Synergistic Effects of Alkali, Salt, and Thickness Reduction on the Preparation and Properties of Low-Protein Noodles.

Low-protein foods are important clinical diet requirements for some medical diseases. The work aimed to develop low-protein noodles (LPNs) with good structural integrity, cooking and sensory properties. Based on a three-step noodle fabrication process, the effects of low-protein source, designated noodle width, drying condition, cooking time, alkali and salt addition, and dough sheet thickness on the properties of LPNs were explored to obtain ideal noodles. All results suggested these factors had obvious effects on the preparation of the LPNs. The optimal cooking times were 6 and 8 min for the wet and dry LPNs, respectively. Alkali and/or salt addition could increase the fastness to boiling to a certain extent, increase the sensory properties, and slow the starch digestion of the LPNs. Even without alkali and/or salt addition, dough sheet thickness reduction to 0.5 mm could significantly increase the fastness to boiling to an almost perfect extent. In addition, lower dough sheet thickness induced faster starch digestion percentages. The obtained LPNs were optimized with a low protein content of 0.62 g/100 g. The synergistic combination of the alkali of 0.5% low-protein powder, the salt of 1.0% low-protein powder, and a dough sheet thickness of ≤ 1.0 mm induced no gaps in the LPNs and almost no noodle fracture after cooking. Therefore, the synergistic use of alkali, salt, and thickness reduction could achieve the development of LPNs with good structural integrity. These results were beneficial to understand the relationship between the preparation and properties of the low-protein foods.