Microfluidized Ant Egg Protein for Sustainable food emulsions

Abstract

The growing demand for sustainable and functional protein ingredients has intensified the search for alternative food biopolymers capable of replacing conventional animal-derived emulsifiers. Edible insect proteins offer a promising solution owing to their high nutritional value and low environmental footprint; however, limited knowledge of their techno-functional properties restricts their commercial utilization. Aligned with the United Nations Sustainable Development Goals (SDGs 9, and 12), this study investigated the influence of microfluidization under varying pressures and processing cycles on the structural, physicochemical properties of red weaver ant (Oecophylla smaragdina) egg protein and pH , thermal stability, particle size and surface charge studied for the emulsion prepared from ant egg protein. Microfluidization significantly improved protein functionality by increasing protein solubility to approximately 83%, increased water and oil holding capacities (4.58 ± 0.9) and (2.28 ± 0.1), enhanced emulsifying activity and stability index (60.34 ± 0.2 and 68.8 ± 0.97, respectively), pH stability, and centrifugal stability compared with the untreated control (p < 0.05). SDS–PAGE analysis indicated partial fragmentation of high-molecular-weight protein aggregates, suggesting structural modification that contributed to improved interfacial activity. Increasing microfluidization pressure and processing cycles significantly reduced the mean particle size from 836 to 238 nm (p < 0.05), producing finer and more uniformly dispersed emulsions. Emulsions processed at pressures exceeding 70 MPa exhibited minimal cream layer formation, demonstrating enhanced physical stability during storage. Although the surface charge decreased slightly with increasing protein concentration, the emulsions remained highly stable over a broad pH range, with expected flocculation occurring only near the isoelectric point (pH ≈ 4). Rheological evaluation further revealed that highly pressurized samples exhibited near-Newtonian flow behaviour with reduced apparent viscosity, indicating improved flowability without compromising emulsion stability. These findings demonstrate that microfluidization is an effective green processing technology for tailoring the functionality of ant egg protein into a highly stable, fine-particle emulsion with enhanced physicochemical properties. The study highlights the potential of red weaver ant egg protein as a sustainable, clean-label food emulsifier and supports its application as an innovative alternative protein ingredient, thereby contributing to resilient food systems, responsible production, and sustainable food innovation