1.2.3.3. Pectin-polypyrrole hydrogel composites: swelling index andloss of water The hydrogels were produced by submitting the PC-PPy and dPC-PPy dispersions to CaCl2 as described in the experimental section. Due to the importance of the application of the hydrogels indifferent conditions, the swelling index (SI) and the loss of waterwere evaluated. The SI of the hydrogels h-PC-PPy and h-dPC-PPy was accessed in gastric and intestinal pH.