Higher-quality grapes and wines with deeper colour and more intense aromas thanks to ultraviolet light. This is the focus of a study by the University of Pisa, published in the scientific journal Plants, which investigated the effects of targeted UV-C applications directly in the vineyard. This technology is already used to control vine diseases and reduce the use of chemical treatments.
The study, carried out on Cabernet Sauvignon vineyards at the Ornellaia estate in Bolgheri, Tuscany, demonstrated that additional UV-C light applications during the grape ripening phase stimulate the plant to produce greater amounts of natural compounds responsible for the wine’s colour and aromatic profile. Treated grapes showed higher concentrations of anthocyanins and flavonols, substances that that enhance colour intensity and stability in wine over time, as well as higher levels of aromatic compounds that make the wine more complex and fragrant. At the same time, no significant differences emerged in the vine’s vegetative and productive indices, nor in the overall quantity of grapes produced.
The most relevant finding is that this response can be achieved without radically altering agronomic practices. UV-C technology is already used in vineyards to contain certain diseases; the research simply tested a slightly modified protocol, adding a few targeted interventions during the ripening phase with the aim of enhancing the grapes’ secondary metabolite content. This practical approach, closely aligned with the real needs of wine producers, also opens up new prospects for more climate-resilient viticulture.
“We knew that UV light can stimulate the plant to produce molecules linked to wine quality, but until now these effects had mainly been observed under laboratory conditions,” explains Claudio D’Onofrio, Professor of Viticulture at the University of Pisa and coordinator of the research. “In this study, we demonstrated that even under real vineyard conditions it is possible to increase grape colour and aroma without compromising yield. It is an interesting result because it uses an existing technology in a more targeted and informed way.”
“The findings suggest that UV-C light could become an additional tool for improving grape quality while at the same time reducing the environmental impact of viticulture,” D’Onofrio concludes. “This is a highly topical issue for the sector, which is called upon to reconcile sustainability, innovation and quality in an increasingly complex climate context.”
