Optimisation de la fertilisation du Cot sur le Causse de l’Appellation d’Origine Contrôlée Cahors

Global climate change is currently affecting vine phenology and causing a decoupling between technological and phenolic maturity of the grapes [1]. Wine industry has to face the challenge of making quality wines from grapes with an unbalanced phenolic composition.

Botrytis cinerea, an Ascomycota pathogen with a broad host range, infects over 1200 plant species. Grapes infected by this pathogen, which subsequently develop a noble rot, remain in the vineyard for an extended period, thus being exposed to a diverse array of physical, chemical and biological factors, which give rise to a complex microbial community.

One of the major issues for wine production in Australia is the management and eradication of powdery and downy mildews and the associated yield losses they present, costing Australian grape growers upwards of AUD$160M per annum [1].

Chitin is the main structural component of a large number of organisms (i.e., mollusks, insects, crustaceans, fungi, algae), and marine invertebrates including crabs and shrimps. The main derivative of chitin is chitosan (CH), produced by N-deacetylation of chitin in alkaline solutions. Over the past decade, the OIV/OENO 338A/ 2009 resolution approved the addition of allergen-free fungoid CH to must and wine as an adjuvant for microbiological control, prevention of haziness, metals chelation and ochratoxins removal (European Commission. 2011). Despite several studies on application of CH in winemaking, there are still very limited and controversial data on its interaction with acidic components in wine (Colan-gelo et al., 2018; Castro Marin et al., 2021).

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.