Observation of chitosan coated lipid nanoparticles with different lipid compositions under simulated in vitro digestion system

The effects of lipid composition and chitosan coating on lipid digestion ability were investigated using a simulated in vitro digestion system, including oral, gastric, and small intestine stages. Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) were prepared with only palm oil and the mixture of palm oil and medium-chain triglyceride (MCT) oil, respectively. Chitosan-coated SLNs (CS-SLNs) and NLCs (CS-NLCs) were prepared with a drop-wise method. CS-NLCs were more completely digested than the NLCs, while the NLCs showed higher free fatty acid release than SLNs. Chitosan coating increased the particle size of both SLNs and NLCs from 100.0 to 104.9 nm to 130.0 and 146.5 nm, respectively. Chitosan coating also increased the initial digestion rate of NLCs by modulating lipid droplet aggregation. But, chitosan coating showed little impact on the digestion of SLNs because SLNs did not strongly impact the lipid droplet aggregation state. These results have important implications for the fabrication of functional foods and beverages to achieve control of lipid digestion in the gastrointestinal tract.