Development of Flexible and Thin Films from Underutilized Indian Finger Millet (Eleusine coracana) Starch

Abstract

The present work explores the possibilities of developing finger millet starch (FMS) films with sorbitol (DS) at various concentrations. Therefore, starch is isolated from three diverse underutilized Indian finger millet varieties (VL‐149, VL‐371, and VL‐376). The results reveal that amylose content, moisture content, and ash content of FMS are observed in the range of 31.12 ± 0.37–33.87 ± 0.64%, 8.47 ± 0.75–9.87 ± 0.37%, and 0.33 ± 0.18–0.78 ± 0.91%, respectively. In addition, the solubility and swelling index of the FMS is found to be in the range of 1.5 ± 0.34–1.7 ± 0.11% and 9.98 ± 0.31–11.25 ± 0.64% at 60 °C. This work investigates the effects of varying concentrations (20%, 30%, 40%, and 50%) of sorbitol (DS) as a plasticizer on the FMS film's main functional properties, thermal, and structural. The results present that elongation at break‐point is increased while film density, swelling index, water vapor permeability, tensile strength, and solubility are reduced upon the addition of DS. Scanning electron microscope images show that the FMS film surfaces with DS are more homogeneous and continuous without air bubbles than those without DS. Thermal gravimetric analysis and differential scanning calorimetry results indicate that the thermal stability of the FMS film improves with DS.