The effects of a series of organic acids--malic, citric and phytic acids--on the properties of edible gelatin films were studied by scientists.
The effects of a series of organic acids--malic, citric and phytic
acids--on the properties of edible gelatin films were studied by
scientists. An increase in the acid concentration of malic acid films
can lead to a systematic decrease in their tensile strength and elastic
modulus. Increases in tensile strength were found also for some
concentrations of citric and phytic acids, but these changes were not
monotonic with acid concentration. The tensile strength of 1% malic acid
film at twice that of the control film may be caused by ionic
cross-linking. This cross-linking effect did not significantly affect
the water vapor permeability of the malic and citric acid films. Films
made with the more bulky phytic acid did, however, show a 50% increase
in water vapor permeability. All the acids lead to a decrease in the DSC melting temperature of the films, compared with the control. Contact:
Robert Kimmel, Department of Packaging Science, Clemson University,
B-212 Poole Agricultural Center, Box 340370, Clemson, SC 29634. Phone:
864-656-6534. Email: firstname.lastname@example.org.