Encapsulation of rosemary essential oil

Encapsulation protects sensitive food ingredients against oxygen, heat, moisture, pH and it masks the unwanted taste of nutrients. The objective of the study was to encapsulate the rosemary essential oil in micron size and to find the optimum coating material formulation by investigating the physicochemical properties and storage stability of microcapsules. In the capsule preparation two different ratios of whey protein concentrate (WP) and maltodextrin (MD) (1:3 and 3:1), three different core to coating ratios (1:40, 1:20 and 1:10) and two different dextrose equivalent (DE) MD (DE:13-17 and DE:4-7) were used. Emulsions were analyzed for their particle size distributions and freeze dried capsules were analyzed for their drying efficiencies, encapsulation efficiencies, surface morphologies, and concentrations of 1,8-cineole during storage. Increasing WP:MD ratio was found to increase both drying and encapsulation efficiencies. Also, capsules having core to coating ratio of 1:20 and MD with DE:13-17 gave the highest drying and encapsulation efficiency values. Changing DE value of MD did not have any significant effect on particle size distributions and surface morphologies of the capsules. Lastly, encapsulation was found to be an effective method for increasing the storage stability of 1,8-cineole. (C) 2015 Elsevier Ltd. All rights reserved.