Effects of Altitude on Pomological Traits, Bioactive Composition, and Antioxidant Capacity of ‘Çataloğlu’ Apricot Cultivar

Altitude exerts a decisive influence on the physicochemical and functional attributes of apricots, yet its effects on the traditional Malatya dried apricot cultivar ‘Çataloğlu’ remain less studied. In this study, fruits harvested in 2024 from commercial orchards in low-altitude Battalgazi (~730 m) and high-altitude Darende (~1150 m) were compared in terms of pomological traits, bioactive composition, and antioxidant capacity. Fruits grown at high altitude had greater fruit length, flesh firmness of 6.32 kg cm⁻², titratable acidity, soluble solids content of 24.12%, and higher a* redness values, whereas no altitude-related differences were found in some size and other color parameters (L* and b*). Flesh firmness at low altitude was 6.00 kg cm⁻² and soluble solids content was 22.49%. Bioactive analysis showed that total phenolic content reached 784.14 µg GAE g⁻¹ FW at high altitude compared to 481.60 µg GAE g⁻¹ FW at low altitude. Similarly, DPPH and ABTS antioxidant activities were higher at high altitude, measuring 15.31 and 2.94 µmol TE g⁻¹ FW, respectively, versus 8.51 and 1.24 µmol TE g⁻¹ FW at low altitude. In contrast, total carotenoid content was higher at low altitude with 8.15 µg β-carotene g⁻¹ FW, while high-altitude fruits contained 6.08 µg β-carotene g⁻¹ FW. These contrasting tendencies reflect altitude-driven microclimatic differences: cooler temperatures in uplands stimulate phenolic accumulation, whereas warmer lowland conditions promote carotenoid biosynthesis. The findings highlight a clear quality balance. High-altitude fruits stand out for their antioxidant potential and functional health value, whereas low-altitude fruits are notable for their higher carotenoid content and bright yellow-orange color. These results can guide cultivar and site selection according to market demands and consumer preferences. With its relative tolerance to spring frost and drought, ‘Çataloğlu’ could see increased cultivation in high-altitude orchards under future climate change scenarios.