Effect of <i>Sedum aizoon</i> L. Powder Addition on the Rheological Properties and Gluten Structure Characteristics of Dough and the In Vitro Digestibility of Noodles

Noodles were prepared by replacing wheat flour with 0%-25% Sedum aizoon L. (FSAL) powder, and the effects of FSAL addition on dough rheology, gluten structure, noodle quality, descriptive sensory attributes, antioxidant activity, and in vitro starch digestibility were investigated. In parallel, gluten proteins were characterized by Fourier transform infrared spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, intrinsic fluorescence, SDS-PAGE, surface hydrophobicity, sulfhydryl/disulfide content, and noncovalent interaction analysis. The data indicated that FSAL markedly affected starch thermal transitions, with retrogradation enthalpy decreasing from 9.5 J/g for the control sample to 5.8 J/g after FSAL incorporation. Moderate FSAL addition improved several cooking and textural quality attributes, and the FSAL20 sample exhibited a relatively balanced descriptive sensory profile, with high perceived intensities of hardness, elasticity, chewiness, taste, and aroma. At elevated inclusion levels, however, disruption of the gluten network was observed, indicative of weakened protein organization and a decline in cooking, textural, and sensory quality attributes. FSAL also enhanced the antioxidant capacity of noodles, with DPPH and ABTS radical scavenging activities increasing from 42% and 12% in the control to 63% and 80%, respectively, at 25% FSAL addition. In vitro digestion showed that resistant starch increased from 49% to 63%, whereas rapidly digestible starch decreased from 33% to 12%. Collectively, these results indicate that FSAL influences noodle quality primarily by altering gluten conformation and intermolecular interactions within the dough matrix. The present results support the use of FSAL powder as an effective functional component in cereal products, and a 20% inclusion level achieved a suitable balance between the descriptive sensory attribute profile and functional benefits. PRACTICAL APPLICATIONS: Appropriate incorporation of Sedum aizoon L. powder improves noodle texture, antioxidant capacity, and dietary fiber enrichment while reducing starch digestibility in vitro. These results support the development of functional noodle products with enhanced nutritional value and potential commercial application.