Stabilization of sesame paste via a capillary bridge-driven oleogel strategy

Sesame paste is susceptible to phase separation during storage, which results in the formation of an upper oil layer and a lower solid sediment, which impairs product consistency and consumer acceptability. This study systematically investigated a simple strategy without additional chemical additives that leverages capillary bridge-mediated particle assembly to stabilize sesame paste. By controllably introducing water as the secondary fluid, a three-dimensional particulate network was formed, transforming the paste into a self-supporting oleogel. The stabilization effect was critically dependent on the secondary fluid saturation ( S ). At S  = 35%, the system reached an optimal water-in-oil microstructure (funicular state), exhibiting maximum rheological moduli and texture parameters, and zero oil leakage during 90-day storage. Nevertheless, this enhanced physical stability was accompanied by accelerated oil oxidation at higher water content and a significant deterioration in sensory quality when S exceeds 10%. In contrast, at a lower saturation ( S  = 4%), the paste retained sensory attributes indistinguishable to the control while substantially enhancing physical stability, presenting a promising balance for practical application. Moreover, at S  = 35%, the mechanical strength of the gel network was highly sensitive to environmental conditions: strongly acidic pH (2) reinforced the network, whereas increasing ionic strength weakened it. Collectively, this research established capillary bridges regulation as a scalable, clean-label approach to enhance the physical stability of sesame paste, offering fundamental insights into the structure-performance relationship of oil-continuous systems in food matrices.