Chain association of pectic molecules during calcium‐induced gelation

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.