Evaluation of Starch Properties for Selecting Sorghum Planted under Environmental Stress with Superior Noodle‐Making Properties

KT and Nuo sorghum are planted in saline‐alkali (SA) soil (KT‐S, Nuo11‐S) and nonsaline‐alkali (NSA) soil (KT‐S, Nuo11‐NS) to demonstrate the impact of SA stress on the structure and properties of sorghum starch. SA decreases the amylose content (27.57%–20.43%) but increases the B2 + B3 chain content of branched amylopectin (18.86%–19.57%) in KT, in contrast to Nuo. The X‐ray diffraction (XRD) and small‐angle X‐ray scattering (SAXS) results confirms the crystallinity of sorghum starch, and the degree of ordering in semicrystalline lamellae is arranged as follows: Nuo11‐S > Nuo11‐NS > KT‐S > KT‐NS. Differential scanning calorimetry (DSC) confirms that SA improves thermal stability of starch granules. The noodles made of sorghum starch exhibit significant hydrolysis resistance compared to common noodles, and a higher hydrolysis rate is shown in SA‐starch noodles. Overall, it is essential to understand the fine structure and physicochemical properties of starch isolated from sorghum planted in different soils to help determine its appropriate applications.