water molecules , which correspond to
non-freezable bound water . This immobilized
water is that not involved in chemical reactions responsible for
degradation of hydro-sensitive biomolecules such as AA. The rest
(73%) of the alginate macromolecule
is not able to immobilized water in a non-freezable form.
Water is responsible for hydrolysis and the irreversible opening of
the lactone ring of the AA molecule, to produce 2-keto-L-gulonic
acid through an acid catalyzed reaction .
As RH of film equilibration increases, the polymeric network leaves
a higher proportion of water with higher mobility, available for
chemical reactions .