Blueberries are valued for their flavor and nutritional content, yet postharvest data on rabbiteye (RE; V. virgatum A.) genotypes remain limited. In this study fruit quality of 16 RE and 3 southern highbush (SHB; V. corymbosum L.) genotypes were evaluated through cold storage. Fruit harvested in 2024 from E.V. Smith Research Center (Tallassee, AL) were stored at 4°C and 85% relative humidity in a randomized complete block design. Measurements were taken on days (d) 0, 14, 28, and 42 including color attributes (L*, a*, b*, C*, h* CIELAB units), soluble solids content (SSC, °Brix), titratable acidity (Tacid) and pH. Total anthocyanins (mg/g), phenolics (mg/100g), and DPPH antioxidant capacity (mM/100g) were quantitated via UV-VIS spectrophotometry. Significant interaction for days in storage*genotype were observed in Tacid and SSC:Tacid ratio. Tacid was highest in ‘MS1228R’ and ‘MS1234R’ (42d; 0.73 and 14d; 0.77) and lowest in ‘Legacy’ and ‘NC5303’ (42d; 0.30 and 0d; 0.31). The SSC:Tacid ratio was highest in ‘Brightwell’ (0d; 47.47) and lowest in ‘Vernon’ (0d; 19.76). SSC decreased with increased storage time (0d to 28d) by 0.69 °Brix while pH increased from 0d (3.31) to 42d (3.54). Genotype differences indicated ‘Brightwell’ and ‘Ochlocknee’ had the highest SSC (16.5 and 15.9 °Brix) compared to ‘T-3075’ and ‘New Hanover’ (12.4 and 12.1 °Brix). pH was highest in ‘Legacy’ and ‘New Hanover’ (3.67 and 3.63) and lowest in ‘T-3075’ and ‘MS1234R’ (3.25 and 3.19). Across all storage timepoints, RE genotypes were higher in total anthocyanins, phenolics and antioxidant activity at 16.54 mg/g, 298.40 mg/100g and 21.41 mM/100g, respectively compared to SHB genotypes at 11.35 mg/g, 213.90 mg/100g and 17.19 mM/100g. Hierarchical cluster analysis (HCA) indicated 3 clusters of interest. In cluster I, ‘Vernon’, ‘Overtime’ and ‘MS1595R’ had enhanced C* and h*. In cluster II, ‘Brightwell’ and ‘Ochlocknee’ indicated enhanced anthocyanin, phenolic and antioxidant activity, while ‘T-3075’ and ‘T-3072’ had suppressed phytonutrient content in cluster III. The industry accepted range for blueberry SSC is 11.2-14.3 °Brix and all genotypes in this study met industry standards. Some RE selections, e.g., MS selections, were above the U.S. accepted range (0.2 to 0.5) for Tacid relating to sour/tart flavors. HCA was useful in sub-selecting RE and SHB genotypes for sensory and electronic analysis to assess flavor patterns. Identifying fruit quality and flavor traits postharvest will aid in selecting superior RE germplasm to enhance consumer acceptance and inform breeding efforts.
