Blown film of PLA for packaging with green tea and fish industrial residues: An insight on their properties

The use of food waste on the production of packaging can be seen as a promising strategy to cost reduction and new properties. Moreover, packaging, besides food physical protection, should establish a barrier to light and oxygen together with antioxidant and antibacterial activity, to extend the shelf-life of perishable products. In this study, PLA films with the incorporation of natural additives (cold fish protein - cFG and green tea extract - GTE) were successfully produced by blown film extrusion. While PLA exhibits favorable water vapor barrier properties due to its hydrophobic nature, a significant drawback in terms of high oxygen permeability. Although the cFG and GTE incorporation into the PLA matrix decreased the water vapor barrier and mechanical properties, it improves the oxygen barrier along with wettability and antioxidant activity. Moreover, GTE polyphenol compounds seem to improve molecular interaction between the PLA and cFG particles by establishing a better dispersion with enhanced compatibility. These results exhibit the benefits of adding cFG and GTE to a PLA matrix to produce an active film with reliable properties for food packaging.