This work investigated the impact of three drying methods on structural and functional properties of potato flour (PF), as well as the quality characteristics of fresh noodles made from wheat-potato flours. The results indicated that ethanol drying (ED) and oven drying (OD) had small effects on the properties of starch in potato flour, however, freeze drying (FD) caused some pores and channels on the starch granules and disruption of the long- and short-range ordered structure of starch. The maximum addition of potato flour in fresh noodles was 40% for FD-PF and 50% for both ED-PF and OD-PF. With increasing addition of potato flour in noodles, the L* (lightness) values of noodles decreased gradually, while the a* (redness) and the b* (yellowness) values, as well as the hardness and springiness values of fresh potato noodles increased. This study clearly showed that drying methods have different effects on the properties of potato flour, and in turn the quality of fresh noodles made with potato flour.

α-Glucosidase inhibitors (AGIs) significantly regulate blood glucose by delaying carbohydrate digestion and slowing glucose absorption, thus playing a critical role in glycemic control. Structurally, dihydromyricetin (Unless otherwise stated, the term dihydromyricetin used throughout this manuscript refers to trans-(2R,3R)-(+)-dihydromyricetin.) differs from myricetin in that the C2=C3 double bond in the C-ring is saturated, resulting in a dihydroflavonol instead of a flavonol. This study investigated the inhibition mechanism of α-glucosidase by the C2=C3 double bond structure using a set of integrated and multi-perspective approaches combining enzyme kinetics, multi-spectroscopic methods, molecular docking, isothermal titration calorimetry (ITC), and surface plasmon resonance (SPR). Myricetin (IC₅₀ = 13.648 ± 0.157 μM) was found to be a more potent α-glucosidase inhibitor than dihydromyricetin (IC₅₀ = 453.922 ± 1.643 μM). Enzyme kinetics indicated that myricetin acted as a competitive inhibitor, whereas dihydromyricetin functioned as a non-competitive inhibitor. To further examine these interactions, multi-spectroscopic analysis demonstrated that binding of myricetin caused significant changes in the microenvironment around fluorescent amino acids (such as tyrosine and tryptophan) in α-glucosidase, resulting in slight unfolding of the enzyme structure. Additionally, molecular docking provided a detailed molecular perspective, identifying hydrogen bonding and hydrophobic interactions as the primary forces driving the binding of two flavonoids to α-glucosidase. Delving deeper into the binding mechanism, ITC analysis provided thermodynamic evidence that myricetin (K_D = 6.215 ± 0.022 μM) exhibited a stronger binding affinity to α-glucosidase than dihydromyricetin (K_D = 232.648 ± 1.236 μM), with both interactions being enthalpy-driven and primarily mediated by hydrogen bonds. Building on this, SPR analysis offered additional insights into the binding process, showing that myricetin not only had a higher binding affinity (K_D = 3.416 ± 0.015 μM) but also a faster association rate (k_a = 1668 ± 23 M⁻¹ s⁻¹) compared to dihydromyricetin (K_D = 11.539 ± 0.056 μM, k_a = 339.7 ± 17.1 M⁻¹ s⁻¹). In conclusion, this study demonstrated that the C2=C3 double bond plays a key role in enhancing α-glucosidase/inhibitor interactions, providing a theoretical basis for the design of novel AGIs and proposing a new set of multi-perspective methods for elucidating these inhibition mechanisms.