Characterization of flours from some underutilized carbohydrate sources of Thailand for potential food applications

Northern Thailand's underutilized crop flours were examined for morphology, chemical composition, thermal, and techno-functional properties to broaden carbohydrate sources and assess their potential as plant-based food analogs and other food ingredients. Samples were as follows: Elephant foot yam (A), and Purple yam or Greater yam (DA-P), Water yam (DA-W), Five-leaf yam (DP), D. daunaea Prain & Burkill (DD), and Lesser yam (DE). Scanning electron micrographs revealed varied starch granule shapes and size ranging from 9 to 31 mm. XRD showed A-type crystallinity for sample A, B-type for DA-P, DA-W, DP, and DE, and C-type for DD. DP flour has the highest protein and starch content. DD and DE flours had the highest fat and fiber content with the least amylose content. DP, DA-P, and A flours displayed excellent thickening capacity, whereas DD and DE flours exhibited low viscosity and resistance to disintegration induced by heat and shear. DA-W flour exhibits moderate physicochemical properties, rendering it versatile for a multitude of applications. Gelatinization enthalpy (ΔH) ranged from 3.46 J/g to 8.14 J/g, indicating DA-P granular structure had more crystallites while A flour had lower thermostability. All flours exhibited unique characteristics, offering diverse options as texturizing agents for food analog formulation.