Date of Graduation
Master of Science in Food Science (MS)
Renee T. Threlfall
Second Committee Member
wine production, juice production, industry growth, postharvest quality attributes
Arkansas has a long history of grape and wine production, and muscadine grapes (Vitis rotundifolia Michx.), a native disease-resistant grape, are an important part of that industry. Muscadine grapes can be sold as a fresh-market grape or made into juice, wine, and other products. Additionally, the University of Arkansas System Division of Agriculture (UA System) breeding program has a focus on creating new muscadine cultivars with commercial potential. The objectives of this research were to evaluate muscadine grape genotypes (cultivars and breeding selections) for fresh market consumption and wine production in 2020 and 2021. 33 seeded and seedless genotypes of muscadines grown in Kings Mountain, North Carolina and at the UA System Fruit Research Station in Clarksville, Arkansas were evaluated for fresh market potential. At harvest, most physical and all composition attributes of the muscadines from both locations were significantly impacted by genotype. These grapes that were packaged in clamshells were also evaluated for postharvest storage potential for 14 and 28 d at 2 °C. Most genotypes had good storability with low weight loss (<9%) after 28 d even though berry firmness tended to decrease and weight loss and unmarketable berries increased. Of the genotypes evaluated in each year and location, only seven of 33 had unmarketable berries greater than 10%. The color of the berry skins showed that the L* decreased during storage, with dark/black muscadines having much less decreases in L* compared to bronze muscadines. This data provided information on physical, composition, and postharvest attributes of muscadine grapes that can be used for developing recommendations for standards for grades, marketing, and supporting breeding efforts. For wine production, AM-77 and ‘Noble’ muscadine grapes were harvested from a commercial vineyard as well as at the UA System Fruit Research Station and processed into wine using two skin contact times (0 and 3 d) during fermentation. The 2020 wines were evaluated at bottling and during storage at 15 °C, and the 2021 wines were evaluated at bottling. AM-77 wine had lower pH and higher titratable acidity than ‘Noble’, but ‘Noble’ wines had higher red color, brown color, and color density during 12-months of storage. ‘Noble’ wines with increased skin contact had higher red color and astringent flavors. For the 2020 wines, the wines with 0-days skin contact had fruitier, candy like aromas characteristic of muscadine juice, and AM-77 0-day skin contact was preferred over all ‘Noble’ wines and 3-day skin contact wines in consumer sensory (n=54) evaluation. AM-77 showed potential as compared to ‘Noble’, the commercial standard for muscadine wine production. Overall, this research showed that muscadine grapes including new genotypes, have potential for both fresh market consumption and wine production.
Rawls, J. C. (2022). Muscadine Grapes: Identifying Unique Attributes and Postharvest Practices. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/4683