Fabrication, characterization and biological properties of pectin and/or chitosan-based films incorporated with noni (Morinda citrifolia) fruit extract

Noni (Morinda citrifolia) fruit is a natural food source rich in antioxidant and antimicrobial compounds. In this study, the phytochemicals of noni fruit extract (NFE) were identified by using HPLC-ESI-qTOF/MS method. Subsequently, casting method was adopted to prepare pectin and/or chitosan (CH)-based films incorporated with NFE. The influence of NFE addition on the physicochemical, microstructure, and biological properties of pectin and/or CH-based films was evaluated. Results confirmed that incorporation of NFE into pectin and/or CH-based films increased the tensile properties, water vapor permeability (WVP) and opacity of the films, but declined the thickness, moisture content and water solubility slightly. However, pectin-based films showed higher water solubility than CH-based films followed by pectin/CH-based films. In addition, the addition of NFE slightly decreased the film's thermal stability, and CH-based films showed better thermal stability compared to pectin or pectin/CH-based films. Regardless of the NFE addition, no significant morphological changes of pectin and pectin/CH-based films were observed using scanning electron microscopy (SEM). Compared with the control films, the average roughness of CH-based film surface was evidently increased. FTIR results showed that the addition of NFE had no remarkably influences on chemical structures of the films. More importantly, the addition of NFE effectively improved the antioxidant and antibacterial activities of the pectin and/or CH-based films, which was due to phenolic compounds existed in NFE. In short, pectin and/or CH-based films incorporated with NFE is characterized with eco-friendliness, reliability and multiplex bio-activities, which is expected to be a promising alternative for the plastics food packaging film.