RESUMO
Background: With this research an inertizing and cooling process for grapes cryomaceration has been set up. The process in question has been performed by an innovative plant that cooled the grapes rapidly in about 8 sec until they reached the set cryo-maceration temperature, using direct injection of liquid CO2. It works with a grape flow of approximately 2-3 tons/h, with a maximum thermal gradient of 20 K between the grape inlet and outlet temperature. For this plant a vibrating device was set up that allowed that only one grape cluster layer to be formed on the ribbon conveyor after the grapes had been put into the feedbox. A numerical model was set up for the cooling tunnel, and numerical simulations were performed to investigate the operative parameters of the machine in question. The numerical results were validated by means of experimental tests. Results: The wines obtained by using the considered plant (IW) were chemically analysed, and a comparison was performed with wines obtained with the same grape without the use of the plant (TW). All phenolic parameters were higher in IW wines, while other substances such as alcohol, reducing sugars, acids, and volatile acidity were less affected by the different winemaking technique. A deeper yellow colour was a direct consequence of the higher phenolic content of IW wines. Panelists preferred the IW wines, which had a richer, more delicate aroma. Conclusions: The study showed that careful exclusion of air combined with preventing oxidation during the cooling process, that is realized with the considered innovative cooling plant, effectively yields pleasing wines with more character.
Assuntos
Fermentação , Indústria Vitivinícola/métodos , Refrigeração , Vitis , Vinho , Sensação , PaladarRESUMO
Introducción: La calidad del vino viene definida por diversos factores, siendo el clima y, dentro de este, las temperaturas máximas determinantes en todas las etapas de crecimiento de la vid ,participando en la composición final del vino. Material y métodos: Se ha realizado un seguimiento de cinco añadas (2005-2009) sobre la acidez, grado alcohólico probable (GAP) y en las tres últimas(2007-2009) de antocianos de vinos obtenidos a partir de la variedad Tempranillo, así como un seguimiento de las temperaturas máximas junto con la determinación del índice de Winkler. Resultados: se produjo un descenso estadísticamente significativo para los parámetros acidez(4,98±0,44 vs 8,21±0,95) y antocianos (110,75±29,13 vs 216,64±43,95) y un aumento en el grado alcohólico probable (GAP) (12,97±0,49 vs 11,62±0,63), siendo las diferencias estadísticamente significativas entre los distintos años. Conclusión: En el presente estudio se observó que un incremento de las temperaturas máximas en la zona de estudio se relacionó con un mayor grado alcohólico, una menor acidez y concentración de antocianos en vinos(AU)
Introduction: The quality of wine is defined by different factors, and is the climate and especially the maximum temperatures that are decisive in all grown stages of grapevine and that participating in the final wine composition. Material and methods: it was realised a tracking during five years (2005-2009) about the wine composition of acidity, alcoholic probable degree (GAP) and during last three years about wine anthocyanins to Tempranillo variety and about maximum temperatures for determination Winkler index. Results: There was a statistically significant decrease acidity parameters (4,98±0,44 vs 8,21±0,95) and anthocyanins (110,75±29,13 vs 216,64±43,95) and a increase of alcoholic probable degree (GAP) (12,97±0,49 vs 11,62±0,63). The different was statistic significant between different years. Conclusion: In this work we observe that highest maximum temperature in our area of study, it was connected with a highest GAP levels and lower concentrations of acidity andanthocyanins in wine(AU)
