Quality correlation network analysis between the multiscale microstructure, physicochemical properties of sweetpotato starch, cooking properties, and textural properties of sweetpotato starch noodles

Here the microstructure and physicochemical properties of sweetpotato starch and their effects on the quality of sweetpotato starch noodles were studied. Five varieties of sweetpotato starch had a particle size (D [4,3]) of 23.75-34.00 mu m and amylose content of 20.98-22.74%, while their degree of branching (DB) and relative crystallinity were 1.119-5.181% and 20.26-27.60%, respectively. The starches exhibited different thermal, pasting, gel, and rheological properties. Sweetpotato starch noodles prepared from variety Xushu 32 had the best cooking properties. The particle size, short-range ordered structure, amylose content, amylopectin chain length distribution, DB, relative crystallinity, and lamellar structure of the sweetpotato starch significantly affected the swelling power and pasting, gel, and rheological properties of the starch paste. The thermal, pasting, gel, and rheological properties and the solubility of the starch paste affected the cooking and textural properties of the sweetpotato starch noodles. In addition, a quality correlation network of "starch-starch paste-starch noodles" was found. The critical microstructure, including the particle size and relative crystallinity of the sweetpotato starch, regulated the elasticity of the starch noodles by influencing the final viscosity during starch gelatinization.