Sea Squirt Shell Protein and Polylactic Acid Laminated Films Containing Cinnamon Bark Essential Oil.

Unlabelled: Sea squirt (Halocynthia roretzi) shell protein (SSP) was used as a biodegradable film material and laminated with polylactic acid (PLA) to improve its physical and water barrier properties. Cinnamon bark oil (CBO) was incorporated into the SSP film as a bioactive material. After laminating with PLA, the tensile strength and elongation at break of the SSP film increased from 4.07 to 9.09 MPa and from 8.68 to 138.84%, respectively. In addition, water vapor permeability and water solubility decreased from 5.62 to 0.91 × 10 g m/m s Pa and from 42.17% to 23.93%, respectively. DSC results of the SSP films indicate that melting point temperature increased 140.05 to 163.52 °C by laminating PLA. The addition of 0.5%, 0.7%, and 1.0% CBO conferred the antimicrobial activity against four pathogenic bacteria to the SSP/PLA-laminated films. The SSP/PLA-laminated films containing CBO also had antioxidant activities. Therefore, the SSP/PLA-laminated films containing CBO are applicable as biodegradable packaging films.

Practical Application: Sea squirt shell has been discarded after the consumption of sea squirt, and sea squirt shell protein can be a base material for biodegradable films. In this study, sea squirt shell protein and polylactic acid laminated films containing cinnamon bark essential oil were developed. The developed films are promising environmentally-friendly alternatives for active packaging material.