INFLUENCE OF EXTRUSION PARAMETERS ON THERMAL AND MECHANICAL PROPERTIES OF STARCH BASED FILMS

GONZALES SELIGRA, PAULA; OCHOA YEPES, OSWALDO; GUZ, LUCAS; GOYANES, SILVIA; FAMÁ, LUCÍA

Simposio; Frontiers in Physical Sciences; 2016

The use of edible films in the food industry has been constantly increasing, and starch-basedfilms play a key role in this application, as starch is cheaper and more readily availableworldwide than other natural resources [1]. In its native form, starch is not processable as athermoplastic since its melting temperature is higher than its degradation temperature, so itis necessary to add plasticizers, heat and/or mechanical work to induce the starchgelatinization process and produce a thermoplastic material. Thermal extrusion is one of themost widely used techniques to process starch-based polymers. During extrusion processstarch granules are subjected to high pressure, heat and mechanical shearing forces in arelatively low moisture environment [2].Cassava starch based films were developed by the extrusion process using a laboratory twinscrewextruder. Glycerol and water were used as plasticizers. Different temperature profileswere evaluated with temperatures between 80°C and 140°C and the influence of screw speedwas studied for a range from 25 to 120 rpm. Effects of extrusion parameters were investigatedthrough the determination of thermal and mechanical properties of the starch films.