Lipid Digestion of Oil-in-water Emulsions Stabilized with Low Molecular Weight Surfactants
Lipid digestion kinetics and fatty acid bioaccessibility were compared between oil-in-water (o/w) emulsions stabilized with monoglycerides (i.e., glycerol monostearate (1-GMS), glycerol monooleate (1-GMO), or sn-2 glycerol monooleate (2-GMO)) or commonly-used synthetic surfactants (i.e., Span 60, Span 80, Tween 60, or Tween 80) using a multi-compartmental, simulated digestion model (TIM-1). Although statistically significant differences in induction time and rate of lipid digestion were not observed, total bioaccessibility was significantly lower for emulsions stabilized with Span 80 and 2-GMO. Comparable trends were observed between area under the curve (AUC) of the absolute bioaccessibility and total overall bioaccessibility obtained by fitting a three-parameter shifted logistic model to the cumulative bioaccessibility. No significant differences for overall bioaccessibility were observed between oil-in-water emulsions stabilized by commercial 1-GMO and 1-GMS, Span 60, Tween 60 and Tween 80. The results confirm that sn-position and surfactant choice influence the total extent of lipid digestion (total bioaccessibility) in vitro.