Polysaccharide-protein gums are complex polymers with many applications in emulsion and emulsion-based products. It is crucial to enclose a concept on understanding of functional properties of polysaccharide-protein biopolymer in order to select the appropriate one based on the application scope. The main objective of the current study was to investigate the effect of three extraction variables on the surface activity, particle uniformity, apparent viscosity, and protein content of a natural polysaccharide-protein biopolymer from durian fruit seed. Three extraction variables namely water: seed (W/S) ratio (20:1–60:1), temperature (25.0–85.0 °C) and pH (4.0–10.0) were considered as independent variables. The results indicated that durian seed gum induced very low viscosity (0.93–4.98 mPa.s) with pseudoplastic rheological behavior in the aqueous system. The current study revealed that the extraction variables had the most significant (p < 0.05) effect on the emulsifying surface activity of the natural biopolymer from durian fruit seed. This might be due to the significant (p < 0.05) effect of the proteineous constituent present in the chemical structure of the biopolymer from durian fruit seed. The aqueous extraction variables showed the most and least significant (p < 0.05) effect on the specific surface area and protein content, respectively. Among all extraction variables, W/S ratio and pH exhibited the highest and lowest significant (p < 0.05) effect on the physicochemical and functional properties of the natural biopolymer from durian fruit seed.
