Title : PLA-based films reinforced with carbon quantum dots derived from avocado peel for active food packaging
Abstract:
Polylactic acid (PLA) is one of the most promising biodegradable polymers for food packaging applications due to its biocompatibility, transparency, and renewability. However, its limited antimicrobial activity and low barrier properties hinder its broader application. In this context, carbon quantum dots (CQDs) derived from avocado peel waste (APCQDs) have emerged as potential nanofillers with antimicrobial and antioxidant functionalities. This study explores the fabrication and characterization of PLA films reinforced with APCQDs and doped APCQDs (NSP-APCQDs), incorporated at different concentrations (3% and 10%) via melt extrusion. The films were evaluated in terms of thermal behavior (DSC), and functional performance (antioxidant and antimicrobial activity). Results indicate that the incorporation of APCQDs significantly enhanced the radical scavenging capacity of the PLA films, especially at higher concentrations, as demonstrated by DPPH and ABTS assays. Additionally, NSP-APCQDs provided superior antimicrobial activity against foodborne pathogens such as Listeria monocytogenes. The dispersion of quantum dots within the polymer matrix was confirmed by microscopy and spectroscopic techniques, revealing a homogeneous distribution at 3% and slight aggregation at 10%. Despite this, the films remained transparent and flexible, making them suitable for real packaging applications. This study highlights the potential of upcycled avocado waste in producing functional nanomaterials for sustainable food packaging. The combination of PLA with multifunctional CQDs paves the way for eco-friendly packaging solutions with active properties, aligning with the principles of circular bioeconomy and food safety.
