Impact of Must Replacement and Hot Pre-Fermentative Maceration on the Color of Uruguayan Tannat Red Wines

Abstract

This research aimed to evaluate the impact of different options for winemaking on the color composition of Uruguayan Tannat red wines. The techniques evaluated were the substitution of ripe grape juice with immature grape juice and the heating of the crushed grapes before fermentation, called must replacement and hot pre-fermentative maceration, respectively. These procedures were proposed to reduce the alcohol content and increase the phenolic composition of the wine, according to the expected effects of climate change and current trends in consumer preferences. The investigation was made over three consecutive years (2016, 2017, and 2018). Both winemaking techniques allow the enhancement of the chromatic characteristics of wines via the modification of the phenolic composition. Additionally, such techniques allow the overcoming of the well-known limitations in the extractability of anthocyanins presented by the Tannat cultivar. Hot pre-fermentative maceration increases the proportion of the most oxidizable molecules delphinidin-3-O-glucoside, cyanidin-3-O-glucoside, and petunidin-3-O-glucoside, suggesting heat inactivation of polyphenoloxidases enzymes. Must replacement and hot pre-fermentative maceration are technological alternatives that could significantly improve the intensity and chromatic characteristics of red wines.

Empleo de mostos Ugni blanc para reducir el contenido de alcohol y el pH de los vinos Tannat

“…La sustitución de mosto de Tannat por mosto de uva Ugni blanc, con menores concentraciones de azúcares (Tabla 1) implica una disminución en el contenido de alcohol del vino. Estos resultados están de acuerdo con los trabajos de Kontoudakis et al [21] y Rolle et al [22] y Piccardo et al [23,24,25] donde emplearon diferentes técnicas de sustitución de mosto de uvas maduras con resultados similares.…”

“…Sin embargo, los resultados obtenidos sugieren que la sustitución de un 20% de mosto de uva Tannat por mosto de Ugni blanc no disminuye la concentración de antocianos en el vino, ya que la mayor extracción ocurre durante la maceración fermentativa. Los resultados obtenidos coinciden con los obtenidos en los trabajos realizados por Kontoudakis et al [21], Rolle et al [22] y Piccardo et al [23,24,25] aplicando diferentes técnicas de sustitución de mosto comparables a la evaluada en esta investigación.…”

“…La menor concentración de etanol podría dificultar la extracción de flavonoles polimerizados de las uvas durante la fermentación [28]. Por otra parte, de acuerdo con los resultados obtenidos por Gil et al [29], y Piccardo et al [23,24,25]no observaron efecto sobre la concentración de proantocianidina ni su grado medio de polimerización.…”

Identification of Tentative Traceability Markers with Direct Implications in Polyphenol Fingerprinting of Red Wines: Application of LC-MS and Chemometrics Methods

“…During post-harvest processing, the maceration-fermentation step has strong implications on the optimum extraction of polyphenols [3,8,[56][57][58].…”

Modern Technologies and Their Influence in Fermentation Quality

“…Modern enology has studied ways to increase the extraction and to increase the stability of these molecules during the winemaking process. Recent technologies such as must replacement and hot pre-fermentative maceration increase the phenolic content and enhance the chromatic characteristics of wine while inactivating polyphenol oxidases enzymes able to degrade colored molecules and promoting condensation between anthocyanins and tannins [5]. Other modern technologies to increase wine color from a microbiological point of view are related to the production of highly stable forms of anthocyanins during alcoholic fermentation.…”