Rheology and crystallisation of cocoa butter in the presence of pea protein

The effects of pea protein isolate (PPI) particles on the crystallisation and rheological properties of cocoa butter (CB) were evaluated. PPI particles were milled to produce two size classes, coarse and fine. Milled PPI particles were found to aggregate in molten CB, increasing the viscosity of the system and forming an elastic network. Greater aggregation was observed as the size of PPI particles was reduced. PPI particles had no effect on the crystal structure of CB, or the polymorphic transition pathway. However, the induction time of crystallisation was shorter, and the crystalline domain size in the α-phase was smaller for CB crystals + PPI, indicating heterogeneous nucleation effects. PPI particles increased the elasticity of the system by an order of magnitude only during the early stages of CB crystallisation. This study demonstrates that PPI particles can be incorporated into fat-based systems without disrupting fat crystal structure, with the potential to enhance mechanical strength. This highlights their potential as functional rheological modifiers upon milling in confectionery applications.