<p>Texture is an important quality criterion for white-salted udon noodles, a representative type of noodle in Japan. Although it is known that hand-stretched and machine-made udon noodles exhibit different textures, quantitative studies examining the relationship between gluten structure and texture are limited. Using five kinds of hand-stretched and 11 types of machine-made udon noodles, this study aimed to investigate the relationship between gluten structure and mechanical behavior in cooked noodles. Frozen sliced sections of cooked udon noodles were stained with acid magenta and observed under a fluorescence microscope to visualize their gluten structure, and their structural characteristics were quantified using image analyses. Shear tests were conducted on the cooked noodles to determine their stress–strain relationship and obtain their mechanical characteristic parameters, such as elastic modulus, yield stress, strain, and strain energy. Correlation analyses revealed significant positive associations between gluten structural “coherency” and lower yield stress, as well as between the “endpoints” parameter and strain changes at yield points. These findings indicate that gluten structure is closely related to the mechanical behavior of cooked noodles beyond their upper yield point. Principal component analysis of these parameters clearly separated hand-stretched and machine-made noodles into distinct groups. Overall, the proposed method provides a useful approach for observing and quantifying gluten structures in white-salted udon noodles. These insights could inform the development of optimized noodle production techniques and enhance the understanding of gluten’s role in food texture and mechanical properties.</p>