Resumen de Cabernet Sauvignon Aging Stability Altered by Microoxygenation

Angelita Gambuti, Luigi Picariello, Luigi Moio, Andrew L. Waterhouse

• Microoxygenation (MOx) is used to reduce vegetal aroma and improve color by converting anthocyanins to stable pigments. A Cabernet Sauvignon wine treated with different levels of sulfur dioxide (SO2) and glutathione (GSH) was microoxygenated, bottled with equivalent free SO2 levels, and stored under controlled conditions for 28 months. After bottle aging, the MOx-treated wines, particularly those treated with relatively low levels of SO2 and GSH during MOx, showed much more acetaldehyde and stable polymeric pigments and very stable color compared to wines without MOx treatment. MOx-treated wines also lost more SO2 during aging. Higher SO2 during treatments with or without MOx resulted in more protein-reactive tannins after aging, suggesting implications for wine mouthfeel. The addition of SO2 and, to a lesser extent, GSH before MOx, was associated with slowed wine oxidation reactions during aging and reduced color stability, leading to greater color loss. These results show that MOx prior to bottling has a dramatic effect on the evolution of wine during aging. The MOx-treated wines had a more stable color, but they also lost SO2 protection more quickly, and thus may need more SO2 before bottling to ensure comparable stability during aging. These results suggest that MOx treatment removes some preservative factors in new wine, possibly phenolics that act as stabilizers.