Leaf and Fruit Responses of ´riesling´ Grapevines to Uv-Radiation in the Field

Effect of grape bunch sunlight exposure and UV radiation on phenolics and volatile composition of Vitis vinifera L. cv. Pinot noir wine

“…In this study, in comparison to UVÀ treatment, UV+ treatment increased 2-phenylethanol concentration in the final wine by 22%, in accordance with the result of Lafontaine et al (2004). However, sun exposure did not significantly increase the concentration of 2-phenylethanol.…”

“…Sunlight exposure treatment increased the amount of b-ionone. Neither b-ionone nor b-damascenone was affected by UV radiation, although Lafontaine et al reported that UV radiation increased the content of b-damascenone in Riesling wine (Lafontaine et al, 2004).…”

“…As a protective response against UV radiation stress, the synthesis of secondary metabolites mainly UV absorbing phenols such as flavonoids were stimulated in grape berries (Kolb et al, 2003;Spayd et al, 2002). It was assumed that UV radiation could result in the changes of volatile compounds in the finished wines because the volatile precursors including carotenoids, amino acids, and total glycosides in grape berries were affected by UV radiation (Lafontaine, Schultz, Lopes, Bálo, & Váradi, 2004;Schultz et al, 1998). However, there is little information on the effects of natural UV radiation on Pinot noir wine aroma compounds.…”

Climate change associated effects on grape and wine quality and production

“…Caldwell et al (2007) reviewed works that described the improvement of frost tolerance from UV-B in several plants. With regards to grape aroma, major effects may stem from changes in the composition of phenolic compounds (Lafontaine, Schultz, Lopes, Balo, & Varadi, 2005;Schultz et al, 1998), which play a significant role as photoprotective pigments in vines (Caldwell et al, 2007), and as antioxidants, color, aroma and mouthfeel relevant compounds in wines. Schultz (2000) reviewed some examples of possible UV-B radiation mediated consequences but the overall effects of increased UV-B radiation levels remain understudied.…”

Influence of ultraviolet exclusion and of powdery mildew infection on Sauvignon Blanc grape composition and on extraction of pathogenesis-related proteins into juice

“…In a later study, Lafontaine et al. () reported that exposure to UV‐B radiation increased the concentration of both total bound glycosidic secondary metabolites and phenolic substances. These increased phenolic substances, which may interact with both proteins and cell walls, could affect the concentration of proteins in pre‐fermentation grape juice.…”