High-Barrier, Biodegradable Food Packaging

Biodegradable, high-barrier, flexible and transparent food packaging are required to replace current multilayered, metal- or halogen-containing packaging that is nonrecyclable and nondegradable. An “all-green” solution for food packaging made of a polylactic acid (PLA) foil (25 µm) furnished with a glycol chitosan-clay nanocomposite coating (1.4 µm) is presented here that surpasses state-of-the-art high-performance materials like metallized poly(ethylene terephthalate) or poly(vinylidene chloride) even at harsh conditions (OTR = 0.17 cm ³ m ⁻² day ⁻¹ bar ⁻¹ at 75% relative humidity). While the barrier side of the foil inhibits bacterial colonization, the uncoated PLA side assures biodegradability. Such a Janus feature in combination with the superb barrier performance renders this waterborne bio-nanocomposite coating a valuable alternative to conventional less eco-friendly food packaging materials.