Characterization of Bitter and Astringent Proanthocyanidins During Winemaking

AVF Proj. ID: 2074 / /Cat.: ,
Primary Investigator(s): Susan Ebelerby

Project Title: Characterization of Bitter and Astringent Proanthocyanidins during

Winemaking

Principal Investigators

  • Dr. Susan E. Ebeler, Department of Viticulture & Enology, University of California, Davis,

530-752-0380

  • Dr. Hildegarde Heymann, Department of Viticulture & Enology, University of California,

Davis, 530-752-0380

Summary

Polyphenols, including proanthocyanidins (i.e., tannins), are widely distributed in foods and

beverages, including grapes and wines and they are key constituents impacting bitter and

astringent perception. Due, at least in part, to their chemical complexity, the changes in

proanthocyanidin concentration and chemical structure that occur during winemaking and that

impact sensory properties have not been fully evaluated.

During the past year we have developed an ultra-high performance liquid chromatography

quadrupole time-of-flight mass spectrometry (UHPLC-qTOF MS) approach to characterize the

subunit composition and molecular weight/average degree of polymerization of wine

proanthocyanidins. Wines with different maceration treatments were analyzed and we are in the

process of completing the data analysis and comparison of the treatments. This work is

beginning to provide important insight into the impact of maceration treatments on

proanthocyanidin composition of wines.