Prevention of the appearance of light-struck taste in white wine = Prevenzione della comparsa del gusto di luce nel vino bianco

The light-struck taste is a defect of bottled white wine due to the light exposure and involving the riboflavin (RF), as a photosensitizer, and methionine. The reaction pathways lead to the formation of volatile sulfur compounds, methanethiol and dimethyldisulphide, conferring cabbage-like aromas. The development of this defect is limited at low RF concentrations. In this study, the yeast-mediated release of RF, RF degradation kinetics in model solution and white wine, and RF removal by using insoluble adjuvants were investigated. The results showed the RF release was a strain-dependent property and the fermentation rate did not affect the RF synthesis. The RF degradation followed a 1st order kinetic in both model solution and white wine in which the degradation rate was halved. Among the adjuvants tested, bentonite and active charcoal were the most effective in RF removal and higher concentrations were needed for effectively treating white wine. The selection of low RF-producing yeasts and the treatment with active charcoal could represent useful tools to avoid the white wine spoilage during the shelf-life.