100B-5 |
Evaluation of the crystallinity of cassava starch biofilms by x-ray diffraction |
A. R. P. SCAMPARINI1, P. G. Veiga1, M. Tomiyama2, C. K. Susuki2, and M. P. Cereda3. (1) Dept. of Food Science, Univ. Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, PO Box 6121, Campinas, Brazil, (2) Dept. of Material Engineering, Univ. Estadual de Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, PO Box 6122, Campinas, Brazil, (3) Roots & Starch Tropical Center, Univ. de Sao Paulo, Fazenda Lageado, PO Box 237, Botucatu, Brazil The use of synthetic package films results in critical environmental problems. As an alternative solution, biodegradable packages has been studied. Meanwhile, the greatest difficulty to substitute conventional packages by biofilms is to maintain the same efficacy in the shelf life of the products. Film crystallinity is associated with mechanical and barrier properties. Although many studies had already evaluated the crystallinity of biofilms, little was investigated about the combined influence of sucrose with the effect of acidification on the crystallization of starch films. With the aim to find additives and changes in process that minimize the protection differences between conventional and biodegradable films, the influence of sucrose and medium acidification on the crystallinity of starch films ha been investigated. For further comparison, crystallinity was also investigated for flexible petroleum films. The films was obtained by casting, and the crystallinity was evaluated by X-ray diffraction (2q in a range of 5 to 80°, with copper tube, 40 kV, 20mA angular step of 2q=0.1 °, CPS=3). Cassava starch films were also analyzed during a storage period of 48 days. All formulations were effective to film forming, with the exception of the samples containing sucrose 5%, which showed high adhesivity. The totality of the films obtained by cassava starch presented amorphous halo in as-prepared samples. The presence of sucrose decreased cassava starch films stability for crystallization, while its acidification, increased cassava starch-sucrose films stability. Among the petroleum films analyzed, only low-density polyethylene films presented confirmed crystallinity. Such results indicate that sucrose and the film-forming solution pH had great influence in cassava starch-films. Beyond the advantage of being biodegradable, the production of cassava starch-films and cassava starch-sucrose films utilizes low coasts ingredients, turning its industrial application economically feasible.
Session 100B, Food Packaging
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