Comparison of Properties of Films Prepared from Potato Starch Modified by Annealing and Heat–Moisture Treatment
Ditimoni Dutta, Nandan Sit
Abstract
Abstract 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 °C is performed for a day. For HMT, native starch is exposed to 110 °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.