Diosmin-functionalized chitosan films as sustainable packaging materials for shrimp shelf-life extension

Shrimp, a highly perishable seafood, undergoes rapid quality deterioration during storage and distribution, leading to nutritional and financial loss. With growing environmental concerns regarding petroleum-based plastics, bioactive and biodegradable packaging alternatives are gaining attention. In this study, chitosan (CH)-based reactive films incorporated with diosmin (DM) were developed to improve the barrier and preservation properties of shrimp storage. At 5 % DM incorporation, film thickness increased from 0.30 ± 0.015 mm (CH) to 0.47 ± 0.028 mm, whereas moisture content and swelling ability decreased from 24.4 % to 15.03 % and 85.37 % to 47.90 %, respectively, indicating improved structural stability. Similarly, the water vapor transmission rate (WVTR) decreased from 36.47 to 17.87 g·m^-2·h^-1, demonstrating enhanced water resistance. The mechanical properties were also improved, with the tensile strength increasing by 48.33 % compared to that of pure CH films. The 5 % DM films exhibited strong antioxidant activity, scavenging 36.45 % of DPPH radicals, and demonstrated potent antimicrobial effects, reducing total viable bacterial counts in shrimp by 6.87 log CFU/g after 15 days of refrigeration compared to the control. Furthermore, the DM-loaded films increased the water contact angle from 70.81° (CH film) to 104.58°, thereby improving hydrophobicity, which is advantageous for meat packaging. Sensory evaluation confirmed that DM films better preserved shrimp freshness, odour, and texture than pure CH films. These findings indicate that DM-incorporated CH films can serve as eco-friendly functional packaging materials, offering superior preservation performance while reducing environmental impact compared to conventional plastics.