Effect of Surface Roughness on Rehydration Kinetics of Spaghetti

Abstract

Surface roughness of spaghetti depends on the die material used during production, and affects the momentarily rehydrated amount of water. The calculated average roughness of spaghetti surfaces, R_a, was evaluated for geometry measurements using a laser microscope. Smoothness of the spaghetti surface decreased, depending on the type of the die used during the preparation in the following order: Teflon, polypropylene, polycarbonate, aluminum, and bronze. For hypothetically smooth cylindrical spaghetti, the momentarily rehydrated amount of water per unit surface area was larger for spaghetti with larger R_a values. In contrast, the amount of water per surface area, which was estimated considering the roughness of the surface, did not affect the R_a value. This showed that the initial rehydration rate of spaghetti could be controlled by altering the surface roughness.