Impact of ε-polylysine and pectin on the potential gastrointestinal fate of emulsified lipids: In vitro mouth, stomach and small intestine model

ε-Polylysine (ε-PL) is a broad-spectrum antimicrobial biopolymer, suitable for use in foods; however, some studies suggest that it may also inhibit lipid digestion. We therefore examined the effect of polylysine on the digestion of corn oil-in-water emulsions, using a simulated gastrointestinal tract (GIT) that included oral, gastric, and intestinal phases. Both mucin and polylysine had pronounced influences on the particle size, charge, and aggregation state throughout the GIT. However, surprisingly, we found that ε-polylysine did not have a significant impact on lipid digestion, either in the presence or absence of anionic mucin. However, it did form strong electrostatic complexes with mixed micelles, which could decrease the transport and absorption of lipids in the small intestine. These results have important implications for the incorporation of polylysine into food systems, particularly those containing lipophilic nutrients.