Physical Properties and In Vitro Starch Digestibility of Noodles Substituted with Tartary Buckwheat Flour

The effects of Tartary buckwheat flour (TBF)/wheat flour ratio on the physical properties, and starch digestion, of noodles are investigated. Incorporation of TBF significantly changes the physical character of noodles. As TBF levels increase in noodles, the color of dough sheet become darker and noodle texture is affected deleteriously. Starch gelatinization temperature increases with TBF inclusion, and the relaxation time by low-field nuclear magnetic resonance (LF-NMR) system (including T 21 , T 22 , and T 23 ) decreases due to the close combination of water with macromolecule such as protein and starch. Near-infrared reflectance spectroscopy (NIRS) results in all of the cooked noodles show that both energy, and protein content, decrease significantly. Compared with noodles without substitution, TBF noodles reduce the production of reducing sugar released during an in vitro starch digestion. These findings suggest that incorporation of TBF in noodles could improve noodle nutrition but care is required to ensure appropriate textural characteristics are maintained.