73D-35 |
Characterization of degradable films obtained from gelatin and phthalate acetate cellulose mixtures |
C. R. F. GROSSO and F. M. Fakhouri. Dept. of Food Planning & Nutrition, State Univ. of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-970, Brazil Degradable and/or edible films to be utilized in foods were initially developed to function as barriers to water and oxygen permeation. New applications include active films and films which regulate the diffusion of components with biological or chemical specific activities. The objectives of this work is to develop composed and multilayer films from gelatin and phthalate acetate cellulose mixtures containing glycerol as a plasticizer and characterize them according to their mechanical resistance, water permeability and solubility at different pH levels. The polymers were dissolved separately and the films obtained through the casting technique utilizing plaxiglass plates. The polymeric solutions were mixed immediately before being spread in order to obtain composed films. For the obtaining of multilayer films a second layer was spread over the first one (which was being formed) an hour afterwards. A texturometer was utilized for the mechanical resistance. Permeability to water and solubility of films at pH 1 and 7 were also determined. The gelatin film was more resistant, less permeable to water vapor and less soluble in water than cellulose phthalate acetate film. The addition of cellulose to gelatin increases the solubility in water, the permeability and elongation, reducing the mechanical resistance. The producing process through multilayers did not improve its functionality, which was about the same as that of the film obtained through mixture at the same concentration. However, the multilayer films were more transparent and easier to handle. The possibility of modeling the diffusion of components through films and substituting the non-degradable packaging support the development of new formulations.
Session 73D, Food Packaging
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