Fabrication and characterization of chitosan/anthocyanin intelligent packaging film fortified by cellulose nanocrystal for shrimp preservation and visual freshness monitoring

In this study, a multi-functional packaging film was fabricated, utilizing the natural polysaccharide chitosan (CS) as the base material, integrating natural blueberry anthocyanin (AN) as pH-responsive indicator, and reinforced with cellulose nanocrystals (CNCs). The implications of addition levels of CNCs on the characteristics of the films were systematically investigated, resulting in that CS-AN-CNCs 9 % film exhibited optimal performance. Specifically, the film showed a substantial enhancement in maximum tensile strength from 15 MPa to 35 MPa; On the other hand, the swelling degree properties, the oxygen permeability and water vapor permeability decreased from 159.2 % to 92.0 %, from 51.7 g/(m2d) to 12.2 g/(m2d), from 31.6 × 10−12 g/(m·s·Pa) to 1.6 × 10−12 g/(m·s·Pa), respectively. Moreover, the CS-AN-CNCs 9 % film exhibited antioxidant, antibacterial, coupled with a color metrically responsive to pH variations, displaying great potential in indicating the shrimp freshness and delaying spoilage. Another notable advantage of the-prepared packaging material lies in its completely biodegradability, therefore meeting the requirement of environmental protection. Therefore, the prepared CS-AN-CNCs film as an intelligent packaging solution with potential applications in food preservation and freshness monitoring applications. A novel multi-functional intelligent packaging film based on chitosan (CS), natural blueberry anthocyanin (AN) and cellulose nanocrystals (CNCs) was fabricated for shrimp preservation and visual freshness monitoring. CS-AN-CNCs film exhibited antioxidant, antibacterial and had a color metrically responsive to the variation of ambient pH conditions, displaying great potential to indicate the shrimp freshness and delay spoilage. [Display omitted] •Chitosan-based intelligent films were fabricated using anthocyanin and cellulose nanocrystals (CNCs).•CNCs improved the mechanical and barrier properties of the film.•The film was antioxidant, antibacterial and biodegradable.•Intuitive monitoring of shrimp freshness and slowing the spoilage process.