Biofilms based on cassava starch containing extract of yerba mate as antioxidant and plasticizer

C. MEDINA JARAMILLO; P. GONZÁLEZ SELIGRA; S. GOYANES; C. BERNAL; L. FAMÁ

STARCH/STARKE

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2015 vol. 67 p. 1 - 10

0038-9056

The incorporation of antioxidants into biodegradable and edible films is a current strategy to increase the shelf life of foods and preventing spoilage reactions. Cassava starch based films containing different concentration of extract of yerba mate as antioxidant (0 wt%, 5 wt% and 20 wt%) were developed by casting. The influence of the incorporation of the extract on the antioxidant activity, structure and physicochemical properties of the biofilms was evaluated. Important antioxidant capacity in the film with only 5 wt% of extract of yerba mate (TPS-Y5), after drying the starch filmogenic solution, was demonstrated. The addition of both extract concentrations led to increased values of surface roughness and contact angle, indicating hydrofobic behavior of the films surface. The hydrophobic nature of the systems containing the extract reverberated on the water vapor permeability and water content, causing decrease on both parameters. The use of yerba mate resulted in a significant improvement in the elasticity of the biofilms, suggesting the conformation of a flexible coaitng. The relaxations associated to the glycerol-rich and starch-rich phases shifted to lower temperatures when the extract was incorporated. The observations of the mechanical properties of the starch-yerba mate extract films revealed a typical behavior of a plasticized film. Finally, the antioxidant and plasticizer effect of the extract of yerba mate on cassava starch films leads us to think about their possible use as coatings of food products in order to retard their oxidation, avoid cracking during handling and increase their shelf life.