Emulsifying potential of Hypnea musciformis carrageenan: A natural alternative for oil-in-water emulsions

Background: Polysaccharides such as carrageenans, extracted from red algae, are widely used in food and pharmaceutical industries due to their gelling, stabilizing, and emulsifying properties. However, the potential of carrageenan extracted from Hypnea musciformis, a red macroalga native to tropical coastal regions, remains underexplored, particularly in terms of its emulsifying properties. Objective: To evaluate the emulsifying potential of carrageenan extracted from H. musciformis by comparing the physicochemical stability of emulsions formulated with this biopolymer to those stabilized with sodium alginate (ALG), a widely used reference polysaccharide. Methods: Oil-in-water emulsions containing 20% sesame oil were elaborated using varying concentrations of carrageenan or ALG. Their physical stability was assessed through droplet size distribution, polydispersity index (PDI), zeta potential, surface tension, and visual inspection over 31 days of storage at room temperature. Results: Emulsions stabilized with carrageenan exhibited comparable droplet size, PDI, and surface tension values to those formulated with ALG, indicating similar emulsifying capacity. Notably, formulations containing 1% carrageenan demonstrated enhanced long-term physical stability. Zeta potential values remained consistently negative (−35 mV to −45 mV), suggesting electrostatic stabilization. Conclusion: Carrageenan extracted from Hypnea musciformis demonstrated effective emulsifying properties in 20% sesame oil emulsions, comparable to those of ALG. These findings support its potential as a natural emulsifier for food and cosmetic formulations, highlighting the relevance of exploring underutilized marine resources for biotechnological applications.