Physicochemical, Technofunctional and Antiglycaemic Properties of Telfairia occidentalis Leaf and Seed Powders

The global prevalence of type 2 diabetes continues to rise, highlighting the need for culturally relevant, plant-based functional ingredients capable of attenuating postprandial glycaemic responses. This study explored the physicochemical, technofunctional, antioxidant and in vitro antiglycaemic properties of Telfairia occidentalis leaf and seed powders, with emphasis on their application in low-glycaemic food systems. The leaf powder (TLP) was characterised by high dietary fibre (9.42 ± 0.56 g/100 g) and polyphenol (TPC: 76.59 ± 1.62 mg GAE/g; TFC: 44.58 ± 0.77 mg QE/g), exhibiting strong antioxidant activity. In contrast, the seed powder (TSP) was rich in protein (29.52 ± 0.34 g/100 g) and lipids (19.71 ± 0.73 g/100 g), demonstrating superior oil-holding, emulsifying and structural properties. Both fractions exhibited complementary antiglycaemic effects, including enzyme inhibition, glucose adsorption and reduced glucose diffusion, indicating multiple mechanisms of action. TSP exhibited moderate α-amylase (IC₅₀: 2580 ± 0.04 μg/mL) and α-glucosidase inhibition (IC₅₀: 2230 ± 0.00 μg/mL), although lower than TLP (α-amylase IC₅₀: 1530 ± 0.08 μg/mL; α-glucosidase inhibition IC₅₀: 840 ± 0.02 μg/mL) but was higher than acarbose (IC₅₀: 530 ± 0.05 and 330 ± 0.02 μg/mL, respectively). Scanning electron micrographs and Fourier-transform infrared (FTIR) spectra revealed distinct microstructural and molecular differences between TLP and TSP, highlighting a fibre-rich porous matrix in the leaf and a protein-lipid-dominated structure in the seed. Functionally, TLP contributes fibre- and polyphenol-mediated glucose regulation and antioxidant protection, whereas TSP provides protein-lipid-driven functional performance and modulation of glucose release and transport. These findings suggest that integrating TLP and TSP into composite formulations represents a promising strategy for developing low-glycaemic, antioxidant-rich foods with potential relevance for type 2 diabetes management.