Preparation of edible films from pectin/carboxymethyl chitosan incorporating polyphenol-rich roselle leaf extracts for food packaging applications.

Abstract

This study aimed to design an innovative antioxidant and antibacterial film for functional and health-promoting food packaging materials using food-grade polysaccharides incorporated with polyphenol-rich roselle leaf extracts (RLE). The films were fabricated using the casting method of pectin (P), carboxymethyl chitosan (CMC), and RLE. Six sets of films; 3 control films such as pectin (P-0), carboxymethyl chitosan (CMC-0), pectin plus carboxymethyl chitosan (PCMC-0), and 3 treated films such as pectin (PR-3), carboxymethyl chitosan (CMCR-3), (PCMCR-3) with 3 % RLE were prepared respectively to study the effects of RLE on the properties and function of prepared films. The water vapor permeability of the films ranged from 4.16 ± 0.04 g mm/h·m2·kPa to 6.93 ± 0.07 g mm/h·m2·kPa, with RLE-incorporated samples exhibiting lower permeability than the control sample. The maximum tensile strength (53.00 ± 1.07 MPa) and elongation of break (85.83 ± 2.81 %) were observed at PCMCR-3 containing 3 % RLE. The highest water contact angle (109.4 ± 0.16) was also noted in the PCMCR-3 film. The incorporation of RLE decreased the roughness of the film microstructure. The addition of RLE film CMC-R and PCMCR-3 notably enhanced the antibacterial and antioxidant properties of the edible film. Overall, the PCMCR-3 films extended the shelf life of fresh fish preserved at 4 ± 1 °C, offering promising innovative food preservation packaging materials for preserving perishable food products.