Impact of chitosan on lipid digestion under simulated gastro-intestinal conditions.

Previous studies demonstrated chitosan's ability to inhibit free fatty acid (FFA) release in emulsions, yet its structural impacts (molecular weight, MW; deacetylation degree, DD) on lipid digestion remained unclear. This study systematically evaluated chitosan variants (MW: 3.2-670 kDa; DD: 71.2-92.5 %) under simulated gastrointestinal conditions. The results revealed that all chitosan formulations suppressed corn oil digestion to varying degrees. Notably, high molecular weight chitosan (670 kDa) with elevated DD (90 %) exhibited the strongest inhibitory activity, reducing the FFA release rate by approximately 77 %. Mechanistically, this resulted from severe emulsion flocculation limiting enzyme access, coupled with enhanced bile salt adsorption (30 % binding) and lipolysis suppression (57 % inhibition). These findings highlight MW/DD as critical determinants of chitosan's lipid-modulating efficacy, offering a strategic basis for designing functional foods targeting controlled nutrient delivery or reduced caloric uptake.