Development of antimicrobial whey protein-based film containing silver nanoparticles biosynthesised by Aspergillus Niger

摘要

Applications of whey protein concentrate (WPC)-based films have been limited in the food industry due to their poor mechanical properties. This research aims to evaluate the effect of silver nanoparticles (AgNPs) synthesised by Aspergillus niger on the mechanical and antimicrobial properties of WPC-based films. The biosynthesised AgNPs solution was added into the WPC film formula at the concentration of 0, 0.25 and 1.25 mM. The film samples containing AgNPs inhibited the growth of Staphylococcus aureus, Escherichia coli O157:H7, Salmonella Enteritidis, Listeria monocytogenes, Williopsis saturnus or Aspergillus sydowii with zones of inhibition ranging from 13 to 19.7 mm. Incorporation of AgNPs improved tensile strength and water barrier properties of the films by 84% and 67%, respectively. However, per cent elongation at the break of the film decreased from 37% to 11% by the addition of 1.25 mM AgNPs. This work provides a protocol for preparing improved antimicrobial WPC films with AgNPs.