Casein Micelles Nano-Structure-Function Properties
Harte, F. M.  2013.  IFT Annual Meeting, 2013 IFT Annual Meeting, July 13 16, 2013, Chicago Illinois.

The casein micelle (CM) is a spherical protein quaternary structure of ca. 250 nm diameter. It is widely accepted that its main biological function is to transport calcium from mother to young. However, detailed structure-function properties of the CM remain under discussion. Cryo-electron tomography reconstruction of the CM showed the presence of serum filled cavities (ca. 20-30nm) and channels (>ca. 5 nm), 700-800 high density calcium phosphate clusters of ca. 6-12nm, and the absence of spherical sub-sub-micelles. The native CM exhibited binding affinity towards hydrophobic small molecules (e.g., retinyl palmitate) suggesting biological function other than transporting calcium. This presentation will highlight the need to further our basic understanding of milk constituents to improve dairy products and create new food and non-food applications. It will introduce the concept nanotechnology for elucidating the structure-function properties of milk components and will also draw attention to current and future trends in the use of novel technologies for the processing of milk, with examples on high hydrostatic pressure and high pressure homogenization for yogurt and cheese manufacturing. New applications for traditional milk components such as the use of milk proteins to transport flavors will be discussed. Throughout the presentation, the casein micelle from bovine milk will be used as a constant example of a milk component where basic understanding is needed, new technologies have a direct impact on functionality, and new applications / opportunities are being generated