with 14.8% v/v alcohol by pervaporation through a PDMS membrane (polydimethylsiloxane) was addressed. The influence of the process temperature on the economy of the process, the composition of volatile aroma compounds and wine sensory characteristics was deeply analyzed.To do so, partial dealcoholization experiments at lab scale were run with the pervaporation setup operated at a permeate pressure of 0.013 bar and at three different temperatures; i.e. 35, 40 and 45°C. Two types of runs were carried out: i) simple runs to build a conceptual model of the process and ii) repetitions to accumulate an adequate volume of partially dealcoholized wine (10.5% v/v) to allow the sensory analysis of the following Malbec wines: the initial wine, the partially dealcoholized wines and the blends in a 70/30 ratio (13.5% v/v)).From the conceptual modeling stage the required value of the fractional pervaporation advance η_req of 0.09 was obtained, as well as the average values of permeate overall fluxes at 35, 40 and 45 C; i.e., 1.02, 1.38 and 1.82 kgm-2h-1, respectively. For all variants, a permeate product with an alcohol content of 54% v/v was estimated. Experimental values agreed reasonably well with those obtained from the model simulation.The conceptual modeling of the process enabled the scaling-up of the process and the subsequent economic analysis. The best figures corresponded to the design with heat integration at 45°C when earnings estimated from the sale of the ethanol-rich permeate to the local market was taken into account.Fresh Malbec, partially dealcoholized wines at the selected temperatures, and their corresponding blends were chemical and sensory characterized. Dealcoholized wines showed differences concerning the operating temperature on the volatile and total acidity, fructose, anthocyanins, tannins, total polymers, and CIELAB parameters, except lightness. The total and volatile acidity were affected by the temperature and showed an increase in dealcoholized and blended wines with the respective decrease of the pH. Dealcoholization favored the presence of large polymeric pigments (0.6 in initial wines and an average of 0.96 in blends), which are associated positively with color stability. Volatiles were also affected by the operating temperature, decreasing the concentration of all chemical groups in these wines. A total of thirty-two free volatile organic compounds (VOCs) including higher alcohols (HA), medium chain fatty acid ethyl esters (MCFAEE), higher alcohol acetates (HAA), medium chain fatty acids (MCFA), norisoprenoids (NI) and terpenoids (TP) were identified and quantified.Finally, sensory evaluation demonstrated that partially dealcoholized wines could not be differentiated by the operation temperature. The fullness, astringency, pungency, floral notes, bitterness, color intensity, and sweetness were significant variables that allowed differentiate between initial, partially dealcoholized, and blend wines. Despite the loss of volatile compounds, blended wines showed higher intensity of floral attributes, and in mouth were lesser astringent, bitter, and pungent than the fresh wine. From an overall perspective, pervaporation of fresh wine with a PDMS membrane at 45°C and the adoption of a dilution ratio of 70/30 for initial wine to partially dealcoholized wine result in a promising strategy to reduce the alcohol content without affecting the sensory quality of the final red wine.Fil: Figueroa Paredes, Danilo Alexander. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Assof, Mariela. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Mendoza-san Juan. Estacion Experimental Agropecuaria Mendoza. Agencia de Extension Rural Lujan de Cuyo.; ArgentinaFil: Sánchez, Ramiro Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Sari, Santiago Eduardo. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Mendoza-san Juan. Estacion Experimental Agropecuaria Mendoza. Agencia de Extension Rural Lujan de Cuyo.; ArgentinaFil: Catania, Anibal Alejandro. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Mendoza-san Juan. Estacion Experimental Agropecuaria Mendoza. Agencia de Extension Rural Lujan de Cuyo.; ArgentinaFil: Fanzone, Martín Leandro. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Mendoza-san Juan. Estacion Experimental Agropecuaria Mendoza. Agencia de Extension Rural Lujan de Cuyo.; ArgentinaFil: Espinosa, Hector Jose Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin

Batch experiments of pervaporation involved in the partial dealcoholization of Malbec wine

Pervaporation experiments of binary ethanol-water mixtures with a PDMS membrane were accomplished by duplicate. In each experiment, an initial solution of 550 g with ethanol mass fractions of 0.084 and 0.117 was employed. Under a permeate pressure of 0.013 bar, three permeate samples were collected at intervals of 25, 35, 40, and 60 minutes, corresponding to operating temperatures of 30, 35, 40 and 45 °C, respectively. Partial dealcoholization experiments at lab scale were run with the pervaporation setup (28 cm2) operated at a permeate pressure of 0.013 bar and at three different temperatures; i.e. 35, 40 and 45°C. In all cases, the feed to the process consisted of 550 g of a Malbec wine with an alcohol content of 14.8% v/v. Two types of runs were carried out: i) simple runs to build a conceptual model of the process and ii) repetitions to accumulate an adequate volume of partially dealcoholized wine (10.5% v/v).Fil: Figueroa Paredes, Danilo Alexander. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Assof Roa, Mariela Vanesa. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Sánchez, Ramiro Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; ArgentinaFil: Sari, Santiago Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan; ArgentinaFil: Catania, Anibal Alejandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan; ArgentinaFil: Fanzone, Martín Leandro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; ArgentinaFil: Espinosa, Hector Jose Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentin