Phenolic and carotenoid profiles and antioxidant potential of Idesia polycarpa var. vestita fruits from different geographic origins

Idesia polycarpa var. vestita is a promising woody fruit resource rich in bioactive phenolic compounds and carotenoids. However, the influence of geographic origin on its phytochemical composition and antioxidant potential remains insufficiently understood. To explore the geographic variation in fruit quality, fruits collected from six regions were compared in terms of phenotypic traits, phytochemical composition, and in vitro antioxidant capacity. Metabolite profiling annotated 33 phenolic compounds and 37 carotenoids. Salicinoid-type glycosides dominated the phenolic fraction, while the carotenoid profile was characterized by abundant lutein esters, particularly lutein diesters. Their accumulation differed considerably among geographic origins, accompanied by variation in antioxidant activity. Total phenolic content ranged from 8.60 to 16.20 mg GAE/g DW and was positively correlated with DPPH, ABTS, and FRAP activities. Total carotenoid content varied from 156.0 to 577.0 μg β-carotene equivalents/g DW and showed a positive correlation with ORAC activity. Beyond these total-content indices, variation in antioxidant potential was more closely associated with the abundance of specific metabolites. Salicinoids and related phenolic glycosides, together with lutein diesters, were among the characteristic metabolites associated with regional differences in antioxidant potential. Geographic differentiation of I. polycarpa var. vestita fruits thus primarily reflected shifts in the abundance of dominant phenolic and carotenoid metabolites rather than major changes in metabolite classes. These results link geographic origin with phytochemical variation and antioxidant properties and provide a basis for further evaluation of I. polycarpa var. vestita as a carotenoid- and phenolic-rich food resource.