Multiple rounds of nuclei induced whey protein concentrate fibril formation at varying ionic species and concentrations.

Mature whey protein concentrate (WPC) fibrils can act as secondary nuclei to induce fibrillation. Multiple rounds of nuclei induced aggregation could introduce differences in their ability to form fibrils. The second induction fabricated the highest population of fibrils, while the sixth induction lost the ability of fibrillation. Salt-tolerant fibrils through multiple inductions were produced, but less with each cycle owing to a decreased salt tolerance. The difference in fibrillation between spontaneous formation and multiple rounds of induction was associated with the ability of ions to bind to the protein aggregations. More cations were distributed on the surface of fibrils after the sixth cycle of induction compared with that of the second induction. Divalent salts had much stronger effects than monovalent salts on inhibiting protein fibrillation due to fewer divalent cations distributed on the surface of the fibril. Cation binding appeared to be an important factor in the formation of fibrils. [ABSTRACT FROM AUTHOR]