Impact of salt and lipid type on in vitro digestion of emulsified lipids

This study examined the effects of oil type and NaCl addition on the micro-structural changes that occur to emulsified lipids as they pass through a model gastrointestinal tract (GIT). Oil-in-water emulsions stabilized by a non-ionic surfactant (Tween 20) were prepared using different kinds of lipids (3% soybean oil, corn oil, olive oil or lard). The emulsified lipids were passed through an in vitro digestion model that simulated the composition (pH, minerals, surface active components, and enzymes) of the human GIT. Prior to digestion, emulsified lipid droplets appear to be bridging flocculation in 1% NaCl added emulsified lipids, moreover lipid droplets of 1% NaCl added emulsified lipids seems to be more disrupted than no NaCl added emulsified lipids. Mean particle size prepared with lard was smaller than those of other emulsified lipids. Free fatty acid contents increased after in vitro digestion in all emulsified lipids. Especially, free fatty acid content of emulsified lipid made from lard and olive oil were significantly higher than those of other emulsions after in vitro digestion.