Del Bel, Emily2017-11-272017-11-272014-08https://hdl.handle.net/11299/191181University of Minnesota M.S. thesis.August 2014. Major: Food Science. Advisor: Zata Vickers. 1 computer file (PDF); x, 134 pages.Marquette and Frontenac, red wine grapes released by the University of Minnesota in 2006 and 1997, respectively, comprise almost 75% of the cold-hardy vines planted in Minnesota. Maturity of wine grapes at harvest is an important factor in the quality of the resulting wine. This study was designed to define the aroma, flavor, and astringency attributes of Marquette and Frontenac wine grapes and to explore the changes to these sensory attributes that occur during the ripening process and the resulting changes in their respective wines. When the sugar levels of the grapes increased from low to medium to high, panelists rated the sweetness of the grapes higher, the sourness lower, and the astringency and bitterness lower. Panelists also tended to rate the jammy and dried fruit attributes higher as the sweetness of the grapes increased, though this may be due to confusion with the sweetness.enThesis or Dissertation