A novel bigel type featured as O1/W/O2 microstructure achieved by whey protein aggregates as dual-interfaces mediator: Enabling dual functions in low-fat cream cheese simulation and co-delivery of pterostilbene/gallic acid

To address the conflicting challenges of fat reduction, texture fidelity, and co-delivery of hydrophilic and hydrophobic bioactive compounds, this study explored an innovative O 1 /W/O 2 -microstructured bigel system, WGB(O 1 /W/O 2 ). The system was stabilized through whey protein aggregates rapidly adsorbing at dual interfaces as an amphiphilic mediator, along with hydrogen bonding formation with guar gum in hydrogel matrix. The extended multilayered structure enabled WGB(O 1 /W/O 2 ) demonstrated favorable cream cheese simulation performance in appearance, viscoelastic properties, melting behavior, and texture characteristics. Sequential degradation of each phase during digestion (O 2 -W-O 1 ) increased the intestinal release of PTS and GA by up to 3.3-fold and 1.8-fold, respectively, over conventional bigels (O/W or bicontinuous). Among the bigels, cream cheese texture similarity ranked O 1 /W/O 2  > bicontinuous>O/W. The delivery efficiency for hydrophobic PTS followed O 1 /W/O 2  > O/W > bicontinuous, while that for hydrophilic GA followed O 1 /W/O 2  > bicontinuous>O/W. This study highlights broad application prospects of WGB(O 1 /W/O 2 ) for fat-reduced and nutrient-enhanced dual-functional foods, while advances understanding of bigel microstructure evolution-properties relationships.