Thermo-responsive adipose tissue mimetics stabilized by protein fibril-sodium alginate complex and enhanced by glycerolysis lipids

Plant-based fat mimetics are increasingly needed as healthier and sustainable alternatives to animal fats. However, current emulsion gels are inherently limited in their capacity to replicate the thermal behavior of animal adipose tissue. In this study, pea protein fibril (PPF) and sodium alginate (SA) complexes were investigated for their potential to fabricate adipose tissue mimetics enhanced by glycerolized palm olein (PO). The PPF–SA complexes at mass ratios of 10:3 exhibited superior interfacial activity and a higher thermal degradation temperature compared to non-fibrillated complex. Cryo-scanning electron microscopy revealed that the PPF–SA complex coexisted around droplets forming an extracellular matrix-like network and providing thermal-responsive elasticity properties. Optimization of the oil/water ratio and Ca2+ concentration endowed the emulsion with a robust network architecture. The glycerolysis lipids provided thermal softening behavior, in which a higher monoacylglycerol (MAG) content effectively reduced interfacial tension and emulsion droplet size. The reduction consequently increased the available cross-linking sites within the PPF-SA network and significantly enhanced the oil binding capacity and freeze-thaw stability. This study demonstrates that PPF-SA in combination of glycerolysis lipids forms a cross-linking and crystalline network that simulates the thermo-responsive behavior to mimics that of porcine back fat.