Enoforum 2021
IVES 9 IVES Conference Series 9 Enoforum Web 9 Enoforum Web Conference 2021 9 Oxidation vs reduction: the fate of tannins, pigments, vscs, color,SO2 and metabolomic fingerprint

Oxidation vs reduction: the fate of tannins, pigments, vscs, color,SO2 and metabolomic fingerprint


The management of oxygen during winemaking and aging is a big issue in order to achieve high quality wines. The correct amount of O2 improves aroma, astringency, bitterness and color, however an excess of oxygen promotes the appearance of yellow and brown colors and oxidative off-odors, while its absence leads to the formation of reductive aromas. Even thought our knowledge about the reactions occurring during wine oxidation are very rich and detailed, the scientific data about the wine behaviour under reductive storage is limited. The main objective of this work was to study the metabolomic changes of eight red wines caused by the storage under different oxidative and reductive conditions.

Eight red wines were stored under eight different conditions, which include a) micro-oxygenators at 25 ºC for 3 months; b) anoxic atmosphere at 25 °C for 1, 2 and 3 months; c) anoxic atmosphere at 35 °C for 3 months; and d) control.  The following physicochemical analysis were made: LC-MS based metabolomic fingerprint, CIELab color, analyses of volatile sulfur compounds, redox potential, and basic oenological analysis. 

Changes of concentration of H2S and methanethiol (higher amount of free forms under reductive conditions) and redox potential results showed the reliability of the sample set. Color of samples evolved in a different way depending on the storage conditions, getting darker the reduced samples. Metabolomic study revealed reactions with SO2 and direct linked tannin-anthocyanin (T-A) adducts were favoured under anoxia but in the presence of oxygen, reactions with acetaldehyde and ethyl-linked T-A and tannin-tannin (adducts) were the favoured. The reaction mechanism of these reactions favoured in absence of oxygen could explain the observed changes during reductive storage.


Publication date: April 23, 2021

Issue: Enoforum 2021

Type: Article


Ignacio Ontañón1, Diego Sánchez1, Vania Sáez2, Fulvio Mattivi2,3, Vicente Ferreira1, Panagiotis Arapitsas2

Laboratorio de Análisis del Aroma y Enología. Departamento de Química Analítica. Facultad de Ciencias. Instituto Agroalimentario de Aragón –IA2- (Universidad de Zaragoza-CITA). C/ Pedro Cerbuna, 12. 50009. Zaragoza, Spain.
Research and Innovation Centre, Food Quality and Nutrition Department, Fondazione Edmund Mach, via E. Mach 1, 38010 San Michele all’Adige, Italy
Center Agriculture Food Environment, University of Trento, San Michele all’Adige, Italy

Contact the author


Enoforum 2021 | IVES Conference Series


Related articles…

Characterization of non-Saccharomyces yeast and its interaction with Saccharomyces cerevisiae with investigation of fermentation kinetics and aromatic composition

[lwp_divi_breadcrumbs home_text="IVES" use_before_icon="on" before_icon="||divi||400" module_id="publication-ariane" _builder_version="4.20.4" _module_preset="default" module_text_align="center" module_font_size="16px" text_orientation="center"...

Risposte enologiche del Nero d’Avola su suoli a diverso grado di salinità

Vengono riportati i risultati enologici di uno studio condotto sul Nero d’Avola in un tipico ambiente viticolo siciliano, in cui insistono suoli che presentano un diverso grado di salinità.


As wine resilience is the result of different variables, including the wine pH and the concentration of wine components, a detailed knowledge of the relationships between the adjuvant to attain stability and the oenological medium is fundamental for process optimization and to increase wine durability till the time of consumption.

Under-vine management effects on grapevine vegetative growth, gas exchange and rhizosphere microbial diversity

The use of cover crops under the vines might be an alternative to the use of herbicides or tillage, improving grapevine quality and soil characteristics. The aim of this research was to study the implications of different management strategies of the soil under the vines (herbicide, cultivation or cover crops) on grapevine growth, water and nutritional status, gas exchange parameters and belowground microbial communities.
The experimental design consisted in 4 treatments applied on 35L-potted Tempranillo vegetative grapevines with 10 replicates each grown in an open-top greenhouse in 2022 and 2023. Treatments included two cover crop species (Trifolium fragiferum and Bromus repens), herbicide (glyphosate al 36%) and an untreated control.

Microclimatic differences in fruit zone of vineyards on different elevations of ‘nagy-eged hill’ in eger wine region, Hungary

The Bull’s Blood of Eger (‘Egri Bikavér’) is one of the most reputed red wines in Hungary and abroad, produced in the Northeastern part of the country.