APPLICATION OF DEEP EUTECTIC SOLVENT CONTAINING ASTAXANTHIN EXTRACTED FROM SHRIMP SHELLS TO ENHANCE THE PROPERTIES OF CHITOSAN FILM

Abstract

This study evaluates the impact of incorporating deep eutectic solvents (DES) containing astaxanthin into chitosan-based films to enhance material properties for food preservation applications. The results indicate that the addition of DES and astaxanthin reduces the tensile strength of chitosan films from 5.53 MPa to 4.13 MPa, while increasing the elongation at break from 45.65% to 54.45%, thereby improving film flexibility. The water vapor permeability (WVP) of the DES – astaxanthin films is approximately twice that of chitosan – glycerol films, making them well – suited for fresh fruit and vegetable packaging by regulating gas exchange, minimizing condensation, and reducing spoilage risk. Fourier-transform infrared spectroscopy (FTIR) analysis confirms the formation of stable hydrogen bonding interactions among chitosan, DES, and astaxanthin, contributing to improved structural stability. Scanning electron microscopy (SEM) reveals a more homogeneous surface morphology, while atomic force microscopy (AFM) demonstrates microstructural changes that enhance film stability. Additionally, chitosan – DES films exhibit significantly enhanced antioxidant activity – 15 – fold higher based on ABTS and 5 – fold higher based on DPPH assays – compared to pure chitosan or chitosan – glycerol films. The films also show strong antibacterial activity, effectively inhibiting the growth of Staphylococcus aureus and Salmonella typhimurium, potentially due to increased diffusion of astaxanthin within the polymer network. These properties highlight the promising potential of DES – astaxanthin enhanced chitosan films as intelligent packaging materials, capable of extending food shelf life and offering improved microbial control.