From interfacial chemistry to the future plate: Novel emulsifiers and bioactive lipids for tweaking the digestibility of food emulsions

The growing interest in healthier foods stimulates ongoing efforts to improve human diets by rational design of foods and/or their reformulation. For that, a toolbox of possibilities is needed to facilitate rational design of emulsions with engineered digestive performance in the consumer gut. This work aims to explore different approaches for fabrication of colloid-stabilized multifunctional-emulsions and to study their potential digestive fate.

First, we describe the emulsion Pickering-type stabilization by electrostatic deposition of anionic alginate (ALG) and i-carrageenan (CAR) onto lactoferrin (LF) based nano-particles. In turn, such emulsion formulation exhibit altered physicochemical stability to digestive events. Specifically, utilizing LF-CAR nano-particles will be shown to yield emulsions with exacerbated intestinal lipolysis (increased by 10%) while the use of LF-ALG nano-particles retards intestinal lipolysis (reduced by 14%). Secondly, a hydrophobically modified inulin alters emulsion droplet properties and stability (size & z-potential) as well as overall responsiveness to pH (8.0 – 2.0), dynamic in vitro gastric digestion (0-2 h), ionic strength (0-40 mM CaCl₂), and simulated intestinal lipolysis. Lastly, we will discuss the possibility to modulate emulsion digestive lipolysis by doping the lipid droplets with low amounts of defined triglycerides. This was done by doping oil droplets from olive (composed of mainly 18:1 FA), hemp seed (composed primarily of 18:2 FA) or pomegranate seed (rich in 18:3 FA) with triolein (TOLN). Results indicate implications of doping on emulsion stability, droplet size and size distributions. Also, TOLN markedly accelerated and enhanced the lipolysis of pomegranate seed oil containing emulsions. Fatty acid methyl esters (FAME) profiling of intestinal digesta indicated the preferential liberation of saturated, then monounsaturated and lastly polyunsaturated FA from the various droplets. Overall, these and other studies offer new insights to help improve our ability to engineer droplet interfaces and droplet compositions towards specific performances in the gut of different consumers.