INVESTIGADORES
CAMPOS Carmen Adriana
congresos y reuniones científicas
Título:
Release of potassium sorbate from tapioca starch films
Autor/es:
CONTE A., FLORES S.K., CAMPOS C., GERSCHENSON L., DEL NOBILE M.A.
Lugar:
Nápoles, Italia
Reunión:
Simposio; CIGR Section VI - 3rd International Symposium. Food And Agricultural Products: Processing And Innovations; 2007
Resumen:
In this work the release of potassium sorbate from tapioca starch-based edible films, with glycerol as plasticizer, was studied and mathematically modelled.
Tapioca starch its an interesting polymeric matrix because its price is lower than
starches from other sources. In order to describe the phenomena involved in the active
compound release, the diffusion of water molecules into the polymeric film, the counter
diffusion of the active compound and the swelling of the polymeric matrix, a semiempirical
approach was proposed.
The starch-based films were prepared by casting technique, using three methods:
method 1 (slow gelatinization and slow dry), method 2 (rapid gelatinization and slow
dry) method 3 (rapid gelatinization and rapid dry). Before testing, the obtained dried
films were conditioned at 25º C, over saturated solution of NaBr (water activity, aW @
0.575) for 7 days. Both kinetic of preservative release to a liquid medium and swelling
kinetic were evaluated at pH 3 and 4.
From the obtained results it can be inferred that the proposed model satisfactorily fits
the experimental data allowing concluding that casting technique which produce films
with high amorphous degree determines a greater contribution of matrix relaxation to
sorbate release. This trend can be attributed to the increased influence of matrix
relaxation on the water sorption kinetic. The pH of the receiving media contributed
slightly to antimicrobial release and its effects seem to be related to the influence of
this variable on antimicrobial solubility.