Enological characterization of mold resistant varieties grown in the Trentino Alpine Region

La création officielle du groupe Experts Zonage Vitivinicole à l’O.I.V., qui s’inscrit dans la Commission Viticulture, est récente. Le Professeur Mario FREGONI en assure la présidence depuis 1998, assisté du vice-président et du secrétaire général Mario FALCETTI. Ils ont été confirmés dans leurs fonctions lors des sessions de mars 2001. Actuellement, le groupe d’experts Zonage Vitivinicole de l’O.I.V. se compose de 40 délégués, représentant 18 pays membres. La mise en place de ce groupe a tout d’abord été initiée par l’Instituto Agrario de San Michele (Italie) et l’Unité de Recherches Vigne et Vin du Centre INRA d’Angers (France). Une collaboration entre les chercheurs s’est installée très tôt, dès 1987.

Over the last few years a drastic reduction has been noted in the survival rate of vine cuttings in nurseries, as well as in young vineyards in the Western Cape Province of South Africa. The low average take percentages of young vines can be attributed to several factors, including fungal, bacterial and viral diseases, insect and nematode pests,

Recently, foliar treatments with mineral-based compounds have shown positive effects on grapevine production by protecting grape from thermal excesses and reducing the decoupling between technological and phenolic maturity caused by climate change. Unraveling the effect of mineral particle applications on grape-associated microbes is pivotal for successful wine processing, due to the influence of the microbiota on wine composition and stability. To our knowledge, this is the first work that comprehensively studied the effects of kaolin and chabasite-rich zeolitites treatments on grape-related microorganisms (by real-time PCR quantification of total fungi, Hanseniospora uvarum, Metschnikowia pulcherrima, plant-associated bacteria and lactic acid bacteria), the expression of genes related to the flavonoid biosynthesis (PAL1, CHS1, F3H2, DFR, LDOX, UFGT, MYBA1, GST4, FLS4 genes) and the berry composition (°Brix, pH, acidity and anthocyanin concentrations) in cv. Sangiovese during ripening in two growing seasons (2019 and 2020).

Despite its relevance for wine quality and stability, red wine colloids have not still been
sufficiently investigated, an occurrence due to the lack of suitable analytical techniques to study them as they are present in wine.

Pre-fermentative skin maceration is a technique used in white wine production to enhance varietal aroma, but it can increase protein concentration, leading to protein instability and haze formation [1]. To prevent protein instability, wine producers typically use fining agents such as bentonite, before wine bottling, which can negatively impact sensory characteristics and produce waste [2,3]. The aim of this study was to understand the impact of alternative techniques such as the application of polysaccharides (k-carrageenan and chitosan) on protein stability and on the wine macromolecular composition.