Though a general picture for the gelation of alginate wasidentified for more than 30 years,6,7a continuous revision andimprovement has been carried out based on new experimentalevidence. Numerous physicochemical studies have been per-formed in order to obtain information regarding the mechanismsand the structural features involved in the gelation process.Morris et al.6,7have shown that calcium ions induce chain-chain association and proposed a model for the junction zone,popularly known as the “egg-box model” (Figure 1). The egg-box model is based on X-ray fiber diffraction and dialysis ofCa2+ion.6-10However because calcium alginate fibers give avery poor diffraction pattern, it is impossible to deduce th