Whey protein-constructed oleogels as cheese fat replacers: Modulating cheese functional behavior via protein structure modification

Whey protein aggregates (WPA), formed through controlled thermal denaturation and aggregation, have emerged as novel oleogelators with exceptional functional properties. This study aims to investigate the relationship between WPA's structure and their oleogelation performance in sunflower oil, while evaluating their potential as fat replacers in cheese formulations. By modulating heating condition (85–95 °C/15 min) and protein concentrations (5–20 %), distinct WPA microstructures were engineered. Results revealed a structure-function dependency: large-size WPA (28.1 μm) showed superior oil-holding capacity (85.4 %), whereas smaller WPA (21.3 μm) exhibited enhanced solid-like properties and thermal stability. The oleogels functioned as inert fillers in cheese matrices without significant structural effects and improved its textural and viscoelastic properties by increasing the mobile water content (7-times). These findings demonstrated that oleogels with specific properties could be customized by modulating the molecular structure of oleogelators – WPA, of which the knowledge benefits the effective fat replacement in cheese with desired texture.