A research team from the Rancho la Merced Center of IFAPA together with the Universities of Seville, Cadiz and Bordeaux has obtained a new antioxidant and antimicrobial compound called ST99 for use as an additive in rosé wines as an alternative to sulfites, the most widely used preservative in the industry today. It has been confirmed that the extract does not alter the characteristics and qualities of the wines and would therefore be suitable for people with sulfite allergies.
Sulfite is a chemical compound used in the wine industry as an additive to prevent oxidation and the growth of microorganisms such as bacteria or yeasts, which can alter its qualities and characteristics. However, some people are sensitive to this compound, so they cannot consume those products that use it as a preservative.
Thus, researchers are looking for alternatives that achieve the same antioxidant and antimicrobial qualities of sulfur, but also maintain the characteristics of each wine. In the article ‘Grapevine shoots extract as an alternative to SO2 in rosé wines. A double approach: Classical measurements and 1H NMR metabolomics’ published in the journal Food Control, they propose the use of a new extract obtained from the remains of the wine industry as a source of stilbenes, a family of polyphenols, which provide the same functions.
Specifically, the experts first confirmed their potential with a commercial extract containing 29% stilbenes. Subsequently, they created their own product from the remains of vine pruning, called ST99, which contains 99% of these antimicrobial polyphenols. “In previous studies we confirmed its suitability in white wines, now it is the turn of rosé, obtaining even better results. In addition, we have carried out the relevant toxicological tests that indicate its safety for human consumption”, says Emma Cantos Villar, researcher at the Rancho la Merced Center of IFAPA, author of the article, to the Descubre Foundation.
Therefore, it is ready for the wine industry to start using it and for people with allergies to be able to drink its wines.
Rosé is not just a color
The color and stability of rosé wines are the result of the grape variety used, but the fermentation process, the length of time and the chemical reactions that take place during vinification are the main differences between one product and another. Thus, wineries differentiate their wines in these processes.
The modification of any of its components or treatment can directly affect what characterizes a particular brand or differentiates it from others. Specifically, sulfur is one of the protagonists in the industry due to its high capacity to preserve the qualities of the wine intact after bottling. However, it is an allergen that can cause health problems, from dermatitis to anaphylaxis, in people who are sensitive to it. In addition, its concentration accumulates in the body. For this reason, the European Food Safety Authority (EFSA) recommended in 2016 not to exceed a daily intake of 0.7 mg of sulfur dioxide per kilogram of weight per day, and the International Organisation of Vine and Wine (OIV) set the limit at 200 milligrams per liter in rosé wines.
From the vineyard to the bottle
For red wines there are some alternatives to sulfur, but in whites and rosés there are still no valid additives that fulfill the same function without altering their qualities. In fact, ST99, tested in white, slightly altered the color and its shelf life was shortened. “However, in trials with rosé, we have found that the main properties are maintained in terms of composition and characteristics, such as color, aroma and flavor,” adds the researcher.
The experts are focused on the commercial implementation of the new additive. Specifically, they will present their results with ST99 to the world’s leading specialists in viticulture and enology at the 44th World Congress of Vine and Wine being held June 5-9 in Jerez de la Frontera, Cadiz, Spain.
The research has been funded through the project ‘Estilbenos como alternativa sostenible al SO2 en el vino’ from the State Research Agency and FEDER funds.
References:
Webinar recording: Vinos sin anhídrido sulfuroso: hacia una vitivinicultura más sostenible y circular
Article : Rocío Gutiérrez Escobar, María José Aliaño González, Inès Le Mao, Almudena Marrufo Curtido, María Carbú, María Jesús Jiménez Hierro, Belén Puertas, Tristan Richard, Emma Cantos Villar. ‘Grapevine shoots extract as an alternative to SO2 in rosé wines. A double approach: Classical measurements and 1H NMR metabolomics’. Food Control. 2023
Source: Fundación Descubre
