Application of uv-led in wine as an alternative to sulphur dioxide

Abstract

Sulfites (SO2) are commonly used in the wine industry to preserve products during storage for antiseptic and antioxidant purposes (Oliveira et al., 2011). However, the presence of sulfites at varying concentrations has been linked to allergic reactions in some consumers, such as dermatitis, urticaria, abdominal pain, among others (Vally & Thompson, 2001). UV-LED irradiation has been is an attractive technology of non-thermal nature and is an alternative to partially or totally replace the addition of SO2 to wine, due to its antimicrobial effect (Conner et al., 1998; Falguera et al., 2013). In this study, the effect of the UV-LED irradiation on the activity of Acetobacter aceti ATCC 15973 of white wine (Sauvignon blanc) and red wine (Pinot noir) was evaluated. A laboratory scale static UV LED irradiation system was designed, composed of four diodes with wavelengths of 278 nm (8-12 mW), 275 nm (3-5 mW) and 265 nm (1-3 mW) and irradiation times of 10, 20 and 30 min. The results indicate that irradiation at a wavelength of 278 nm for 30 minutes completely eliminated the A. aceti concentration (CFU/ml) in white wine. Irradiation of white wine at wavelengths of 275 and 265 nm for 30 min resulted in a logarithmic reduction of approximately 2.4. UV-LED irradiation processing of red wine was not as efficacious in eliminating A. aceti (CFU/ml), however, a logarithmic reduction of 4 was evidenced over 30 min. Therefore, the results obtained from the static UV LED irradiation process for white wine (Sauvignon blanc) and red wine (Pinot noir) showed that with diodes at a wavelength of 278 nm and a time of 30 min, the concentration of A. aceti ATCC 15973 was significantly reduced, which is relevant to control to maintain the quality of the wines. Furthermore, this technology could be an advantageous alternative to avoid the excessive use of sulphites in wine products. The effect on the final quality aspects of wine needs to be further clarified.