Red wine maceration with grapevine-cane residues: Influence of format and toasting level

Grape production generates a significant amount of pruning waste that could be repurposed for different applications. Recently, the use of pruning canes as potential additives to enhance wine quality has been proposed and studied, but further research is needed to better understand their effects. Therefore, the aim of this study was to characterize some of the physicochemical properties of Cabernet Sauvignon grapevine canes, and to assess the impact of their maceration in red wine, using different formats (i.e., powder, granules, and discs) and toasting levels (i.e., low and high). The results show that the canes analyzed are rich in phenolics such as <i>trans</i>-ε-viniferin and <i>trans</i>-resveratrol (i.e., 30.1 ± 0.2 and 5.3 ± 0.1 mg/g extract respectively), and that their maceration in red wine, produced variable outcomes depending mainly on the format employed. For instance, treatments with powder vine canes led to a reduction in total phenolics (-19.4 %), antioxidant capacity (-14.9 %), total anthocyanins (-19.5 %), and catechins (-9.5 %), compared to the untreated control. Instead, granules and discs produced no significant variation when compared to untreated or oak treated samples, after 24 days of maceration. Given that the cane format employed significantly influences the phenolic composition of the wines, future studies could explore the mechanisms behind these differing effects, as well as the sensorial implications of these changes.