Dry Heat Treatment of Finger Millet Starch for Thin Films-Studies on Physicochemical, Mechanical, and Barrier Properties

This research work aims to investigate the impact of dry heat treatment (DHT) on the morphological, structural, and physicochemical properties of native finger millet starch (FMS), with the goal of enhancing its applicability in thin films. The influence of DHT on FMS is examined through various parameters, including moisture content, amylose content, ash content, swelling power, and solubility. Subsequently, a sequential evaluation is conducted to assess the morphology, structural and thermal stability, film thickness, water vapor permeability, water solubility, and mechanical properties of thin films produced from both FMS and DHT-modified FMS. Regarding the modification of FMS, the solubility of FMS exhibits improvement, while amylose content, swelling, ash, and moisture content exhibit a decline. Thin films fabricated using DHT-modified FMS displays enhanced homogeneity and continuity, devoid of cracks and holes typically observed in native FMS-based thin films. Furthermore, the mechanical properties, water solubility, and water vapor permeability of the films are also improved as a result of the DHT treatment.These results demonstrate that DHT can be useful for enhancing the physical and chemical properties of high amylose finger millet starch for its applications in edible films and coatings. FMS modification via DHT: Spread 50 g FMS in a petri dish, heat at 120 & DEG;C for 4 h, cool naturally at 25 & DEG;C for 30 min. Mix 3 g modified starch with 30% w/w D-sorbitol in 100 mL, heat at 90 & DEG;C for 35 min with stirring. After cooling to 40 & DEG;C, degas starch solutions, fill Petri dishes with 25 mL of solution, and dry at 25 & DEG;C for 24 h.image