In this video recording of the IVES science meeting 2024, Silvina Dayer (PhD in Agronomy, Les Sanctuaires du Mirazur-Groupe Mauro Colagreco, Menton, France) speaks about grapevine drought response to increase vineyard sustainability. This presentation is based on an original article accessible for free on IVES Technical Reviews.

Nutrient availability – nitrogen, lipids, vitamins or oxygen – has a major impact on the kinetics of winemaking fermentations. Nitrogen is usually the growth-limiting nutrient and its availability determines the fermentation rate, and therefore the fermentation duration. In some cases, in particular in Champagne, grape musts have high nitrogen concentrations and are sometimes clarified with turbidity below 50 NTU. In these conditions, lipid deficiencies may occur and longer fermentations can be observed. To better understand this situation, a study was realized using a synthetic medium simulating the composition of a Champagne must : 180 g/L of sugar, 360 mg/L of assimilable nitrogen and a lipid content ranging from 1 to 8 mg/L of phytosterols (mainly β-sitosterol).

Elemental composition, measured as the concentrations of different elements present in a given tissue at a given time point, is a key indicator of vine health and development. While elemental composition and other high-throughput phenotyping approaches yield tremendous insight into the growth, physiology, and health of vines, costs and labor associated with repeated measures over time can be cost-prohibitive. Recent advances in handheld sensors that measure hyperspectral reflectance patterns of leaf tissue may serve as an affordable proxy for other types of phenotypic data, including elemental composition. Here, we ask if reflectance patterns of dried Chambourcin leaf tissue from an experimental grafting vineyard can predict the known elemental composition of those leaves.

Colour is an important quality parameter in wines and is the result of a complex mixture of pigments
(including anthocyanins and their derivatives, quinones, xanthyllium compounds, etc.). Red wine colour changes over time as pigments react between themselves and with other wine macromolecules
(particularly polyphenols). During wine tasting, colour is normally assessed on the outer rim of the wine profile in a tilted glass, since most wines are too opaque to be analysed in the middle of the glass. Therefore, depending on the depth of observation considered, the perception of wine colour can be different.

In the challenge of transforming waste into useful products that can be re-used in a circular economy perspective, winery by-products can be considered as a source of potentially bioactive molecules such as polyphenols. The wine industry generates each year 20 million tons of by-products. Kombucha fermentation is an ancestral process which allow to increase the biological properties of tea by the action of a microbial consortium formed by yeasts and bacteria called SCOBY. It belongs to the field of healthy food for which the interest of consumers is growing. The objective of this work was to propose a new functional beverage made from winemaking by-products fermented by a Kombucha SCOBY.