| Abstract: | The chain association of pectic molecules with different levels and patterns of esterification during calcium-induced gelation was studied by methods such as light scattering, viscometry, and determination of calcium activity coefficient and of calcium transport parameter. A gel point can be determined, assuming a power law including a critical ratio (equivalent concentration of calcium ions/pectin carboxylic groups) and quasi-critical exponents varying in the range 0.50–1.26. The values of these critical parameters were discussed as a function of polymer concentration, of level and pattern of esterification, and of the nature of the divalent counterion. The lower these values are, the better, apparently, the gel-forming ability of the pectins is. |
