Advancing grapevine science through genomic research

The work was carried out with five white Vitis vinifera, L. varieties (Verdejo, Tempranillo Blanco, Airén, Macabeo and Albariño), four of them cultivated in the Denomination of Origin (D.O.) where they have the greatest area planted of Spain (Verdejo in Rueda, Tempranillo Blanco in Rioja, Airén in La Mancha and Albariño in Rías Baixas) and Macabeo, that although it is not the most important variety in Extremadura, its study was considered there for the importance that it has in all Spain.

Nitrogen (N) fertilizer is important for grape growth and the quality of wine. It is essential to address the mismatch between N application and wine composition. Cabernet Gernischt (Vitis vinifera L.), as one of the main wine-grape cultivars in China, was introduced to Yantai wine region in 1892. This grape cultivar is traditionally used for quality dry red wine with fruit, spices aroma, ruby red and full-bodied wines. In order to regulate vine growth and improve grape and wine quality, Cabernet Gernischt grapevines were subjected to decreased levels of N treatments, compared to normal N supply treatment, during grape growing seasons of 2019 and 2020.

Oak barrels form an integral part of wine production, especially that of high quality wines. However, due to its porosity, wood presents an ecological niche for microbial proliferation and is highly susceptible to microbial spoilage which could cause considerable economic losses. Brettanomyces bruxellensis, the most commonly encountered microorganism responsible for spoilage during barrel ageing, can remain in barrels after barrel sanitation to contaminate new batches of wine after refilling. Therefore, effective sanitation treatments are of utmost importance to prevent recurring wine spoilage.

It is well known that the vinification of grapes at full maturation can produce rich, full-bodied wines,
with intense and complex flavour profiles. However, the juice obtained from such grapes may have very
high sugar concentration, resulting in wines with an excessive concentration of ethanol. In addition, the decoupling between technological maturity and phenolic/aromatic one due to global warming, exacerbates this problem in some wine-growing regions. In parallel with the increase of the mean alcohol content of wines on the market, also the demand for reduced alcohol beverages has increased in recent years, mainly as a result of health and social concerns about the risks related to the consumption of alcohol.

The objective of this work is to characterize the different fractions obtained, based on their malic, tartaric and total acidity. Twenty fractions of must were discriminated in order during the pressing for further physical-chemical analysis by Fourier Transform (FTIR).