Antimicrobial and antioxidant chitosan solutions enriched with active shrimp (Litopenaeus vannamei) waste materials

Several shrimp active materials, including protein concentrates, protein hydrolysates and a carotenoid extract, were recovered from shrimp (Litopenaeus vannamei) processing residues (head and exoskeleton) and characterized in terms of chemical composition and antioxidative properties (Ferric ion reducing power and ABTS radical scavenging capacity). Different coating solutions were prepared by solubilizing chitosan, which was obtained from the residual chitinous material, in lactic acid and blending it with the various recovered materials. Chitosan-based solutions were tested for their viscosity and their antioxidative and antimicrobial properties against 26 selected microbial strains. All blend solutions showed higher antioxidant capacity and reduced viscosity as compared to the base chitosan solution. The incorporation of an astaxanthin-rich protein concentrate increased the antimicrobial capacity of the blend solution, but no further effect was observed after extra addition of the carotenoid extract.