Phenolic compounds as natural alternatives to sulfur dioxide in winemaking

Abstract

Winemaking involves a complex series of biochemical transformations where the use of additives is a standard practice to ensure product quality, safety, and stability. Among these, sulfur dioxide (SO₂) constitutes the primary additive used in oenology due to its potent antioxidant and antimicrobial properties. However, increasing clinical evidence regarding sulfite hypersensitivity, ranging from respiratory distress to allergic reactions1, has shifted consumer preference toward “clean-label” and bio-based alternatives. In response to this demand, the addition of phenolic extracts or individual compounds is being explored as a novel wine-protection strategy. The increasing employment of these molecules in the food industry as substitutes for conventional antioxidants has drawn particular interest, as they not only provide functional preservation through their high radical-scavenging capacity, but could also offer potential nutraceutical benefits. Furthermore, since polyphenols are naturally occurring in Vitis vinifera, they might represent inherently compatible candidates for oenological applications, enriching the wine’s existing polyphenolic matrix2,3. This study evaluates the potential of key phenolic compounds, such as catechin and resveratrol, as partial or total substitutes for SO₂. The research focuses on their efficacy in maintaining the oxidative stability of red and rosé wines while assessing their impact on the organoleptic profile. Treated wines were monitored over time and compared against SO₂-treated controls. Analytical methods included spectrophotometric techniques for color and total polyphenol content and HPLC-UV-Vis/Fluorescence for quantifying major markers (anthocyanins, flavan-3-ols, procyanidins). Molecular interactions were monitored via LC-DAD-QQQ, while overall antioxidant capacity was determined through DPPH, FRAP, ORAC, and ABTS assays. Finally, sensory profiles were evaluated and correlated with the chemical data. Initial results highlight the promising role of catechin and resveratrol, showing antioxidant capacities comparable to SO₂ within the wine matrix. However, technical challenges remain regarding the dissolution and homogenization of resveratrol. This preliminary work contributes to the development of sustainable strategies for producing high-quality, low-sulfite wines that align with contemporary health-conscious market trends without compromising sensory characteristics.

References

1. Vally, H. Role of Sulfite Additives in Wine Induced Asthma: Single Dose and Cumulative Dose Studies. Thorax 2001, 56 (10), 763–769. https://doi.org/10.1136/thorax.56.10.763.
2.  Esparza, I.; Martínez-Inda, B.; Cimminelli, M. J.; Jimeno-Mendoza, M. C.; Moler, J. A.; Jiménez-Moreno, N.; Ancín-Azpilicueta, C. Reducing SO2 Doses in Red Wines by Using Grape Stem Extracts as Antioxidants. Biomolecules 2020, 10 (10), 1369. https://doi.org/10.3390/biom10101369.
3. Raul Francisco Pastor; Magdalena Raquel Gargantini; Marcelo Murgo; Sebastián Prieto; Humberto Manzano; Carla Aruani; Claudia Inés Quini; Maria-Isabel Covas; Roberto Héctor Iermoli. Enrichment of Resveratrol in Wine through a New Vinification Procedure. J. Life Sci. 2015, 10 (7). https://doi.org/10.17265/1934-7391/2015.07.005