Experimental Investigation on Physical Stability of RPO-in-Water Emulsion Stabilized by Protein and SiO2 Nanoparticles

Abstract

As a source of Vitamin-A precursor, the stability of red palm oil (RPO) against oxidation was addressed to be improved. Emulsion containing 10% (v/v) RPO was produced using two-step homogenization, namely at 9000 rpm and 18000 rpm. This research aims to study the effect of emulsification process of RPO to enhance its stability. The used emulsifiers are whey protein concentrate (WPC), soy protein isolate (SPI), and SiO2 nanoparticles with concentration from 2.5% to 15%. The physical stability of the resulting emulsion is analyzed based on the parameters of surface colour, separation index, flow properties, and droplet size distribution. Results showed that higher emulsifier concentration (c) contributes to improve emulsion stability during storage. In this study, emulsion stabilized by SiO2/SPI 15% (SSP15) and SPI 5% (SPI5) were found as the most stable emulsion based on tested physical attributes.