Heat-Moisture Treatment on Pinhao Starch Impacts the Properties of the Biodegradable Films

Using non-conventional starch can benefit the industry since it can present different properties. It also can lead to new properties upon physical modification, which improves its derivate film properties. Therefore, the aim of this work is to evaluate the heat-moisture treatment (HMT) on pinhao starch and its effectiveness in film properties. After isolation using water as a solvent, the pinhao starch is treated by HMT for 16 h at 110 degrees C. Native and HMTed starches are used to produce biodegradable films. Pinhao starch and starch films chemical and physical properties are properly characterized. The HMT causes some changes in short-range ordered structures, reduces the relative crystallinity, and shifts the pinhao starch from C-type to A-type. Also, HMT decreases the peak viscosity and the breakdown, and improves thermal stability. These starch changes upon HMT reduces water vapor permeability, increases tensile strength, and elongation at the break of pinhao starch films. Desirable changes in starch and film properties are achieved by physically modifying pinhao starch using HMT, which is a promising alternative to chemical modifications.