Photodegradation of retsina wine: does pine resin protect against light-induced changes?

Abstract

Retsina is a wine deeply rooted in Greek tradition but often misunderstood, largely due to the poor quality associated with past production. Historically, pine resin was used to seal wine transport containers, and over time, its distinctive aroma led to its intentional incorporation into winemaking. While Retsina has a long history, it gained widespread popularity after World War II as an inexpensive, highly aromatic, and widely consumed wine. Today, Retsina is classified under the Designation of Traditional Appellation and is exclusively produced in Greece as a white or rosé dry wine, using the traditional method of adding pine resin to the must. Typically, retsina wine is bottled in flint glass bottles, and although is know that light can damage wine aroma compounds [1], the effect of light in aromatised wines, like Retsina, has never been studied before. It remains unknown whether the enrichment of the wine with resin-derived phenolic compounds (antioxidants) and terpenes can protect it from photodegradation. To address this gap, this project aimed to study the behaviour of Retsina’s volatile components when stored in flint glass bottles. For this purpose, 12 Retsina wines, prepared with three levels of resin addition (0.1, 0.3, and >0.5 g/L), were stored for four weeks at room temperature under two conditions: a) Exposed to natural and artificial light in flint glass bottles, b) Stored in a box without any light exposure. After this period, the wines were analyzed using a state-of-the-art fast GC-MS/MS method, recently published [2]. The results were categorized into four groups: i) compounds that increased with resin addition, ii) compounds that decreased with resin addition, iii) compounds that increased due to light exposure, and iv) compounds that decreased due to light exposure. Notably, several terpenes increased with resin addition but decreased due to light exposure, while norisoprenoids decreased under light exposure. Some esters were reduced due to resin addition, and 2-AAP (2-aminoacetophenone) was increased by light exposure.

In conclusion, this study demonstrated that the addition of resin significantly influences the aroma profile of Retsina, affecting both primary and secondary volatile metabolites. Furthermore, flint glass should be avoided for bottling, as resin does not provide sufficient protection against photodegradation.

References

[1] Carlin, S., Mattivi, F., Durantini, V., Dalledonne, S., & Arapitsas, P. (2024). Flint glass bottles cause white wine aroma identity degradation. https://doi.org/10.1073/pnas

[2] Carlin, S., Lotti, C., Correggi, L., Mattivi, F., Arapitsas, P., & Vrhovšek, U. (2022). Measurement of the Effect of Accelerated Aging on the Aromatic Compounds of Gewürztraminer and Teroldego Wines, Using a SPE-GC-MS/MS Protocol. Metabolites, 12(2).