|M.Sc Student||Semo Efrat|
|Subject||Casein Micelle as a Natural Nano-Capsular Vehicle for|
|Department||Department of Biotechnology and Food Engineering||Supervisor||Professor Yoav Livney|
|Full Thesis text|
Casein micelles (CM) are in effect nano-capsules created by nature to deliver nutrients, such as calcium, phosphate and protein, to the neonate. The micelles are composed mainly of caseins, proteins of remarkable self assembly properties, and of inorganic calcium and phosphate.
A novel approach is herein presented, to harness CM for nano-encapsulation, solubilization and protection of sensitive hydrophobic nutraceuticals (HN) for enrichment of non-fat or low-fat food products. Such nano capsules may be incorporated in dairy products without modifying their sensory properties, and promote the bioavailability of the encapsulated HN. This study introduces new possibilities for encapsulation and delivery of sensitive health-promoting substances using natural GRAS (generally regarded as safe) ingredients.
As a model HN we studied the fat-soluble vitamin D2, which is essential for calcium metabolism and is sensitive to UV light, oxygen and heat.
A protocol for incorporation of vitamin D2 into CM was established. The encapsulation process was evaluated in terms of effectiveness, efficiency, preservation of micelle properties, and the protective effect of the micelles against photochemical degradation of the vitamin.
We have demonstrated, for the first time, the possibility to load a HN into CM, utilizing the natural self-assembly tendency of bovine caseins. The feasibility of the concept was shown, and when quantified the vitamin was found to be about 5.5 times more concentrated within the micelles than in the serum where it was only present bound to residual soluble caseins. Moreover, the morphology and average diameter of the re-assembled micelles were very similar to those of naturally occurring CM. Still, they were less stable to shear treatment.
We have also demonstrated that the re-assembled CM can provide partial protection against UV-light-induced degradation to vitamin D2 contained in them, suggesting two mechanisms to be further studied.
This study suggests that CM may be useful as nano-vehicles for entrapment, protection and delivery of sensitive HN within food products.