Fortifying foods with hydrophobic nutraceuticals can be challenging, both because of solubility and phase partitioning issues, as well as susceptibility to oxidative, UV and heat-induced degradation. One solution to such challenges, nano-encapsulation, is attractive because it can be achieved using natural, food-derived proteins and other biopolymers. An example is β-conglycinin (β-con), a storage protein found in soybeans, one of the world’s most ubiquitous crops. β -con possesses amphiphilic properties due to interspersed sequences of hydrophobic and hydrophilic residues1, suggesting the ability to bind hydrophobic compounds in an aqueous environment. We have formed nano-complexes between β-con and Vitamin D3 (VD3), a nutrient whose large public health significance2 and poor formulation properties (water-insolubility and sensitivity to degradation) make it an ideal candidate for nano-encapsulation. When added to aqueous β-con solutions at both pH 6.8 and 2.5, VD3 binds to the protein, co-assembling into two particle populations: 0-50 nm particles which account for 70-90% of the total particle volume, and 50-250 nm particles accounting for the remaining 30-10% . To test the protective effect of β-con nano-encapsulation, we subjected our β-con -VD3 particles to simulated pasteurization, shelf life and gastric digestion conditions. In all experiments, degradation of VD3 was significantly slowed when bound to β-con, compared to the control. For example, after simulated pasteurization, 75% of the unprotected vitamin degraded, compared to only 2.5% of the β-con -bound vitamin. This functionality of β-con, in addition to the fact that it is derived from an abundant crop, and is Kosher Parve, makes it a promising candidate for delivery of hydrophobic nutraceuticals in food systems in general, and beverages in particular.
Principal investigator: Prof. Yoav D. Livney livney@technion.ac.il
References
1. Tsumura, K.; Saito, T.; Tsuge, K.; Ashida, H.; Kugimiya, W.; Inouye, K., 2005, Lwt-Food Science and Technology 38, (3), 255-261.
2. Holick, M. F., 2007, New England Journal of Medicine 357, (3), 266-281.
