Tunable Physicochemical and Bactericidal Activity of Multicarboxylic‐Acids‐Crosslinked Polyvinyl Alcohol Membrane for Food Packaging Applications

Abstract The present study demonstrates the role of multicarboxylic acids as crosslinkers to polyvinyl alcohol (PVA) films were fabricated by solution casting method for food packing applications. Effect of incorporating different carboxylic acids namely oxalic acid (OA), succinic acid (SA) and citric acid (CA) on physicochemical and bioactive properties of PVA were investigated in detail. The crystalline phase, optical absorptions and the functional group were analyzed through X‐Ray diffraction (XRD), UV‐Vis and Fourier Transform Infrared (FTIR) Spectroscopy. Thermal, microstructure and surface analysis were studied by Differential thermal analysis (TG/DTA) and Scanning Electron Microscope (SEM) analysis and the chief anti‐bacterial activity. The rheological study was carried out using precursor polymer solutions with different crosslinkers reveal that viscosity of PVA/CA solution is higher. Surface topography and roughness exert a strong influence on bactericidal properties of films as evidenced by Atomic Force Microscope (AFM) analysis. Among they studied films, PVA/CA exhibits higher bacterial inhibition efficiency mainly due to the ability of CA to alter local pH and cause an alteration in the permeability of microbial membrane by disrupting bacterial substrate transport. In addition to this food quality analysis results of microbial tests revealed an increase in the microbial shelf life of sliced carrot from 1 to 5 days for PVA/CA film compared to the control and commercial.