Production of chitosan-based biodegradable active films using bio-waste enriched with polyphenol propolis extract envisaging food packaging applications
Developing biodegradable active films has been a promising green approach to overcoming global concerns over
the environmental pollution and human health caused by plastic utilization. This study aimed to develop active
films based on chitosan (CS), produced from waste crayfish (Procambarus clarkii) shells enriched with bioactive
extract (5–20%) of propolis (PS) and to characterize its properties, envisaging food packaging applications. The
chromatographic profile of PS extract confirmed its richness, with 41 phenolic compounds. With increasing
extract addition to the chitosan, the thickness of the films increased from 61.7 to 71.7 μm, causing a reduction in
the light transmission rate, along with a greenish colour shift. The interactions between PS extract and CS was
confirmed by infrared spectroscopy, at the same time that the microstructural integrity of the films was checked
on the scanning electron microscopy micrographs. The findings also showed that addition of PS enhanced the
films thermal stability and mechanical properties e.g., tensile modulus, yield strength, and stress at break. Besides,
it improved the antioxidant and antimicrobial activities. Overall, CS-based composite films seem a
promising green alternative to petroleum-based synthetic plastics allowing to extend the shelf life of food
products due to their eco-friendly nature.
