Characterization of Defatted Rice Bran Properties for Biocomposite Production

Commercial defatted rice bran (DRB) was characterized to produce biocomposite. DRB extracted protein plasticized with glycerol presented viscoelastic properties. The whole DRB with different amount and type of plasticizers was extruded into pellets. All extrudates presented pseudoplastic behavior as determined by capillary rheometer. Power-law index (n) and flow behavior consistency (K) of all DRB extrudates were respectively in a range of 0.30-0.32 and 1.2-3.8 x 10(4) which is closed to agro-polymer due to a modification of DRB structure after extrusion process. In addition, extrusion process promoted protein aggregation. However, no significant effect of plasticizer type and content on DRB protein aggregation for a given temperature processing was observed. The effect of plasticizer content on tensile properties presented the same trend as viscosity results. Extrudate that had a high viscosity presented high mechanical properties.