Seed Maturation Dynamics in Cabernet Sauvignon and Pinot Noir Grapes During Berry Ripening in Cool Climate Zones

Abstract

The physical and chemical changes of the polyphenols in grape seeds during berry maturation significantly influence the sensory characteristics of red wine. This study investigates the development of tannins and flavan-3-ols in Cabernet Sauvignon (CS) and Pinot Noir (PN) grape seeds between veraison and full ripeness, alongside concurrent alterations in seed physical characteristics. Our findings demonstrate a peak in tannin and flavan-3-ol concentrations at veraison, followed by a subsequent decline and varying trends in the mean degree of polymerization of tannins. Moreover, the study reveals that CS seeds exhibit relatively constant hardness and toughness, while PN seeds experience an increase in these physical properties during ripening. These dynamic changes in seed polyphenols and physical attributes hold considerable implications for red wine quality. Understanding these changes can offer valuable insights into optimizing harvest timing.