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…

Wine consumption in Ukraine: trends, socio-economic aspects, and public perception

This article explores the contemporary culture of wine consumption in Ukraine through the lens of social, economic, and cultural transformations triggered by European integration, the COVID-19 pandemic, and the full-scale war since 2022.

Irrigation as a tool for heatwave mitigation: the effect of irrigation intensity and timing in Cabernet Sauvignon

Heatwave events, defined as 2 or more days reaching ≥ 38 °C, are an increasingly frequent phenomenon threatening grape production worldwide. Heat stress has been shown to have negative consequences on grapevine physiology, leading to increased evaporative demand and intensified water stress. Due to heatwaves overlapping with important stages of grapevine reproductive development, spanning from berry set to the ripening stage, severe heat can potentially compromise yield and grape quality. The physiological response of grapevine to heat stress suggests a potential use of irrigation to mitigate heatwaves, however there is limited information regarding the irrigation amounts and timings needed for this purpose. Following up on a pivotal trial conducted between 2019 and 2022, in this study irrigation treatments with varying intensity and timing of application were refined to determine their potential mitigation of heat-associated damage to yield and fruit composition.

Oenococcus oeni clonal diversity in the carbonic maceration winemaking

This essay was aimed to describe the clonal diversity of Oenococcus oeni in the malolactic fermentation of the carbonic maceration (CM) winemaking. The free and the pressed liquids from CM were sampled and compared to the wine from a standard winemaking with previous destemming and crushing (DC) of grapes [1]. O. oeni strain typification was performed by PFGE as González-Arenzana et al. described (2014) [2]. Results showed that 13 genotypes, referred as to letters, were distinguished from the 49 isolated strains, meaning the genotype “a” the 27%, the “b” the 14%, the “c” the 12%, the “d and e” the 10 % each other, and the remaining ones less than the 8% each one.

Prediction of the production kinetics of the main fermentative aromas in alcoholic fermentation

Fermentative aromas (especially esters and higher alcohols) highly impact the organoleptic profile of young and white wines. The production of these volatile compounds depends mainly on temperature and Yeast Available Nitrogen (YAN) content in the must. Available dynamic models predict the main reaction
(bioconversion of sugar into ethanol and CO2 production) but none of them considers the production kinetics of fermentative aroma compounds during the process of fermentation. We determined the production kinetics of the main esters and higher alcohols for different values of initial YAN content and temperature, using an innovative online monitoring Gas Chromatography device.

Rootstock regulation of scion phenotypes: the relationship between rootstock parentage and petiole mineral concentration

Rootstocks not only provide tolerance to Phylloxera, but also ensure the supply of water and mineral nutrients to the whole plant. Rootstocks are an important way of adapting to environmental conditions while conserving the typical features of scion varieties. We can exploit the large diversity of rootstocks used worldwide to aid this adaptation. The aim of this study was to characterise rootstock regulation of scion mineral status and its relation with scion development.