Characterization and stability of zinc oxide nanoparticles stabilized multiphase system composed of red palm oil and water

This study investigated the stability and rheological properties of multiphase systems comprising red palm oil and water, with zinc oxide nanoparticles (ZnO) as stabilizers. Multiphase systems with 60 % and 70 % (v/v) oil contents exhibited excellent physical stability. To achieve a stable multiphase system, a 60 % (v/v) oil content required 1.50 % (w/v) ZnO. However, when the oil content was increased to 70 % v/v, only 0.75 % (w/v) ZnO were required. Increasing ZnO concentration enhanced system stability, as demonstrated by minimal changes in the total carotenoid content and reduced lipid oxidative product formation. Based on rheological characterization, these multiphase systems exhibited shear-thinning flow behavior and viscoelastic properties. The multiphase system consisting of 70 % (v/v) RPO stabilized by 1.50 % (w/v) ZnO was identified as the best multiphase formulation. Conclusively, the findings in this study are valuable insights for formulating stable multiphase systems, composed of red palm oil and water.