4. Conclusions
In the presence of CA in films, the RH and glycerol, separately
and through their interaction, affected the pseudo first order rate
constants of AA hydrolysis in a direct relationship. Water was the
factor responsible for AA hydrolysis, and glycerol (plasticizer) may
facilitate the water penetration from the environment into the
polymeric network. Browning development in films was due only
to the AA degradation since CA content did not change during film
storage. Additionally, the film browning was slowed down at longer
storage times by CA, which changed the kinetic order of the
browning reaction and, hence, the reaction mechanism. CA protons
may catalyze the formation of unstable color compounds. Hence
CA, which improves the activity of proper antioxidants like AA
through its metal chelator capacity, can be used together with AA
for the development of antioxidant alginate based edible films,
using a glycerol (plasticizer) proportion lower than 54.8 g/100 g
alginate and RH of storage below 75.2%. In the present work it was
possible to determine that the AA and CA were effectively loaded
(100% of recovery) after casting. Also, the half life of films as active
interfaces to achieve antioxidant protection was determined.
Considering these results alginate films can be potentially useful to
avoid oxidation in confectionary and nuts.
Acknowledgments
This work was supported by grants from University of Buenos
Aires, National Research Council (CONICET) and Agencia Nacional
de Promocion Científica y Tecnologica of Argentina (ANPCyT).