Portuguese Sorbus taxa as underexplored sources of food-relevant bioactives: composition, functional evidence, and bibliometric insights

Sorbus taxa occurring in Portugal remain underexplored from a food science perspective, despite growing interest in the genus as a source of phenolic-rich fruits and other bioactive plant materials. This review critically examines the available literature on Portuguese-relevant Sorbus taxa, with emphasis on composition, functional evidence, and the main limitations to food-oriented translation, and complements this analysis with bibliometric mapping of the field. Across the literature, the strongest and most consistent evidence concerns Sorbus aucuparia, particularly in fruit- and pomace-based matrices, whereas S. domestica, S. aria, and S. torminalis remain more unevenly characterised. Phenolic acids, flavonols, anthocyanins, procyanidins, organic acids, minerals, and volatile constituents dominate reported phytochemical profiles. Still, their distribution varies markedly across species, cultivars, plant organs, extraction systems, and analytical methods. The most recurrent functional evidence concerns in vitro antioxidant capacity, antimicrobial activity, and enzyme inhibition relevant to glycaemic modulation. However, comparability is frequently limited by heterogeneous reporting bases, non-harmonised extraction conditions, and the widespread use of non-food-grade solvents or enriched fractions. In contrast, evidence for bioaccessibility, processing stability, real food applications, and technologically validated ingredient performance remains scarce. Bibliometric analysis further indicates that Sorbus research is still dominated by descriptive phytochemistry, taxonomy, and preliminary bioactivity screening, whereas application-oriented food science studies remain comparatively underrepresented. The current literature supports Sorbus, especially fruit- and pomace-derived materials, as a potentially valuable but still insufficiently validated source of food-relevant bioactives rather than as an established functional ingredient platform. Future progress will depend on taxonomic clarity, harmonised compositional reporting, food-grade extraction approaches, safety assessment, and stronger validation in real or model food systems.