Ricardo JURADO, Technical and R+D+i Director Agrovin

Belén BAUTISTA ORTÍN, Universidad de Murcia

In recent years, the winemaking industry has undergone a great evolution, introducing technologies and products with the aim of optimizing and making processes more profitable, as well as achieving a higher quality of the final product and differentiation.

This study evaluates whether or not there is synergy between the combined use of ultrasound and oenological pectolytic enzymes in order to produce a greater extraction of polyphenolic compounds and ensure their stabilization over time. In order to achieve these objectives, the following variables were set: time of addition of the enzyme as well as the degree of ripening of the grapes.

The experiments were carried out with Monastrell grapes at two stages of ripening (12ºBé, equivalent to 21.8ºBrix, and 14ºBé, equivalent to 25.4ºBrix) harvested in a vineyard in Jumilla (Murcia, Spain). The grapes were destemmed and crushed and six different vinifications were carried out (in triplicate) for each type of grape: two control vinifications without enzymatic or ultrasonic treatment with 3 or 7
days of maceration, two vinifications with sonicated grapes and 3 or 7 days of maceration and two vinifications where a pectolytic enzyme or in combination with US was used.

The results showed that ultrasound had a greater effect than oenological enzymes when used separately, especially when the ripest grapes were used.

The combination of powerful ultrasound (ULTRAWINE – PERSEO) and pectolytic type enzyme could be considered a very interesting practice to reduce maceration times, thus increasing the productivity of wineries, since a reduction of more than 50% in maceration time is possible. In addition, this study has determined that the combination of sonication and long maceration times can facilitate the extraction of phenolic compounds, making it possible to obtain wines of great color from less ripe grapes. This would also serve to reduce the alcohol content of the wines without reducing the amount of phenols extracted, an aspect of great interest in view of the worrying situation with “Climate Change grapes” characterized by a time lag between phenolic and technological ripening.