Development of functional extruded snacks using corn and apple blends

There is increasing concern about the consumption of snacks and its long term implications on health. This study considered whether the incorporation of apple powder into corn based extruded snacks could improve the nutritional value of extruded snacks. To produce nutritionally rich and organoleptically acceptable snacks, it is necessary to understand the changes that occur in physical properties of snacks during extrusion processing. In present study, effect of composition, feed moisture, screw speed and barrel temperature on physical characteristics of corn -based apple incorporated snacks was investigated to optimize the blending levels of corn flour and apple powder for the production of extruded breakfast snacks. Co-rotating twin screw extruder was used for the production of corn based apple incorporated extrudates. Response surface methodology (RSM) at varying apple powder concentration ( 0-40%), feed moisture (12.5-22.5%), temperature (110-190 °C) and screw speed ( 150-550rpm) was used to analyze the effect of each process variable on physical parameters viz. specific mechanical energy (SME), bulk density (BD), water absorption index (WAI), water solubility index (WSI), expansion ratio (ER) and breaking strength (BR) of corn- based apple incorporated snacks. Response surface models were established to determine the responses as function of process variables. Regression models were highly significant (p0.95). The optimum conditions obtained after response surface analysis for the preparation of corn-based apple incorporated snacks were corn flour to apple powder ratio (90:10), feed moisture (15%), screw speed (450 rpm) and barrel temperature (170 °C).