Food safe basic polyelectrolytes? Pectin is an example of a food safe polyelectrolyte. It acts as an acid because it is a proton donor and develops negative charges along the polymer.

Can you think of any examples of food safe polyelectrolytes that act as bases and develop positive charges along the polymer?
Pectin is a heteropolysaccharide rich in galacturonic acid:



The carboxylic acid in galacturonic acid gives pectin the ionizable character. Pectin can react with bases to form carboxylate anions along the polysaccharide chain.

There exists a sugar-derivative and polysaccharide with opposite behavior - they react with acids to produce cations along the polysaccharide chain. The modified sugar is glucosamine, and the polysaccharides are chitin and chitosan(http://en.wikipedia.org/wiki/Chitosan). The amine ($\ce{NH2}$) group on glucosamine is basic and will react with acids to become cationic.



Glucosamine is used as a dietary supplement, and chitin and chitosan are found in various foods, like fungi and shellfish.