Polysaccharides transitions

The reported effect of konjac GaM on the glass transition of high-sugar/polysaccharide mixtures [242] can be utilized in sugar, hard-boiled and frozen confectionery products and might replace gelatin, which is refused by some consumers due to diet and health problems. 

Hirao, T., Sato, T., Teramoto, A., Matsuo, T., and Suga, H., Solvent effects on the co-operative order-disorder transition of aqueous solutions of schizophyl-lan, a triple helical polysaccharide, Biopolymers, 29, 1867, 1990. 

Morris, E. R., Rees, D. A., Young, G., Walkinshaw, M. D., and Darke, A., Order-disorder transition for a bacterial polysaccharide in solution. A role for polysaccharide conformation in recognition between xanthomonas pathogen and its plant host, J. Mol. Biol., 110,1,1977. 

Paoletti, S., Cesaro, A., and Delben, F., Thermally induced conformational transition of xanthan polysaccharide, Carb. Res., 123, 173, 1983. 

It did not give rise to phase separation or precipitation. Similar behavior was observed when other types of polysaccharides were examined [53,54]. By now all the commercially important polysaccharides have been applied to the fabrication of hybrid silica nanocomposites in accordance with Scheme 3.2. What is more, various proteins have been entrapped in silica by the same means. In all instances the THEOS demonstrated good biocompatibility with biopolymers, even though its amount in formulations was sometimes up to 60 wt%. Biopolymer solutions after the precursor admixing remained homogeneous to the point of transition into a gel state. 

Asymmetric hydrogenations catalyzed by supported transition metal complexes have included use of both chiral support materials (poly-imines, polysaccharides, and polyalcohols), and bonded chiral phosphines, although there have been only a few reports in this area. 

Metal ions of transition and other elements of variable valency, e.g. Ce, Co, Fe, V, Mn, etc., are known to oxidize polysaccharides rather selectively, producing macroradicals as intermediates which are capable of adding vinyl monomers and form graft copolymers. These initiators are redox systems which differ from those previously described by not producing free radicals of low molecular weight. Only macroradicals on the substrate are formed in the redox reaction. Some homopolymer may still be formed in the process, e.g. due to oxidation of monomer or other side reactions. ... 

Biliaderis, C. G. (1998). Structures and phase transitions of starch polymers. In "Polysaccharide Association Structures in Food" (R. H. Walter, ed.), pp. 57-168. Marcel Dekker Inc., New York, NY. 

Transitions such as this in monomer ring geometries, which can arise spontaneously in MD simulations but which cannot be easily incorporated into static conformational energy calculations, could have important consequences if they occurred in polysaccharides. 

Such chair-to-boat transitions have been suggested to play a role in determining polysaccharide structure (end-to-end lengths) in aqueous solution (51). 

Marszalek PE, Li H, Oberhauser AE, Eemandez JM. Chair-boat transitions in single polysaccharide molecules observed with force-ramp atomic force microscopy. Proc Natl Acad Sci USA 2002 99 4278-4283. 

Figure 6.5 shows experimental data relating to the self-assembly of sodium K-carrageenan, as induced by cooling in the presence of 0.1 M NaCl, and occurring simultaneously with the coil-to-helix transition for the same polysaccharide (Semenova et al., 1988). In what follows we consider this system in some detail. 

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