Effect of fibre–protein additions and process parameters on microstructure of corn extrudates

Abstract

A study was conducted on the application of high-fibre components (everlasting pea wholemeal, oat bran) for the modification of microstructure and physical properties of corn extrudates. The extrusion was conducted using a single screw extruder type S-45 (Metalchem, Poland). The effect of the material blend composition and of the variable process parameters: material blend moisture (11, 13.5, 16%), barrel temperature distribution profile (120/145/115, 130/155/115, 140/165/115 °C) on the microstructure and the physical properties of the extrudates was analysed. All extrudates obtained were characterised by typical cellular structure and “crunchy” texture characteristic of the “ready to eat” type products. The microstructure of the products obtained was determined both by the material composition of the blend and by the process parameters. The differences observed in the size, number of shapes of air cells and in the cell wall thickness indicate extensive possibilities of modification of the physical properties and sensory traits of extrudates.