Rheological and Stability Properties of Citrullus Lanatus Mucosospermus, Lanatus Citroides and Moringa Oleifera Seed Hydrocolloids in Oil-in-Water Emulsion

This study investigates the development, characterisation, and functional application of plant-based hydrocolloids extracted from <i>Citrullus lanatus mucosospermus</i> (egusi), <i>Citrullus lanatus citroides</i> (makataan), and <i>Moringa oleifera</i> seeds for use as natural emulsifiers in oil-in-water food systems. The research responds to the global demand for sustainable, clean-label ingredients by exploring underutilised African oilseeds as alternative sources of high-protein hydrocolloids capable of replacing synthetic stabilisers in food formulations.The study involves the extraction of hydrocolloids using an optimised hot-water treatment process followed by detailed compositional, functional, and rheological evaluation. Key analyses include protein and fat quantification, particle size analysis, viscosity behaviour under varying shear conditions, viscoelastic properties, and gelation mechanisms at different concentrations. Emulsion stability trials are conducted to determine droplet size distribution, creaming index, and formulation ratios that yield optimum stability.Findings demonstrate pseudoplastic flow behaviour and distinct structural formation patterns at critical concentration thresholds. Moringa hydrocolloids form weaker elastic gels through hydrophobic interactions, while egusi and makataan develop stronger elastic networks driven by hydrophilic cross-linking. Emulsion optimisation further reveals that hydrocolloid concentrations between 20–30% combined with 37–40% oil and 25–45% water promote the most stable formulations.Overall, the study contributes to food science by providing mechanistic insight into the behaviour of indigenous seed hydrocolloids and validating their potential as sustainable emulsifiers for food product development. The work expands scientific knowledge on under-utilised crops, supports food security objectives, and promotes the valorisation of natural plant resources in clean-label and climate-smart processing systems.