Application of colloidal silver versus sulfur dioxide during vinification and storage of Tempranillo red wines

Abstract

Background and Aims The antiseptic effect of the addition of colloidal silver (CAgC) alone or in combination with a small quantity of sulfur dioxide (SO2) was examined in both vinification and storage of red wines. Methods and Results Four treatments of grapes and wines with SO2 and CAgC alone or in combination with a small quantity of SO2 were established. All treatments of grapes provided similar control of yeast and lactic acid bacteria, however, the three treatments with CAgC were more effective in the control of acetic acid bacteria. The addition of CAgC did not affect fermentation, and the wines had physicochemical, aromatic and sensory characteristics similar to that of the control, but a lower alcohol content. None of the treatments maintained control of bacteria during storage. After 1 month of stabilisation and 4 months of storage, the wines produced with CAgC had a higher colour intensity and a lower concentration of both anthocyanins and total polyphenols. Moreover, the final wines showed little difference in volatile and biogenic amine composition, which affected neither their quality nor their sensory characteristics. Conclusions Under the conditions studied, addition of SO2 could be reduced or replaced by CAgC. Overall, wines elaborated with CAgC showed no microbiological problems, and moreover, they had a higher colour intensity and similar aromatic composition and biogenic amines concentration to that of the control; their sensory characteristics were well rated. Significance of the Study Colloidal silver could be a promising antiseptic in the elaboration and storage of young wines.