Development of alginate microspheres containing thyme essential oil using ionic gelation. (1st August 2016) - Benavides, Sergio
Highlights: This research provides information for the design of alginate microspheres. It was possible to relate the dispersion degree of the oil, and microsphere capacity. It was determined that the oil content affected the size and shape of the microsphere. It was possible to relate the dispersion degree of oil, and encapsulation efficiency. Abstract: Essential oils are a good antimicrobial and antioxidant agent alternative in human or animal feed. However, their direct use has several disadvantages such as volatilization or oxidation. The development of essential oil microspheres may help to avoid these problems. The objective of the present research was to microencapsulate thyme essential oil by generating emulsions with different dispersion degrees. The emulsions were encapsulated in calcium-alginate microspheres by ionic gelation. The microspheres were evaluated regarding size, shape, encapsulation efficiency, loading capacity and antimicrobial properties. The results indicate that encapsulation efficiency and loading capacity are dependent on concentration and degree of dispersion. The best encapsulation conditions were obtained at 2% v/v of thyme essential oil with a high dispersion degree (18, 000 rpm/5 min), which was achieved with an efficiency of 85%. Finally, the microspheres obtained showed significant antimicrobial effect, especially in gram-positive bacteria.