Influence of modified starches as wall materials on the properties of spray-dried lemongrass oil.

Abstract

The use of lemongrass oil as food preservative present great potential, however it has high volatility and intense aroma, making them limited to be used as food additives. Microencapsulation processes become interesting alternatives to overcome these issues. This work investigated the influence of the partial replacement of gum arabic by modified starches on the microencapsulation of lemongrass oil as core material. Gum arabic and its combinations with modified starches: cassava and corn maltodextrins with different dextrose equivalent (DE) and octenyl succinic anhydride modified starch (OSA-starch) were studied. The emulsions were spray dried at controlled temperature of 170°C. The evaluated parameters particles solubility, moisture content, and oil composition did not showed significant differences among the treatments. Replacement of gum arabic by maltodextrin DE20 and OSA-starch resulted in higher wetting times. Oil retention was increased (81.2%) when gum arabic was replaced by OSA-starch; the treatment without substitution, with only gum arabic had 67.5% of oil retention. Application of OSA-starch in association with gum arabic in microencapsulation by spray drying of lemongrass oil presented greater potential to be used due to its higher oil retention. Polymer blends should be assessed since they present advantages over individually applied polymers. Although maltodextrins show some differences compared to the treatment with only gum arabic, it may also be a viable alternative because of its lower cost.