Digestion patterns and bioactive peptide release of lactoferrin produced by different processes: An in vitro study...

In this study, the digestive behaviors of freeze-drying and spray-drying lactoferrin (F-LF and S-LF) were characterized using an in vitro dynamic digestion system (DHSI-IV) simulating gastrointestinal conditions in the elderly. The surface morphology results showed that S-LF was more thoroughly hydrolyzed than F-LF. Proteolysis profile showed that F-LF and S-LF were resistant to gastric hydrolysis, especially F-LF. After 60 min digestion, the dominant band was observed in 40 kDa. In this case, the LF secondary and tertiary structures were destroyed. A total of 79, 74, 77, and 77 peptides with 7-30 amino acid residues were identified in FI60, FI120, SI60, and SI120 by DIA relative quantitative peptidomics. Based on bioinformatics analysis, six peptides with good bioactivity, toxicity, solubility and stability were selected for molecular docking with acetylcholinesterase (AChE). Among them, the APVDAFK was embedded inside AChE through hydrogen bonding and hydrophobic interactions, exhibiting the highest "-CDOCKER Energy" (9.1). These findings indicated that LF undergoes protein degradation and structural breakdown in the elderly GI environment, while simultaneously producing bioactive peptides. These results provide a theoretical basis for understanding LF digestion and the release of bioactive peptide in the elderly.