In vitro dynamic infant digestion model: effects of 1,3‐dioleoyl‐2‐palmitoyl glycerol, lactoferrin, and casein phosphopeptide fortification on infant formula protein and fat digestion

Background This study investigated the effects of fortifying infant formulas (IFs) with casein phosphopeptide (CPP), lactoferrin (LTF), and 1,3‐dioleoyl‐2‐palmitoyl glycerol (OPO) on protein and fat digestion, using an in vitro infant dynamic digestion model with human milk (HM) as the standard. Four formulas were examined: an unfortified control (CC) and three fortified variants (F1, F2, and F3), each containing the same fortifying components at varying concentrations. Results Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE) showed that most proteins were completely hydrolyzed during gastrointestinal digestion, except β ‐lactoglobulin ( β ‐Lg). After 180 min, protein digestibility ranged from 97.6% to 99.08%, with F2 reaching the highest value (99.08%), comparable to HM (98.92%). Amino acid fit analysis indicated strong similarity to HM in F2 (96.67%) and F3 (94.87%). Protein hydrolysis and free amino acid (FAA) release were significantly greater ( P < 0.05) in F2 and F3 than in CC and F1. The fortified IFs showed peptide profiles and lipolysis degrees (LDs) closer to HM than the control, although HM had the greatest peptide release. In total, 145 bioactive peptides were identified, 77 of which were common to all IFs. Conclusion These findings suggest that fortification with CPP, LTF, and OPO can modulate the protein and fat digestion patterns in IF, increasing its similarity to HM.