Microscopic Analysis of Extruded and Pelleted Barley and Sorghum Grains

Scanning Electron Microscopy (SEM) technique has been used in food and feed industry to characterize the final product with the main focus on changes that occur to starch material. This study demonstrates the use of SEM for examining the changes that occur to starch granules after exposing sorghum and barley grains to mild (pelleting) and intensive (extrusion) feed processing methods. In this study, SEM images analysis is proved to be a useful tool to recognize the changes that occur to grains after a different processing method. The present study showed that the swelling and melting of starch granules are influenced by the severity of the processing method. In case of pelleting process, oval shape appearance of starch granules remained intact after the pelleting process; however, absence of intact oval shape of starch granules occurred after the extrusion process.