Mechanical and barrier properties of composite films based on rice flour and cellulose fibers

Abstract

Rice flour is a low-cost starchy material, produced from rice that is broken during processing. Rice flour-based films have promising application on food packaging, because of their environmental appeal and low cost. Nevertheless, their mechanical and moisture barrier properties should be improved. The aim of this study was to develop biodegradable films based on rice flour and enhance their properties by reinforcing them with cellulose fibers. In this way, rice flour films with and without fibers were prepared by casting, with glycerol or sorbitol as plasticizer. Their physicochemical, microscopic and mechanical properties were studied. SEM analysis of films revealed compact structures. Films prepared with fibers presented lower water vapor permeabilities if compared with films without fibers. Films containing sorbitol were less permeable to water and more rigid. The incorporation of fibers reinforced mechanically the flour-based films, which presented higher tensile strength, but did not influence their deformation capacity. Therefore, preparing biodegradable films from rice flour is a new alternative of using this raw material. The use of cellulose fibers as reinforcing agent is a viable alternative to improve the properties of rice flour-based films, because they are biodegradable and available at low cost.