Protein-polysaccharide interaction

Dickinson, E. (1998). Stability and rheological implications ofelectrostatic milk protein-polysaccharide interactions. Trends Food Sci. TechnoL, 9, 347-354. 

Benichou, A., Aserin, A., Garti, N. (2002). Protein-polysaccharide interactions for stabilization of food emulsions. Journal of Dispersion Science and Technology, 23, 93-123. 

Dickinson, E. (2008). Interfacial structure and stability of food emulsions as affected by protein-polysaccharide interactions. Soft Matter, 4, 932-942. 

Dickinson, E. (1993). Protein-polysaccharide interactions. In Dickinson, E., Walstra, P. (Eds). Food Colloids and Polymers Stability and Mechanical Properties, Cambridge, UK Royal Society of Chemistry, pp. 77-93. 

Doublier, J.-L., Gamier, C., Renard, D., Sanchez, C. (2000). Protein-polysaccharide interactions. Current Opinion in Colloid and Interface Science, 5, 202-214. 

Tolstoguzov, V.B. (1997). Protein-polysaccharide interactions. In Damodaran, S., Paraf, A. (Eds). Food Proteins and their Applications, New York Marcel Dekker, pp. 171— 198. 

Schaink, H.M., Smit, J.A.M. (2007). Protein-polysaccharide interactions the determination of the osmotic second virial coefficients in aqueous solutions of p-lactoglobulin and dextran. Food Hydrocolloids, 21, 1389-1396. 

Surface shear rheology at the oil-water interface is a sensitive probe of protein-polysaccharide interactions. In particular, there is considerable experimental evidence for a general increase in surface shear viscosity of protein adsorbed layers as a result of interfacial complexation with polysaccharides (Dickinson et al., 1998 Dickinson and Euston, 1991 Dickinson and Galazka, 1992 Semenova et al., 1999a Jourdain et al., 2009). One such example is the case of asi-casein + pectin at pH = 5.5 and ionic strength = 0.01 M (Ay = - 334 x 10 cm /mol) the interfacial viscosity after 24 hours was found to be five times larger in the presence of pectin (i.e., values of 820 80 and 160 20 mN m 1 with and without pectin, respectively) (Semenova et al., 1999a). 

Figure 7.18 Protein-polysaccharide interactions in emulsions subjected to high pressure treatment (HPT). Influence of pH on average effective particle diameter d43 determined by static light scattering (Malvern Mastersizer) in emulsions (20 vol% soybean oil, 0.5 wt% p-lactoglobulin) prepared with untreated protein (open symbols) and high-pressure-treated (800 MPa for 30 min filled symbols) protein in the absence (O, ) and presence (A, ) of 0.5 wt% pectin. Reproduced from Dickinson and James (2000) with permission.

Tolstoguzov, V.B. (1991). Functional properties of food proteins and role of protein-polysaccharide interaction. Food Hydrocolloids, 4, 429 168. 

In general, surface activity behaviour in food colloids is dominated by the proteins and the low-molecular-weight surfactants. The competition between proteins and surfactants determines the composition and properties of adsorbed layers at oil-water and air-water interfaces. In the case of mixtures of proteins with non-surface-active polysaccharides, the resulting surface-activity is usually attributed to the adsorption of protein-polysaccharide complexes. By understanding relationships between the protein-protein, protein-surfactant and protein-polysaccharide interactions and the properties of the resulting adsorbed layers, we can aim to... 

In the case of a protein + polysaccharide mixture, whether the adsorption process is competitive or cooperative in character will depend on the concentration and surface activity of each adsorbed biopolymer species, and on the nature and strength of the protein-polysaccharide interactions (Murray, 2002 Baeza et al., 2005 Dickinson, 2008). In addition, the... 

Protein-polysaccharide complexation affects the surface viscoelastic properties of the protein interfacial layer. Surface shear rheology is especially sensitive to the strength of the interfacial protein-polysaccharide interactions. Experimental data on BSA+ dextran sulfate (Dickinson and Galazka, 1992), asi-casein + high-methoxy pectin (Dickinson et al., 1998), p-lactoglobulin + low-methoxy pectin (Ganzevles et al., 2006), and p-lactoglobulin + acacia gum (Schmitt et al., 2005) have all demon-... 

Figure 8.12 illustrates the effect of complex formation between protein and polysaccharide on the time-dependent surface shear viscosity at the oil-water interface for the system BSA + dextran sulfate (DS) at pH = 7 and ionic strength = 50 mM. The film adsorbed from the 10 wt % solution of pure protein has a surface viscosity of t]s > 200 mPa s after 24 h. As the polysaccharide is not itself surface-active, it exhibited no measurable surface viscosity (t]s < 1 niPa s). But, when 10 wt% DS was introduced into the aqueous phase below the 24-hour-old BSA film, the surface viscosity showed an increase (after a further 24 h) to a value around twice that for the original protein film. Hence, in this case, the new protein-polysaccharide interactions induced at the oil-water interface were sufficiently strong to influence considerably the viscoelastic properties of the adsorbed biopolymer layer. 

Ganzevles, R.A., Zinoviadou, K., van Vliet, T., Cohen Stuart, M.A., de Jongh, H.H.J. (2006). Modulating surface rheology by electrostatic protein-polysaccharide interactions. Langmuir, 22, 10089-10096. 

Ward-Smith, R. S., Hey, M. J., and Mitchell, J. R. (1994). Protein-polysaccharide interactions at the oil-water interface. Food Hydrocoll. 8 309-315. 

Turbidimetry indicated that precipitate formation depended on the concentration of the protein as well as on that of the polysaccharide, the time-period of incubation, and the ratio of protein to polysaccharide.121,359,360 Precipitin curves determined turbidimetrically differed from those determined by analysis of precipitated nitrogen.360 For these reasons, early turbidimetric studies conducted on crude (rather than purified) con A are difficult to interpret. The quantitative precipitin method, wherein increasing amounts of polysaccharide or glycoprotein are added to standard aliquots of con A, and the resulting precipitate is washed, and analyzed for nitrogen, is now considered the method of choice for studying protein-polysaccharide interaction.170,320... 

The properties of protein-polysaccharide complexes formed near the protein lEP are independent of the way in which their have been produced. This indicates an equilibrium nature of complexing under conditions of weak protein-polysaccharide interaction. 

In the pH range close to the protein s lEP an interesting phenomenon of non-uniform redistribution of protein molecules among polysaccharide chains occurs (Tolstoguzov et al. 1985). The reason is that in the vicinity of the protein lEP the hydrophobic protein-protein and electrostatic protein-polysaccharide interactions can be energetically comparable with each other. Protein-protein association on the anionic polysaccharide matrix (or self-association of proteins), which is mainly due to hydrophobic interactions, is usually enhanced when the pH approaches the protein lEP. Accordingly, under conditions of a relatively weak protein-polysaccharide interaction, each free site situated near the site on the polysaccharide chain already occupied by a protein molecule becomes thermodynamically preferable for further binding of protein molecules. This leads to cooperative protein adsorption on an anionic polysaccharide. Some parts of polysaccharide chains tend to be completely covered by protein molecules (as in a virus) while other parts are completely free of protein. 

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