Structural modulation of oleogel-based ice cream: Effect of ultrasonically treated whey protein isolate fibrils on fat coalescence and aeration properties.

The effect of ultrasonically treated whey protein isolate fibrils (WPIFs) on fat coalescence and aeration properties of oleogel (OG)-based ice cream was investigated. An 8-minute ultrasonication treatment at 500 W and 20 kHz facilitated the fragmentation of WPIF into short fibrils with an average length of 225.88 ± 22.75 nm. This procedure increased the exposure of hydrophobic residues (H0 = 262.43 ± 1.14) and improved interfacial adsorption. The incorporation of modified WPIFs into the ice cream emulsion promoted the formation of denser and smaller fat and ice crystals, and enhanced the viscoelastic properties. The WPIF-8-OG ice cream demonstrated a partial coalescence degree of 217.60 ± 7.62%, an overrun of 70.63 ± 0.92%, and a hardness of 1474.10 ± 21.62 g. This sample exhibited favorable lubrication properties in oral tribological analysis, along with improved melting behavior and air bubble distribution. However, ultrasonication treatment for 12 min induced irregular ice crystal formation and compromised the viscoelastic properties of emulsion, thereby increasing the frictional force observed in ice cream. These findings provide valuable insights for the design strategies of OG-based frozen dairy formulations.