Postharvest Quality and Shelf Life of Three Thornless Blackberry Cultivars over Two Seasons

Postharvest deterioration remains a major challenge for blackberries, particularly in warm climates where shelf life is limited. This study evaluated the postharvest performance of three thornless cultivars grown under subtropical conditions: ‘Prime-Ark® Freedom’, ‘Osage’, and ‘Sweet-Ark™ Ponca’ using a two-phase cold storage regime (0 °C for 7 days, then 5 °C for 9 days). Over two seasons (2023–2024), fruit quality was assessed at days 0, 7, 12, and 16, focusing on weight loss, leakiness, red drupelet reversion (RDR), soluble solids content (SSC), titratable acidity (TTA), SSC/TTA ratio, and ascorbic acid. Cultivar responses varied: ‘Prime-Ark® Freedom’ showed strong storage resilience with minimal weight loss and fewer disorders, although SSC and ascorbic acid levels were lower. ‘Osage’ maintained high SSC, SSC/TTA, and ascorbic acid, favoring shorter storage for fresh markets. ‘Sweet-Ark™ Ponca’ had high SSC/TTA ratios but was prone to leakiness and RDR. Ascorbic acid declined during storage in 2023 but was better preserved in 2024, especially with ‘Prime-Ark® Freedom’. Our results provide actionable insights for cultivar selection in postharvest strategies that are critical to preserving fruit quality and extending shelf life in blackberries.