Effect of acetaldehyde addition on the phenolic substances and volatile compounds of red Tempranillo wines

Abstract

Background and Aims The introduction of controlled amounts of oxygen into red wines influences the composition of the phenolic substances and volatiles, and therefore the sensory properties of the wines. The main aim of this study was to evaluate the impact of a simulation of the micro‐oxygenation technique through acetaldehyde addition, on colour, and on the composition of phenolic substances and volatiles of Tempranillo wines after 12 months of bottle storage. Methods and Results The analytical and sensory data were subjected to ANOVA, principal component analysis and orthogonal projection in latent structures discriminant analysis. Addition of acetaldehyde led to an increase in the anthocyanin fraction in coloured form, thus increasing wine colour, together with a change in the composition of the volatiles. Acetaldehyde addition appeared to strongly impact wine ester composition, along with fatty acids and volatile phenols; furthermore, acetaldehyde addition positively influenced the concentration of volatiles. Conclusions Acetaldehyde addition to red wine caused an increase in the polymeric fraction of the phenolic substances with its corresponding effect on wine colour density and astringency index. Moreover, the volatiles fraction has been better protected during ageing in wines to which acetaldehyde has been added. The acetaldehyde treatment therefore led to a clear difference in the chemical composition of the wines. Significance of the Study An increase in acetaldehyde in red wines can lead to profound changes in the composition of phenolic substances and volatiles of the wines and may serve as an alternative to oxygen addition in red wines where oxidation is studied.

A New Approach to the Reduction of Alcohol Content in Red Wines: The Use of High-Power Ultrasounds

“…Therefore, detection of gluconic acid allows estimation of the health status of the grape harvest and wine quality within the production cycle at a winery. OIV stated that levels of gluconic acid of 200–300 mg/L or lower indicates sound grapes, whereas levels up to 1.0 g/L indicate an initial stage of fungus infection [ 52 ]. The maximum level detected in our wines was 0.34 g/L in C16 wine.…”

The kinetics of oxygen and SO2 consumption by red wines. What do they tell about oxidation mechanisms and about changes in wine composition?

“…Acetaldehyde is known to react to anthocyanins, flavanols and tannins to form ethyl-bridged polymeric pigments which have less astringency (Cheynier, Duenas-Paton, Salas, Maury, Souquet, Sarni-Manchado, et al, 2006;Vidal, Francis, Noble, Kwiatkowski, Cheynier, & Waters, 2004) and which become resistant to sulfite bleaching (Sheridan & Elias, 2015). According to recent data acetaldehyde may react not only to anthocyanidins, but to phenolic acids and flavonols (Aleixandre-Tudo, Lizama, Alvarez, Nieuwoudt, Garcia, Aleixandre, et al, 2016) or to catechin itself (Sheridan & Elias, 2016). The reaction of some of these ARPs with acetaldehyde is much faster than previously expected and takes places, albeit at lower rates, even in the presence of equimolar amounts of SO 2 (Sheridan & Elias, 2016).…”

Reaction of Acetaldehyde with Wine Flavonoids in the Presence of Sulfur Dioxide

“…Recent studies in our group and elsewhere have shown that exogenous acetaldehyde can be used to improve red wine color stability and astringency. − The use of exogenous acetaldehyde provides benefits for the wine without the risks of reactive intermediates formed due to oxygen exposure. Adducts formed by acetaldehyde are found to be bridged by an ethylidene moiety (Figure ), , which can occur via C6 or C8 on the A-ring of the flavonoid molecule. − Ethylidene-bridging reactions can involve tannins and anthocyanins to form modified tannins as well as polymeric pigments. , Bridged products from reaction with acetaldehyde have been found in red wine and in model wine systems, ,− and evidence for ethylidene-bridged products of native tannins has been observed indirectly by phloroglucinolysis; however, these compounds are difficult to observe without fragmentation during ionization for MS.…”