Reducción del dióxido de azufre en la vinificación: la bioprotección como alternativa sostenible 

Reducing Sulfur Dioxide in winemaking: bioprotection as a sustainable alternative 

Isabelle Masneuf-Pomarède_Univ. Bordeaux, Bordeaux INP, Bordeaux Sciences Agro 

Sulfur dioxide (SO₂) has long been a cornerstone of oenological practice due to its antimicrobial, antioxidant, and antioxidasic properties. However, winemakers are increasingly compelled to reduce its use for health, regulatory (e.g., organic dry wines), and consumer-driven reasons. Among the most promising alternatives, bioprotection, particularly through the use of non-Saccharomyces yeasts, has attracted considerable interest. In the food industry, bioprotection is defined as the application of antagonistic microbial cultures to suppress pathogens and/or prolong product shelf life, all while preserving sensory qualities. In oenology, this strategy primarily relies on species such as Torulaspora delbrueckii and Metschnikowia pulcherrima.
Over the past decade, numerous studies have assessed the effectiveness of bioprotective yeasts as a substitute for SO₂. Experiments conducted on both white and red grape varieties have compared bioprotection (applied at harvest or during the pre-fermentation stage) with sulfite addition and no-treatment controls. Inoculation of grape must with non-Saccharomyces yeasts decreases the abundance of filamentous fungi, which are generally associated with a decline in grape must quality. Results regarding the suppression of Hanseniaspora spp. which may contribute to ethyl acetate and acetic acid formation remain inconclusive. Reduced efficacy in overripe grapes suggests that bioprotection doses may need to be adjusted based on grape maturity. The ability to limit oxidation phenomena was also studied: some species, such as M. pulcherrima, are highly efficient consumers of O₂, and this ability can negatively impact acetic acid bacteria during the pre-fermentation stage. However, in the production of dry white wines, this antioxidant capacity of bioprotection remains to be completed by an anti-oxidase activity yet to be developed. Finally, while the use of non-Saccharomyces yeasts for bioprotection effectively preserves and enhances the sensory quality of wines, their co-inoculation with Saccharomyces cerevisiae remains the most efficient strategy for intensifying fruity aromas. Current research underscores the importance of selecting appropriate yeast species/strains aligned with winemaking objectives and adjusting bioprotection doses according to grape maturity and vinification conditions.

Sara Windholtz1-5, Thibon Cécile1, Georgia Lytra1, Claudia Nioi1, Stéphane Becquet2, Emmanuel Vinsonneau3, Joana Coulon4, Isabelle Masneuf-Pomarède1

Empleo de la bioprotección como herramienta de gestión del SO₂ 

Use of bioprotection as a SO₂ management tool  

Victor Puente Lopez_Laffort

El continuo incremento del pH observado en los últimos años conlleva que el SO₂ molecular y el SO₂ libre de los vinos sean cada vez más bajos para una misma concentración de sulfuroso total. Ante este hecho, la pérdida del control microbiológico puede provocar un incremento indeseado de metabolitos como el acetaldehído, principal responsable del aumento del So2 combinado de los vinos. El control y su reducción durante el proceso fermentativo se presenta fundamental para disminuir los niveles de SO₂ combinado. En este trabajo se presenta la Bioprotección como herramienta en la reducción del empleo de SO₂ en mosto y en uva, y se posiciona como proceso en el control de la producción de acetaldehído, mostrando resultados en diferentes aplicaciones con el objetivo de controlar la población microbiana de contaminación durante diferentes fases del proceso de fermentación.