Development of nanocomposite biodegradable film containing iron nanoparticles biosynthesized by Saccharomyces cerevisiae

The present study has sheds light on the synthesis of iron oxide nanoparticles (IONPs) by Saccharomyces cerevisiae yeast as a green method by using the components of yeast cell walls as reducing agents to promote more beneficial effects in life applications. The main objective of the study is to examine the antimicrobial and mechanical properties of whey protein based edible films contained IONPs. At the present study, IONPs were synthesized by using S. cerevisiae from iron chloride (FeCl3) precursor at three different concentrations (0.5, 1.0, and 1.5 mM). These iron oxide nanoparticles and lysed yeast cells residue (YSR) were used with whey protein concentrate and glycerine to prepare nanocomposite edible films contained 0, 0.25, 0.5 and 0.75 mM IONPs. The results have shown successful synthesis of IONPs as hematite (Fe2O3) according to the XRD analysis with crystal average size (24-35 nm), while FTIR spectrum indicated the presence of IONPs with the protein matrix of the films. The FESEM images have shown the presence of nanomaterials in range between 43 and 127 nm. The films have shown zero inhibitory effects against the growth of tested bacterial strains. Tensile strength (TS) of the films containing 0.5 mM and 0.75 mM IONPs increased significantly (P<0.05) compared to the control films (without IONPs). E% at break and water vapor permeability of the films with IONPs decreased significantly (P<0.05) when compared to WPC films with no IONPs. The colour change (∆) was increased significantly (P<0.05) in IONPs contained films as well as the whiting index and yellowing index. In conclusion, incorporative IONPs into whey protein film showed no influence as antibacterial agent. Yet, IONPs enhanced the mechanical properties of whey protein based edible films.