Exploring the Evolution of Postharvest Quality and Composition in Novel Mini Plum Tomatoes with Different Fruit Pigmentations

This study evaluated the postharvest evolution in terms of quality and functional traits of recently introduced mini plum tomato cultivars, differing for fruit pigmentation. The cultivars Santy Naranja (orange fruit) and Melange (dark red, green-striped fruit), along with the well-established ‘Angelle’ (red fruit), were monitored during refrigerated storage (10 °C) for 0, 7, and 14 days (hereafter S0, S7, and S14, respectively) inside closed polylactic acid trays. ‘Melange’ displayed the highest fruit fresh weight loss and total soluble solids (TSS) (9.28 °Bx), along with the lowest firmness (4.69 N), whereas ‘Santy Naranja’ showed the strongest color deviation during the storage period. Titratable acidity (TA) was relatively stable in ‘Melange’, while ‘Angelle’ experienced the highest decrease between S7 and S14, resulting in stronger TSS/TA fluctuations. Regarding the functional traits, ‘Melange’ had the highest total polyphenols content (TPC), whereas ‘Angelle’ excelled in total carotenoid content (TCC), ascorbic acid content (AsA), and fruits’ antioxidant activity, as revealed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. With reference to storage time, the O2 concentration in the headspace, TPC, AsA, and DPPH decreased between S0 and S14, whereas CO2 concentration, TCC, and FRAP increased, but these variations were mostly cultivar-dependent. This study provides insights into the postharvest behavior of novel mini plum tomato typologies and their ability to maintain quality over time, providing information for developing strategies to preserve their sensory and nutraceutical characteristics during refrigerated storage.