Pectin influences the kinetics of in vitro lipid digestion in oil-in-water emulsions

Oil-in-water emulsions were prepared with 5% (w/v) carrot-enriched olive oil and stabilized with Tween 80 (TW), phosphatidylcholine (PC), citrus pectin (CP) or a combination of these emulsifiers. Additionally, the methylesterification degree (DM) of citrus pectin was modified, resulting in three different studied pectin structures: CP82, CP38 and CP10. All initial emulsions presented small initial oil droplet sizes and were submitted to an in vitro simulated gastric and small intestinal phase. The latter was executed in a kinetic way to determine the time dependency of the lipolysis reaction, micelle formation and carotenoid bioaccessibility. The results showed that the pectin DM mainly influenced the reaction rate constants, while the emulsifier (combination) determined the extent of lipolysis and carotenoid bioaccessibility. Moreover, a direct relation was observed between the lipolysis reaction and bioaccessibility extent. The presented study showed that targeted emulsion design can be used to tailor lipid digestion kinetics.