This study aimed to better understand the mechanisms of formation of 2-aminoacetophenone (2-AAP) in white wines, the main compound responsible for atypical aging (ATA), a phenomenon associated with a rapid loss of the fruity aroma of white wine and the development of unpleasant odors.

Two studies using 139 white wines from Central Europe investigated the varietal effect on the tendency of wine to form 2-AAP during aging. The role of some antioxidants and important transition metal ions present in the wine (Fe, Cu and Mn) on the formation of 2-AAP was also investigated.

The analyses showed that Muscat andRiesling wines showed significantly higher 2-AAP concentrations than Chardonnay and some other regional varieties grown in Central Europe, such as Grüner Veltliner, Welschriesling and Zelen. The origin of the varietal effect could not be correlated with the concentration of any 2-AAP precursor.

On the other hand, a significant effect of the wine matrix was observed. Some variability was observed in the ability of different antioxidants to limit 2-AAP formation. The addition of commercial tannins to the wines was shown to be more effective than glutathione in preserving the wines against 2-AAP formation.

Moreover, the results suggest that when wines are aged in barrels on heavy lees, the tannins extracted from the wood could be more effective in limiting 2-AAP formation than the antioxidant activity of the lees. Some synergistic effect between the two classes of antioxidants cannot be excluded in some wines, .

Transition metal ions significantly affected 2-AAP synthesis through complex interactions. In general, Fe and Mn tended to favor 2-AAP formation, whereas the presence of Cu limited it. The higher concentration of transition metal ions significantly enhanced the ability of antioxidants to reduce 2-AAP formation.

Further studies investigating the origin of the varietal effect and the complex matrix effects involving metal ions and antioxidants on 2-AAP production are needed.

Reference article:
Radovanović Vukajlović, T.; Philipp, C.; Eder, P.; Šala, M.; Šelih, V.S.; Vanzo, A.; Šuklje, K.; Lisjak, K.; Sternad Lemut, M.; Eder, R.; et al. New Insight on the Formation of 2-Aminoacetophenone in White Wines.
 Appl. Sci. 2023, 13, 8472. https://doi.org/10.3390/app13148472.