Melanoidins in madeira wines: Contribution to antioxidant capacity and color stability

Madeira wines, produced in styles ranging from dry to sweet and typically marketed as 3-, 5-, and 10-year-old blends, are renowned for their longevity. This study focused on isolating and characterizing melanoidins, high-molecular-weight brown polymers present in these wines, and evaluating their role in antioxidant activity and chromatic properties. The melanoidins fraction was found to contribute substantially to wine color, accounting for 65–75% of the browning index, 70–77% of the overall CI and 76–88% of To. In vitro antioxidant assays (DPPH) revealed that melanoidins contributed between 77% and 90% of the total radical scavenging activity. These results suggest that melanoidins play a critical role in the sensory and functional properties of Madeira wines. These findings provide early evidence of the functional potential of Madeira wine melanoidins as natural antioxidants. Future research should encompass a broader range of wines and further studies are needed to elucidate their chemical structures and bioavailability.