Effect of Wheat and Oat Bran on the Physicochemical Properties of Edible Starch-Based Films Obtained by Extrusion for Food Packaging Applications

Abstract

Obtaining edible and biodegradable films for food packaging applications has been a strong desire of consumers, scientific community and industry for years. In this context, edible films from cassava starch with wheat or oat bran (0, 5 and 10 wt.%) manufactured from an industrially established process for packaging, such as extrusion technique, were investigated. Wheat bran was found to have a high content of total dietary fiber, being able to provide a nutritional contribution to the packaging and to consumers. Some broken bran grains smaller than 1 µm were observed, distributed quite homogeneously in the matrix and without the presence of phase separation, suggesting great miscibility between the components. Brans acted as reinforcement in concentrations of 10 wt.%, leading in the case of wheat bran to increases of 850%, 45% and 25% in Young modulus, strength at break and toughness, respectively, and to decreases in moisture content. The incorporation of bran did not significant change the thermal stability and biodegradation of the films. This investigation showed that biodegradable and edible cassava starch-based films can be manufactured by a scalable process with possible improvements in nutrition and mechanical strength using 10 wt.% of bran for its potential employ as food packaging.