From Fig. 4 it can be concluded that h-dPC-PPy exhibited the highest degree of swelling in simulated gastric pH. This resul treflects the lower degree of calcium crosslinks in dPC, a high DM pectin. Under equilibrium conditions, the polymer-solvent mixing contribution opposes the retractile forces that arise from the elas-tic response of the chains (Flory, 1953). Since dPC is a high DMpectin, lower Ca-crosslinks are expected in pH 1.2, lowering there tractile force contribution in this sample. Also, at this pH the hydrogen bonds between water and pectin are favored, increasing the polymer/water interaction. Other possibility is the highercontent of protein in dPC since the characteristic amino acids in atypical pectin sample are mainly hydrophilic, such as aspartic andglutamic acids (Anderson, McDougall, & McNab, 1897).