Postharvest Behavior of New Muscadine 'gold Delight' Compared with Bronze Muscadines 'granny Val', 'triumph', and 'Hall'

This study presents the first report on the postharvest responses of ‘Gold Delight’ muscadine as newly developed bronze cultivar compared with three bronze commercial muscadines ‘Granny Val’, ‘Triumph’, and ‘Hall’ during 28 d of cold storage at 4 °C. Weight loss differed markedly among cultivars, with ‘Gold Delight’ showing the lowest final loss (2.11% ± 0.05%) and ‘Hall’ the highest (3.29% ± 0.11%). Firmness decreased in all cultivars, with reductions from 190.8 ± 3.0 to 171.9 ± 1.6 g·mm−1 in ‘Gold Delight’ and from 202.9 ± 3.2 to 159.8 ± 4.0 g·mm−1 in ‘Triumph’, confirming the greater firmness retention of ‘Gold Delight’. Total soluble solids (TSS) remained relatively constant, titratable acidity (TA) decreased gradually, and pH increased slightly during storage. By day 28, ‘Triumph’ showed the highest TSS/TA ratio (27.04 ± 0.45), followed by ‘Hall’ (25.47 ± 0.50). Total phenolic content showed slight reductions by day 28, with final values of 33.11 ± 0.54 mg·L−1 gallic acid equivalents (GAE; (‘Gold Delight’), 26.03 ± 0.63 mg·L−1 GAE (‘Granny Val’), 35.98 ± 0.75 mg·L−1 GAE (‘Triumph’), and 39.40 ± 0.62 mg·L−1 GAE (‘Hall’). Total antioxidant activity decreased moderately across cultivars, ending at 54.42 ± 1.35, 49.20 ± 1.22, 66.65 ± 1.24, and 77.35 ± 1.87 μmols TE·L−1 for ‘Gold Delight’, ‘Granny Val’, ‘Triumph’, and ‘Hall’, respectively. Color parameters showed only minor changes across cultivars. Overall, this evaluation demonstrated clear cultivar-dependent differences in postharvest behavior, providing practical guidance for selecting muscadines best suited for fresh-market consumption and cold-storage handling.