FORMULATION AND CHARACTERIZATION OF ULTRASOUND-ASSISTED NANOEMULSIONS CONTAINING PALM OIL (Elaeis guineensis Jacq) IN WATER

Abstract

This study aimed to optimize ultrasound-assisted palm oil-in-water nanoemulsions. The influence of hydrophilic-lipophilic balance (HLB), oil and surfactants concentrations, ultrasound intensity and processing time were investigated by means of two experimental designs. Desirability profiles were applied to detect the optimal conditions for preparing the nanoemulsion. Stable nanoemulsions with small droplet size and polydispersity index (PDI) were obtained at an HLB of 6.5, oil and surfactant concentrations of 2.8 wt%, ultrasound intensity of 200 W.cm-2 and processing time of 15 minutes. The nanoemulsion presented stability for 30 days at three different temperatures (4°C, 25°C and 40°C), which makes it suitable for application in the food and cosmetic industries. Ultrasound was shown to be a promising technology to produce nanoemulsions containing palm oil.

Hydrolysis of macauba kernel oil: ultrasound application in the substrates pre-emulsion step and effect of the process variables

“…Ultrasound application promotes greater dispersion of oil in water, leading to a larger interfacial area and smaller droplet size, thus favoring the hydrolysis initial rate (Huang et al 2010). Ultras ound treatment promotes an increase in the microscopic droplet formation speed, an increase in the contact surface and in the cohesive forces, resulting in the formation of microemulsions (Martines et al 2000, Dal Prá et al 2019.…”

“…Hydrolysis of triacylglycerols occurs at the oil and water interface, since these substrates are immiscible with each other. The contact and mixture of oil and water phases are commonly promoted by mechanical agitation, but recently there has been an attempt to reduce the mass transfer limitations through the application of ultrasound (Feiten et al 2014, Michelin et al 2015, Ramón et al 2015, Remonatto et al 2015, Awadallak et al 2016, Zenevicz et al 2016, Dal Prá et al 2019. The cavitation (bubble formation, growth and implosive collapse in the reaction medium) generated in these reactions act through three main mechanisms, in combination or isolated.…”

“…The ultrasound system has been considered an eco-friendly green technology due to its high efficiency, reduction or absence of organic solvents use in several reactions, and possibility of reducing the amount of reagents added. Besides the significant decrease in reaction or processing times compared to other conventional techniques and its low instrumental requirements, the ultrasound system presents an economically viable performance, with increased yield and selectivity, favoring reactions that normally do not occur under normal conditions (Martines et al 2000, Li et al 2005, Mason 2007, Feiten et al 2014, Remonatto et al 2015, Dal Prá et al 2019.…”