Development of nanoemulsions from Oocotea odorifera (Vell.) rohwer through a low energy approach: An ecological larvicide against Aedes aegypti and Culex quinquefasciatus

Ocotea odorifera is also known as sassafras and cinnamon sassafras. It was used as flavoring agent in beverages and other food industrial products, being now used in disinfectants and insecticides. The essential oil, of sassafras, as well as other Brazilian species, has great potential for the food industry, although it is occasionally affected by its volatile composition. New products, such as aqueous nano-emulsions, are considered extremely powerful since they enhance the properties of the oils. Therefore, the aim of this study was to develop this type of colloidal systems with O. odorifera essential oil. The best results were achieved with blends of polysorbate 20/sorbitan monooleate (size diameter <200 nm and polydispersity index <0.1) and no major alterations were observed after the storage. The critical interpretation of the molecular characteristics of the phytochemicals of this essential oil presents an interesting analysis about these essential oil-based nano-emulsions. For Aedes aegypti the estimated LC₅₀ and LC₉₀ values, are respectively, 37.646 and 46.3408 ppm; while for Culex quinquefasciatus the estimated LC₅₀ and LC₉₀ values are 33.3365 and 47.8939 ppm, respectively. The low energy/ecofriendly approach using different non-ionic surfactants by a non-heating method is in accordance with a sustainable concept. Therefore, it opens perspectives for the preparation of sassafras nano-emulsions.