Comparative effects of enzymatic hydrolysis by four proteases on the structure, functional properties, and...

This study investigated the effects of Alcalase, ficin, trypsin, and papain on the structure, function, and bioactivities of lactoferrin (LF). The results demonstrated that LF was hydrolyzed by all four proteases, with Alcalase being most effective. Treatment with the four proteases modified the particle size distribution of LF, resulting in a decrease in large particles and generation of abundant low-molecular-weight fragments. Treatments with four proteases increased the free amino acid content. These enzymatic treatments reduced the α-helix structure of LF while enhancing intrinsic fluorescence and reducing extrinsic fluorescence, indicating modifications in secondary and tertiary structures. Ficin hydrolysate exhibited the strongest foaming capacity, foaming stability and fat absorption capacity, whereas papain hydrolysate demonstrated the highest emulsifying activity index. Notably, Alcalase hydrolysate displayed superior DPPH radical scavenging activity, Fe²⁺ chelating activity and Caco-2 cell inhibitory activity. This study provides a theoretical foundation and scientific evidence for modifying LF through enzymatic hydrolysis.