Coffee oil as a natural surfactant

Abstract

Coffee oil is known to be food and therapeutic supplement, both. However, the surface active nature of the oil has not yet been investigated. The present research explored the surface active components in coffee oil, and those responsible for stability of microbubbles at the air–water interface, facilitating its surfactant behavior. The oil’s performance was examined through surface tension analysis, foam formation, coalescence rate and foam characteristics (using coffee as a model beverage for foam characterization). These observations confirmed the suitability of coffee oil as a natural substitute for Tween series of surfactants. The 1H NMR and LC-MS/MS assessments revealed trigonelline, caffeic acid, caffeine, feruloyl quinic acid, di-caffeoyl quinic acid, quinic acid, coumaroyl quinic acid as polar constitutes in coffee oil. These constituents help in formation of the self-assembly (chlorogenic acid – hydrophilic head, hydrocarbon – hydrophobic tail), ultimately forming micelle in coffee. Coffee oil also aided maintenance of a well sustained foam in coffee, similar to other synthetic surfactants.