Behavior of Emulsions Stabilized by a Hydrophobically Modified Inulin Under Bio-Relevant Conditions of the Human Gastro-Intestine

There is a constant need for novel and bioactive ingredients that can offer the ability to enhance and extend emulsion functionality. Inulin, an established prebiotic fiber, is finding increased use in various food products; however, it has poor performance as an emulsifier, thus, a hydrophobically modified inulin (HMI) has been developed. This research systematically evaluated the impact of HMI on emulsion functionality and susceptibility to key isolated components of human digestion.

Emulsion stability (assessed through analytical centrifugation), size and electrokinetic charge (assessed through laser scattering techniques) following high pressure homogenization indicate stable emulsions with sub-micro sized droplets (mean d_4,3 = 0.55 ± 0.01 μm) can be obtained. Evaluation of emulsion stability to pH (2.0 < pH < 10.0) and CaCl₂ (0–40 mM) highlight the extended emulsion functionality compared to simple emulsions, such as protein-stabilized emulsions. Further, emulsions were subjected to in vitro gastric or intestinal digestion as well as mixing with bile (0–25 mg/mL). These experiments suggest HMI does not alter emulsion susceptibility to bile yet improves emulsion stability to the dynamic conditions of the human stomach and accelerate intestinal lipolysis. Overall, this study shows the prospect of HMI in multifunctional emulsion systems intended for oral consumption. Such novel formulations could offer consumers controlled and targeted delivery of bioactives to the upper gastro-intestine and concomitantly offer additional potential benefits which could arise from the consumption of functionalized prebiotics.