Melt-Extruded Home Compostable Films Based On Blends Of Thermoplastic Gliadins And Poly(ε-Caprolactone) Intended For Food Packaging Applications

Biodegradable polymers for food applications have emerged as a sustainable alternative to reduce plastic waste. In this work, compostable films based on blends of poly(ε-caprolactone) (PCL) and thermoplastic gliadins (TPG) were developed for packaging applications. Firstly, gliadins were extracted from wheat gluten and plasticized with glycerol. Then, PCL/TPG films were prepared by cast-extrusion processing at pilot scale and samples were characterized in terms of their structural, morphological, thermal, mechanical, barrier and optical properties. The addition of TPG increased the glass transition temperature (Tg) of PCL, reduced the oxygen permeability at 0% and 50% relative humidity values, and improved the seal strength properties of the films, having a minimal effect on the thermal stability, transparency, and the high stretchability characteristic of PCL. On the other hand, the presence of gliadins led to more water sensitive materials, resulting in a slight increase in the water vapor permeability. Finally, the home-compostability assessment of the films revealed that the presence of gliadins accelerated the aerobic biodegradation and the disintegration with respect to pristine PCL film, thus, showing the potential interest of the developed materials for sustainable packaging applications. Graphical Abstract: [Figure not available: see fulltext.]

The authors would like to express their gratitude to the Generalitat Valenciana (Grant IMAMCA/2022/10) and the Spanish Ministry of Science and Innovation (Grant PID2021-123077OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by the "ERDF A way of making Europe") for their financial support.

Peer reviewed