I. Arvanitoyannis et al., EDIBLE FILMS MADE FROM HYDROXYPROPYL STARCH AND GELATIN AND PLASTICIZED BY POLYOLS AND WATER, Carbohydrate polymers, 36(2-3), 1998, pp. 105-119
Two methods, known as the low and the high temperature methods, which
consist of casting aqueous solutions of hydroxypropyl starch and gelat
in at 20 and 60 degrees C, respectively, were employed for film prepar
ation. The physical (thermal, mechanical and gas/water permeation) pro
perties of these composite films, plasticized with water or polyols, w
ere studied. An increase in the total plasticizer content resulted in
a considerable decrease in elasticity modulus and tensile strength (up
to 60% of the original values when 25% plasticizer was added), wherea
s the percentage elongation increased (up to 200% compared to the orig
inal values). The low temperature method led to the development of hig
her percentage renaturation (crystallinity) of gelatin which resulted
in a decrease, by one or two magnitude orders, of CO2 and O-2 permeabi
lity in the hydroxypropyl starch/gelatin bleeds. An increase in the to
tal plasticizer content (water, polyols) of these blends was found to
be proportional to an increase in their gas permeability. (C) 1998 Els
evier Science Ltd. All rights reserved.