Shape factors’ measurements were performed by means of optical microscopy. Several microscope images were recorded from an optical microscope (Kruss Optronik, Germany) with a 10 magnification connected with a camera (SONY, Topica TP-1002DS). Samples were prepared by mixing flour and isopropyl alcohol on a slide and placing a cover slip over the suspension . Image analysis was carried out using image analysis software (Image-Pro Plus 7.0, Media Cybernetics, USA). Roundness, aspect and box X/Y were calculated