Biodegradable Quercetin-Incorporated Poly(Lactic Acid)/Chitosan Functional Films: A Study of the Properties and Application in Enhancing Fish Preservation

Traditional plastic packaging materials have brought serious environmental pollution and a number of health risks; so the development of biodegradable polymers as an alternative has received increasing attention. Here, active packaging materials with antioxidant, antimicrobial, and biodegradable properties were prepared using poly(lactic acid) (PLA) and chitosan loaded with quercetin. The experimental results demonstrate that the PLA/chitosan/quercetin film achieved an impressive ABTS radical scavenging rate of up to 98.2%, and the inhibition rates against Gram-negative (<i>E. coli</i>) and Gram-positive (<i>S. aureus</i>) bacteria were 87.60% and 80.45%, respectively. Furthermore, the composite film exhibited excellent oxygen barrier properties and biodegradability. Shelf life tests demonstrate that the PLA/chitosan/quercetin film retarded fish spoilage by 2 days compared to commercial polyethylene film. Additionally, the color changes in the film showed significant correlation with fish freshness, serving as an effective freshness indicator. Therefore, the PLA/chitosan composite film containing quercetin has a good application prospect in fish preservation and intelligent monitoring of fish freshness.