Influence of extrusion process conditions on starch film morphology

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

LEBENSMITTEL-WISSENSCHAFT UND-TECHNOLOGIE-FOOD SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017

0023-6438

The conditions of extrusion process for food packaging are determinant on their morphology and, asconsequence, on their functionality. The effect of the screw speed of a starch-glycerol system extruded atthe same temperature profile was evaluated. The process at 80 rpm led to a material with the starchcompletely gelatinized, while the systems fabricated at 40 rpm and 120 rpm presented broken starchgrains. The morphology and density of the broken grains depended on the screw speed. The material at120 rpm showed broken grains with smaller size and lower concentration than that observed in thesystem at 40 rpm. After pressing at 120 rpm, the film formed (TPS120) resulted similar than that at80 rpm (TPS80), while the film at 40 rpm (TPS40) kept some broken grains. TGA of the material obtainedat 40 rpm showed more than one degradation process of the glycerol due to the inhomogeneous glyceroldispersion. DRX revealed more cristallinity in TPS40, being TPS120 the most amorphous. TPS80 had thehighest strain at break while the others the higher modulus and stress at break. Water vapor permeabilityof TPS80 and TPS120 showed similar results and lower than TPS40.