Film Extrusion of Crambe abyssinica/Wheat Gluten Blends

Crambe abyssinica is a plant with potential for use in industrial (non-food) plant oil production. The side stream from this oil production is ahigh-protein crambe meal that has limited value, as it is not fit for food or feed use. However, it contains proteins that could potentially makeit a suitable raw material for higher-value products. The purpose of this study was to find methods of making this side stream into extrudedfilms, showing that products with a higher value can be produced. The study mainly considered the development of material compositions andmethods of preparing and extruding the material. Wheat gluten was added as a supportive protein matrix material, together with glycerol as aplasticizer and urea as a denaturant. The extrudate was evaluated with respect to mechanical (tensile testing) and oxygen barrier properties,and the extrudate structure was revealed visually and by scanning electron microscopy. A denser, more homogeneous material had a loweroxygen transmission rate, higher strength, and higher extensibility. The most homogeneous films were made at an extruder die temperature of125-130 °C. It is shown here that a film can be extruded with promising mechanical and oxygen barrier properties, the latter especially after afinal compression molding step.