Comparative analysis of the fine molecular structures and pasting properties of zhiqu and bread wheat starch

Wheat serves as raw material for daqu and bread production, while starch fine structure and pasting properties differ poorly understood between zhiqu and bread wheat cultivars. This study determined the starch-related properties of the two wheat types. The results showed that the amylose content of zhiqu wheat ranged from 27.44% to 27.90%, which was lower than that of bread wheat (28.38-30.94%). Zhiqu wheat had larger medium-sized starch granules (46.61 μm) compared with bread wheat (43.68 μm). XRD analysis confirmed that zhiqu wheat exhibited higher relative crystallinity (24.6%-26.1%) than bread wheat (24%-24.9%). In terms of pasting properties, zhiqu wheat showed higher peak viscosity, trough viscosity and final viscosity, as well as a lower degree of starch branching. Principal component analysis (PCA) revealed that zhiqu wheat had relatively stable and consistent quality traits. These findings deepen understanding of zhiqu wheat starch functionality and guide zhiqu wheat variety selection.