Muscadine grapes are native to the southeastern U.S. and are known for their unique flavor and aroma. Rapid postharvest deterioration of muscadine berries is a major barrier in market expansion. This study investigated the change in muscadine berries’ general composition over a four-week storage period. The vines were planted at the Chilton Research and Extension Center, Clanton, AL in a randomized complete block design with four single plant replications. Berries from the perfect-flowered cultivars ‘Hall’, ‘Paulk’, and ‘Southern Home’, and from the pistillate cultivars ‘Eudora’ and ‘Supreme’ (standard) were studied. Experimental vines were harvested on Aug. 2 and Sept. 4, 2024. One-pound clamshells were filled with berries collected from each experimental vine. Fresh samples (Week 0) were compared for berry quality changes occurring after 1, 3, and 4 weeks of cold storage at 4°C and 85% RH. After completing each storage period exposure, the berry samples were allowed to rest for 1 hour at room temperature. The change in berry weight and firmness was recorded after each storage treatment and 5 berry subsample was frozen at -80°C for later analysis of total soluble solids (TSS), titratable acidity (TA), TSS:TA ratio and pH. Our results indicate that the 4 Weeks storage period led to a significant weight loss of 11.3% in ‘Paulk’ and 7.6% in ‘Supreme’ berries in comparison to Week 0. It was found out that both cultivar and storage duration were accountable for the significant firmness reduction with ‘Paulk’ and ‘Supreme’ experiencing 51.4% and 46.2% reduction by Week 4 in storage. Titratable acidity increased significantly over time in all cultivars. The highest TA at Week 4 (0.67) was recorded for ‘Southern Home’, while ‘Paulk’ berries had the lowest TA (0.44), indicating strong cultivar effect (p < 0.0001). After the first week of storage, berries of ‘Hall’ were significantly sweeter than ‘Paulk’, while at Week 4, all cultivars had similar sweetness. Due to an increasing acidity trend, fruit pH decreased with increase in storage time exposure. Both cultivar and storage duration affected the berry pH. TSS:TA ratios varied significantly by cultivar and storage period duration with ‘Supreme’ maintaining its sweetness level throughout the four weeks of storage. Overall, the prolonged storage period resulted in significant firmness reduction and increased acidity with ‘Paulk’ exhibiting the highest reduction of berry firmness while ‘Supreme’ consistently maintained sweetness level over the 4-week period.
