Whey gelation

Bolder, S.G., Hendrickx, H., Sagis, L.M.C., van der Linden, E. (2006). Ca2+-induced cold-set gelation of whey protein isolate fibrils. Applied Rheology, 16, 258- 264. 

In the case of cold-induced aggregation and gelation, two different types of gel microstructure, namely filamentous and particulate (Figure 2.1), have been obtained by adding different concentrations of a ferrous salt to solutions of pre-denatured p-lactoglobulin (the major whey protein). This substantial difference in microstructure turns out to have a major impact on the iron delivery, due to the different sensitivities of the structures to the relevant environmental conditions, such as pH and the presence of digestive enzymes. In particular, the filamentous gel micro-... 

Beaulieu, L., Savoie, L., Paquin, P., Subirade, M. (2002). Elaboration and characterization of whey protein beads by an emulsification/cold gelation process application for the protection of retinol. Biomacromolecules, 3, 239-248. 

Roff, C.F., Foegeding, E.A. (1996). Dicationic-induced gelation of pre-denatured whey protein isolate. Food Hydrocolloids, 10, 193-198. 

Other Protein Components. Other protein components In complex food systems and In protein Ingredient preparations may Interfere with or modify gelation reactions. Protein Interaction between whey protein and casein upon heating has a profound Influence on the characteristics of the casein gel structure In cheesemaking. Similarly protein Interactions are Important to meat structures. Protein-protein Interaction between soy and meat proteins has also been demonstrated with heat treatment (28). While concrete Interaction data have not been collected on protein gels formed from protein combinations, gelation properties of whey proteln/peanut flour blends have been Investigated GU) ... 

The gelation of whey protein has also been shown to be affected by the presence of lipids and the presence of lactose (29). 

Although the gelation properties of whey proteins are of great importance in many foods (Mulvihill, 1992) and it is possible to form a weak gel in creams by the formation of a continuous network of fat globules, most important milk gels are those involving casein micelles which can be made to form a gel matrix either by isoelectric precipitation (acid-induced gel) or by the action of a proteolytic enzyme (rennet-induced gel). Both gel types... 

Schmidt, R. H., Illingworth, B. L., Deng, J. C. and Cornell, J. A. 1979. Multiple regression and response surface analysis of the effects of calcium chloride and crysteine on heat-induced whey protein gelation. J. Agr. Food Chem. 27, 529-532. 

Enzymatic gelation of partially heat-denatured whey proteins by trypsin, papain, pronase, pepsin, and a preparation of Streptomyces griseus has been studied (Sato et al., 1995). Only peptic hydrolysate did not form a gel. The strength of the gel depended on the enzyme used and increased with increasing DH. Hydrolysis of whey protein concentrate with a glutamic acid specific protease from Bacillus licheniformis at pH 8 and 8% protein concentration has been shown to produce plastein aggregates (Budtz and Nielsen, 1992). The viscosity of the solution increased dramatically during hydrolysis and reached a maximum at 6% DH. Incubation of sodium caseinate with pepsin or papain resulted in a 55-77% reduction in the apparent viscosity (Hooker et al., 1982). 

Aguilera, J.M. 1995. Gelation of whey proteins. Food Technol. 49(10), 83-89. 

The formation of beads is a two-step process based on the cold gelation of whey proteins in the presence of divalent cations, such as Ca2+ [67], Briefly, the whey protein isolate (WPI) solution (10% w/v in deionized water) was (i) adjusted at pH 7 to favor the apparition of negative charges implied in ionic bounds with Ca2+ ions and (ii) heated (80 °C, 45 min) to denaturate the proteins. Recombinant cells in the beginning of their stationnary growth phase were suspended in a sterile solution of... 

Hongsprabhas, P., and Barbut, S. (1998), Ca2+-induced cold gelation of whey protein isolate Effect of two-stage gelation, Food Res. Int., 30, 523-527. 

Other protein systems have been successfully used for encapsulation. For example, conjugated linoleic acid has been microencapsulated using whey proteins (Jimenez et al. 2004). A whey protein bead delivery system was prepared by emulsification of soybean oil containing retinol with pre-denatured whey protein followed by the addition of calcium ions to induce gelation. The encapsulant system protected... 

Lee, S.J., and Rosenberg, M. (2000). Whey protein-based microcapsules prepared by double emulsification and heat gelation. Lebensm. Wiss. Technol. 33, 80-88. 

Bryant, C. M. and McClements, D. J. 2000. Influence of NaCl and CaCl2 on cold-set gelation of heat-denatured whey protein. J. Food Sci. 65 801-804. 

A few studies have also reported on the effects of non-gelling neutral polysaccharides on whey protein gelation (Olsson et al., 2000, 2002 Monteiro et al., 2005 Tavares et al., 2005), revealing interesting relationships between the microstructure of the biphasic mixed networks and the observed viscoelastic behavior and pointing out the importance of the structural characteristics of the polysaccharide. 

Monteiro, S. R., Tavares, C. A., Evtuguin, D. V, Moreno, N., and Lopes da Silva, J. A. 2005. Influence of galactomannans with different molecular weights on the gelation of whey proteins at neutral pH. 

Tziboula, A. and Home, D. S. 1999. Influence of whey protein denaturation on re-carrageenan gelation. Colloid Surf. B Biointeifaces 12 299-308. 

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