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IVES 9 IVES Conference Series 9 OIV 9 OIV 2024 9 Short communications - Oenology, methods of analysis 9 Impact of winemaking practises on the formation of pinking

Impact of winemaking practises on the formation of pinking

Abstract

The pinking is a phenomenon that can occur in white wine produced with white grape causing the color change from yellow to red-salmon hue. Even if its appearance is highly variable and dependent to the vintage, the wines from certain grape varieties, such as sauvignon blanc, chardonnay, riesling and trebbiano di lugana, have been identified to be more susceptible to the pinking. This color change seems to primarily occur when a reductive winemaking is carried out [1] followed by the exposure to oxygen during the processing, such as during the bottling. However, the impact of the winemaking procedures needs to be further investigated.  This study aimed to provide new insights on the development of pinking related to certain winemaking practises applied.  A surface response methodology approach was used considering two different designs of experiment (doe). Specifically, the must clarification, the aeration during the alcoholic fermentation and the yeast strain were examined in doe1, and the must clarification, the content of phenols and the addition of glutathione (gsh) were considered in doe2. A trebbiano di lugana must was fermented for both trials. Once the alcoholic fermentations were completed, the wines were racked and the pinking susceptibility (ps) was determined by the addition of hydrogen peroxide [2]. The wines were bottled with and without sulfur dioxide (so2), stored for 4 months and the ps was newly assessed. The results showed that the management of both the pre-fermentation steps and the fermentation have an important role in the appearance of pinking. In particular, strongly clarified musts, obtained by flotation, could lead to wines more susceptible to pinking. Although gsh may be involved in this color variation, its use before the alcoholic fermentation did not favor the formation of pinking, probably because it is metabolised by the yeast or combined with phenols or other compounds (e.g., so2) present in wine. The yeast strain could favor the pinking as well as the content of phenols. The presence of so2, added to limit the browning, did not make the wines less susceptible to pinking despite it maintained the yellow color of wines. On the contrary, the ps of wines added with so2 was even higher than that of wines without so2. The clarification of the must, the yeast strain, the aeration during the alcoholic fermentation and the concentration of phenols have a relevant role in pinking appearance suggesting the winemaking should be properly managed to prevent this defect.  

References [1] Andrea-Silva, J., Cosme, F., Ribeiro, L. F., Moreira, A. S. P., Malheiro, A. C., Coimbra, M. A., Domingues, M. R. M., & Nunes, F. M. (2014). Origin of the pinking phenomenon of white wines. Journal of agriculture and food chemistry, 62, 5651–5659. https://doi.org/10.1021/jf500825h. [2] Simpson R.F. (1977). Oxidative pinking in white wines. Vitis, 16, 286-286.

Impacto de las prácticas enológicas en la formación del pinking

El pinking es un fenómeno que puede ocurrir en los vinos blancos elaborados con uvas blancas, provocando un cambio de color del amarillo al rojo salmón. Aunque su formación es muy variable y depende de la cosecha, se ha identificado que los vinos de algunas variedades de uva, como sauvignon blanc, chardonnay, riesling y trebbiano di lugana, son más susceptibles al color rosado. Este cambio de color parece ocurrir principalmente cuando se realiza la vinificación por reducción [1] seguida de la exposición al oxígeno durante el procesamiento, como durante el embotellado. Sin embargo, es necesario estudiar más a fondo el impacto de los procedimientos de elaboración del vino. Este estudio tuvo como objetivo proporcionar nueva información sobre el desarrollo del pinking relacionado con la aplicación de algunas prácticas enológicas. Se utilizó un enfoque basado en la response surface methodology considerando dos diseños experimentales (doe) diferentes. En concreto, en doe1 se examinó la clarificación del mosto, la aireación durante la fermentación alcohólica y la cepa de levadura, mientras que en doe2 se consideró la clarificación del mosto, el contenido de fenoles y la adición de glutatión (gsh). Para ambas pruebas se fermentó un mosto de trebbiano di lugana. Una vez finalizadas las fermentaciones alcohólicas, los vinos se decantaron y se determinó la susceptibilidad al pinking (ps) mediante la adición de peróxido de hidrógeno [2]. Los vinos fueron embotellados con y sin dióxido de azufre (so2), almacenados durante 4 meses y se reevaluó el ps. Los resultados mostraron que el manejo tanto de la fase prefermentativa como de fermentación tiene un papel importante en la aparición del color pinking. En particular, los mostos muy clarificados, obtenidos por flotación, podrían dar lugar a vinos más susceptibles a la formación de color pink. Aunque el gsh puede estar implicado en este cambio de color, su uso antes de la fermentación alcohólica no favorece la formación de pinking, probablemente porque es metabolizado por levaduras o combinado con fenoles u otros compuestos (p. Ej. So2) presentes en el vino. La cepa de levadura podría promover el color pink y el contenido fenólico. La presencia de so2, añadido para limitar el pardeamiento, no hizo que los vinos fueran menos susceptibles al pinking a pesar de mantener el color amarillo de los vinos. Por el contrario, el ps de los vinos adicionados con so2 fue incluso mayor que el de los vinos sin so2. La clarificación del mosto, la cepa de levadura, la aireación durante la fermentación alcohólica y la concentración fenólica juegan un papel relevante en la aparición del pinking, lo que sugiere que la elaboración del vino debe gestionarse adecuadamente para prevenir este defecto. 

Referencias [1] Andrea-Silva, J., Cosme, F., Ribeiro, L. F., Moreira, A. S. P., Malheiro, A. C., Coimbra, M. A., Domingues, M. R. M., & Nunes, F. M. (2014). Origin of the pinking phenomenon of white wines. Journal of agriculture and food chemistry, 62, 5651–5659. https://doi.org/10.1021/jf500825h. [2] Simpson R.F. (1977). Oxidative pinking in white wines. Vitis, 16, 286-286.

Impatto delle pratiche enologiche sulla formazione del pinking

Il pinking è un fenomeno che può verificarsi nei vini bianchi prodotti con uve bianche provocando un cambiamento di colore dal giallo al rosso-salmone. Anche se la sua formazione è molto variabile e dipendente dall’annata, i vini di alcuni vitigni, come sauvignon blanc, chardonnay, riesling e trebbiano di lugana, sono stati identificati come più suscettibili al pinking. Questo cambiamento di colore sembra verificarsi principalmente quando si effettua una vinificazione in riduzione [1] seguita dall’esposizione all’ossigeno durante la lavorazione, come durante l’imbottigliamento. Tuttavia, l’impatto delle procedure di vinificazione necessita di essere ulteriormente studiato. Questo studio mirava a fornire nuove informazioni sullo sviluppo del pinking correlato all’applicazione di alcune pratiche enologiche. E stato utilizzato un approccio basato sulla response surface methodology considerando due diversi disegni sperimentali (doe). Nello specifico, nel doe1 sono stati esaminati la chiarifica del mosto, l’aerazione durante la fermentazione alcolica e il ceppo di lievito, mentre nel doe2 sono stati considerati la chiarifica del mosto, il contenuto di fenoli e l’aggiunta di glutatione (gsh). Per entrambe le prove è stato fermentato un mosto di trebbiano di lugana. Una volta completate le fermentazioni alcoliche, i vini sono stati travasati e la suscettibilità al pinking (ps) è stata determinata mediante l’aggiunta di acqua ossigenata [2]. I vini sono stati imbottigliati con e senza anidride solforosa (so2), conservati per 4 mesi e il ps è stato nuovamente valutato. I risultati hanno mostrato che la gestione sia delle fasi pre-fermentative che della fermentazione hanno un ruolo importante nella comparsa del pinking. In particolare, i mosti fortemente chiarificati, ottenuti per flottazione, potrebbero portare a vini più suscettibili alla formazione del colore rosa. Sebbene il gsh possa essere coinvolto in questa variazione di colore, il suo utilizzo prima della fermentazione alcolica non favorisce la formazione del pinking, probabilmente perché viene metabolizzato dal lievito o combinato con fenoli o altri composti (es. So2) presenti nel vino. Il ceppo di lievito potrebbe favorire il pinking così come il contenuto di fenoli. La presenza di so2, aggiunta per limitare l’imbrunimento, non ha reso i vini meno suscettibili al pinking nonostante mantenga il colore giallo dei vini. Al contrario, il ps dei vini addizionati con so2 era addirittura superiore a quello dei vini senza so2. La chiarifica del mosto, il ceppo di lievito, l’aerazione durante la fermentazione alcolica e la concentrazione dei fenoli hanno un ruolo rilevante nell’aspetto del pinking suggerendo che la vinificazione dovrebbe essere gestita adeguatamente per prevenire questo difetto. 

Riferimenti [1] Andrea-Silva, J., Cosme, F., Ribeiro, L. F., Moreira, A. S. P., Malheiro, A. C., Coimbra, M. A., Domingues, M. R. M., & Nunes, F. M. (2014). Origin of the pinking phenomenon of white wines. Journal of agriculture and food chemistry, 62, 5651–5659. Https://doi.org/10.1021/jf500825h. [2] Simpson R.F. (1977). Oxidative pinking in white wines. Vitis, 16, 286-286.

Publication date: November 18, 2024

Issue: OIV 2024

Type: Article

Authors

Daniela Fracassetti¹, Francesca Domenighini¹, Davide Ballabio²

¹ Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Italy
² Department of Earth and Environmental Sciences, Università di Milano-Bicocca, Italy

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Tags

IVES Conference Series | OIV | OIV 2024

Citation

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