Physical properties and prebiotic activity of maize starch-based functional films

The development of active packing materials has been focused on the incorporation of additives into the materials to afford more attractive and functional properties. In this paper, maize starch-based functional films were prepared by adding prebiotics into the starch matrix. It was shown that with the addition of prebiotics and a decrease in their molecular weight, the starch-based films became more soluble and more flexible. Specifically, the time for the waxy maize starch-based films to be dissolved in water was reduced from 150 to 10 s. This could be ascribed to the disruption of starch film integration by the water-soluble prebiotic, which enhanced the penetration of water to the films. Besides, the elongation at break of the films was increased from 15 to 46%, apparently due to the plasticization effect of the prebiotics. Moreover, the in vitro microorganism results indicated that the prebiotic activity of the functional films would not be affected by the film preparation (solution casting) process. These results demonstrated that starch-based functional films can be prepared with prebiotic activity and instant water-dissolution property. These films could be used as the packaging materials for water soaking foods, such as freeze-drying vegetables.