Characterization of Cissus quadrangularis L. (Veldt Grape) aerial fractions: Integrating nutritional and biophysical properties for functional food potential

In this study, we investigated the nutritional and biophysical properties of underutilized L. (Veldt grape) aerial fractions, leaf (CQL), stem pulp (CQP) and stem pulp with peel (CQWP), to assess their functional food potential. Each fraction exhibited tissue-specific biochemical traits. CQL showed elevated protein (16.82%) with moderate protein digestibility (47.55%), enriched essential amino acids (6.22%), unsaturated fatty acids (3.38%) and a favourable nutritional index (6.88%). However, its limited biomass and high oxalate (9.62%) restrict direct applicability. CQWP, characterized by high fibre (18.31%) and minerals, yet elevated antinutrients, impede protein digestibility (19.33%). CQP presented a balanced nutritional profile, characterized by moderate protein (11.32%), elevated essential amino acid index (EAAI: 50.95%), lower antinutrient levels, and a favourable nutritional index (5.76%). Its predominant amorphous structure (~ 80%) enhanced palatability and protein digestibility (53.57%). All fractions exhibited a flavonoid-rich antioxidant profile, with GC-MS confirming the presence of shared and distinct phytochemicals. Biophysical analyses (FTIR, XRD, SEM), thermal studies (TGA, DSC) and colloidal behaviour (zeta potential, PDI) further demonstrated structural functionality, thermal stability and dispersibility relevant to food processing. Collectively, these findings provide the unique nutritional and structural profiles of veldt grape aerial fractions that can support specific food applications. This work establishes a scientific basis for positioning the veldt grape as a nutrient-dense, underexploited crop resource with promising value in future functional food innovations.