Comparison of Properties of Films Prepared from Potato Starch Modified by Annealing and Heat-Moisture Treatment

This study modified potato starches using hydrothermal treatment, i.e., annealing (ANN) and heatmoisture treatment (HMT). ANN in the ratio (1:2) of potato starch and water at 60 degrees C is performed for a day. For HMT, native starch is exposed to 110 degrees C maintained at 20% moisture content (M.C.) for 8 h. Potato bio-films (native and modified) are prepared by solution casting method using glycerol as a plasticizer. The properties of native and modified starches along with developed films are evaluated. HMT-modified starches showed lower solubility (10.5%), lower swelling power (21.2 g g(-1)), lower freeze-thaw stability, and exhibited non-Newtonian fluid behavior. Films produced from HMT starch have decreased solubility (13.57%), WVP (0.20 g mm m(-2) h(-1) kPa(-1)), and enhanced mechanical properties (7.62 MPa tensile strength, elongation of 11.36%, and seal strength 4.06 MPa) compared to annealed and native starch films. ANN starch increased the elongation (9.36%) with lower solubility (17.31%) and WVP (0.65 g mm m(-2) h(-1) kPa(-1)) of the starch films compared to the native starch. Also, the result shows that the potato starch-based films biodegraded within 15 days. The developed biodegradable packaging films could meet various packaging requirements using physically modified potato starch which has better film forming properties and is also eco-friendly.

Automated summary

This study modified potato starch using hydrothermal treatment and developed biodegradable packaging films with improved film forming properties. The heat-moisture treated starch showed better solubility, swelling power, and mechanical properties compared to the annealed starch. The potato starch-based films exhibited lower solubility and water vapor permeability.