Enhancing the Deformation Resistance of Oleogels Using Monoglycerides Combined with Polyglyceryl Esters of Fatty Acids: A Novel Alternative to Conventional Shortening in Toasts

Traditional oleogels prepared using monoglycerides (MGs) were found to exhibit needle-shaped crystals, relatively large crystal sizes, coarse crystal aggregation, loose network architecture and inferior structural stability, which resulted in low viscosity and poor structural recoverability. To address the issue, multiple gelling agents were applied to prepare a novel oleogel. Results demonstrated that the composite of polyglyceryl esters of fatty acids (PGEFs) and MGs showed excellent properties. Application of 3% PGEF intercalated into MG lamellar spaces, facilitated ordered lipid stacking and constructed dense, continuous layered crystalline networks while retaining the intrinsic hydrogen-bonding interactions of oleogels. The crystal growth shifted from random one-dimensional aggregation to well-organized two-dimensional lamellar stacking, accompanied by an increase in nucleation density. Accordingly, the composite oleogels exhibited notable improvements in network compactness (10.22%), oil binding capacity (99.17%) and elasticity-based rheological stability (82.03%). However, LEC was intercalated into MGs to refine crystals and strengthen networks, whereas over-dosage was observed to destroy gel integrity. Inferior anti-staling performance was obtained compared with PGFE systems. During toast preparation, the dense PGEF-MG crystalline networks acted as a strong physical barrier, which effectively suppressed water migration and starch retrogradation, improved moisture retention and anti-staling, and improved the uniformity and structural stability of crumbs. The staling rates of the toast were decreased from 116.68% to 5.27%, and baking loss was decreased by 44.76%. This study elucidated the molecular assembly and crystal regulation mechanisms of PGEF-MG oleogels, laying a solid theoretical foundation for the development of high-performance plant-based oleogels as fat replacers for bakery use.