Effect of grape ripeness, alcohol content, and maceration duration on phenolic content and composition of cabernet sauvignon wines

Cabernet Sauvignon grapes were harvested at three different maturities (unripe, ripe, overripe, represented by Harvest 1, 2 and 3) and used for winemaking, adjusting total soluble solids of each harvest to three concentrations (∼11 %, 14 %, and 16.5 % alcohol) and then subjected to either 10 or 240 days extended maceration (Control and EM). Phenolic compounds in both wines and grapes were measured with multiple methods (protein precipitation, phloroglucinolysis, UHPLC-MS-Q-ToF). Protein precipitable tannins significantly increased with the EM treatment, while alcohol only increased their extraction in the EM wines. Both Harvest 1 and EM wines showed higher seed extraction according to tannin size and composition. Harvest 1 presented higher protein precipitable tannin content in the grape seeds and skins, but did not increase the tannin content in the wine. Anthocyanins and Tannin-Anthocyanin Adducts were characteristic of the Control wines, while Flavanyl pyranoanthocyanins and aldehyde-bridged flavan-3-ol-anthocyanins were prevalent in the EM wines.