Rheological Properties of Somen Noodles—A Traditional Japanese Wheat Product

Abstract

We investigated the rheological properties of the Japanese wheat product tenobe somen noodles manufactured using a unique traditional process-"Te-nobe (hand-stretched)." In an extension test, the maximum resistance to extension (R(max)) and extensibility until rupture (Erup) of boiled somen noodles were measured on a Texture Analyzer in the tension test mode and compared with those of machine-made somen noodles. The R(max) and Erup values per unit cross-sectional area were significantly higher for boiled tenobe somen noodles than for machine-made somen noodles, clearly indicating the higher resistance to extension and extensibility of the former. A compression test performed using the Texture Analyzer in the biting-test mode revealed that although the maximum force of compression (F(max)) was lower for boiled tenobe somen noodles than for machine-made somen noodles, the former had more characteristic texture than the latter, which was shown by comparing the force-deformation curve of each somen noodle. Scanning electron microscopy revealed differences between dried tenobe and machine-made somen noodles, which may reflect their rheological differences. Lateral and sectional micrographs of tenobe somen noodles showed regular arrays of starch granules and gluten networks, and some air spaces. Tenobe somen noodles exhibited significantly higher dityrosine content than the flour used for their manufacture, indicating that tyrosine residues in gluten proteins cross-link during the manufacturing process; however, the dityrosine content in tenobe somen noodles were not higher than that in machine-made somen noodles.