PRODUCT TEMPERATURE RESPONSE OF A LOCALLY DEVELOPED EXTRUDER TO DIFFERENT EXTRUSION CONDITIONS

ABSTRACT

In this study, the product temperature response of a single screw extruder developed locally was investigated for the extrusion process of the flour and starch of maize and cassava which are grown in Nigeria in large quantity but yet underutilized. These were compared with wheat flour which is commonly used for the production of alimentary pastes in a factorial experiment in completely randomized design A maximum temperature of 150oC per 30 minutes was attained through viscous dissipation and up to a moisture loss of 55% w.b. Also, product temperature is strongly related to the starch type and the extrusion process parameters under study. Product temperature decreased with increasing moisture content. The highest values of product temperature were demonstrated by maize starch and cassava flour extrudates while the lowest values were observed on maize flour and wheat flour extrudates. The equations relating the various dependent and independent variables were established to predict the performance of the machine. 


Key words: Extrusion, Product temperature, Cassava starch, flour, Maize, Wheat.