Microencapsulation of Zataria multiflora Boiss. essential oil by complex coacervation using gelatin and gum arabic: Characterization, release profile, antimicrobial and antioxidant activities

The microcapsules containing "Zataria multiflora" Boiss. essential oil (ZMEO) were prepared by complex coacervation using gelatin and gum arabic. The transglutaminase was utilized as a cross-linking agent. The characteristics and release profile of microcapsules were investigated using different core/wall ratios, concentrations of cross-linking agent, and hardening time. The antimicrobial activity of microcapsules was also studied against foodborne microorganisms. The microcapsule with a core/wall ratio of 2:1 had the highest size and encapsulation efficiency. The contents of carvacrol and thymol in microcapsules were higher than it was in free oil. The lowest cumulative release of ZMEO (only 14.49%) was observed at 4℃. The controlled release of oil was improved by increasing the concentration of cross-linking agent and cross-linking time. Microencapsulation of the ZMEO could improve its antimicrobial and antioxidant activities. The results of the present study confirm the suitability of ZMEO microcapsules for food preservation. Novelty impact statement In this study, the sustained release, encapsulation efficiency as well as antimicrobial and antioxidant properties of coacervate microcapsules containing ZMEO were improved by the optimization of production parameters. The coacervate microcapsules of ZMEO synthesized in this study can be utilized as a novel preservative in the food industry. The results of this study can also be used for the encapsulation of other bioactive compounds to improve their bioavailability.