Optimizing the Functional Characteristics of Puffed Corn Snacks via Response Surface Methodology

Abstract

The study investigates the effect of extrusion processing on functional attributes of puffed corn snacks utilizing response surface methodology to optimize the process. These snacks are popular not only among the children but also in adults. The acceptability of extruded snacks depends mainly on functional properties. Therefore, optimization of the process to attain the required quality characteristics of form is very important. This study examined the impact of three independent variables: feed moisture content (12-16%), screw speed (400-500 rpm), and extrusion temperature (120-180°C). Puffed corn snacks were evaluated for specific water absorption index (WAI), water solubility index (WSI), bulk density (BD), specific mechanical energy (SME), and hardness.  All the processing variables affect the functional attribute of extrudates however, moisture and temperature have more effect than screw speed. It was observed that temperature increases resulted in decreased SME, BD, WAI, and hardness, but enhanced WSI in puffed corn snacks. An Increase in moisture resulted in a decrease in SME and WSI and an increase in BD, WAI and hardness. The extruded snack market is one of the biggest markets in the food sector and current study helps to provide a better understanding of the interaction of operating variables such as temperature, screw speed and feed moisture on the quality of the extrudates. Quadratic model established in this study to elaborate the effect of extrusion variable on the functional properties is very helpful in understanding the behavior of puffed corn snacks.