Screening of different commercial wine yeast strains: the effect of sugar and copper additions on fermentation and volatile acidity production

Microsatellite markers are a valuable tool to facilitate the management of germplasm collections and assess genetic diversity. This study reports the genetic characterization of a large collection of 379 rootstocks and other non-viniferaaccessions maintained at the University of Milan, Italy.

Context and purpose of the study. The primary fungal diseases affecting grapevines in Europe are downy mildew and powdery mildew.

The wine sector generates a considerable amount of wealth but is facing a growing problem of fraud. Wine counterfeiting is one of the oldest and most common cases of food fraud worldwide. Therefore, the authenticity and traceability of wine are major concerns for both the industry and consumers. To address these issues, robust and reliable analysis and control methods are necessary. Several methods have been developed, ranging from simple organoleptic tests to more advanced methodologies such as isotopic techniques or residual radioactivity measurements.

Lugana Protected Designation of Origin (PDO) wines are made from Turbiana grapes. The aroma of Lugana wines results from the combined contribution of esters, terpenes, norisprenoids, sulfur compounds and the benzenoid methyl salicylate. This study aims to investigate how volatile aroma compounds are affected by different nitrogen supplies and yeast strains. Wines were produced with a standard protocol with 2021 Turbiana grapes with two different yeasts Zymaflore Delta e Zymaflore X5 (Laffort, France).During the alcoholic fermentation of the must, when H2S appeared, additions of various nitrogen supply were made: inorganic nitrogen, organic nitrogen, a mix of inorganic and organic nitrogen and organic nitrogen with an addition of pure methionine. During wine fermentation, a daily measurement of hydrogen sulfide was carried out.

Spain is one of the main producers of high-quality fortified wines. Particularly some of them elaborated in Andalusia have acquired a great prestige for being unique due to their production in a specific geographical area with traditional methods, the grape variety used, the climate and the soil. Such is their distinguishing feature achieved that they have been protected by the European Union with the indication “Protected Designation of Origin” (PDO). Thus, there are four PDO of fortified wines in Andalucía (‘Condado de Huelva’, ‘Jerez Xérès Sherry’, ‘Manzanilla Sanlúcar de Barrameda’, and ‘Montilla-Moriles’). Furthermore, within each PDO,there are different categories according to their particular characteristics and winemaking conditions such as the aging process.