Gelation property

Other examples illustrating the effect of substituent distribution on properties include (/) enzymatic stabiUty of hydroxyethjlceUulose (16,17) (2) salt compatibihty of carboxymethylceUulose (18,19) and (J) thermal gelation properties of methylceUulose (20). The enzymatic stabUity of hydroxyethylceUulose is an example where the actual position of the substituents within the anhydroglucose units is considered important. Increasing substitution at the C2 position promotes better resistance toward enzymatic cleavage of the polymer chain. Positional distribution is also a factor in the other two examples. 

Consistent with their chemical differences, the molecular structures of i- and K-carrageenans are not identical. A shorter pitch and an offset positioning of the two chains in the kappa helix is compatible with the lack of sulfate group on every 3,6-anhydrogalactose residue. The variations in molecular structures mirror the types of junction zones formed by these polymers and relate to the observed gelation properties. 

Anderson JM, Andukuri A, Lim DJ et al (2009) Modulating the gelation properties of self-assembling peptide amphiphiles. ACS Nano 3 3447-3454... 

The importance of the degree of esterification (%DE) to the gelation properties of pectins makes it desirable to obtain a fast and robust method to determine (predict) the %DE in pectin powders. Vibrational spectroscopy is a good candidate for the development of such fast methods as spectrometers and quantitative software algorithms (chemometric methods) becomes more reliable and sophisticated. Present poster is a preliminary report on the quantitative performance of different instrumentations, spectral regions, sampling techniques and software algorithms developed within the area of chemometrics. 

The gelation process is considered a very specific process. This specificity is interpreted on a structural basis. Therefore some relationships between the chemical constitution and gelation properties of pectins and some related polysaccharides are outlined. 

Although there is no direct evidence that molecular structure and gelation properties show such a close correlation, this hypothesis may help to show that the mechanism of gelation is a very specific reaction analogous to specific biochemical reactions, like antigen-antibody reactions, etc., in which polysaccharides are also involved. 

Matthew JE, Nazario YL, Roberts SC et al (2002) Effect of mammalian cell culture medium on the gelation properties of Pluronic F127. Biomaterials 23 4615-4619... 

Aldonamides 5 display smectic thermotropic as well as lyotropic mesophases [70,71] they form helical tubes with diameters between 40 and 500 A and lengths of several pm and have gelation properties [72-76]. 

TABLE 1. Gelation Properties of Reaction Product of ot,o>-bis(3-mercapropropyl)-polyethylene Glycol and Polyethylene Glycol Triacrylate and 37°C at 10 Hz as a Function Poly(ethylene Glycol Content)... 

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) ... 

Dialysis to minimize ash and lactose Improved gelation properties of WPC systems with an ability to form gels but did not... 

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... 

Beginn developed Percec-type dendrimers, which are known to form supramolecu-lar channels, with polymerizable acrylate groups in order to obtain ion-permeable membranes [97-99]. First, the dendron 78 (Scheme 40) was dissolved in a polymerizable acrylate mixture that does not shrink on polymerization. The second step was the thermo-reversible gelation of the acrylate mixture, which was followed by the last step, polymerization to fix the supramolecular channel structure (Scheme 40). In the first experiments, compounds with only one polymerizable group were used but it turned out that the gelating properties were not sufficient [100, 101] so threefold modified 78 had to be developed. 

Sarkar, N. (1979). Thermal gelation properties of methyl and hydroxypropyl methylcellulose. /. Appl. Polym. Sci. 24 1073-1087. 

Z Gel strength, syneresis Z Water binding, gelation properties Covalent incorporation of lysyl peptides... 

Design of amphiphiles for the modulation of catalytic, membranous and gelation properties... 

In a similar way, other derivatives of diamines (S,S)-28 and (R,R)-29 were evaluated for their gelation properties. As an example, trans-(R,R) 1,2-bis(dodecy-lureido)cyclohexane and trans-(R,R)-1,2-bis(octadecylureido)cyclohexane can cause physical gelation in a wide variety of organic solvents [76]. As an extension of these studies, novel polymerizable organogelators based on tra s-(7 ,7 )-l,2-bis(ur-eido)cyclohexane derivatives have been reported [77]. In these molecules, the presence of methacrylate-functionalized carboxylic acid groups determines the... 

---