Abstract:Whey protein concentrate (WPC) is capable of self-assembling into amyloid fibril aggregates under certain denature conditions, such as high temperature with low pH and low ionic strength.There are two pathways for WPC to form amyloid fibril aggregates with spontaneous pathway and nucleation-induction pathway, which play an important role in improving the functional properties of WPC. The effect of CaCl2 on nucleation formation, nucleation-induction and mature fibrils was investigated through the relationships between interface properties and fibrils structure. The results showed that the nucleation-induction method was more resistant to CaCl2 than the spontaneous mode. When the CaCl2 concentration was 50mmol/L, the emulsification stability of the fibrous polymer formed by homogeneous nucleation-induction and two nucleation-induced whey protein was decreased by 30.92% and 34.09%, respectively, and the foam stability was decreased by 68.18% and 78.59%, respectively. The addition of 20~50mmol/L CaCl2 can increase the polymerization rate of protein and reduce the activation energy of the reaction. However, the rapid polymerization destroyed the orderly assembly process of fiber. Compared with the spontaneous mode, the nucleation-induction mode was more tolerant to CaCl2 because it accelerated the formation of fiber polymer.