Encapsulation of Zataria multiflora essential oil in electrosprayed zein microcapsules: Characterization and antimicrobial properties

Abstract

This research was carried out to make zein microcapsules containing Zataria multiflora essential oil (Z. multiflora EO) by the electrospraying method to evaluate the antimicrobial properties of the microcapsules on Z. tritici and F. graminearum fungi, as well as X. translucens and R. tritici bacteria. To achieve this aim, Z. multiflora EO was encapsulated at different concentrations (0, 5,10%, and 15% v/v) in electrosprayed zein microcapsules and the characteristics of the electrosprayed zein microcapsules were examined using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Porosity and specific surface values were measured by the BET method. Then, the amount of loaded Z. multiflora EO was determined for efficiency. The antifungal and antibacterial activities of the electrosprayed zein microcapsules were measured using the agar well diffusion method. The results of SEM showed that the morphology of the electrosprayed zein microcapsule was influenced by the concentration of Z. multiflora EO (p < 0.05). DSC results indicated the compatibility between the Z. multiflora EO and the zein polymer. The FTIR spectrum showed that adding Z. multiflora EO changed the secondary structure of the zein protein. XRD patterns showed that the electrosprayed zein microcapsules were in a semi-crystalline state. The BET results determined the average pore diameter of microcapsules. Electrosprayed zein microcapsules containing Z. multiflora EO had inhibitory effects on both fungi and bacteria (p < 0.05). According to the results, the electrosprayed zein microcapsules containing Z. multiflora EO can be used as an antimicrobial compound for fruit and vegetable products.