Estudo da estabilidade de emulsões à base de óleos vegetais de Patauá e Pracaxi em água utilizando tensoativos não iônicos

Abstract

In this work samples were prepared with emulsification low energy methods, Emulsion Inversion Point (EIP) and Phase Inversion Temperature (PIT), both based on minimal surface tension, combined with Hydrophilic-Lipophilic Balance (HLB) to form emulsions of patauá (Oenocarpus bataua) vegetable oil and pracaxi (Pentaclethra macroloba) vegetable oil in water with non-ionic surfactants. The non-ionic surfactants used in this work were Span® 80, Tween® 20, Tween® 60 and Tween® 80. The best kinetic stability conditions were observed in the samples prepared with Span® 80 and Tween® 80. The samples’ composition was 80 wt% aqueous phase (distilled water), 15 wt% non-ionic surfactants and 5 wt% oil phase (patauá or pracaxi vegetable oil). For patauá and pracaxi vegetable oil, the required HLB numbers – resulting in kinetically stable oil-water emulsion (O/W) samples – were, respectively, 12,86 and 9,61. The average PIT obtained for the emulsion samples based on patauá vegetable oil was 84,05 ºC and for the pracaxi vegetable oil it was 79,50 ºC. The kinetic stability of the vegetable oil emulsions was characterized by parameters, such as: creaming index (IC), droplet size, pH and electric conductivity. The electric conductivity was intensively influenced by the droplet size.