Influences of added surfactants on the water solubility and antibacterial activity of rosemary extract.

Rosemary extract (RE) has significant antioxidant and antibacterial properties; however, the application of RE to areas with an aqueous solution is limited due to its poor solubility. There is a need for research focused on finding a method to improve water solubility for incorporating RE into aqueous systems, such as food and cosmetic. Therefore, in this study, the micellar solubilization of RE is conducted using four types of surfactants (Tween 20, polyglyceryl-10-laurate, polyglyceryl-10-myristate, and polyglyceryl-10-monooleate) to increase the water solubility of RE and the effects of various surfactant types and concentration on solubility were investigated. Antibacterial activities of the mixture solutions containing RE and surfactants were also examined. The water solubility of RE significantly improved when surfactants were added into the RE solution and especially in polyglyceryl-10-monooleate, with the longest tail, was the most effective for increasing solubility. In terms of the antibacterial effect on Bacillus subtilis, it was observed that a relatively lower concentration of surfactants was effective. The results of this study provide useful information for the development of a new RE-loaded delivery system for food and cosmetic application. © The Korean Society of Food Science and Technology 2020.