Employment of ultra-violet (UV-C) radiation as na alternative technology to sulfites for the microbiological stability of red wine – preliminary results

Abstract

This work consisted in the evaluation of the effect of UV-C radiation on the microbiological stability of red wine as well as its and also its influence on some physical and chemical parameters and on the sensory profile. Thus, wine without sulfites was subjected to UV-C radiation in two different doses, 778 J.L^‑1 and 1415 J.L^‑1, and a control sample was also prepared to which 40 mg.L^‑1 of sulfur dioxide was added. The wines (C dose 1 and dose 2) were analyzed over time (0, 1, 2, 3, 6 and 9 months). The results show that UV-C technology is effective in the microbiological control of wine, without any differences to the standard method for the considered parameters. As for the physical-chemical characteristics, there were no differences between the various treatments for the majority of parameters which were analyzed. It has been verified that this technology has a very positive effect on the stability of the colour (intensity and hue) over time, compared with the wine with sulfur dioxide. The sensory analysis of the wines showed that the wine subjected to treatment with UV-C radiation had better stabilization of colour, but there was some depreciation in the aroma and flavour of the wine, which attenuated over time.