Multifunctional cassava starch bilayers with basil extract and eco-friendly synthesized silver nanoparticles for...

Plastic packaging remains essential for food safety; however, improper disposal severely affects ecosystems. The challenge lies in developing sustainable packaging that preserves food quality while reducing environmental harm. This research focused on developing biodegradable bilayer nanocomposites made from two layers of cassava starch. One-layer incorporated basil extract, while the other varying concentrations (1 %, 2 %, or 3 % w/w) of silver nanoparticles (AgNPs), which were synthesized using basil extract and cassava starch. All films were produced through an extrusion-thermoforming process. The bilayer with 3 % w/w AgNPs could not be evaluated due to early cracking during thermoforming process. The bilayers with 1 % and 2 % w/w nanoparticles exhibited antimicrobial activity against E. coli and demonstrated enhanced mechanical resistance. The basil extract-infused layer offered antioxidant properties, UV protection, and reduced water wettability. The bilayer nanocomposite containing 1 % w/w AgNPs demonstrated better interlayer compatibility and material integrity when in contact with water than the 2 % w/w formulation. The starch-based bilayer nanocomposite with 1 % w/w nanoparticles shows great potential for sustainable functional food packaging, combining antioxidant and antimicrobial properties, UV protection, improved mechanical strength, and reduced water wettability. However, increasing the concentration of AgNPs is challenging due to the differences in the thermoforming behavior of the layers.