Development of antioxidant and antimicrobial bioactive films based on Oregano essential oil/mesoporous nano-silica/sodium alginate

Abstract

In this study, Oregano essential oil (OEO) was embedded into mesoporous silica nanoparticles (MSNPs). To protect post-harvest Agaricus bisporus from Curvularia lunata (C. lunata), OEO-MSNPs/sodium alginate (SA) films were prepared by solvent casting method. The effect of the different OEO-MSNPs concentration on the active film was investigated. Scanning electron microscopy (SEM) analysis showed that the 0.8 wt% concentration of OEO-MSNPs was conducive to obtain a more even distribution of OEO-MSNPs in the films. The results of Fourier transform infrared (FT-IR) spectroscopy revealed that hydrogen bonds were formed between OEO-MSNPs and SA molecule. X-ray diffraction (XRD) showed that original structures of the SA were disordered. Moreover, the mechanical properties and physical properties of the films were affected by the dosage of OEO-MSNPs, and the optimal OEO-MSNPs dosage was found to be 0.8 wt%. The addition of OEO-MSNPs markedly improved the properties of film against UV light. An examination of the inhibitory effect of DPPH showed that the SA film with 1.0 wt% OEO-MSNPs had the strongest antioxidant capacity in 95 % ethanol food simulant, with the inhibition of 75.31 %. The SA film with 1.0 wt% OEO-MSNPs exhibited prominent antimicrobial activity against C. lunata.