Extraction and Characterization of Starches from Non-Conventional Sources: Turmeric (Curcuma longa) and Mangarito (Xanthosoma sagittifolium)

Abstract

The characterization of alternative starch sources is crucial for industrial applications. This study evaluated starches from turmeric (Curcuma longa L.) and mangarito (Xanthosoma riedelianum), considering extraction yield, proximate composition, amylose content, morphology, hydration properties, viscoamylographic behavior, and crystalline and thermal characteristics. Mangarito starch showed a higher yield (11.6%) than turmeric starch (5.6%). Turmeric granules were heterogeneous (triangular, ellipsoidal, oval), while mangarito granules were predominantly rounded. Turmeric starch exhibited higher amylose content (55.1%) compared to mangarito starch (25.9%). Hydration and viscoamylographic analyses indicated that turmeric starch had higher solubility (2.36%) and water absorption (2.88 g/g), higher peak viscosity (3147.5 cP), lower breakdown (83.5 cP), and greater retrogradation tendency (9806 cP). In contrast, mangarito starch demonstrated enhanced thermal stability (breakdown 1824 cP; final viscosity 4763.5 cP). X-ray diffraction revealed a semicrystalline A/B-type pattern for turmeric starch and a predominantly A-type crystalline structure for mangarito starch. DSC indicated glass transition temperatures of 114.7 °C (turmeric) and 120.1 °C (mangarito), while TGA confirmed greater thermal stability for mangarito starch, with a narrower decomposition range and higher residual mass. These results suggest that turmeric starch, due to its high amylose content, is suitable for rapid gelatinization and firm gel formation, whereas mangarito starch is more appropriate for applications requiring superior thermal stability and structural integrity.