Effect of Silver Nanoparticles Prepared from Saraca asoca Leaf Extract on Morphological, Functional, Mechanical, and Antibacterial Properties of Rice Starch Films

Abstract

AbstractThis study aims to evaluate functional properties of rice starch‐based nanocomposite (NC) films. Silver nanoparticles (SNP) are synthesized using Saraca asoca leaf extract and found to be spherical with diameters ranging between 27 and 45 nm. The SNP solution is added at three different levels: 50, 100, and 150 mL to filmogenic solution (150 mL) and these films are designated as SNP‐50, SNP‐100, and SNP‐150, respectively. In addition to a control film, two more films are made by adding AgNO3 solution (150 mL) and plant extract (150 mL) into filmogenic solutions. Addition of SNP improves tensile strength and decreases elongation at break of rice starch films. NC films show enhanced UV–vis light barrier properties due to increased color intensity and opacity. SNP added films exhibit lower water solubility, water holding capacity, and water vapor permeability. Scanning electron microscopy suggests that control film, SNP‐50, and SNP‐100 have the smoothest surfaces in comparison to all films. SNP incorporation delays biodegradation of films. Silver nanoparticles in the form of colloid, filmogenic solution, and even as discrete films show excellent antibacterial activity against common food pathogens. The SNP concentration significantly correlates (R2 = 0.62–0.96) to the functional properties of films.