Antimicrobial multi-crosslinking tamarind xyloglucan/protein-chitosan coating packaging films with self-recovery and biocompatible properties.

Natural and high-quality biomass-based coating films are considered promising packaging to consumers. However, the poor mechanical properties and weak antimicrobial activity of biomass materials have limited their practical application. A cleaner and low-cost strategy is used to prepare antimicrobial, self-recovery, and biocompatible coating films using tamarind kernel powder (TKP) and chitosan (CS). The TKP protein and chitosan chains were covalently cross-linked with tetrakis(hydroxymethyl)phosphonium chloride (THPC) to form a three-dimensional network based on THPC-amine dynamic bonds, and act as a sacrificial bond. Then, the hydrogen bond forms an interpenetrating network to build a strong multi-network film. Thus, the THPC multi-crosslinking TKP based films showed enhanced stretchable property (increased from 3.23 % to 77.54 %), and self-recovery after 30 min of recovery. Additionally, the film has been found to exhibit low water vapor permeability, low oxygen transmittance rate, and excellent antimicrobial efficiency (maximum inhibition zones: 24.39 mm). Moreover, the prepared films were demonstrated to be biocompatible and non-hemolytic based on cell viability and hemolytic activity assays. The method described herein could broaden the scope of biomass-based materials in the realm of antimicrobial coating films.