CHITOSAN FILMS INCORPORATED WITH DES-CONTAINING ASTAXANTHIN: STRUCTURAL CHARACTERISTICS, RELEASE MECHANISM, AND APPLICATION IN SHRIMP PRESERVATION

Abstract

In response to the increasing demand for improved protection and delivery of bioactive compounds in food packaging materials, this study focuses on the development of a chitosan-based film integrated with a deep eutectic solvent (DES) system containing astaxanthin, aiming to enhance its functionality for cold storage, particularly in peeled shrimp preservation. The study aimed to compare pure chitosan films with those containing DES–astaxanthin in terms of physicochemical characteristics, mechanical properties, and preservation performance. The DES–astaxanthin films exhibited superior flexibility, as indicated by a smaller decrease in elongation at break (from 52.37% to 32.14%), compared to the pure chitosan films (from 39.17% to 27.64%). These films also demonstrated enhanced structural stability and mechanical integrity throughout 10 days of refrigerated storage. In terms of preservation efficiency, the DES–astaxanthin films reduced shrimp weight loss (3.76%) more effectively than both the chitosan-only films (6.2%) and the control samples (8.94%). Furthermore, they contributed to maintaining pH stability, lowering total volatile basic nitrogen (TVB-N) accumulation, and inhibiting lipid oxidation, with TBARS values reduced by 60% relative to the control. Sensory quality, particularly color retention (measured via whiteness index, WI), was better preserved in the DES–astaxanthin group, while microbial growth (total viable count, TVC) was significantly suppressed. The release profile of astaxanthin from the film matrix was described using two kinetic models, with the second-order model providing a better fit for the release behavior over the storage period. These findings suggest that chitosan films incorporated with DES–astaxanthin present a promising strategy for the development of active packaging materials for cold-chain seafood products. However, further validation in real food systems is necessary to confirm their comprehensive preservative efficacy.