Macrowine 2021
IVES 9 IVES Conference Series 9 Maturation under different SO2 environments: the impact on amino acid and volatile profile for two white wines

Maturation under different SO2 environments: the impact on amino acid and volatile profile for two white wines

Abstract

EU countries are in the top 16 of the world’s wine producers. To respond to a public health concern, caused by SO2 excessive exposure, EU has required a warning in the products indicating that sulphites are present if concentrations are higher than 10mg/L and its reduction or replacement whenever possible. This additive is used as a preservative agent in the winemaking process, due to its antioxidative and antimicrobial properties[3]. Wine aroma depends on many factors, being grape variety and winemaking process that most contributes to volatile organic composition (VOC) found in wines where amino acid composition, due to their biosynthetic products play an important role. Also, during wine ageing VOCs can change depending on many factors such as temperature, pH or oxidation process[4]. In this work, the impact of different doses of SO2 (added after alcoholic fermentation) was evaluated on wine VOCs over time and amino acids content after 3 months over lees.

HS-SPME-GC/MS was used to identify and semi-quantify VOCs, and HPLC-DAD was used for amino acids quantification. Two white wines were studied: one varietal (Antão Vaz; AV) and one blend (BL) of Portuguese varieties. After being kept for 3 months over lees, wines were bottled and VOCs and amino acids were analysed after 3 and 6 months.

A total of 83 compounds were tentatively identified,70 compounds in monovarietal wine and 73 in the blend wine. The chemical functional groups observed were esters, alcohols, carboxylic acids, aldehydes and 12 miscellaneous compounds. When a Principal Component Analysis (PCA) was performed on VOCs semi-quantification of each wine it is observed that PCA plots present different trends throughout the factors under study. In Antão Vaz was attain lower samples distinction for different SO2 doses on sample with 3 and 12 months. However, for the evolution time of 6 months, samples were well separated. In this case, both factors seem to influence the distribution of samples with a similar weight. For the blend wine, a worse distribution of the samples was observed for evolution time of 3 and 6 months. This indicates that they might be more sensitive to SO2 doses and evolution time when compared with Antão Vaz wines. Regarding amino acids profile it was observed that maturation on lees lead to an increasing concentration of AA. However, Antão Vaz was more influenced by the SO2 doses applied.

DOI:

Publication date: September 13, 2021

Issue: Macrowine 2021

Type: Article

Citation

Related articles…

Emerging pest pressures in viticulture: a brief review of Argyrotaenia Ljungiana in Eastern Europe

As viticulture faces increasing threats from emerging pests, understanding and dealing with new infestations is crucial.

Read More

Inhibition of Oenococcus oeni during alcoholic fermentation by a selected Lactiplantibacillus plantarum strain

The use of selected cultures of the species Lactiplantibacillus plantarum in Oenology has grown in prominence in recent years. While initial applications of this species centred very much around malolactic fermentation (MLF), there is strong evidence to show that certain strains can be harnessed for their bio-protective effects. Unwanted spontaneous MLF during alcoholic fermentation (AF), driven by rogue Oenococcus oeni, is a winemaking deviation that is very difficult to manage when it occurs. This work set out to determine the efficacy of one particular strain of Lactiplantibacillus plantarum(Viniflora® NoVA™ Protect), against this problem in Cabernet Sauvignon must. The work was carried out at commercial scale and in a winery environment and compared the bio-protective culture with the more traditional approach of reducing must pH by the addition of tartaric acid. The combination of both was also investigated. The concentration of both Oenococcus oeni and Lactiplantibacillus plantarum was determined using qPCR. The adventitious Oenococcus oeni showed the most growth during AF in the control wine, whereas in the wines treated with Lactiplantibacillus plantarum a bacteriostatic effect against this species was observed. This effect was comparable to the wines treated with tartaric acid. This has particular commercial relevance for controlling the flora in musts with high pH, or when the addition of tartaric acid is either not permitted or is prohibitive for other reasons.

Read More

Double success of combining technical management with low pesticide inputs in the vineyard to obtain PDO wines in France

Viticulture is a major contributor to the antagonism of positive reputation and negative environmental impacts of agriculture. Vine contributes to structure landscape in the world, resulting, for example, in the delimitation of protected designations of origin (PDO). PDO vine is currently subject to the double challenge of sustainability and climate change adaptation. As vine is very sensitive to diseases and pests, vine requires a high use of pesticides to achieve its quality and yield goals. This high need for pesticides is the most important negative impact of environmental components.

Read More

Methodology to assess vine cultivation suitability using climatic ranges for key physiological processes: results for three South African regions

Le climat a de fortes implications sur le bon fonctionnement physiologique de la vigne et a besoin d’être quantifié afin de déterminer l’aptitude des régions à la culture de la vigne. Une méthode, qui pourrait éventuellement servir à prévoir l’aptitude des régions à la culture de la vigne, est proposée.

Read More

Climate change projections in serbian wine-growing regions

Changes in bioclimatic indices in wine-growing region of Serbia are analyzed under the RCP 8.5 IPCC scenario.

Read More