Physicochemical, Functional, Pasting, and Thermal Properties and Digestibility of Precooked Unripe Plantain (Musa paradisiaca L.) and Sweet Potato (Ipomoea batatas) Flours

Abstract

This study evaluated the physicochemical, functional, pasting, and thermal properties and digestibility of precooked unripe plantain (Musa paradisiaca L. cv. Hartón) and sweet potato (Ipomoea batatas cv. Agrosavia Aurora) flours. Both raw materials were subjected to steam cooking at 4 min, followed by drying at 60 °C and grinding to particle sizes below 150 µm. Sweet potato flour exhibited higher protein (3.82%), fat (0.22%), crude fiber (2.92%), ash (3.40%), total phenolic content (180.45 mg GAE/100 g), antioxidant activity (58.22% DPPH inhibition), β-carotene (3.85 mg/100 g), and water/oil absorption capacities. In contrast, unripe plantain flour showed higher carbohydrate content (94.30%), starch content (76%), greater swelling power at elevated temperatures, and higher peak, breakdown, and final viscosities. The precooking process reduced the pasting temperature and modified the viscosity profiles of both flours compared to unprocessed counterparts, expanding their technological versatility. FTIR analysis confirmed the presence of typical starch, lipid, protein, and phenolic vibrational bands, with β-carotene-related peaks in sweet potato flour. Powder flowability analysis revealed that sweet potato flour presented higher cohesiveness and lower flowability than plantain flour. These results demonstrate that both precooked flours exhibit complementary nutritional and functional properties, supporting their potential application as gluten-free ingredients for functional food development and the industrial valorization of tropical perishable crops.