Effects of molecular weight of hydrolysate on the formation of soy protein isolate hydrolysate nanofibrils: Kinetics, structures, and interactions.

Enzymatic hydrolysis prior to protein fibrillation was an effective way to facilitate the formation of nanofibrils. This study aimed to investigate the effects of molecular weights of hydrolysate on the kinetics, structures, and interactions of soy protein isolate (SPI) hydrolysate nanofibrils. The results showed that hydrolysate with molecular weight > 10 kDa showed a distinct fibrillation kinetics curve and a higher apparent rate constant (27.72) during fibrillation, indicating their vital role in determining the fibrillation. Hydrolysate with molecular weight > 10 kDa could form nanofibrils with higher radius gyration (17.11 ± 0.77 Å) due to stronger hydrophobic interaction, showing a stronger fibrillation ability. Hydrolysate with molecular weight within 5–10 kDa exhibited enhanced π-π stacking interactions during fibrillation, thereby promoting the extension of nanofibrils, and contributing to the formation of more nanofibrils. Hydrolysate with molecular weight < 5 kDa tended to randomly aggregate during fibrillation, resulting in a significant loss of cross-β structures in nanofibrils. Therefore, hydrolysate with different molecular weights exhibited synergistic effects during fibrillation. • Hydrolysate with molecular weight > 10 kDa determined the fibrillation rate. • Hydrolysate with molecular weight within 5–10 kDa promoted nanofibril formation. • Hydrolysate with molecular weight < 5 kDa tended to random aggregate. • Molecular weight affected hydrophobic interaction and π-π interaction of fibrillation. [ABSTRACT FROM AUTHOR]