Fabrication of novel gallic acid functionalized chitosan/pullulan active bio-films for the preservation and shelf-life extension of green chillies

Abstract

The need for eco-friendly and sustainable packaging films for the preservation of fresh food products has received considerable interest. Hence, here we developed green and active bio-films based on chitosan (CS)/pullulan (PL) bio-polymers functionalized with different weight percentages of gallic acid (GA) through the solvent casting technique. The developed CS/PL/GA (CPG) films' properties were investigated through different characterization techniques. The CPG films containing 15 wt% GA exhibited excellent UV ray blocking and high tensile properties (∼27.53%) compared to the pristine CS/PL blend film. Further, the barrier property towards water vapor (∼21.41%) and oxygen (∼34.14%) was significantly enhanced with the GA content, while moisture retention capacity and surface wettability improved but not significantly. Besides these, CPG films showed an overall migration lower than the acceptable limit of 10 mg dm⁻². In addition, compared to the neat CS/PL film, CPG films exhibited excellent antioxidant (∼42.54%) and antimicrobial activities against foodborne pathogens. Moreover, the developed CPG15% film was practically tested for green chilli packaging at room temperature. Comparing CPG15% packed green chillies to unpacked green chillies, the shelf life of the green chillies was extended up to 18 days without affecting the quality. Overall, these findings imply that the developed CPG films attain promising conditions for active packaging applications of fresh food products.