Pea protein's interfacial behavior and emulsifying capacity as affected by high-pressure homogenization treatments: an in-depth study with dilatational rheology characterization

This study evaluated the effects of high-pressure homogenization (HPH) at 60 and 100 MPa (5 cycles) on the interfacial properties and emulsifying activity of pea proteins (PP, PP60, and PP100). Pendant drop analysis showed that HPH treatments decreased the interfacial activity of pea proteins, altering the viscoelasticity of the adsorbed layer in a frequency-dependent manner. Structural analysis revealed that HPH promoted protein aggregation, mainly affecting legumins, which was directly linked to weaker interfacial interactions. As a result, emulsions stabilized with treated proteins (EP60 and EP100) exhibited immediate destabilization phenomena, such as flocculation and creaming, as confirmed by droplet size distribution, backscattering profiles, and Turbiscan® Stability Index measurements. The HPH-processing conditions adopted in this study impaired the emulsifying performance of pea proteins. These findings highlight the importance of selecting appropriate processing conditions to balance protein functionality. Future research should explore alternative pressure/cycle combinations to unveil the optimized conditions to induce beneficial structural changes while minimizing aggregation/oligomerization. Overall, this work provides insights into how HPH affects pea protein structure, interfacial behavior, and emulsion stability, supporting the design of more stable plant-based emulsions. • High pressure homogenization reduced pea protein interfacial properties. • Treatments promoted the formation of oligomers, at the expense of legumins. • Oligomers decreased treated protein's elastic response at the interface during time. • Treated pea proteins formed non-homogeneous layer with weaker interactions. • Emulsions with treated proteins underwent flocculation and creaming.