Whey protein particles

A combination of heat and shear has been used to create whey protein particles with controlled particle size and properties. A well-known example of the use of microparticulation of thermally denatured whey protein is for the production of Simplesse 100, a whey-based fat replacer (Lieske and Konrad, 1993). Shear can be used to modulate gel properties of whey protein isolate gels. 

O Kennedy, B.T., Halbert, C., and Kelly, P.M. (2001). Formation of whey protein particles using calcium phosphate and their subsequent stability to heat. Milchwissenschaft 56, 625-628. 

Whey proteins that have been heat precipitated under very high shear have a particle size between 1 and 3 micrometers, and give the impression of fat in some products. These microparticulated whey proteins are being used as fat replacers in frozen desserts and processed cheese substitutes. 

The whey proteins are molecularly dispersed in solution or have simple quaternary structures, whereas the caseins have a complicated quaternary structure and exist in milk as large colloidal aggregates, referred to as micelles, with particle masses of 106-109 Da. 

The use of HPLC for the analysis of bovine milk proteins was introduced by Diosady et al. (59), who compared SE-HPLC on two SynChropac GPC-100 columns in series and RP-HPLC on a lO-jUm-particle-sizc RP-8 column, both with UV detection, for the separation of dialyzed freeze-dried whey proteins. Column temperature was 40°C and 47°C, respectively. Samples were eluted with Tris-buffer pH 6 for SE-HPLC and a linear gradient of two solvents, i.e., 98% 0.5 M KH2P04, pH 2, and 98% isopropanol, each with 2% 2-methoxyethanol for RP-HPLC. They... 

Irrespective of specific product systems to be produced, principally the same heat induced reaction between whey proteins and caseins resulting in gels from coaggregated particles can be applied. Important factors in this respect are the calcium level and the casein/whey protein ration as was found by Kennel (1994) and Beyer... 

McHugh, T.H., and Krochta, J.M. (1994b). Dispersed phase particle size effects on water-vapor permeability of whey protein beeswax edible emulsion films. J. Food Processing Preservation. 18, 173-188. 

Filtration of small (nano) particles from solvent using a filter with extremely small pores (0.001-0.010 micron) finer than ultrafiltration, not as fine as reverse osmosis. Used for the removal of viruses from plasma protein products. See Yaroshchuk, A.E., Dielectric exclusion of ions from membranes, Adv. Colloid Interface Sci. 85,193-230,2000 Rossano, R., D Elia, A., and Riccio, R, One-step separation from lactose recovery and purification of major cheese-whey proteins by hydroxyapatite — a flexible... 

Microfiltration processing for clarification and defatting of cheese whey, for selective separation and concentration of micellar caseins from milk for various purposes, for fractionation of caseins and their peptides, for recovery of native whey proteins from milk, for gentle sterilization of milk to produce extended shelf fife liquid milk and cheese milk, for fractionation of globular milk fat and its components, for the reduction of microorganisms in cheese brine, and for the removal of colloidal particles in membrane cleaning solutions. 

This work focused on the comparison of the separation characteristics of whey proteins using three strong anion exchange membranes (CIM QA, QlOO, and HiTrap Q). In an analytical column (3.9 x 300 mm), the experiments were performed at a particle size of 15 pm with large pore sizes of 300 pm. The mobile phase was a binary system of water with 0.1% of TEA and ACN with 0.1% of TEA. 

When particles interact through relatively permanent bonds, the displacement induced by compression leads to wrinkles that line up perpendicular to the direction of compression. This feature has been observed experimentally, for example, for proteins found in limg surfactants (Lipp et al., 1998), and the various desorption mechanisms induced by compression have been identified, for example, in 2-hydroxytetracosanoic acid monolayers (Ybert et al., 2002). Furthermore, we believe that the same type of behavior might also be found for adsorbed milk proteins, especially heat-treated whey proteins. The expansion of films formed by particles that crosslink through transient bonds leads to fracture of the films, a mechanism also seen with globular milk proteins (Hotrum et al., 2003). 

Anema, S.G. 2008a. Effect of milk solids concentration on whey protein denaturation, particle size changes and solubilization of casein in high-pressure-treated skim milk. International Dairy Journal 18 228-235. 

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