Effect of Cladosporium rot on the composition and aromatic compounds of red wine

Abstract

High incidences of Cladosporium rot frequently occur (over 50% infected berries per clusters) in delayed harvests in Cabernet Sauvignon and other red cultivars of Vitis vinifera in Chile. The objective of this study was to determine the effect of Cladosporium rot (Cladosporium cladosporioides and C. herbarum) on composition and aroma of red wine. Cabernet Sauvignon and Carménère wines made with 50% of Cladosporium rot infected grapes (CRG) were characterized and compared with wines made identically with apparently healthy grapes (AHG). Wine composition, color, and aroma were determined and the wines were subjected to sensory evaluation. Differences in volatile acidity, residual sugar, anthocyanins, color hue, and tannins between CRG wines and AHG wines of both Cabernet Sauvignon and Carménère were significant (p<0.05). In Cabernet Sauvignon, differences in the aromatic profiles were obtained between CRG wines and AHG wines. Panelists negatively differentiated the aroma and astringency of the CRG wines. Cladosporium rot reduced color, aroma, and flavor in Cabernet Sauvignon and Carménère wines. To our knowledge, this is the first report demonstrating the effect of Cladosporium rot, a common late fall disease of grapevine in Chile, on red wines, and the results suggest the need to prevent it for obtaining high quality wines.