Physicochemical, antibacterial and food preservation properties of active packaging films based on chitosan/e-polylysine-grafted bacterial cellulose

To address the environmental and food contamination issues caused by plastics and microorganisms, antimi-crobial films using natural polymers has attracted enormous attention. In this work, we proposed a green, convenient and fast approach to prepare antimicrobial films from chitosan (CS), bacterial cellulose (BC) and e-polylysine (e-PL). The effects of different concentrations of e-PL (0 %, 0.25 %, 0.5 %, 0.75 %, 1 %, w/v) on the physicochemical properties and antibacterial activity of composite films (CS-DABC-x%PL) were systematically investigated. Furthermore, a comprehensive comparison with purely physically mixed CS-BC-x%PL films pro-vides a deeper understanding of the subject matter. Characterization tests of the films were conducted using scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results suggested that the incorporation of 0.5 % e-PL reduced the water solubility of the composite film by 19.82 %, along with improved the tensile strength and thermal stability by 37.31 % and 28.54 %. As e-PL concentration increased to 1 %, the antibacterial performance of the films gradually enhanced. Additionally, the CS-DABC-0.5% PL film demonstrated effectiveness in delaying the deterioration of tilapia. These findings imply that this novel green packaging material holds significant potential in food preservation due to its promising antibacterial properties.

Automated summary

This study investigated the properties and antibacterial activity of antimicrobial films prepared from chitosan, bacterial cellulose, and e-polylysine. The results showed that the addition of 0.5% e-polylysine improved the texture stability and tensile strength of the films, as well as exhibited good antibacterial properties and a certain effect in delaying the deterioration of certain foods.