Relationship between terroir and vegetative potential, productivity, yield and must composition of Vitis Vinífera L. Cvs. Cabernet Sauvignon under warm climate conditions

In this video recording of the IVES science meeting 2023, Fernando Zamora (Department of biochemistry and biotechnology, Faculty of oenology, Universitat Rovira i Virgili, Spain) speaks about the effects of using cationic exchange for reducing pH on the composition and quality of sparkling wine. This presentation is based on an original article accessible for free on OENO One.

The objective of the present work was to study the influence of the foliar application of seaweed (Laminaria japonica), on the bunch and on the must in the ‘Cabernet Sauvignon’ grape. The experiment was carried out in the years 2021/2022, in a 21-year-old commercial vineyard, in the municipality of “Dom Pedrito” – “Rio Grande do Sul” (RS). A completely randomized experimental design was used, with 4 treatments and 4 replications (7 plants per replication). The treatments were: T1- control treatment; T2- Exal Powder 5 g L-1; T3- Hidro Exal 15 ml L-1; T4- Exal Powder 5 g L-1+ Hidro Exal 15 ml L-1.

Amino acids are crucial nitrogen sources in yeast metabolism, influencing both biomass production and fermentation rate. The breakdown byproducts of amino acids contribute to the aroma of the wine and wine’s health benefit compounds. This study focused on the yeast’s extracellular metabolic profile of tryptophan, tyrosine, and phenylalanine belonging to the group of aromatic amino acids in experimental Maraština wines. Alcoholic fermentations were conducted on sterile grape Maraština must using seven autochthonous non-Saccharomyces yeasts in sequential fermentation with commercial Saccharomyces cerevisiae.

Wine varietal aroma is the result of a mixture of compounds formed or liberated from specific grape-aroma precursors. Their liberation/formation from their specific precursors can occur spontaneously by acid catalyzed rearrangements or hydrolysis or by the action of the yeast enzymatic activities. The influence of yeast during fermentation on the production of these volatile compounds has been widely studied however, the effect of this influence during aging is not fully understood. In order to evaluate these processes several indirect strategies have been used to study aroma precursors although they are not useful to understand the chemistry of the process.

The yeast Metschnikowia pulcherrima is a microorganism of great biotechnological interest, both for improving winemaking processes and for other applications outside the wine supply chain.