Metabolomic study of mixed Saccharomyces cerevisiae yeast during fermentation

In this video recording of the IVES science meeting 2021, Alice Maria Correia Vilela (University of Trás-os-Montes and Alto Douro, Vila Real, Portugal) speaks about bio-modulating wine acidity: the role of non-Saccharomyces yeasts. This presentation is based on an original article accessible for free on IVES Technical Reviews.

In alcuni lavori condotti alcuni anni or sono, abbiamo analizzato per un verso le tendenze della domanda di prodotti enologici, ed il comportamento del consumatore, e per un altro verso le motivazioni alla base delle scelte dell’enoturista, ovvero di colui che va per vigne e cantine per fruire di risorse enogastronomiche.

Heatwave events, defined as 2 or more days reaching ≥ 38 °C, are an increasingly frequent phenomenon threatening grape production worldwide. Heat stress has been shown to have negative consequences on grapevine physiology, leading to increased evaporative demand and intensified water stress. Due to heatwaves overlapping with important stages of grapevine reproductive development, spanning from berry set to the ripening stage, severe heat can potentially compromise yield and grape quality. The physiological response of grapevine to heat stress suggests a potential use of irrigation to mitigate heatwaves, however there is limited information regarding the irrigation amounts and timings needed for this purpose. Following up on a pivotal trial conducted between 2019 and 2022, in this study irrigation treatments with varying intensity and timing of application were refined to determine their potential mitigation of heat-associated damage to yield and fruit composition.

In winemaking grapes, it is known that most aroma compounds are present as non-volatile precursors, such as glycosidic precursors. In fact, there is strong evidence supporting the connection between the content of aroma precursors and the aromatic quality of wine [1]. Acid hydrolysis is preferred to reveal the aroma potential of winemaking grapes, as it predicts more accurately the chemical rearrangements occurring during fermentation in acidic environments [2]. In this study, a method involving a fast fermentation followed by acid hydrolysis at 75ºC was used to evaluate the accumulation of aroma compounds over time in fractions obtained from six different varieties of winemaking grapes.

The consumption of wine in traditional wine-producing countries like Italy, Spain, and France is decreasing.