Quality and bioactive compound dynamics during ripening of <i>Salpichroa origanifolia</i> fruit: A South American native species with nutraceutical value

Background Salpichroa origanifolia (Lam.) Baill. (Lily of the Valley vine) is a native South American species whose edible fruits remain largely unexplored despite their potential nutritional and functional value. Objective This study aimed to provide the first characterisation of S. origanifolia fruit quality, focusing on physicochemical, nutraceutical, and cell wall traits across two ripening stages: light green (LG) and ripe white (RW). Methods Fruits at LG and RW stages were analysed for weight, size, pH, titratable acidity, sugars, starch, chlorophylls, anthocyanins, carotenoids, phenolic acids, flavonoids, and vitamin C. Cell wall composition was determined, and functional properties were assessed through in vitro wall swelling and Botrytis cinerea growth assays. Results Ripening significantly increased fruit weight, size, and titratable acidity, while starch content remained low and stable (0.95 vs 0.88 g kg − 1 ). Total sugars increased markedly from 7.20 to 47.70 g kg − 1 and reducing sugars from 5.17 to 44.75 g kg − 1 , suggesting carbohydrate accumulation primarily involves reducing sugars derived from translocated photoassimilates rather than starch degradation. Bioactive compounds were higher in LG than RW fruits, with carotenoids decreasing from 16.33 to 9.54 mg kg − 1 , phenolic acids from 1235.50 to 1113.20 mg kg − 1 , flavonoids from 2039.60 to 1139.70 mg kg − 1 , and ascorbic acid from 259.10 to 194.90 mg kg −1 . Despite this reduction, RW fruits retained levels comparable to or exceeding those of several conventional fleshy fruits. Cell wall analysis revealed decreased alcohol-insoluble residues and neutral sugars, increased galacturonic acid, and unchanged hemicellulose content. RW fruits also showed greater cell wall swelling and enhanced B. cinerea growth, implying ripening-associated structural remodelling. Conclusions This study provides the first detailed insights into S. origanifolia fruit ripening, highlighting its bioactive compounds and functional traits. These findings support its valorisation as a promising underutilised native fruit with potential contribution to biodiversity-based food systems.