The interest in nutrition for promoting human health is propelling the development of low/non-fat foods enriched with nutraceuticals. However, the development of effective natural carrier systems, which solubilize, protect and maximize the bioavailability of the ingested nutraceuticals, remains a major challenge. The structural and physicochemical properties and the high nutritional value of milk proteins makes them excellent carrier systems for nutraceuticals1. The novel use of proteins as vehicles for lipophilic nutraceuticals raises important questions regarding the bioavailability of the entrapped lipophilic nutraceutical, the effect of the vehicle structure on the bioavailability of the entrapped nutraceutical and the nutraceutical absorption mechanism in the GI tract in the absence of fat. To examine these questions, we focused on vitamin D3 (VD3) loaded within re-assembled casein micelles (rCM) as a model system, and 0% fat yoghurt (the most widely consumed nonfat milk product) as a model food. Dynamic In vitro gastric and duodenal digestion of the VD3 loaded rCM and empty rCM was implemented to screen for potential ramifications to casein proteolysis and VD3 bio-accessibility. SDS-PAGE analyses of digesta samples revealed that the micelles undergo enzymatic degradation in the stomach and enter the small intestine as casein peptides irrespective of their loading with VD3. As efficacy must be supported by in vivo data, a large scale (94 healthy volunteers) double-blind placebo-controlled clinical trial was performed to examine how the bioavailability of VD3would be affected by its delivery in protein nanoparticles, rather than in the fat, and in its absence. The results of this single high dose ingestion clinical trial indicated that the bioavailability of VD3in the protein based nanoparticles in the absence of fat did not significantly differ (p>0.1) from its bioavailability in fat. Overall, this work provides pioneering evidence that protein-based nano-vehicles present an excellent alternative to fat for delivery of hydrophobic nutraceuticals in foods.
Principal investigator: Prof. Yoav D. Livney livney@technion.ac.il
1. Livney Y. D., 2010, Current Opinion in Colloid & Interface Science, 15(1–2), 73-83.
