The Effect of Milling Process and Particle Size Distribution on the Rheological Properties and Structure of Sesame Paste

In this paper the effect of different milling processes (high shear blender, ceramic mill and ball mill, and stone mill) on the structure and size distribution of sesame paste particles was investigated and rheological properties of the resulting paste samples were analyzed. Sesame paste was a fluid suspension of protein–oil. The results indicated that the stone mill for 10 min in comparison to other mill processing can significantly affect on size reduction of the particles in sesame paste, improving the rheological properties and stability of the product. The results indicated that the colloidal stability of sesame paste was improved by decreasing the median particle size to values below 5 µm. Shear thinning behaviors were observed for different sesame paste samples. Creep test showed that the elastic structure of sesame paste changed to a viscous behavior with decreasing particle size that was also related to the milling method. Whiteness (L-values) of sesame paste decreased with the reduction of particle size.