A Study on the Emulsification of Algal Oil using Quillaja Saponin

Introduction

Algal oil is a vegan-friendly source of DHA (Docosahexaenoic acid), a primary omega-3 fatty acid essential for brain, eye, and heart health. However, its lipophilicity, oxidative sensitivity, and poor oral bioavailability adversely affect its functional efficacy. Emulsions facilitate the delivery of lipophilic compounds by enhancing their aqueous dispersibility and physicochemical stability. This work outlines the formulation of algal oil emulsion using Quillaja saponin as a natural surfactant.

Methodology

Quillaja saponin weighing 1 g was dissolved in 90 mL of the water phase, followed by glycerol (1 mL) and ascorbic acid (200 mg) using a magnetic stirrer for 10 min. Further, 10 g of oil phase (Algal oil) was added dropwise and homogenized at 12,000 rpm for 10 min. The coarse emulsion was then ultrasonicated using a probe sonicator at 75% amplitude. The resulting pale white emulsions were qualitatively assessed based on particle size, polydispersity index (PDI), and zeta potential, with variations in the water phase, additives, and ultrasonication time.

Results and Discussion

The choice of water phase, whether phosphate buffer or distilled water, and the inclusion of additives such as glycerol and ascorbic acid did not markedly influence the particle size. However, different ultrasonication times (10 and 15 min) showed a notable impact. Higher ultrasonication times increased particle size, which could be attributed to intensified cavitation, creating strong shear forces that break oil droplets into smaller sizes. Across all trials, a PDI less than 0.5 and zeta potential greater than -30 was obtained, indicating good colloidal stability. This study is prospective in the development of functional formulations of lipophilic nutrients.